Merge branch 'develop' into trunc-stats

Conflicts:
	src/include/wiredtiger.in

52 files changed, 1660 insertions, 1108 deletions

diff --git a/bench/wtperf/wtperf.c b/bench/wtperf/wtperf.c
index 44aff59963c..9ac96862fa1 100644
--- a/bench/wtperf/wtperf.c
+++ b/bench/wtperf/wtperf.c
@@ -653,7 +653,7 @@ op_err:			if (ret == WT_ROLLBACK && ops_per_txn != 0) {
 					goto err;
 				}
 				++trk->latency_ops;
-				usecs = ns_to_us(WT_TIMEDIFF(stop, start));
+				usecs = WT_TIMEDIFF_US(stop, start);
 				track_operation(trk, usecs);
 			}
 			/* Increment operation count */
@@ -936,7 +936,7 @@ populate_thread(void *arg)
 				goto err;
 			}
 			++trk->latency_ops;
-			usecs = ns_to_us(WT_TIMEDIFF(stop, start));
+			usecs = WT_TIMEDIFF_US(stop, start);
 			track_operation(trk, usecs);
 		}
 		++thread->insert.ops;	/* Same as trk->ops */
@@ -1068,7 +1068,7 @@ populate_async(void *arg)
 			goto err;
 		}
 		++trk->latency_ops;
-		usecs = ns_to_us(WT_TIMEDIFF(stop, start));
+		usecs = WT_TIMEDIFF_US(stop, start);
 		track_operation(trk, usecs);
 	}
 	if ((ret = session->close(session, NULL)) != 0) {
@@ -1386,7 +1386,7 @@ execute_populate(CONFIG *cfg)
 	}
 
 	lprintf(cfg, 0, 1, "Finished load of %" PRIu32 " items", cfg->icount);
-	msecs = ns_to_ms(WT_TIMEDIFF(stop, start));
+	msecs = WT_TIMEDIFF_MS(stop, start);
 
 	/*
 	 * This is needed as the divisions will fail if the insert takes no time
@@ -1444,7 +1444,7 @@ execute_populate(CONFIG *cfg)
 		}
 		lprintf(cfg, 0, 1,
 		    "Compact completed in %" PRIu64 " seconds",
-		    (uint64_t)(ns_to_sec(WT_TIMEDIFF(stop, start))));
+		    (uint64_t)(WT_TIMEDIFF_SEC(stop, start)));
 		assert(tables == 0);
 	}
 	return (0);
@@ -2423,7 +2423,7 @@ worker_throttle(int64_t throttle, int64_t *ops, struct timespec *interval)
 	 * If we did enough operations in less than a second, sleep for
 	 * the rest of the second.
 	 */
-	usecs_to_complete = ns_to_us(WT_TIMEDIFF(now, *interval));
+	usecs_to_complete = WT_TIMEDIFF_US(now, *interval);
 	if (usecs_to_complete < USEC_PER_SEC)
 		(void)usleep((useconds_t)(USEC_PER_SEC - usecs_to_complete));
 
@@ -2457,7 +2457,7 @@ drop_all_tables(CONFIG *cfg)
 		}
 	}
 	(void)__wt_epoch(NULL, &stop);
-	msecs = ns_to_ms(WT_TIMEDIFF(stop, start));
+	msecs = WT_TIMEDIFF_MS(stop, start);
 	lprintf(cfg, 0, 1,
 	    "Executed %" PRIu32 " drop operations average time %" PRIu64 "ms",
 	    cfg->table_count, msecs / cfg->table_count);
diff --git a/dist/s_define.list b/dist/s_define.list
index d204a11835b..a2b86610755 100644
--- a/dist/s_define.list
+++ b/dist/s_define.list
@@ -36,6 +36,8 @@ WT_READ_BARRIER
 WT_REF_SIZE
 WT_SESSION_LOCKED_CHECKPOINT
 WT_SESSION_LOCKED_TURTLE
+WT_STATS_FIELD_TO_SLOT
+WT_STATS_SLOT_ID
 WT_STAT_DECR
 WT_STAT_DECRV
 WT_STAT_FAST_CONN_DECRV
@@ -45,9 +47,8 @@ WT_STAT_FAST_DECRV
 WT_STAT_FAST_INCR
 WT_STAT_FAST_INCRV
 WT_STAT_FAST_SET
-WT_STATS_FIELD_TO_SLOT
-WT_STATS_SLOT_ID
 WT_STAT_WRITE
+WT_TIMEDIFF_US
 WT_TRET_ERROR_OK
 WT_WITH_LOCK
 __F
diff --git a/dist/s_string.ok b/dist/s_string.ok
index c14f4c961e6..21cd360c144 100644
--- a/dist/s_string.ok
+++ b/dist/s_string.ok
@@ -507,6 +507,7 @@ dev
 dh
 dhandle
 dhandles
+difftime
 dir
 dirlist
 dlclose
diff --git a/dist/stat_data.py b/dist/stat_data.py
index 9c49e20fa61..85ecdeb5be5 100644
--- a/dist/stat_data.py
+++ b/dist/stat_data.py
@@ -199,7 +199,9 @@ connection_stats = [
         'eviction server populating queue, but not evicting pages'),
     CacheStat('cache_eviction_slow',
         'eviction server unable to reach eviction goal'),
-    CacheStat('cache_eviction_split', 'pages split during eviction'),
+    CacheStat('cache_eviction_split_internal',
+        'internal pages split during eviction'),
+    CacheStat('cache_eviction_split_leaf', 'leaf pages split during eviction'),
     CacheStat('cache_eviction_walk', 'pages walked for eviction'),
     CacheStat('cache_eviction_worker_evicting',
         'eviction worker thread evicting pages'),
@@ -479,7 +481,9 @@ dsrc_stats = [
         'data source pages selected for eviction unable to be evicted'),
     CacheStat('cache_eviction_hazard', 'hazard pointer blocked page eviction'),
     CacheStat('cache_eviction_internal', 'internal pages evicted'),
-    CacheStat('cache_eviction_split', 'pages split during eviction'),
+    CacheStat('cache_eviction_split_internal',
+        'internal pages split during eviction'),
+    CacheStat('cache_eviction_split_leaf', 'leaf pages split during eviction'),
     CacheStat('cache_inmem_split', 'in-memory page splits'),
     CacheStat('cache_inmem_splittable',
         'in-memory page passed criteria to be split'),
diff --git a/src/btree/bt_handle.c b/src/btree/bt_handle.c
index 3e611a107ab..dbdf94fc1b6 100644
--- a/src/btree/bt_handle.c
+++ b/src/btree/bt_handle.c
@@ -643,11 +643,13 @@ __btree_page_sizes(WT_SESSION_IMPL *session)
 {
 	WT_BTREE *btree;
 	WT_CONFIG_ITEM cval;
+	WT_CONNECTION_IMPL *conn;
 	uint64_t cache_size;
 	uint32_t intl_split_size, leaf_split_size;
 	const char **cfg;
 
 	btree = S2BT(session);
+	conn = S2C(session);
 	cfg = btree->dhandle->cfg;
 
 	/*
@@ -688,8 +690,8 @@ __btree_page_sizes(WT_SESSION_IMPL *session)
 	WT_RET(__wt_config_gets(session, cfg, "memory_page_max", &cval));
 	btree->maxmempage =
 	    WT_MAX((uint64_t)cval.val, 50 * (uint64_t)btree->maxleafpage);
-	if (!F_ISSET(S2C(session), WT_CONN_CACHE_POOL)) {
-		if ((cache_size = S2C(session)->cache_size) > 0)
+	if (!F_ISSET(conn, WT_CONN_CACHE_POOL)) {
+		if ((cache_size = conn->cache_size) > 0)
 			btree->maxmempage =
 			    WT_MIN(btree->maxmempage, cache_size / 4);
 	}
@@ -723,6 +725,17 @@ __btree_page_sizes(WT_SESSION_IMPL *session)
 	/*
 	 * Get the maximum internal/leaf page key/value sizes.
 	 *
+	 * In-memory configuration overrides any key/value sizes, there's no
+	 * such thing as an overflow item in an in-memory configuration.
+	 */
+	if (F_ISSET(conn, WT_CONN_IN_MEMORY)) {
+		btree->maxintlkey = WT_BTREE_MAX_OBJECT_SIZE;
+		btree->maxleafkey = WT_BTREE_MAX_OBJECT_SIZE;
+		btree->maxleafvalue = WT_BTREE_MAX_OBJECT_SIZE;
+		return (0);
+	}
+
+	/*
 	 * In historic versions of WiredTiger, the maximum internal/leaf page
 	 * key/value sizes were set by the internal_item_max and leaf_item_max
 	 * configuration strings. Look for those strings if we don't find the
diff --git a/src/btree/bt_read.c b/src/btree/bt_read.c
index e60f7b3fb02..389ac761c5b 100644
--- a/src/btree/bt_read.c
+++ b/src/btree/bt_read.c
@@ -586,8 +586,8 @@ skip_evict:
 		 * CPU to no purpose.
 		 */
 		if (stalled)
-			wait_cnt += 1000;
-		else if (++wait_cnt < 1000) {
+			wait_cnt += WT_THOUSAND;
+		else if (++wait_cnt < WT_THOUSAND) {
 			__wt_yield();
 			continue;
 		}
@@ -603,7 +603,7 @@ skip_evict:
 			if (cache_work)
 				continue;
 		}
-		sleep_cnt = WT_MIN(sleep_cnt + 1000, 10000);
+		sleep_cnt = WT_MIN(sleep_cnt + WT_THOUSAND, 10000);
 		WT_STAT_FAST_CONN_INCRV(session, page_sleep, sleep_cnt);
 		__wt_sleep(0, sleep_cnt);
 	}
diff --git a/src/btree/bt_split.c b/src/btree/bt_split.c
index 9e45bf10a5c..eaeac683f9a 100644
--- a/src/btree/bt_split.c
+++ b/src/btree/bt_split.c
@@ -169,54 +169,58 @@ __split_safe_free(WT_SESSION_IMPL *session,
 	return (__split_stash_add(session, split_gen, p, s));
 }
 
+#ifdef HAVE_DIAGNOSTIC
 /*
- * __split_should_deepen --
- *	Return if we should deepen the tree.
+ * __split_verify_intl_key_order --
+ *	Verify the key order on an internal page after a split, diagnostic only.
  */
-static bool
-__split_should_deepen(WT_SESSION_IMPL *session, WT_REF *ref)
+static void
+__split_verify_intl_key_order(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_BTREE *btree;
-	WT_PAGE *page;
-	WT_PAGE_INDEX *pindex;
+	WT_ITEM *next, _next, *last, _last, *tmp;
+	WT_REF *ref;
+	uint64_t recno;
+	int cmp;
+	bool first;
 
 	btree = S2BT(session);
-	page = ref->page;
-
-	/*
-	 * Our caller is holding the parent page locked to single-thread splits,
-	 * which means we can safely look at the page's index without setting a
-	 * split generation.
-	 */
-	pindex = WT_INTL_INDEX_GET_SAFE(page);
-
-	/*
-	 * Sanity check for a reasonable number of keys on-page keys. Splitting
-	 * with too few keys leads to excessively deep trees.
-	 */
-	if (pindex->entries < 100)
-		return (false);
-
-	/*
-	 * Deepen the tree if the page's memory footprint is larger than the
-	 * maximum size for a page in memory (presumably putting eviction
-	 * pressure on the cache).
-	 */
-	if (page->memory_footprint > btree->maxmempage)
-		return (true);
 
-	/*
-	 * Check if the page has enough keys to make it worth splitting. If
-	 * the number of keys is allowed to grow too large, the cost of
-	 * splitting into parent pages can become large enough to result
-	 * in slow operations.
-	 */
-	if (!__wt_ref_is_root(ref) &&
-	    pindex->entries > btree->split_deepen_min_child)
-		return (true);
+	switch (page->type) {
+	case WT_PAGE_COL_INT:
+		recno = 0;		/* Less than any valid record number. */
+		WT_INTL_FOREACH_BEGIN(session, page, ref) {
+			WT_ASSERT(session, ref->key.recno > recno);
+			recno = ref->key.recno;
+		} WT_INTL_FOREACH_END;
+		break;
+	case WT_PAGE_ROW_INT:
+		next = &_next;
+		WT_CLEAR(_next);
+		last = &_last;
+		WT_CLEAR(_last);
 
-	return (false);
+		first = true;
+		WT_INTL_FOREACH_BEGIN(session, page, ref) {
+			__wt_ref_key(page, ref, &next->data, &next->size);
+			if (last->size == 0) {
+				if (first)
+					first = false;
+				else {
+					WT_ASSERT(session, __wt_compare(
+					    session, btree->collator, last,
+					    next, &cmp) == 0);
+					WT_ASSERT(session, cmp < 0);
+				}
+			}
+			tmp = last;
+			last = next;
+			next = tmp;
+		} WT_INTL_FOREACH_END;
+		break;
+	}
 }
+#endif
 
 /*
  * __split_ovfl_key_cleanup --
@@ -267,47 +271,58 @@ __split_ovfl_key_cleanup(WT_SESSION_IMPL *session, WT_PAGE *page, WT_REF *ref)
 }
 
 /*
- * __split_ref_deepen_move --
- *	Move a WT_REF from a parent to a child in service of a split to deepen
- * the tree, including updating the accounting information.
+ * __split_ref_move --
+ *	Move a WT_REF from one page to another, including updating accounting
+ * information.
  */
 static int
-__split_ref_deepen_move(WT_SESSION_IMPL *session,
-    WT_PAGE *parent, WT_REF *ref, size_t *parent_decrp, size_t *child_incrp)
+__split_ref_move(WT_SESSION_IMPL *session, WT_PAGE *from_home,
+    WT_REF **from_refp, size_t *decrp, WT_REF **to_refp, size_t *incrp)
 {
 	WT_ADDR *addr;
 	WT_CELL_UNPACK unpack;
 	WT_DECL_RET;
 	WT_IKEY *ikey;
+	WT_REF *ref;
 	size_t size;
 	void *key;
 
+	ref = *from_refp;
+
 	/*
+	 * The from-home argument is the page into which the "from" WT_REF may
+	 * point, for example, if there's an on-page key the "from" WT_REF
+	 * references, it will be on the page "from-home".
+	 *
 	 * Instantiate row-store keys, and column- and row-store addresses in
-	 * the WT_REF structures referenced by a page that's being split (and
-	 * deepening the tree).  The WT_REF structures aren't moving, but the
-	 * index references are moving from the page we're splitting to a set
-	 * of child pages, and so we can no longer reference the block image
-	 * that remains with the page being split.
+	 * the WT_REF structures referenced by a page that's being split. The
+	 * WT_REF structures aren't moving, but the index references are moving
+	 * from the page we're splitting to a set of new pages, and so we can
+	 * no longer reference the block image that remains with the page being
+	 * split.
 	 *
 	 * No locking is required to update the WT_REF structure because we're
-	 * the only thread splitting the parent page, and there's no way for
-	 * readers to race with our updates of single pointers.  The changes
-	 * have to be written before the page goes away, of course, our caller
-	 * owns that problem.
-	 *
-	 * Row-store keys, first.
+	 * the only thread splitting the page, and there's no way for readers
+	 * to race with our updates of single pointers.  The changes have to be
+	 * written before the page goes away, of course, our caller owns that
+	 * problem.
 	 */
-	if (parent->type == WT_PAGE_ROW_INT) {
+	if (from_home->type == WT_PAGE_ROW_INT) {
+		/*
+		 * Row-store keys: if it's not yet instantiated, instantiate it.
+		 * If already instantiated, check for overflow cleanup (overflow
+		 * keys are always instantiated).
+		 */
 		if ((ikey = __wt_ref_key_instantiated(ref)) == NULL) {
-			__wt_ref_key(parent, ref, &key, &size);
+			__wt_ref_key(from_home, ref, &key, &size);
 			WT_RET(__wt_row_ikey(session, 0, key, size, ref));
 			ikey = ref->key.ikey;
 		} else {
-			WT_RET(__split_ovfl_key_cleanup(session, parent, ref));
-			*parent_decrp += sizeof(WT_IKEY) + ikey->size;
+			WT_RET(
+			    __split_ovfl_key_cleanup(session, from_home, ref));
+			*decrp += sizeof(WT_IKEY) + ikey->size;
 		}
-		*child_incrp += sizeof(WT_IKEY) + ikey->size;
+		*incrp += sizeof(WT_IKEY) + ikey->size;
 	}
 
 	/*
@@ -316,7 +331,7 @@ __split_ref_deepen_move(WT_SESSION_IMPL *session,
 	 * get the address from the on-page cell.
 	 */
 	addr = ref->addr;
-	if (addr != NULL && !__wt_off_page(parent, addr)) {
+	if (addr != NULL && !__wt_off_page(from_home, addr)) {
 		__wt_cell_unpack((WT_CELL *)ref->addr, &unpack);
 		WT_RET(__wt_calloc_one(session, &addr));
 		if ((ret = __wt_strndup(
@@ -330,364 +345,1042 @@ __split_ref_deepen_move(WT_SESSION_IMPL *session,
 		ref->addr = addr;
 	}
 
-	/* And finally, the WT_REF itself. */
-	WT_MEM_TRANSFER(*parent_decrp, *child_incrp, sizeof(WT_REF));
+	/* And finally, copy the WT_REF pointer itself. */
+	*to_refp = ref;
+	WT_MEM_TRANSFER(*decrp, *incrp, sizeof(WT_REF));
 
 	return (0);
 }
 
-#ifdef HAVE_DIAGNOSTIC
 /*
- * __split_verify_intl_key_order --
- *	Verify the key order on an internal page after a split, diagnostic only.
+ * __split_child_block_evict_and_split --
+ *	Ensure the newly created child isn't evicted or split for now.
  */
 static void
-__split_verify_intl_key_order(WT_SESSION_IMPL *session, WT_PAGE *page)
+__split_child_block_evict_and_split(WT_PAGE *child)
 {
-	WT_BTREE *btree;
-	WT_ITEM *next, _next, *last, _last, *tmp;
-	WT_REF *ref;
-	uint64_t recno;
-	int cmp;
-	bool first;
+	/*
+	 * Once the split is live, newly created internal pages might be evicted
+	 * and their WT_REF structures freed. If that happens before all threads
+	 * exit the index of the page which previously "owned" the WT_REF, a
+	 * thread might see a freed WT_REF. To ensure that doesn't happen, the
+	 * newly created page's modify structure has a field with a transaction
+	 * ID that's checked before any internal page is evicted. Unfortunately,
+	 * we don't know the correct value until we update the original page's
+	 * index (we need a transaction ID from after that update), but the act
+	 * of updating the original page's index is what allows the eviction to
+	 * happen.
+	 *
+	 * Once the split is live, newly created internal pages might themselves
+	 * split. The split itself is not the problem: if a page splits before
+	 * we fix up its WT_REF (in other words, a WT_REF we move is then moved
+	 * again, before we reset the underlying page's parent reference), it's
+	 * OK because the test we use to find a WT_REF and WT_PAGE that require
+	 * fixing up is only that the WT_REF points to the wrong parent, not it
+	 * points to a specific wrong parent. The problem is our fix up of the
+	 * WT_REFs in the created page could race with the subsequent fix of the
+	 * same WT_REFs (in a different created page), we'd have to acquire some
+	 * lock to prevent that race, and that's going to be difficult at best.
+	 *
+	 * For now, block eviction and splits in newly created pages until they
+	 * have been fixed up.
+	 */
+	F_SET_ATOMIC(child, WT_PAGE_SPLIT_BLOCK);
+}
 
-	btree = S2BT(session);
+/*
+ * __split_ref_move_final --
+ *	Finalize the moved WT_REF structures after the split succeeds.
+ */
+static int
+__split_ref_move_final(
+    WT_SESSION_IMPL *session, WT_REF **refp, uint32_t entries)
+{
+	WT_DECL_RET;
+	WT_PAGE *child;
+	WT_REF *ref, *child_ref;
+	uint64_t txn_new_id;
+	uint32_t i;
 
-	switch (page->type) {
-	case WT_PAGE_COL_INT:
-		recno = 0;		/* Less than any valid record number. */
-		WT_INTL_FOREACH_BEGIN(session, page, ref) {
-			WT_ASSERT(session, ref->key.recno > recno);
-			recno = ref->key.recno;
-		} WT_INTL_FOREACH_END;
-		break;
-	case WT_PAGE_ROW_INT:
-		next = &_next;
-		WT_CLEAR(_next);
-		last = &_last;
-		WT_CLEAR(_last);
+	/*
+	 * When creating new internal pages as part of a split, we set a field
+	 * in those pages modify structure to prevent them from being evicted
+	 * until all threads are known to have exited the index of the page that
+	 * previously "owned" the WT_REF. Set that field to a safe value.
+	 */
+	txn_new_id = __wt_txn_new_id(session);
 
-		first = true;
-		WT_INTL_FOREACH_BEGIN(session, page, ref) {
-			__wt_ref_key(page, ref, &next->data, &next->size);
-			if (last->size == 0) {
-				if (first)
-					first = false;
-				else {
-					WT_ASSERT(session, __wt_compare(
-					    session, btree->collator, last,
-					    next, &cmp) == 0);
-					WT_ASSERT(session, cmp < 0);
-				}
+	/*
+	 * The WT_REF structures moved to newly allocated child pages reference
+	 * the wrong parent page and we have to fix that up. The problem is
+	 * revealed when a thread of control searches for the child page's
+	 * reference structure slot, and fails to find it because the parent
+	 * page being searched no longer references the child. When that failure
+	 * happens the thread waits for the reference's home page to be updated,
+	 * which we do here: walk the children and fix them up.
+	 */
+	for (i = 0; i < entries; ++i, ++refp) {
+		ref = *refp;
+
+		/*
+		 * We don't hold hazard pointers on created pages, they cannot
+		 * be evicted because the page-modify transaction value set as
+		 * they were created prevents eviction. (See above, we reset
+		 * that value as part of fixing up the page.) But, an eviction
+		 * thread might be attempting to evict the page (the WT_REF may
+		 * be WT_REF_LOCKED), or it may be a disk based page (the WT_REF
+		 * may be WT_REF_READING), or it may be in some other state.
+		 * Acquire a hazard pointer for any in-memory pages so we know
+		 * the state of the page. Ignore pages not in-memory (deleted,
+		 * on-disk, being read), there's no in-memory structure to fix.
+		 */
+		if ((ret = __wt_page_in(session,
+		    ref, WT_READ_CACHE | WT_READ_NO_EVICT)) == WT_NOTFOUND)
+			continue;
+		WT_ERR(ret);
+
+		child = ref->page;
+#ifdef HAVE_DIAGNOSTIC
+		WT_WITH_PAGE_INDEX(session,
+		    __split_verify_intl_key_order(session, child));
+#endif
+		/*
+		 * We use a page flag to prevent the child from splitting from
+		 * underneath us, but the split-generation error checks don't
+		 * know about that flag; use the standard macros to ensure that
+		 * reading the child's page index structure is safe.
+		 */
+		WT_ENTER_PAGE_INDEX(session);
+		WT_INTL_FOREACH_BEGIN(session, child, child_ref) {
+			/*
+			 * The page's home reference may not be wrong, as we
+			 * opened up access from the top of the tree already,
+			 * disk pages may have been read in since then, and
+			 * those pages would have correct parent references.
+			 */
+			if (child_ref->home != child) {
+				child_ref->home = child;
+				child_ref->pindex_hint = 0;
+
+				child->modify->mod_split_txn = txn_new_id;
 			}
-			tmp = last;
-			last = next;
-			next = tmp;
 		} WT_INTL_FOREACH_END;
-		break;
+		WT_LEAVE_PAGE_INDEX(session);
+
+		/* The child can now be evicted or split. */
+		F_CLR_ATOMIC(child, WT_PAGE_SPLIT_BLOCK);
+
+		WT_ERR(__wt_hazard_clear(session, child));
 	}
+
+	/*
+	 * Push out the changes: not required for correctness, but don't let
+	 * threads spin on incorrect page references longer than necessary.
+	 */
+	WT_FULL_BARRIER();
+	return (0);
+
+err:	/* Something really bad just happened. */
+	WT_PANIC_RET(session, ret, "fatal error resolving a split");
 }
-#endif
 
 /*
- * __split_deepen --
- *	Split an internal page in-memory, deepening the tree.
+ * __split_root --
+ *	Split the root page in-memory, deepening the tree.
  */
 static int
-__split_deepen(WT_SESSION_IMPL *session, WT_PAGE *parent)
+__split_root(WT_SESSION_IMPL *session, WT_PAGE *root)
 {
 	WT_BTREE *btree;
 	WT_DECL_RET;
 	WT_PAGE *child;
 	WT_PAGE_INDEX *alloc_index, *child_pindex, *pindex;
 	WT_REF **alloc_refp;
-	WT_REF *child_ref, **child_refp, *parent_ref, **parent_refp, *ref;
-	size_t child_incr, parent_decr, parent_incr, size;
+	WT_REF **child_refp, *ref, **root_refp;
+	size_t child_incr, root_decr, root_incr, size;
 	uint64_t split_gen;
-	uint32_t children, chunk, i, j, moved_entries, new_entries, remain;
-	uint32_t skip_leading, slots;
+	uint32_t children, chunk, i, j, remain;
+	uint32_t slots;
 	bool complete;
 	void *p;
 
 	WT_STAT_FAST_CONN_INCR(session, cache_eviction_deepen);
 	WT_STAT_FAST_DATA_INCR(session, cache_eviction_deepen);
+	WT_STAT_FAST_CONN_INCR(session, cache_eviction_split_internal);
+	WT_STAT_FAST_DATA_INCR(session, cache_eviction_split_internal);
 
 	btree = S2BT(session);
 	alloc_index = NULL;
-	parent_incr = parent_decr = 0;
+	root_decr = root_incr = 0;
 	complete = false;
 
+	/* The root page will be marked dirty, make sure that will succeed. */
+	WT_RET(__wt_page_modify_init(session, root));
+
 	/*
-	 * Our caller is holding the parent page locked to single-thread splits,
+	 * Our caller is holding the root page locked to single-thread splits,
 	 * which means we can safely look at the page's index without setting a
 	 * split generation.
 	 */
-	pindex = WT_INTL_INDEX_GET_SAFE(parent);
-
-	/*
-	 * A prepending/appending workload will repeatedly deepen parts of the
-	 * tree that aren't changing, and appending workloads are not uncommon.
-	 * First, keep the first/last pages of the tree at their current level,
-	 * to catch simple workloads. Second, track the number of entries which
-	 * resulted from the last time we deepened this page, and if we refilled
-	 * this page without splitting into those slots, ignore them for this
-	 * split. It's not exact because an eviction might split into any part
-	 * of the page: if 80% of the splits are at the end of the page, assume
-	 * an append-style workload. Of course, the plan eventually fails: when
-	 * repeatedly deepening this page for an append-only workload, we will
-	 * progressively ignore more and more of the slots. When ignoring 90% of
-	 * the slots, deepen the entire page again.
-	 *
-	 * Figure out how many slots we're leaving at this level and how many
-	 * child pages we're creating.
-	 */
-#undef	skip_trailing
-#define	skip_trailing	1
-	skip_leading = 1;
-	new_entries = pindex->entries - parent->pg_intl_deepen_split_last;
-	if (parent->pg_intl_deepen_split_append > (new_entries * 8) / 10)
-		skip_leading = parent->pg_intl_deepen_split_last;
-	if (skip_leading > (pindex->entries * 9) * 10)
-		skip_leading = 1;
+	pindex = WT_INTL_INDEX_GET_SAFE(root);
 
 	/*
-	 * In a few (rare) cases we split pages with only a few entries, and in
-	 * those cases we keep it simple, 10 children, skip only first and last
-	 * entries. Otherwise, split into a lot of child pages.
+	 * Decide how many child pages to create, then calculate the standard
+	 * chunk and whatever remains. Sanity check the number of children:
+	 * the decision to split matched to the deepen-per-child configuration
+	 * might get it wrong.
 	 */
-	moved_entries = pindex->entries - (skip_leading + skip_trailing);
-	children = moved_entries / btree->split_deepen_per_child;
+	children = pindex->entries / btree->split_deepen_per_child;
 	if (children < 10) {
+		if (pindex->entries < 100)
+			return (EBUSY);
 		children = 10;
-		skip_leading = 1;
-		moved_entries =
-		    pindex->entries - (skip_leading + skip_trailing);
 	}
+	chunk = pindex->entries / children;
+	remain = pindex->entries - chunk * (children - 1);
 
 	WT_ERR(__wt_verbose(session, WT_VERB_SPLIT,
-	    "%p: %" PRIu32 " elements, splitting into %" PRIu32 " children",
-	    parent, pindex->entries, children));
+	    "%p: %" PRIu32 " root page elements, splitting into %" PRIu32
+	    " children",
+	    root, pindex->entries, children));
 
 	/*
-	 * Allocate a new WT_PAGE_INDEX and set of WT_REF objects. Initialize
-	 * the slots of the allocated WT_PAGE_INDEX to point to the pages we're
-	 * keeping at the current level, and the rest of the slots to point to
-	 * new WT_REF objects.
+	 * Allocate a new WT_PAGE_INDEX and set of WT_REF objects to be inserted
+	 * into the root page, replacing the root's page-index.
 	 */
-	size = sizeof(WT_PAGE_INDEX) +
-	    (children + skip_leading + skip_trailing) * sizeof(WT_REF *);
+	size = sizeof(WT_PAGE_INDEX) + children * sizeof(WT_REF *);
 	WT_ERR(__wt_calloc(session, 1, size, &alloc_index));
-	parent_incr += size;
+	root_incr += size;
 	alloc_index->index = (WT_REF **)(alloc_index + 1);
-	alloc_index->entries = children + skip_leading + skip_trailing;
-	for (alloc_refp = alloc_index->index,
-	    i = 0; i < skip_leading; ++alloc_refp, ++i)
-		alloc_index->index[i] = pindex->index[i];
-	for (i = 0; i < children; ++alloc_refp, ++i)
+	alloc_index->entries = children;
+	alloc_refp = alloc_index->index;
+	for (i = 0; i < children; alloc_refp++, ++i)
 		WT_ERR(__wt_calloc_one(session, alloc_refp));
-	parent_incr += children * sizeof(WT_REF);
-	alloc_index->index[alloc_index->entries - 1] =
-	    pindex->index[pindex->entries - 1];
+	root_incr += children * sizeof(WT_REF);
 
 	/* Allocate child pages, and connect them into the new page index. */
-	chunk = moved_entries / children;
-	remain = moved_entries - chunk * (children - 1);
-	for (parent_refp = pindex->index + skip_leading,
-	    alloc_refp = alloc_index->index + skip_leading,
-	    i = 0; i < children; ++i) {
+	for (root_refp = pindex->index,
+	    alloc_refp = alloc_index->index, i = 0; i < children; ++i) {
 		slots = i == children - 1 ? remain : chunk;
 		WT_ERR(__wt_page_alloc(
-		    session, parent->type, 0, slots, false, &child));
+		    session, root->type, 0, slots, false, &child));
 
 		/*
-		 * Initialize the parent page's child reference; we need a copy
-		 * of the page's key.
+		 * Initialize the page's child reference; we need a copy of the
+		 * page's key.
 		 */
 		ref = *alloc_refp++;
-		ref->home = parent;
+		ref->home = root;
 		ref->page = child;
 		ref->addr = NULL;
-		if (parent->type == WT_PAGE_ROW_INT) {
-			__wt_ref_key(parent, *parent_refp, &p, &size);
+		if (root->type == WT_PAGE_ROW_INT) {
+			__wt_ref_key(root, *root_refp, &p, &size);
 			WT_ERR(__wt_row_ikey(session, 0, p, size, ref));
-			parent_incr += sizeof(WT_IKEY) + size;
+			root_incr += sizeof(WT_IKEY) + size;
 		} else
-			ref->key.recno = (*parent_refp)->key.recno;
+			ref->key.recno = (*root_refp)->key.recno;
 		ref->state = WT_REF_MEM;
 
 		/* Initialize the child page. */
-		if (parent->type == WT_PAGE_COL_INT)
-			child->pg_intl_recno = (*parent_refp)->key.recno;
+		if (root->type == WT_PAGE_COL_INT)
+			child->pg_intl_recno = (*root_refp)->key.recno;
 		child->pg_intl_parent_ref = ref;
 
 		/* Mark it dirty. */
 		WT_ERR(__wt_page_modify_init(session, child));
 		__wt_page_modify_set(session, child);
 
-		/*
-		 * Once the split goes live, the newly created internal pages
-		 * might be evicted and their WT_REF structures freed.  If those
-		 * pages are evicted before threads exit the previous page index
-		 * array, a thread might see a freed WT_REF.  Set the eviction
-		 * transaction requirement for the newly created internal pages.
-		 */
-		child->modify->mod_split_txn = __wt_txn_new_id(session);
+		/* Ensure the page isn't evicted or split for now. */
+		__split_child_block_evict_and_split(child);
 
 		/*
 		 * The newly allocated child's page index references the same
-		 * structures as the parent.  (We cannot move WT_REF structures,
+		 * structures as the root.  (We cannot move WT_REF structures,
 		 * threads may be underneath us right now changing the structure
 		 * state.)  However, if the WT_REF structures reference on-page
 		 * information, we have to fix that, because the disk image for
 		 * the page that has an page index entry for the WT_REF is about
 		 * to change.
 		 */
-		child_incr = 0;
 		child_pindex = WT_INTL_INDEX_GET_SAFE(child);
-		for (child_refp = child_pindex->index, j = 0; j < slots; ++j) {
-			WT_ERR(__split_ref_deepen_move(session,
-			    parent, *parent_refp, &parent_decr, &child_incr));
-			*child_refp++ = *parent_refp++;
-		}
+		child_incr = 0;
+		for (child_refp = child_pindex->index,
+		    j = 0; j < slots; ++child_refp, ++root_refp, ++j)
+			WT_ERR(__split_ref_move(session, root,
+			    root_refp, &root_decr, child_refp, &child_incr));
+
 		__wt_cache_page_inmem_incr(session, child, child_incr);
 	}
 	WT_ASSERT(session,
-	    alloc_refp - alloc_index->index ==
-	    (ptrdiff_t)(alloc_index->entries - skip_trailing));
-	WT_ASSERT(session, parent_refp - pindex->index ==
-	    (ptrdiff_t)(pindex->entries - skip_trailing));
+	    alloc_refp - alloc_index->index == (ptrdiff_t)alloc_index->entries);
+	WT_ASSERT(session,
+	    root_refp - pindex->index == (ptrdiff_t)pindex->entries);
 
 	/*
-	 * Confirm the parent page's index hasn't moved, then update it, which
+	 * Confirm the root page's index hasn't moved, then update it, which
 	 * makes the split visible to threads descending the tree. From this
 	 * point on, we're committed to the split.
 	 *
 	 * A note on error handling: until this point, there's no problem with
 	 * unwinding on error.  We allocated a new page index, a new set of
 	 * WT_REFs and a new set of child pages -- if an error occurred, the
-	 * parent remained unchanged, although it may have an incorrect memory
-	 * footprint.  From now on we've modified the parent page, attention
+	 * root remained unchanged, although it may have an incorrect memory
+	 * footprint.  From now on we've modified the root page, attention
 	 * needs to be paid. However, subsequent failures are relatively benign,
 	 * the split is OK and complete. For that reason, we ignore errors past
 	 * this point unless there's a panic.
 	 */
+	WT_ASSERT(session, WT_INTL_INDEX_GET_SAFE(root) == pindex);
+	WT_INTL_INDEX_SET(root, alloc_index);
+	complete = true;
+
+#ifdef HAVE_DIAGNOSTIC
+	WT_WITH_PAGE_INDEX(session,
+	    __split_verify_intl_key_order(session, root));
+#endif
+	/* Fix up the moved WT_REF structures. */
+	WT_ERR(__split_ref_move_final(
+	    session, alloc_index->index, alloc_index->entries));
+
+	/* We've installed the allocated page-index, ensure error handling. */
+	alloc_index = NULL;
+
+	/*
+	 * We can't free the previous root's index, there may be threads using
+	 * it.  Add to the session's discard list, to be freed once we know no
+	 * threads can still be using it.
+	 *
+	 * This change requires care with error handling: we have already
+	 * updated the page with a new index.  Even if stashing the old value
+	 * fails, we don't roll back that change, because threads may already
+	 * be using the new index.
+	 */
+	split_gen = __wt_atomic_addv64(&S2C(session)->split_gen, 1);
+	size = sizeof(WT_PAGE_INDEX) + pindex->entries * sizeof(WT_REF *);
+	WT_TRET(__split_safe_free(session, split_gen, false, pindex, size));
+	root_decr += size;
+
+	/* Adjust the root's memory footprint and mark it dirty. */
+	__wt_cache_page_inmem_incr(session, root, root_incr);
+	__wt_cache_page_inmem_decr(session, root, root_decr);
+	__wt_page_modify_set(session, root);
+
+err:	/*
+	 * If complete is true, we saw an error after opening up the tree to
+	 * descent through the root page's new index. There is nothing we
+	 * can do, there are threads potentially active in both versions of
+	 * the tree.
+	 *
+	 * A note on error handling: if we completed the split, return success,
+	 * nothing really bad can have happened, and our caller has to proceed
+	 * with the split.
+	 */
+	if (!complete)
+		__wt_free_ref_index(session, root, alloc_index, true);
+
+	if (ret != 0 && ret != WT_PANIC)
+		__wt_err(session, ret,
+		    "ignoring not-fatal error during root page split to "
+		    "deepen the tree");
+	return (ret == WT_PANIC || !complete ? ret : 0);
+}
+
+/*
+ * __split_parent --
+ *	Resolve a multi-page split, inserting new information into the parent.
+ */
+static int
+__split_parent(WT_SESSION_IMPL *session, WT_REF *ref, WT_REF **ref_new,
+    uint32_t new_entries, size_t parent_incr, bool exclusive, bool discard)
+{
+	WT_DECL_RET;
+	WT_IKEY *ikey;
+	WT_PAGE *parent;
+	WT_PAGE_INDEX *alloc_index, *pindex;
+	WT_REF **alloc_refp, *next_ref;
+	size_t parent_decr, size;
+	uint64_t split_gen;
+	uint32_t i, j;
+	uint32_t deleted_entries, parent_entries, result_entries;
+	bool complete, empty_parent;
+
+	parent = ref->home;
+
+	alloc_index = pindex = NULL;
+	parent_decr = 0;
+	parent_entries = 0;
+	complete = empty_parent = false;
+
+	/* The parent page will be marked dirty, make sure that will succeed. */
+	WT_RET(__wt_page_modify_init(session, parent));
+
+	/*
+	 * We've locked the parent, which means it cannot split (which is the
+	 * only reason to worry about split generation values).
+	 */
+	pindex = WT_INTL_INDEX_GET_SAFE(parent);
+	parent_entries = pindex->entries;
+
+	/*
+	 * Remove any refs to deleted pages while we are splitting, we have
+	 * the internal page locked down, and are copying the refs into a new
+	 * array anyway.  Switch them to the special split state, so that any
+	 * reading thread will restart.
+	 */
+	for (deleted_entries = 0, i = 0; i < parent_entries; ++i) {
+		next_ref = pindex->index[i];
+		WT_ASSERT(session, next_ref->state != WT_REF_SPLIT);
+		if (next_ref->state == WT_REF_DELETED &&
+		    __wt_delete_page_skip(session, next_ref, true) &&
+		    __wt_atomic_casv32(
+		    &next_ref->state, WT_REF_DELETED, WT_REF_SPLIT))
+			deleted_entries++;
+	}
+
+	/*
+	 * The final entry count consists of the original count, plus any new
+	 * pages, less any WT_REFs we're removing (deleted entries plus the
+	 * entry we're replacing).
+	 */
+	result_entries = (parent_entries + new_entries) - (deleted_entries + 1);
+
+	/*
+	 * If there are no remaining entries on the parent, give up, we can't
+	 * leave an empty internal page. Mark it to be evicted soon and clean
+	 * up any references that have changed state.
+	 */
+	if (result_entries == 0) {
+		empty_parent = true;
+		__wt_page_evict_soon(parent);
+		goto err;
+	}
+
+	/*
+	 * Allocate and initialize a new page index array for the parent, then
+	 * copy references from the original index array, plus references from
+	 * the newly created split array, into place.
+	 */
+	size = sizeof(WT_PAGE_INDEX) + result_entries * sizeof(WT_REF *);
+	WT_ERR(__wt_calloc(session, 1, size, &alloc_index));
+	parent_incr += size;
+	alloc_index->index = (WT_REF **)(alloc_index + 1);
+	alloc_index->entries = result_entries;
+	for (alloc_refp = alloc_index->index, i = 0; i < parent_entries; ++i) {
+		next_ref = pindex->index[i];
+		if (next_ref == ref)
+			for (j = 0; j < new_entries; ++j) {
+				ref_new[j]->home = parent;
+				*alloc_refp++ = ref_new[j];
+			}
+		else if (next_ref->state != WT_REF_SPLIT)
+			/* Skip refs we have marked for deletion. */
+			*alloc_refp++ = next_ref;
+	}
+
+	/* Check that we filled in all the entries. */
+	WT_ASSERT(session,
+	    alloc_refp - alloc_index->index == (ptrdiff_t)result_entries);
+
+	/*
+	 * Confirm the parent page's index hasn't moved then update it, which
+	 * makes the split visible to threads descending the tree.
+	 */
 	WT_ASSERT(session, WT_INTL_INDEX_GET_SAFE(parent) == pindex);
 	WT_INTL_INDEX_SET(parent, alloc_index);
-	split_gen = __wt_atomic_addv64(&S2C(session)->split_gen, 1);
-	complete = true;
+	alloc_index = NULL;
 
 #ifdef HAVE_DIAGNOSTIC
 	WT_WITH_PAGE_INDEX(session,
 	    __split_verify_intl_key_order(session, parent));
 #endif
+
+	/*
+	 * If discarding the page's original WT_REF field, reset it to split and
+	 * increment the number of entries being discarded. Threads cursoring
+	 * through the tree were blocked because that WT_REF state was set to
+	 * locked. Changing the locked state to split unblocks those threads and
+	 * causes them to re-calculate their position based on the just-updated
+	 * parent page's index.
+	 */
+	if (discard) {
+		++deleted_entries;
+		WT_PUBLISH(ref->state, WT_REF_SPLIT);
+	}
+
+	/*
+	 * Push out the changes: not required for correctness, but don't let
+	 * threads spin on incorrect page references longer than necessary.
+	 */
+	WT_FULL_BARRIER();
+
 	/*
-	 * Save the number of entries created by deepening the tree and reset
-	 * the count of splits into this page after that point.
+	 * A note on error handling: failures before we swapped the new page
+	 * index into the parent can be resolved by freeing allocated memory
+	 * because the original page is unchanged, we can continue to use it
+	 * and we have not yet modified the parent.  Failures after we swap
+	 * the new page index into the parent are also relatively benign, the
+	 * split is OK and complete. For those reasons, we ignore errors past
+	 * this point unless there's a panic.
 	 */
-	parent->pg_intl_deepen_split_append = 0;
-	parent->pg_intl_deepen_split_last = alloc_index->entries;
+	complete = true;
+
+	WT_ERR(__wt_verbose(session, WT_VERB_SPLIT,
+	    "%p: %s %s" "split into parent %p, %" PRIu32 " -> %" PRIu32
+	    " (%s%" PRIu32 ")",
+	    ref->page, ref->page == NULL ?
+	    "unknown page type" : __wt_page_type_string(ref->page->type),
+	    ref->page == NULL ? "reverse " : "", parent,
+	    parent_entries, result_entries,
+	    ref->page == NULL ?  "-" : "+",
+	    ref->page == NULL ?
+	    parent_entries - result_entries : result_entries - parent_entries));
 
 	/*
-	 * The moved reference structures now reference the wrong parent page,
-	 * and we have to fix that up.  The problem is revealed when a thread
-	 * of control searches for a page's reference structure slot, and fails
-	 * to find it because the page it's searching no longer references it.
-	 * When that failure happens, the thread waits for the reference's home
-	 * page to be updated, which we do here: walk the children and fix them
-	 * up.
+	 * The new page index is in place, free the WT_REF we were splitting and
+	 * any deleted WT_REFs we found, modulo the usual safe free semantics.
 	 *
-	 * We're not acquiring hazard pointers on these pages, they cannot be
-	 * evicted because of the eviction transaction value set above.
-	 */
-	for (parent_refp = alloc_index->index,
-	    i = alloc_index->entries; i > 0; ++parent_refp, --i) {
-		parent_ref = *parent_refp;
-		WT_ASSERT(session, parent_ref->home == parent);
-		if (parent_ref->state != WT_REF_MEM)
+	 * Acquire a new split generation.
+	 */
+	split_gen = __wt_atomic_addv64(&S2C(session)->split_gen, 1);
+	for (i = 0; deleted_entries > 0 && i < parent_entries; ++i) {
+		next_ref = pindex->index[i];
+		if (next_ref->state != WT_REF_SPLIT)
 			continue;
+		--deleted_entries;
 
 		/*
-		 * We left the first/last children of the parent at the current
-		 * level to avoid bad split patterns, they might be leaf pages;
-		 * check the page type before we continue.
-		 */
-		child = parent_ref->page;
-		if (!WT_PAGE_IS_INTERNAL(child))
-			continue;
-#ifdef HAVE_DIAGNOSTIC
-		WT_WITH_PAGE_INDEX(session,
-		    __split_verify_intl_key_order(session, child));
-#endif
-		/*
-		 * We have the parent locked, but there's nothing to prevent
-		 * this child from splitting beneath us; ensure that reading
-		 * the child's page index structure is safe.
+		 * We set the WT_REF to split, discard it, freeing any resources
+		 * it holds.
+		 *
+		 * Row-store trees where the old version of the page is being
+		 * discarded: the previous parent page's key for this child page
+		 * may have been an on-page overflow key.  In that case, if the
+		 * key hasn't been deleted, delete it now, including its backing
+		 * blocks.  We are exchanging the WT_REF that referenced it for
+		 * the split page WT_REFs and their keys, and there's no longer
+		 * any reference to it.  Done after completing the split (if we
+		 * failed, we'd leak the underlying blocks, but the parent page
+		 * would be unaffected).
 		 */
-		WT_ENTER_PAGE_INDEX(session);
-		WT_INTL_FOREACH_BEGIN(session, child, child_ref) {
+		if (parent->type == WT_PAGE_ROW_INT) {
+			WT_TRET(__split_ovfl_key_cleanup(
+			    session, parent, next_ref));
+			ikey = __wt_ref_key_instantiated(next_ref);
+			if (ikey != NULL) {
+				size = sizeof(WT_IKEY) + ikey->size;
+				WT_TRET(__split_safe_free(
+				    session, split_gen, exclusive, ikey, size));
+				parent_decr += size;
+			}
 			/*
-			 * The page's parent reference may not be wrong, as we
-			 * opened up access from the top of the tree already,
-			 * pages may have been read in since then.  Check and
-			 * only update pages that reference the original page,
-			 * they must be wrong.
+			 * The page_del structure can be freed immediately: it
+			 * is only read when the ref state is WT_REF_DELETED.
+			 * The size of the structure wasn't added to the parent,
+			 * don't decrement.
 			 */
-			if (child_ref->home == parent) {
-				child_ref->home = child;
-				child_ref->pindex_hint = 0;
+			if (next_ref->page_del != NULL) {
+				__wt_free(session,
+				    next_ref->page_del->update_list);
+				__wt_free(session, next_ref->page_del);
 			}
-		} WT_INTL_FOREACH_END;
-		WT_LEAVE_PAGE_INDEX(session);
+		}
+
+		WT_TRET(__split_safe_free(
+		    session, split_gen, exclusive, next_ref, sizeof(WT_REF)));
+		parent_decr += sizeof(WT_REF);
 	}
 
+	/* We freed the reference that was split in the loop above. */
+	ref = NULL;
+
 	/*
-	 * Push out the changes: not required for correctness, but don't let
-	 * threads spin on incorrect page references longer than necessary.
+	 * We can't free the previous page index, there may be threads using it.
+	 * Add it to the session discard list, to be freed when it's safe.
 	 */
-	WT_FULL_BARRIER();
-	alloc_index = NULL;
+	size = sizeof(WT_PAGE_INDEX) + pindex->entries * sizeof(WT_REF *);
+	WT_TRET(__split_safe_free(session, split_gen, exclusive, pindex, size));
+	parent_decr += size;
+
+	/* Adjust the parent's memory footprint and mark it dirty. */
+	__wt_cache_page_inmem_incr(session, parent, parent_incr);
+	__wt_cache_page_inmem_decr(session, parent, parent_decr);
+	__wt_page_modify_set(session, parent);
+
+err:	/*
+	 * A note on error handling: if we completed the split, return success,
+	 * nothing really bad can have happened, and our caller has to proceed
+	 * with the split.
+	 */
+	if (!complete) {
+		for (i = 0; i < parent_entries; ++i) {
+			next_ref = pindex->index[i];
+			if (next_ref->state == WT_REF_SPLIT)
+				next_ref->state = WT_REF_DELETED;
+		}
+
+		__wt_free_ref_index(session, NULL, alloc_index, false);
+
+		/*
+		 * The split couldn't proceed because the parent would be empty,
+		 * return EBUSY so our caller knows to unlock the WT_REF that's
+		 * being deleted, but don't be noisy, there's nothing wrong.
+		 */
+		if (empty_parent)
+			return (EBUSY);
+	}
+
+	if (ret != 0 && ret != WT_PANIC)
+		__wt_err(session, ret,
+		    "ignoring not-fatal error during parent page split");
+	return (ret == WT_PANIC || !complete ? ret : 0);
+}
+
+/*
+ * __split_internal --
+ *	Split an internal page into its parent.
+ */
+static int
+__split_internal(WT_SESSION_IMPL *session, WT_PAGE *parent, WT_PAGE *page)
+{
+	WT_BTREE *btree;
+	WT_DECL_RET;
+	WT_PAGE *child;
+	WT_PAGE_INDEX *alloc_index, *child_pindex, *pindex, *replace_index;
+	WT_REF **alloc_refp;
+	WT_REF **child_refp, *page_ref, **page_refp, *ref;
+	size_t child_incr, page_decr, page_incr, parent_incr, size;
+	uint64_t split_gen;
+	uint32_t children, chunk, i, j, remain;
+	uint32_t slots;
+	bool complete;
+	void *p;
+
+	WT_STAT_FAST_CONN_INCR(session, cache_eviction_split_internal);
+	WT_STAT_FAST_DATA_INCR(session, cache_eviction_split_internal);
+
+	/* The page will be marked dirty, make sure that will succeed. */
+	WT_RET(__wt_page_modify_init(session, page));
+
+	btree = S2BT(session);
+	alloc_index = replace_index = NULL;
+	page_ref = page->pg_intl_parent_ref;
+	page_decr = page_incr = parent_incr = 0;
+	complete = false;
 
 	/*
-	 * We can't free the previous parent's index, there may be threads using
-	 * it.  Add to the session's discard list, to be freed once we know no
-	 * threads can still be using it.
+	 * Our caller is holding the page locked to single-thread splits, which
+	 * means we can safely look at the page's index without setting a split
+	 * generation.
+	 */
+	pindex = WT_INTL_INDEX_GET_SAFE(page);
+
+	/*
+	 * Decide how many child pages to create, then calculate the standard
+	 * chunk and whatever remains. Sanity check the number of children:
+	 * the decision to split matched to the deepen-per-child configuration
+	 * might get it wrong.
+	 */
+	children = pindex->entries / btree->split_deepen_per_child;
+	if (children < 10) {
+		if (pindex->entries < 100)
+			return (EBUSY);
+		children = 10;
+	}
+	chunk = pindex->entries / children;
+	remain = pindex->entries - chunk * (children - 1);
+
+	WT_ERR(__wt_verbose(session, WT_VERB_SPLIT,
+	    "%p: %" PRIu32 " internal page elements, splitting %" PRIu32
+	    " children into parent %p",
+	    page, pindex->entries, children, parent));
+
+	/*
+	 * Ideally, we'd discard the original page, but that's hard since other
+	 * threads of control are using it (for example, if eviction is walking
+	 * the tree and looking at the page.) Instead, perform a right-split,
+	 * moving all except the first chunk of the page's WT_REF objects to new
+	 * pages.
 	 *
-	 * This change requires care with error handling: we have already
-	 * updated the page with a new index.  Even if stashing the old value
-	 * fails, we don't roll back that change, because threads may already
-	 * be using the new index.
+	 * Create and initialize a replacement WT_PAGE_INDEX for the original
+	 * page.
 	 */
-	size = sizeof(WT_PAGE_INDEX) + pindex->entries * sizeof(WT_REF *);
-	WT_TRET(__split_safe_free(session, split_gen, 0, pindex, size));
-	parent_decr += size;
+	size = sizeof(WT_PAGE_INDEX) + chunk * sizeof(WT_REF *);
+	WT_ERR(__wt_calloc(session, 1, size, &replace_index));
+	page_incr += size;
+	replace_index->index = (WT_REF **)(replace_index + 1);
+	replace_index->entries = chunk;
+	for (page_refp = pindex->index, i = 0; i < chunk; ++i)
+		replace_index->index[i] = *page_refp++;
 
 	/*
-	 * Adjust the parent's memory footprint.
+	 * Allocate a new WT_PAGE_INDEX and set of WT_REF objects to be inserted
+	 * into the page's parent, replacing the page's page-index.
+	 *
+	 * The first slot of the new WT_PAGE_INDEX is the original page WT_REF.
+	 * The remainder of the slots are allocated WT_REFs.
 	 */
-	__wt_cache_page_inmem_incr(session, parent, parent_incr);
-	__wt_cache_page_inmem_decr(session, parent, parent_decr);
+	size = sizeof(WT_PAGE_INDEX) + children * sizeof(WT_REF *);
+	WT_ERR(__wt_calloc(session, 1, size, &alloc_index));
+	parent_incr += size;
+	alloc_index->index = (WT_REF **)(alloc_index + 1);
+	alloc_index->entries = children;
+	alloc_refp = alloc_index->index;
+	*alloc_refp++ = page_ref;
+	for (i = 1; i < children; ++alloc_refp, ++i)
+		WT_ERR(__wt_calloc_one(session, alloc_refp));
+	parent_incr += children * sizeof(WT_REF);
+
+	/* Allocate child pages, and connect them into the new page index. */
+	WT_ASSERT(session, page_refp == pindex->index + chunk);
+	for (alloc_refp = alloc_index->index + 1, i = 1; i < children; ++i) {
+		slots = i == children - 1 ? remain : chunk;
+		WT_ERR(__wt_page_alloc(
+		    session, page->type, 0, slots, false, &child));
+
+		/*
+		 * Initialize the page's child reference; we need a copy of the
+		 * page's key.
+		 */
+		ref = *alloc_refp++;
+		ref->home = parent;
+		ref->page = child;
+		ref->addr = NULL;
+		if (page->type == WT_PAGE_ROW_INT) {
+			__wt_ref_key(page, *page_refp, &p, &size);
+			WT_ERR(__wt_row_ikey(session, 0, p, size, ref));
+			parent_incr += sizeof(WT_IKEY) + size;
+		} else
+			ref->key.recno = (*page_refp)->key.recno;
+		ref->state = WT_REF_MEM;
+
+		/* Initialize the child page. */
+		if (page->type == WT_PAGE_COL_INT)
+			child->pg_intl_recno = (*page_refp)->key.recno;
+		child->pg_intl_parent_ref = ref;
+
+		/* Mark it dirty. */
+		WT_ERR(__wt_page_modify_init(session, child));
+		__wt_page_modify_set(session, child);
+
+		/* Ensure the page isn't evicted or split for now. */
+		__split_child_block_evict_and_split(child);
+
+		/*
+		 * The newly allocated child's page index references the same
+		 * structures as the parent. (We cannot move WT_REF structures,
+		 * threads may be underneath us right now changing the structure
+		 * state.)  However, if the WT_REF structures reference on-page
+		 * information, we have to fix that, because the disk image for
+		 * the page that has an page index entry for the WT_REF is about
+		 * to be discarded.
+		 */
+		child_pindex = WT_INTL_INDEX_GET_SAFE(child);
+		child_incr = 0;
+		for (child_refp = child_pindex->index,
+		    j = 0; j < slots; ++child_refp, ++page_refp, ++j)
+			WT_ERR(__split_ref_move(session, page,
+			    page_refp, &page_decr, child_refp, &child_incr));
+
+		__wt_cache_page_inmem_incr(session, child, child_incr);
+	}
+	WT_ASSERT(session, alloc_refp -
+	    alloc_index->index == (ptrdiff_t)alloc_index->entries);
+	WT_ASSERT(session,
+	    page_refp - pindex->index == (ptrdiff_t)pindex->entries);
+
+	/* Split into the parent. */
+	WT_ERR(__split_parent(session, page_ref, alloc_index->index,
+	    alloc_index->entries, parent_incr, false, false));
+
+	/*
+	 * A note on error handling: until this point, there's no problem with
+	 * unwinding on error.  We allocated a new page index, a new set of
+	 * WT_REFs and a new set of child pages -- if an error occurred, the
+	 * page remained unchanged, although it may have an incorrect memory
+	 * footprint.  From now on we've modified the parent page, attention
+	 * needs to be paid. However, subsequent failures are relatively benign,
+	 * the split is OK and complete. For that reason, we ignore errors past
+	 * this point unless there's a panic.
+	 */
+	complete = true;
+
+	/* Confirm the page's index hasn't moved, then update it. */
+	WT_ASSERT(session, WT_INTL_INDEX_GET_SAFE(page) == pindex);
+	WT_INTL_INDEX_SET(page, replace_index);
+
+#ifdef HAVE_DIAGNOSTIC
+	WT_WITH_PAGE_INDEX(session,
+	    __split_verify_intl_key_order(session, parent));
+	WT_WITH_PAGE_INDEX(session,
+	    __split_verify_intl_key_order(session, page));
+#endif
+
+	/* Fix up the moved WT_REF structures. */
+	WT_ERR(__split_ref_move_final(
+	    session, alloc_index->index + 1, alloc_index->entries - 1));
+
+	/*
+	 * We don't care about the page-index we allocated, all we needed was
+	 * the array of WT_REF structures, which has now been split into the
+	 * parent page.
+	 */
+	__wt_free(session, alloc_index);
+
+	/*
+	 * We can't free the previous page's index, there may be threads using
+	 * it. Add to the session's discard list, to be freed once we know no
+	 * threads can still be using it.
+	 *
+	 * This change requires care with error handling, we've already updated
+	 * the parent page. Even if stashing the old value fails, we don't roll
+	 * back that change, because threads may already be using the new parent
+	 * page.
+	 */
+	split_gen = __wt_atomic_addv64(&S2C(session)->split_gen, 1);
+	size = sizeof(WT_PAGE_INDEX) + pindex->entries * sizeof(WT_REF *);
+	WT_TRET(__split_safe_free(session, split_gen, false, pindex, size));
+	page_decr += size;
+
+	/* Adjust the page's memory footprint, and mark it dirty. */
+	__wt_cache_page_inmem_incr(session, page, page_incr);
+	__wt_cache_page_inmem_decr(session, page, page_decr);
+	__wt_page_modify_set(session, page);
 
 err:	/*
 	 * If complete is true, we saw an error after opening up the tree to
-	 * descent through the parent page's new index. There is nothing we
-	 * can do, there are threads potentially active in both versions of
-	 * the tree.
+	 * descent through the page's new index. There is nothing we can do,
+	 * there are threads potentially active in both versions of the tree.
 	 *
 	 * A note on error handling: if we completed the split, return success,
 	 * nothing really bad can have happened, and our caller has to proceed
 	 * with the split.
 	 */
-	if (!complete)
-		__wt_free_ref_index(session, parent, alloc_index, true);
+	if (!complete) {
+		__wt_free_ref_index(session, page, alloc_index, true);
+		__wt_free_ref_index(session, page, replace_index, false);
+	}
 
 	if (ret != 0 && ret != WT_PANIC)
 		__wt_err(session, ret,
-		    "ignoring not-fatal error during parent page split to "
-		    "deepen the tree");
+		    "ignoring not-fatal error during internal page split");
 	return (ret == WT_PANIC || !complete ? ret : 0);
 }
 
 /*
+ * __split_internal_lock --
+ *	Lock an internal page.
+ */
+static int
+__split_internal_lock(
+    WT_SESSION_IMPL *session, WT_REF *ref, WT_PAGE **parentp, bool *hazardp)
+{
+	WT_DECL_RET;
+	WT_PAGE *parent;
+	WT_REF *parent_ref;
+
+	*hazardp = false;
+	*parentp = NULL;
+
+	/*
+	 * A checkpoint reconciling this parent page can deadlock with
+	 * our split. We have an exclusive page lock on the child before
+	 * we acquire the page's reconciliation lock, and reconciliation
+	 * acquires the page's reconciliation lock before it encounters
+	 * the child's exclusive lock (which causes reconciliation to
+	 * loop until the exclusive lock is resolved). If we want to split
+	 * the parent, give up to avoid that deadlock.
+	 */
+	if (S2BT(session)->checkpointing != WT_CKPT_OFF)
+		return (EBUSY);
+
+	/*
+	 * Get a page-level lock on the parent to single-thread splits into the
+	 * page because we need to single-thread sizing/growing the page index.
+	 * It's OK to queue up multiple splits as the child pages split, but the
+	 * actual split into the parent has to be serialized.  Note we allocate
+	 * memory inside of the lock and may want to invest effort in making the
+	 * locked period shorter.
+	 *
+	 * We use the reconciliation lock here because not only do we have to
+	 * single-thread the split, we have to lock out reconciliation of the
+	 * parent because reconciliation of the parent can't deal with finding
+	 * a split child during internal page traversal. Basically, there's no
+	 * reason to use a different lock if we have to block reconciliation
+	 * anyway.
+	 */
+	for (;;) {
+		parent = ref->home;
+
+		/* Skip pages that aren't ready to split. */
+		if (F_ISSET_ATOMIC(parent, WT_PAGE_SPLIT_BLOCK))
+			return (EBUSY);
+
+		WT_RET(__wt_fair_lock(session, &parent->page_lock));
+		if (parent == ref->home)
+			break;
+		WT_RET(__wt_fair_unlock(session, &parent->page_lock));
+	}
+
+	/*
+	 * We have exclusive access to split the parent, and at this point, the
+	 * child prevents the parent from being evicted.  However, once we
+	 * update the parent's index, it may no longer refer to the child, and
+	 * could conceivably be evicted.  Get a hazard pointer on the parent
+	 * now, so that we can safely access it after updating the index.
+	 *
+	 * Take care getting the page doesn't trigger eviction work: we could
+	 * block trying to split a different child of our parent and deadlock
+	 * or we could be the eviction server relied upon by other threads to
+	 * populate the eviction queue.
+	 */
+	if (!__wt_ref_is_root(parent_ref = parent->pg_intl_parent_ref)) {
+		WT_ERR(__wt_page_in(session, parent_ref, WT_READ_NO_EVICT));
+		*hazardp = true;
+	}
+
+	*parentp = parent;
+	return (0);
+
+err:	WT_TRET(__wt_fair_unlock(session, &parent->page_lock));
+	return (ret);
+}
+
+/*
+ * __split_internal_unlock --
+ *	Unlock the parent page.
+ */
+static int
+__split_internal_unlock(WT_SESSION_IMPL *session, WT_PAGE *parent, bool hazard)
+{
+	WT_DECL_RET;
+
+	if (hazard)
+		ret = __wt_hazard_clear(session, parent);
+
+	WT_TRET(__wt_fair_unlock(session, &parent->page_lock));
+	return (ret);
+}
+
+/*
+ * __split_internal_should_split --
+ *	Return if we should split an internal page.
+ */
+static bool
+__split_internal_should_split(WT_SESSION_IMPL *session, WT_REF *ref)
+{
+	WT_BTREE *btree;
+	WT_PAGE *page;
+	WT_PAGE_INDEX *pindex;
+
+	btree = S2BT(session);
+	page = ref->page;
+
+	/*
+	 * Our caller is holding the parent page locked to single-thread splits,
+	 * which means we can safely look at the page's index without setting a
+	 * split generation.
+	 */
+	pindex = WT_INTL_INDEX_GET_SAFE(page);
+
+	/* Sanity check for a reasonable number of on-page keys. */
+	if (pindex->entries < 100)
+		return (false);
+
+	/*
+	 * Deepen the tree if the page's memory footprint is larger than the
+	 * maximum size for a page in memory (presumably putting eviction
+	 * pressure on the cache).
+	 */
+	if (page->memory_footprint > btree->maxmempage)
+		return (true);
+
+	/*
+	 * Check if the page has enough keys to make it worth splitting. If
+	 * the number of keys is allowed to grow too large, the cost of
+	 * splitting into parent pages can become large enough to result
+	 * in slow operations.
+	 */
+	if (pindex->entries > btree->split_deepen_min_child)
+		return (true);
+
+	return (false);
+}
+
+/*
+ * __split_parent_climb --
+ *	Check if we should split up the tree.
+ */
+static int
+__split_parent_climb(WT_SESSION_IMPL *session, WT_PAGE *page, bool page_hazard)
+{
+	WT_DECL_RET;
+	WT_PAGE *parent;
+	WT_REF *ref;
+	bool parent_hazard;
+
+	/*
+	 * Page splits trickle up the tree, that is, as leaf pages grow large
+	 * enough and are evicted, they'll split into their parent.  And, as
+	 * that parent page grows large enough and is evicted, it splits into
+	 * its parent and so on.  When the page split wave reaches the root,
+	 * the tree will permanently deepen as multiple root pages are written.
+	 *
+	 * However, this only helps if internal pages are evicted (and we resist
+	 * evicting internal pages for obvious reasons), or if the tree were to
+	 * be closed and re-opened from a disk image, which may be a rare event.
+	 *
+	 * To avoid internal pages becoming too large absent eviction, check
+	 * parent pages each time pages are split into them. If the page is big
+	 * enough, either split the page into its parent or, in the case of the
+	 * root, deepen the tree.
+	 *
+	 * Split up the tree.
+	 */
+	for (;;) {
+		parent = NULL;
+		parent_hazard = false;
+		ref = page->pg_intl_parent_ref;
+
+		/* If we don't need to split the page, we're done. */
+		if (!__split_internal_should_split(session, ref))
+			break;
+
+		/*
+		 * If we've reached the root page, there are no subsequent pages
+		 * to review, deepen the tree and quit.
+		 */
+		if (__wt_ref_is_root(ref)) {
+			ret = __split_root(session, page);
+			break;
+		}
+
+		/*
+		 * Lock the parent and split into it, then swap the parent/page
+		 * locks, lock-coupling up the tree.
+		 */
+		WT_ERR(__split_internal_lock(
+		    session, ref, &parent, &parent_hazard));
+		ret = __split_internal(session, parent, page);
+		WT_TRET(__split_internal_unlock(session, page, page_hazard));
+
+		page = parent;
+		page_hazard = parent_hazard;
+		parent = NULL;
+		parent_hazard = false;
+		WT_ERR(ret);
+	}
+
+err:	if (parent != NULL)
+		WT_TRET(
+		    __split_internal_unlock(session, parent, parent_hazard));
+	WT_TRET(__split_internal_unlock(session, page, page_hazard));
+
+	/* A page may have been busy, in which case return without error. */
+	WT_RET_BUSY_OK(ret);
+	return (0);
+}
+
+/*
  * __split_multi_inmem --
  *	Instantiate a page in a multi-block set.
  */
@@ -901,369 +1594,6 @@ __wt_multi_to_ref(WT_SESSION_IMPL *session,
 }
 
 /*
- * __split_parent_lock --
- *	Lock the parent page.
- */
-static int
-__split_parent_lock(
-    WT_SESSION_IMPL *session, WT_REF *ref, WT_PAGE **parentp, bool *hazardp)
-{
-	WT_DECL_RET;
-	WT_PAGE *parent;
-	WT_REF *parent_ref;
-
-	*hazardp = false;
-	*parentp = NULL;
-
-	/*
-	 * A checkpoint reconciling this parent page can deadlock with
-	 * our split. We have an exclusive page lock on the child before
-	 * we acquire the page's reconciliation lock, and reconciliation
-	 * acquires the page's reconciliation lock before it encounters
-	 * the child's exclusive lock (which causes reconciliation to
-	 * loop until the exclusive lock is resolved). If we want to split
-	 * the parent, give up to avoid that deadlock.
-	 */
-	if (S2BT(session)->checkpointing != WT_CKPT_OFF)
-		return (EBUSY);
-
-	/*
-	 * Get a page-level lock on the parent to single-thread splits into the
-	 * page because we need to single-thread sizing/growing the page index.
-	 * It's OK to queue up multiple splits as the child pages split, but the
-	 * actual split into the parent has to be serialized.  Note we allocate
-	 * memory inside of the lock and may want to invest effort in making the
-	 * locked period shorter.
-	 *
-	 * We use the reconciliation lock here because not only do we have to
-	 * single-thread the split, we have to lock out reconciliation of the
-	 * parent because reconciliation of the parent can't deal with finding
-	 * a split child during internal page traversal. Basically, there's no
-	 * reason to use a different lock if we have to block reconciliation
-	 * anyway.
-	 */
-	for (;;) {
-		parent = ref->home;
-		WT_RET(__wt_fair_lock(session, &parent->page_lock));
-		if (parent == ref->home)
-			break;
-		/* Try again if the page deepened while we were waiting */
-		WT_RET(__wt_fair_unlock(session, &parent->page_lock));
-	}
-
-	/*
-	 * We have exclusive access to split the parent, and at this point, the
-	 * child prevents the parent from being evicted.  However, once we
-	 * update the parent's index, it will no longer refer to the child, and
-	 * could conceivably be evicted.  Get a hazard pointer on the parent
-	 * now, so that we can safely access it after updating the index.
-	 *
-	 * Take care getting the page doesn't trigger eviction work: we could
-	 * block trying to split a different child of our parent and deadlock
-	 * or we could be the eviction server relied upon by other threads to
-	 * populate the eviction queue.
-	 */
-	if (!__wt_ref_is_root(parent_ref = parent->pg_intl_parent_ref)) {
-		WT_ERR(__wt_page_in(session, parent_ref, WT_READ_NO_EVICT));
-		*hazardp = true;
-	}
-
-	*parentp = parent;
-	return (0);
-
-err:	WT_TRET(__wt_fair_unlock(session, &parent->page_lock));
-	return (ret);
-}
-
-/*
- * __split_parent_unlock --
- *	Unlock the parent page.
- */
-static int
-__split_parent_unlock(WT_SESSION_IMPL *session, WT_PAGE *parent, bool hazard)
-{
-	WT_DECL_RET;
-
-	if (hazard)
-		ret = __wt_hazard_clear(session, parent);
-
-	WT_TRET(__wt_fair_unlock(session, &parent->page_lock));
-	return (ret);
-}
-
-/*
- * __split_parent --
- *	Resolve a multi-page split, inserting new information into the parent.
- */
-static int
-__split_parent(WT_SESSION_IMPL *session, WT_REF *ref,
-    WT_REF **ref_new, uint32_t new_entries, size_t parent_incr, int exclusive)
-{
-	WT_DECL_RET;
-	WT_IKEY *ikey;
-	WT_PAGE *parent;
-	WT_PAGE_INDEX *alloc_index, *pindex;
-	WT_REF **alloc_refp, *next_ref, *parent_ref;
-	size_t parent_decr, size;
-	uint64_t split_gen;
-	uint32_t i, j;
-	uint32_t deleted_entries, parent_entries, result_entries;
-	bool complete;
-
-	parent = ref->home;
-	parent_ref = parent->pg_intl_parent_ref;
-
-	alloc_index = pindex = NULL;
-	parent_decr = 0;
-	parent_entries = 0;
-	complete = false;
-
-	/*
-	 * We've locked the parent, which means it cannot split (which is the
-	 * only reason to worry about split generation values).
-	 */
-	pindex = WT_INTL_INDEX_GET_SAFE(parent);
-	parent_entries = pindex->entries;
-
-	/*
-	 * Remove any refs to deleted pages while we are splitting, we have
-	 * the internal page locked down, and are copying the refs into a new
-	 * array anyway.  Switch them to the special split state, so that any
-	 * reading thread will restart.  Include the ref we are splitting in
-	 * the count to be deleted.
-	 */
-	for (deleted_entries = 1, i = 0; i < parent_entries; ++i) {
-		next_ref = pindex->index[i];
-		WT_ASSERT(session, next_ref->state != WT_REF_SPLIT);
-		if (next_ref->state == WT_REF_DELETED &&
-		    __wt_delete_page_skip(session, next_ref, true) &&
-		    __wt_atomic_casv32(
-		    &next_ref->state, WT_REF_DELETED, WT_REF_SPLIT))
-			deleted_entries++;
-	}
-
-	/*
-	 * The final entry count consists of the original count, plus any new
-	 * pages, less any WT_REFs we're removing.
-	 */
-	result_entries = (parent_entries + new_entries) - deleted_entries;
-
-	/*
-	 * If the entire (sub)tree is empty, give up: we can't leave an empty
-	 * internal page.  Mark it to be evicted soon and clean up any
-	 * references that have changed state.
-	 */
-	if (result_entries == 0) {
-		__wt_page_evict_soon(parent);
-		goto err;
-	}
-
-	/*
-	 * Allocate and initialize a new page index array for the parent, then
-	 * copy references from the original index array, plus references from
-	 * the newly created split array, into place.
-	 */
-	size = sizeof(WT_PAGE_INDEX) + result_entries * sizeof(WT_REF *);
-	WT_ERR(__wt_calloc(session, 1, size, &alloc_index));
-	parent_incr += size;
-	alloc_index->index = (WT_REF **)(alloc_index + 1);
-	alloc_index->entries = result_entries;
-	for (alloc_refp = alloc_index->index, i = 0; i < parent_entries; ++i) {
-		next_ref = pindex->index[i];
-		if (next_ref == ref) {
-			for (j = 0; j < new_entries; ++j) {
-				ref_new[j]->home = parent;
-				*alloc_refp++ = ref_new[j];
-
-				/*
-				 * Clear the split reference as it moves to the
-				 * allocated page index, so it never appears on
-				 * both after an error.
-				 */
-				ref_new[j] = NULL;
-			}
-
-			/*
-			 * We detect append-style workloads to avoid repeatedly
-			 * deepening parts of the tree where no work is being
-			 * done by tracking if we're splitting after the slots
-			 * created by the last split to deepen this parent.
-			 *
-			 * Note the calculation: i is a 0-based array offset and
-			 * split-last is a count of entries, also either or both
-			 * i and split-last might be unsigned 0, don't decrement
-			 * either one.
-			 */
-			if (i > parent->pg_intl_deepen_split_last)
-				parent->
-				    pg_intl_deepen_split_append += new_entries;
-		} else if (next_ref->state != WT_REF_SPLIT)
-			/* Skip refs we have marked for deletion. */
-			*alloc_refp++ = next_ref;
-	}
-
-	/* Check that we filled in all the entries. */
-	WT_ASSERT(session,
-	    alloc_refp - alloc_index->index == (ptrdiff_t)result_entries);
-
-	/*
-	 * Confirm the parent page's index hasn't moved then update it, which
-	 * makes the split visible to threads descending the tree.
-	 */
-	WT_ASSERT(session, WT_INTL_INDEX_GET_SAFE(parent) == pindex);
-	WT_INTL_INDEX_SET(parent, alloc_index);
-	split_gen = __wt_atomic_addv64(&S2C(session)->split_gen, 1);
-	alloc_index = NULL;
-
-#ifdef HAVE_DIAGNOSTIC
-	WT_WITH_PAGE_INDEX(session,
-	    __split_verify_intl_key_order(session, parent));
-#endif
-
-	/*
-	 * Reset the page's original WT_REF field to split.  Threads cursoring
-	 * through the tree were blocked because that WT_REF state was set to
-	 * locked.  This update changes the locked state to split, unblocking
-	 * those threads and causing them to re-calculate their position based
-	 * on the updated parent page's index.
-	 */
-	WT_PUBLISH(ref->state, WT_REF_SPLIT);
-
-	/*
-	 * A note on error handling: failures before we swapped the new page
-	 * index into the parent can be resolved by freeing allocated memory
-	 * because the original page is unchanged, we can continue to use it
-	 * and we have not yet modified the parent.  Failures after we swap
-	 * the new page index into the parent are also relatively benign, the
-	 * split is OK and complete. For those reasons, we ignore errors past
-	 * this point unless there's a panic.
-	 */
-	complete = true;
-
-	WT_ERR(__wt_verbose(session, WT_VERB_SPLIT,
-	    "%s split into parent %" PRIu32 " -> %" PRIu32
-	    " (%" PRIu32 ")", ref->page == NULL ?
-	    "reverse" : __wt_page_type_string(ref->page->type),
-	    parent_entries, result_entries, result_entries - parent_entries));
-
-	/*
-	 * The new page index is in place, free the WT_REF we were splitting
-	 * and any deleted WT_REFs we found, modulo the usual safe free
-	 * semantics.
-	 */
-	for (i = 0; deleted_entries > 0 && i < parent_entries; ++i) {
-		next_ref = pindex->index[i];
-		if (next_ref->state != WT_REF_SPLIT)
-			continue;
-		--deleted_entries;
-
-		/*
-		 * We set the WT_REF to split, discard it, freeing any resources
-		 * it holds.
-		 *
-		 * Row-store trees where the old version of the page is being
-		 * discarded: the previous parent page's key for this child page
-		 * may have been an on-page overflow key.  In that case, if the
-		 * key hasn't been deleted, delete it now, including its backing
-		 * blocks.  We are exchanging the WT_REF that referenced it for
-		 * the split page WT_REFs and their keys, and there's no longer
-		 * any reference to it.  Done after completing the split (if we
-		 * failed, we'd leak the underlying blocks, but the parent page
-		 * would be unaffected).
-		 */
-		if (parent->type == WT_PAGE_ROW_INT) {
-			WT_TRET(__split_ovfl_key_cleanup(
-			    session, parent, next_ref));
-			ikey = __wt_ref_key_instantiated(next_ref);
-			if (ikey != NULL) {
-				size = sizeof(WT_IKEY) + ikey->size;
-				WT_TRET(__split_safe_free(
-				    session, split_gen, 0, ikey, size));
-				parent_decr += size;
-			}
-			/*
-			 * The page_del structure can be freed immediately: it
-			 * is only read when the ref state is WT_REF_DELETED.
-			 * The size of the structure wasn't added to the parent,
-			 * don't decrement.
-			 */
-			if (next_ref->page_del != NULL) {
-				__wt_free(session,
-				    next_ref->page_del->update_list);
-				__wt_free(session, next_ref->page_del);
-			}
-		}
-
-		WT_TRET(__split_safe_free(
-		    session, split_gen, 0, next_ref, sizeof(WT_REF)));
-		parent_decr += sizeof(WT_REF);
-	}
-
-	/* We freed the reference that was split in the loop above. */
-	ref = NULL;
-
-	/*
-	 * We can't free the previous page index, there may be threads using it.
-	 * Add it to the session discard list, to be freed when it's safe.
-	 */
-	size = sizeof(WT_PAGE_INDEX) + pindex->entries * sizeof(WT_REF *);
-	WT_TRET(__split_safe_free(session, split_gen, exclusive, pindex, size));
-	parent_decr += size;
-
-	/*
-	 * Adjust the parent's memory footprint.
-	 */
-	__wt_cache_page_inmem_incr(session, parent, parent_incr);
-	__wt_cache_page_inmem_decr(session, parent, parent_decr);
-
-	/*
-	 * Simple page splits trickle up the tree, that is, as leaf pages grow
-	 * large enough and are evicted, they'll split into their parent.  And,
-	 * as that parent grows large enough and is evicted, it will split into
-	 * its parent and so on.  When the page split wave reaches the root,
-	 * the tree will permanently deepen as multiple root pages are written.
-	 *	However, this only helps if first, the pages are evicted (and
-	 * we resist evicting internal pages for obvious reasons), and second,
-	 * if the tree is closed and re-opened from a disk image, which may be
-	 * a rare event.
-	 *	To avoid the case of internal pages becoming too large when they
-	 * aren't being evicted, check internal pages each time a leaf page is
-	 * split into them.  If it's big enough, deepen the tree at that point.
-	 *	Do the check here because we've just grown the parent page and
-	 * are holding it locked.
-	 */
-	if (ret == 0 && !exclusive &&
-	    __split_should_deepen(session, parent_ref))
-		ret = __split_deepen(session, parent);
-
-err:	/*
-	 * A note on error handling: if we completed the split, return success,
-	 * nothing really bad can have happened, and our caller has to proceed
-	 * with the split.
-	 */
-	if (!complete) {
-		for (i = 0; i < parent_entries; ++i) {
-			next_ref = pindex->index[i];
-			if (next_ref->state == WT_REF_SPLIT)
-				next_ref->state = WT_REF_DELETED;
-		}
-
-		/* If we gave up on a reverse split, unlock the child. */
-		if (ref_new == NULL) {
-			WT_ASSERT(session, ref->state == WT_REF_LOCKED);
-			ref->state = WT_REF_DELETED;
-		}
-
-		__wt_free_ref_index(session, NULL, alloc_index, false);
-	}
-
-	if (ret != 0 && ret != WT_PANIC)
-		__wt_err(session, ret,
-		    "ignoring not-fatal error during parent page split");
-	return (ret == WT_PANIC || !complete ? ret : 0);
-}
-
-/*
  * __split_insert --
  *	Split a page's last insert list entries into a separate page.
  */
@@ -1279,6 +1609,9 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	size_t page_decr, parent_incr, right_incr;
 	int i;
 
+	WT_STAT_FAST_CONN_INCR(session, cache_inmem_split);
+	WT_STAT_FAST_DATA_INCR(session, cache_inmem_split);
+
 	page = ref->page;
 	right = NULL;
 	page_decr = parent_incr = right_incr = 0;
@@ -1491,7 +1824,7 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	 */
 	page = NULL;
 	if ((ret = __split_parent(
-	    session, ref, split_ref, 2, parent_incr, false)) != 0) {
+	    session, ref, split_ref, 2, parent_incr, false, true)) != 0) {
 		/*
 		 * Move the insert list element back to the original page list.
 		 * For simplicity, the previous skip list pointers originally
@@ -1513,9 +1846,6 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 		WT_ERR(ret);
 	}
 
-	WT_STAT_FAST_CONN_INCR(session, cache_inmem_split);
-	WT_STAT_FAST_DATA_INCR(session, cache_inmem_split);
-
 	return (0);
 
 err:	if (split_ref[0] != NULL) {
@@ -1543,83 +1873,21 @@ __wt_split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	WT_PAGE *parent;
 	bool hazard;
 
-	WT_RET(__split_parent_lock(session, ref, &parent, &hazard));
-	ret = __split_insert(session, ref);
-	WT_TRET(__split_parent_unlock(session, parent, hazard));
-	return (ret);
-}
-
-/*
- * __wt_split_reverse --
- *	We have a locked ref that is empty and we want to rewrite the index in
- *	its parent.
- */
-int
-__wt_split_reverse(WT_SESSION_IMPL *session, WT_REF *ref)
-{
-	WT_DECL_RET;
-	WT_PAGE *parent;
-	bool hazard;
-
-	WT_RET(__split_parent_lock(session, ref, &parent, &hazard));
-	ret = __split_parent(session, ref, NULL, 0, 0, 0);
-	WT_TRET(__split_parent_unlock(session, parent, hazard));
-	return (ret);
-}
-
-/*
- * __wt_split_rewrite --
- *	Rewrite an in-memory page with a new version.
- */
-int
-__wt_split_rewrite(WT_SESSION_IMPL *session, WT_REF *ref)
-{
-	WT_DECL_RET;
-	WT_PAGE *page;
-	WT_PAGE_MODIFY *mod;
-	WT_REF new;
-
-	page = ref->page;
-	mod = page->modify;
-
-	/*
-	 * This isn't a split: a reconciliation failed because we couldn't write
-	 * something, and in the case of forced eviction, we need to stop this
-	 * page from being such a problem. We have exclusive access, rewrite the
-	 * page in memory. The code lives here because the split code knows how
-	 * to re-create a page in memory after it's been reconciled, and that's
-	 * exactly what we want to do.
-	 *
-	 * Build the new page.
-	 */
-	memset(&new, 0, sizeof(new));
-	WT_ERR(__split_multi_inmem(session, page, &new, &mod->mod_multi[0]));
+	WT_RET(__wt_verbose(
+	    session, WT_VERB_SPLIT, "%p: split-insert", ref->page));
 
-	/*
-	 * The rewrite succeeded, we can no longer fail.
-	 *
-	 * Finalize the move, discarding moved update lists from the original
-	 * page.
-	 */
-	__split_multi_inmem_final(page, &mod->mod_multi[0]);
+	WT_RET(__split_internal_lock(session, ref, &parent, &hazard));
+	if ((ret = __split_insert(session, ref)) != 0) {
+		WT_TRET(__split_internal_unlock(session, parent, hazard));
+		return (ret);
+	}
 
 	/*
-	 * Discard the original page.
-	 *
-	 * Pages with unresolved changes are not marked clean during
-	 * reconciliation, do it now.
+	 * Split up through the tree as necessary; we're holding the original
+	 * parent page locked, note the functions we call are responsible for
+	 * releasing that lock.
 	 */
-	__wt_page_modify_clear(session, page);
-	__wt_ref_out(session, ref);
-
-	/* Swap the new page into place. */
-	ref->page = new.page;
-	WT_PUBLISH(ref->state, WT_REF_MEM);
-
-	return (0);
-
-err:	__split_multi_inmem_fail(session, &new);
-	return (ret);
+	return (__split_parent_climb(session, parent, hazard));
 }
 
 /*
@@ -1636,6 +1904,9 @@ __split_multi(WT_SESSION_IMPL *session, WT_REF *ref, bool closing)
 	size_t parent_incr;
 	uint32_t i, new_entries;
 
+	WT_STAT_FAST_CONN_INCR(session, cache_eviction_split_leaf);
+	WT_STAT_FAST_DATA_INCR(session, cache_eviction_split_leaf);
+
 	page = ref->page;
 	mod = page->modify;
 	new_entries = mod->mod_multi_entries;
@@ -1656,10 +1927,7 @@ __split_multi(WT_SESSION_IMPL *session, WT_REF *ref, bool closing)
 	 * exclusively.
 	 */
 	WT_ERR(__split_parent(
-	    session, ref, ref_new, new_entries, parent_incr, closing));
-
-	WT_STAT_FAST_CONN_INCR(session, cache_eviction_split);
-	WT_STAT_FAST_DATA_INCR(session, cache_eviction_split);
+	    session, ref, ref_new, new_entries, parent_incr, closing, true));
 
 	/*
 	 * The split succeeded, we can no longer fail.
@@ -1697,8 +1965,98 @@ __wt_split_multi(WT_SESSION_IMPL *session, WT_REF *ref, int closing)
 	WT_PAGE *parent;
 	bool hazard;
 
-	WT_RET(__split_parent_lock(session, ref, &parent, &hazard));
-	ret = __split_multi(session, ref, closing);
-	WT_TRET(__split_parent_unlock(session, parent, hazard));
+	WT_RET(__wt_verbose(
+	    session, WT_VERB_SPLIT, "%p: split-multi", ref->page));
+
+	WT_RET(__split_internal_lock(session, ref, &parent, &hazard));
+	if ((ret = __split_multi(session, ref, closing)) != 0 || closing) {
+		WT_TRET(__split_internal_unlock(session, parent, hazard));
+		return (ret);
+	}
+
+	/*
+	 * Split up through the tree as necessary; we're holding the original
+	 * parent page locked, note the functions we call are responsible for
+	 * releasing that lock.
+	 */
+	return (__split_parent_climb(session, parent, hazard));
+}
+
+/*
+ * __wt_split_reverse --
+ *	We have a locked ref that is empty and we want to rewrite the index in
+ *	its parent.
+ */
+int
+__wt_split_reverse(WT_SESSION_IMPL *session, WT_REF *ref)
+{
+	WT_DECL_RET;
+	WT_PAGE *parent;
+	bool hazard;
+
+	WT_RET(__wt_verbose(
+	    session, WT_VERB_SPLIT, "%p: reverse-split", ref->page));
+
+	WT_RET(__split_internal_lock(session, ref, &parent, &hazard));
+	ret = __split_parent(session, ref, NULL, 0, 0, false, true);
+	WT_TRET(__split_internal_unlock(session, parent, hazard));
+	return (ret);
+}
+
+/*
+ * __wt_split_rewrite --
+ *	Rewrite an in-memory page with a new version.
+ */
+int
+__wt_split_rewrite(WT_SESSION_IMPL *session, WT_REF *ref)
+{
+	WT_DECL_RET;
+	WT_PAGE *page;
+	WT_PAGE_MODIFY *mod;
+	WT_REF new;
+
+	page = ref->page;
+	mod = page->modify;
+
+	WT_RET(__wt_verbose(
+	    session, WT_VERB_SPLIT, "%p: split-rewrite", ref->page));
+
+	/*
+	 * This isn't a split: a reconciliation failed because we couldn't write
+	 * something, and in the case of forced eviction, we need to stop this
+	 * page from being such a problem. We have exclusive access, rewrite the
+	 * page in memory. The code lives here because the split code knows how
+	 * to re-create a page in memory after it's been reconciled, and that's
+	 * exactly what we want to do.
+	 *
+	 * Build the new page.
+	 */
+	memset(&new, 0, sizeof(new));
+	WT_ERR(__split_multi_inmem(session, page, &new, &mod->mod_multi[0]));
+
+	/*
+	 * The rewrite succeeded, we can no longer fail.
+	 *
+	 * Finalize the move, discarding moved update lists from the original
+	 * page.
+	 */
+	__split_multi_inmem_final(page, &mod->mod_multi[0]);
+
+	/*
+	 * Discard the original page.
+	 *
+	 * Pages with unresolved changes are not marked clean during
+	 * reconciliation, do it now.
+	 */
+	__wt_page_modify_clear(session, page);
+	__wt_ref_out(session, ref);
+
+	/* Swap the new page into place. */
+	ref->page = new.page;
+	WT_PUBLISH(ref->state, WT_REF_MEM);
+
+	return (0);
+
+err:	__split_multi_inmem_fail(session, &new);
 	return (ret);
 }
diff --git a/src/btree/bt_sync.c b/src/btree/bt_sync.c
index 7395cce11e1..07bb2eb3a01 100644
--- a/src/btree/bt_sync.c
+++ b/src/btree/bt_sync.c
@@ -191,7 +191,7 @@ __sync_file(WT_SESSION_IMPL *session, WT_CACHE_OP syncop)
 		    syncop == WT_SYNC_WRITE_LEAVES ?
 		    "WRITE_LEAVES" : "CHECKPOINT",
 		    leaf_bytes, leaf_pages, internal_bytes, internal_pages,
-		    WT_TIMEDIFF(end, start) / WT_MILLION));
+		    WT_TIMEDIFF_MS(end, start)));
 	}
 
 err:	/* On error, clear any left-over tree walk. */
diff --git a/src/btree/col_srch.c b/src/btree/col_srch.c
index d02f23ed164..e9fa570f97b 100644
--- a/src/btree/col_srch.c
+++ b/src/btree/col_srch.c
@@ -22,7 +22,7 @@ __wt_col_search(WT_SESSION_IMPL *session,
 	WT_INSERT *ins;
 	WT_INSERT_HEAD *ins_head;
 	WT_PAGE *page;
-	WT_PAGE_INDEX *pindex;
+	WT_PAGE_INDEX *pindex, *parent_pindex;
 	WT_REF *current, *descent;
 	uint32_t base, indx, limit;
 	int depth;
@@ -37,10 +37,12 @@ __wt_col_search(WT_SESSION_IMPL *session,
 		goto leaf_only;
 	}
 
+restart_root:
 	/* Search the internal pages of the tree. */
 	current = &btree->root;
-	for (depth = 2;; ++depth) {
-restart:	page = current->page;
+	for (depth = 2, pindex = NULL;; ++depth) {
+		parent_pindex = pindex;
+restart_page:	page = current->page;
 		if (page->type != WT_PAGE_COL_INT)
 			break;
 
@@ -51,8 +53,19 @@ restart:	page = current->page;
 		descent = pindex->index[base - 1];
 
 		/* Fast path appends. */
-		if (recno >= descent->key.recno)
+		if (recno >= descent->key.recno) {
+			/*
+			 * If on the last slot (the key is larger than any key
+			 * on the page), check for an internal page split race.
+			 */
+			if (parent_pindex != NULL &&
+			    __wt_split_intl_race(
+			    session, current->home, parent_pindex)) {
+				WT_RET(__wt_page_release(session, current, 0));
+				goto restart_root;
+			}
 			goto descend;
+		}
 
 		/* Binary search of internal pages. */
 		for (base = 0,
@@ -90,15 +103,13 @@ descend:	/*
 		 * page; otherwise return on error, the swap call ensures we're
 		 * holding nothing on failure.
 		 */
-		switch (ret = __wt_page_swap(session, current, descent, 0)) {
-		case 0:
+		if ((ret = __wt_page_swap(session, current, descent, 0)) == 0) {
 			current = descent;
-			break;
-		case WT_RESTART:
-			goto restart;
-		default:
-			return (ret);
+			continue;
 		}
+		if (ret == WT_RESTART)
+			goto restart_page;
+		return (ret);
 	}
 
 	/* Track how deep the tree gets. */
diff --git a/src/btree/row_srch.c b/src/btree/row_srch.c
index 7b21f1e40bb..d2d8a4640ca 100644
--- a/src/btree/row_srch.c
+++ b/src/btree/row_srch.c
@@ -144,7 +144,7 @@ __wt_row_search(WT_SESSION_IMPL *session,
 	WT_DECL_RET;
 	WT_ITEM *item;
 	WT_PAGE *page;
-	WT_PAGE_INDEX *pindex;
+	WT_PAGE_INDEX *pindex, *parent_pindex;
 	WT_REF *current, *descent;
 	WT_ROW *rip;
 	size_t match, skiphigh, skiplow;
@@ -155,16 +155,16 @@ __wt_row_search(WT_SESSION_IMPL *session,
 	btree = S2BT(session);
 	collator = btree->collator;
 	item = cbt->tmp;
+	current = NULL;
 
 	__cursor_pos_clear(cbt);
 
 	/*
-	 * The row-store search routine uses a different comparison API.
-	 * The assumption is we're comparing more than a few keys with
-	 * matching prefixes, and it's a win to avoid the memory fetches
-	 * by skipping over those prefixes.  That's done by tracking the
-	 * length of the prefix match for the lowest and highest keys we
-	 * compare as we descend the tree.
+	 * In some cases we expect we're comparing more than a few keys with
+	 * matching prefixes, so it's faster to avoid the memory fetches by
+	 * skipping over those prefixes. That's done by tracking the length of
+	 * the prefix match for the lowest and highest keys we compare as we
+	 * descend the tree.
 	 */
 	skiphigh = skiplow = 0;
 
@@ -186,10 +186,11 @@ __wt_row_search(WT_SESSION_IMPL *session,
 	}
 
 	/* Search the internal pages of the tree. */
-	cmp = -1;
+restart_root:
 	current = &btree->root;
-	for (depth = 2;; ++depth) {
-restart:	page = current->page;
+	for (depth = 2, pindex = NULL;; ++depth) {
+		parent_pindex = pindex;
+restart_page:	page = current->page;
 		if (page->type != WT_PAGE_ROW_INT)
 			break;
 
@@ -211,7 +212,7 @@ restart:	page = current->page;
 			WT_ERR(__wt_compare(
 			    session, collator, srch_key, item, &cmp));
 			if (cmp >= 0)
-				goto descend;
+				goto append;
 
 			/* A failed append check turns off append checks. */
 			append_check = false;
@@ -252,7 +253,26 @@ restart:	page = current->page;
 				} else if (cmp == 0)
 					goto descend;
 			}
-		else if (collator == NULL)
+		else if (collator == NULL) {
+			/*
+			 * Reset the skipped prefix counts; we'd normally expect
+			 * the parent's skipped prefix values to be larger than
+			 * the child's values and so we'd only increase them as
+			 * we walk down the tree (in other words, if we can skip
+			 * N bytes on the parent, we can skip at least N bytes
+			 * on the child). However, if a child internal page was
+			 * split up into the parent, the child page's key space
+			 * will have been truncated, and the values from the
+			 * parent's search may be wrong for the child. We only
+			 * need to reset the high count because the split-page
+			 * algorithm truncates the end of the internal page's
+			 * key space, the low count is still correct. We also
+			 * don't need to clear either count when transitioning
+			 * to a leaf page, a leaf page's key space can't change
+			 * in flight.
+			 */
+			skiphigh = 0;
+
 			for (; limit != 0; limit >>= 1) {
 				indx = base + (limit >> 1);
 				descent = pindex->index[indx];
@@ -271,7 +291,7 @@ restart:	page = current->page;
 				else
 					goto descend;
 			}
-		else
+		} else
 			for (; limit != 0; limit >>= 1) {
 				indx = base + (limit >> 1);
 				descent = pindex->index[indx];
@@ -288,9 +308,10 @@ restart:	page = current->page;
 			}
 
 		/*
-		 * Set the slot to descend the tree: descent is already set if
-		 * there was an exact match on the page, otherwise, base is
-		 * the smallest index greater than key, possibly (last + 1).
+		 * Set the slot to descend the tree: descent was already set if
+		 * there was an exact match on the page, otherwise, base is the
+		 * smallest index greater than key, possibly one past the last
+		 * slot.
 		 */
 		descent = pindex->index[base - 1];
 
@@ -298,25 +319,41 @@ restart:	page = current->page;
 		 * If we end up somewhere other than the last slot, it's not a
 		 * right-side descent.
 		 */
-		if (pindex->entries != base - 1)
+		if (pindex->entries != base)
 			descend_right = false;
 
+		/*
+		 * If on the last slot (the key is larger than any key on the
+		 * page), check for an internal page split race.
+		 */
+		if (pindex->entries == base) {
+append:			if (parent_pindex != NULL &&
+			    __wt_split_intl_race(
+			    session, current->home, parent_pindex)) {
+				if ((ret = __wt_page_release(
+				    session, current, 0)) != 0)
+					return (ret);
+
+				skiplow = skiphigh = 0;
+				goto restart_root;
+			}
+		}
+
 descend:	/*
 		 * Swap the current page for the child page. If the page splits
 		 * while we're retrieving it, restart the search in the current
 		 * page; otherwise return on error, the swap call ensures we're
 		 * holding nothing on failure.
 		 */
-		switch (ret = __wt_page_swap(session, current, descent, 0)) {
-		case 0:
+		if ((ret = __wt_page_swap(session, current, descent, 0)) == 0) {
 			current = descent;
-			break;
-		case WT_RESTART:
+			continue;
+		}
+		if (ret == WT_RESTART) {
 			skiphigh = skiplow = 0;
-			goto restart;
-		default:
-			return (ret);
+			goto restart_page;
 		}
+		return (ret);
 	}
 
 	/* Track how deep the tree gets. */
@@ -517,7 +554,7 @@ __wt_row_random(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt)
 
 	__cursor_pos_clear(cbt);
 
-restart:
+restart_root:
 	/* Walk the internal pages of the tree. */
 	current = &btree->root;
 	for (;;) {
@@ -544,7 +581,7 @@ restart:
 		 */
 		if (ret == WT_RESTART &&
 		    (ret = __wt_page_release(session, current, 0)) == 0)
-			goto restart;
+			goto restart_root;
 		return (ret);
 	}
 
diff --git a/src/conn/conn_cache_pool.c b/src/conn/conn_cache_pool.c
index aa14e9aadde..8d16f94c092 100644
--- a/src/conn/conn_cache_pool.c
+++ b/src/conn/conn_cache_pool.c
@@ -734,7 +734,7 @@ __wt_cache_pool_server(void *arg)
 	    F_ISSET(cache, WT_CACHE_POOL_RUN)) {
 		if (cp->currently_used <= cp->size)
 			WT_ERR(__wt_cond_wait(session,
-			    cp->cache_pool_cond, 1000000));
+			    cp->cache_pool_cond, WT_MILLION));
 
 		/*
 		 * Re-check pool run flag - since we want to avoid getting the
diff --git a/src/conn/conn_ckpt.c b/src/conn/conn_ckpt.c
index 8f039e61654..b47e2550b23 100644
--- a/src/conn/conn_ckpt.c
+++ b/src/conn/conn_ckpt.c
@@ -31,7 +31,7 @@ __ckpt_server_config(WT_SESSION_IMPL *session, const char **cfg, bool *startp)
 	 * Checkpoints based on log size also require logging be enabled.
 	 */
 	WT_RET(__wt_config_gets(session, cfg, "checkpoint.wait", &cval));
-	conn->ckpt_usecs = (uint64_t)cval.val * 1000000;
+	conn->ckpt_usecs = (uint64_t)cval.val * WT_MILLION;
 
 	WT_RET(__wt_config_gets(session, cfg, "checkpoint.log_size", &cval));
 	conn->ckpt_logsize = (wt_off_t)cval.val;
diff --git a/src/conn/conn_log.c b/src/conn/conn_log.c
index 007d4273e72..1d44d816467 100644
--- a/src/conn/conn_log.c
+++ b/src/conn/conn_log.c
@@ -538,8 +538,8 @@ restart:
 	while (i < WT_SLOT_POOL) {
 		save_i = i;
 		slot = &log->slot_pool[i++];
-			WT_ASSERT(session, slot->slot_state != 0 ||
-			    slot->slot_release_lsn.file >= log->write_lsn.file);
+		WT_ASSERT(session, slot->slot_state != 0 ||
+		    slot->slot_release_lsn.file >= log->write_lsn.file);
 		if (slot->slot_state != WT_LOG_SLOT_WRITTEN)
 			continue;
 		written[written_i].slot_index = save_i;
diff --git a/src/conn/conn_stat.c b/src/conn/conn_stat.c
index ec3a630581a..455ec9514f0 100644
--- a/src/conn/conn_stat.c
+++ b/src/conn/conn_stat.c
@@ -83,7 +83,7 @@ __statlog_config(WT_SESSION_IMPL *session, const char **cfg, bool *runp)
 	WT_RET(__wt_config_gets(session, cfg, "statistics_log.wait", &cval));
 	/* Only start the server if wait time is non-zero */
 	*runp = cval.val != 0;
-	conn->stat_usecs = (uint64_t)cval.val * 1000000;
+	conn->stat_usecs = (uint64_t)cval.val * WT_MILLION;
 
 	WT_RET(__wt_config_gets(
 	    session, cfg, "statistics_log.on_close", &cval));
diff --git a/src/conn/conn_sweep.c b/src/conn/conn_sweep.c
index a8620ebaa99..b9b46f3211c 100644
--- a/src/conn/conn_sweep.c
+++ b/src/conn/conn_sweep.c
@@ -136,7 +136,8 @@ __sweep_expire(WT_SESSION_IMPL *session, time_t now)
 		    !F_ISSET(dhandle, WT_DHANDLE_OPEN) ||
 		    dhandle->session_inuse != 0 ||
 		    dhandle->timeofdeath == 0 ||
-		    now <= dhandle->timeofdeath + conn->sweep_idle_time)
+		    difftime(now, dhandle->timeofdeath) <=
+		    conn->sweep_idle_time)
 			continue;
 
 		WT_WITH_DHANDLE(session, dhandle,
@@ -276,8 +277,8 @@ __sweep_server(void *arg)
 	while (F_ISSET(conn, WT_CONN_SERVER_RUN) &&
 	    F_ISSET(conn, WT_CONN_SERVER_SWEEP)) {
 		/* Wait until the next event. */
-		WT_ERR(__wt_cond_wait(session, conn->sweep_cond,
-		    (uint64_t)conn->sweep_interval * WT_MILLION));
+		WT_ERR(__wt_cond_wait(session,
+		    conn->sweep_cond, conn->sweep_interval * WT_MILLION));
 		WT_ERR(__wt_seconds(session, &now));
 
 		WT_STAT_FAST_CONN_INCR(session, dh_sweeps);
@@ -329,27 +330,25 @@ __wt_sweep_config(WT_SESSION_IMPL *session, const char *cfg[])
 
 	conn = S2C(session);
 
-	/* Pull out the sweep configurations. */
-	WT_RET(__wt_config_gets(session,
-	    cfg, "file_manager.close_idle_time", &cval));
-	conn->sweep_idle_time = (time_t)cval.val;
-
-	/* Non-zero sweep idle time is incompatible with in-memory */
-	if (conn->sweep_idle_time != 0) {
-		WT_RET(__wt_config_gets(session, cfg, "in_memory", &cval));
-		if (cval.val != 0)
-			WT_RET_MSG(session, EINVAL,
-			    "In memory configuration incompatible with "
-			    "non zero file_manager=(close_idle_time)");
+	/*
+	 * A non-zero idle time is incompatible with in-memory, and the default
+	 * is non-zero; set the in-memory configuration idle time to zero.
+	 */
+	conn->sweep_idle_time = 0;
+	WT_RET(__wt_config_gets(session, cfg, "in_memory", &cval));
+	if (cval.val == 0) {
+		WT_RET(__wt_config_gets(session,
+		    cfg, "file_manager.close_idle_time", &cval));
+		conn->sweep_idle_time = (uint64_t)cval.val;
 	}
 
 	WT_RET(__wt_config_gets(session,
 	    cfg, "file_manager.close_scan_interval", &cval));
-	conn->sweep_interval = (time_t)cval.val;
+	conn->sweep_interval = (uint64_t)cval.val;
 
 	WT_RET(__wt_config_gets(session,
 	    cfg, "file_manager.close_handle_minimum", &cval));
-	conn->sweep_handles_min = (u_int)cval.val;
+	conn->sweep_handles_min = (uint64_t)cval.val;
 
 	return (0);
 }
diff --git a/src/docs/upgrading.dox b/src/docs/upgrading.dox
index 3b227d00198..c40e764e2f6 100644
--- a/src/docs/upgrading.dox
+++ b/src/docs/upgrading.dox
@@ -11,6 +11,13 @@ was relying on this behavior, a connection will be opened with different
 settings after upgrading, which could lead to errors or unexpected behavior.
 </dd>
 
+<dt>Statistic change</dt>
+<dd>
+The statistic "pages split during eviction" was replaced. It has been
+replaced by a pair of statistics "internal pages split during eviction" and
+"leaf pages split during eviction".
+</dd>
+
 <dt>Change to WT_CURSOR::insert</dt>
 <dd>
 The WT_CURSOR::insert method in this release has slightly different semantics
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index 18335d6fb5e..fa6c4f4313f 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -183,10 +183,10 @@ __evict_server(void *arg)
 			    session, &conn->dhandle_lock)) == EBUSY &&
 			    !F_ISSET(cache, WT_CACHE_CLEAR_WALKS);
 			    spins++) {
-				if (spins < 1000)
+				if (spins < WT_THOUSAND)
 					__wt_yield();
 				else
-					__wt_sleep(0, 1000);
+					__wt_sleep(0, WT_THOUSAND);
 			}
 			/*
 			 * If we gave up acquiring the lock, that indicates a
@@ -210,7 +210,7 @@ __evict_server(void *arg)
 		else {
 			/* After being stuck for 5 minutes, give up. */
 			WT_ERR(__wt_epoch(session, &now));
-			if (WT_TIMEDIFF(now, stuck_ts) / WT_BILLION > 300) {
+			if (WT_TIMEDIFF_SEC(now, stuck_ts) > 300) {
 				__wt_errx(session,
 				    "Cache stuck for too long, giving up");
 				(void)__wt_cache_dump(session, NULL);
@@ -601,7 +601,7 @@ __evict_pass(WT_SESSION_IMPL *session)
 			 * that can free space in cache, such as LSM discarding
 			 * handles.
 			 */
-			__wt_sleep(0, 1000 * (uint64_t)loop);
+			__wt_sleep(0, WT_THOUSAND * (uint64_t)loop);
 			if (loop == 100) {
 				/*
 				 * Mark the cache as stuck if we need space
@@ -992,10 +992,10 @@ retry:	while (slot < max_entries && ret == 0) {
 			    session, &conn->dhandle_lock)) == EBUSY &&
 			    !F_ISSET(cache, WT_CACHE_CLEAR_WALKS);
 			    spins++) {
-				if (spins < 1000)
+				if (spins < WT_THOUSAND)
 					__wt_yield();
 				else
-					__wt_sleep(0, 1000);
+					__wt_sleep(0, WT_THOUSAND);
 			}
 			if (ret != 0)
 				break;
diff --git a/src/evict/evict_page.c b/src/evict/evict_page.c
index e49098e90db..94c969fa5bb 100644
--- a/src/evict/evict_page.c
+++ b/src/evict/evict_page.c
@@ -179,9 +179,17 @@ __evict_delete_ref(WT_SESSION_IMPL *session, WT_REF *ref, bool closing)
 		 * something is busy, be sure that the page still ends up
 		 * marked deleted.
 		 */
-		if (ndeleted > pindex->entries / 10 && pindex->entries > 1 &&
-		    (ret = __wt_split_reverse(session, ref)) != EBUSY)
-			return (ret);
+		if (ndeleted > pindex->entries / 10 && pindex->entries > 1) {
+			if ((ret = __wt_split_reverse(session, ref)) == 0)
+				return (0);
+			WT_RET_BUSY_OK(ret);
+
+			/*
+			 * The child must be locked after a failed reverse
+			 * split.
+			 */
+			WT_ASSERT(session, ref->state == WT_REF_LOCKED);
+		}
 	}
 
 	WT_PUBLISH(ref->state, WT_REF_DELETED);
diff --git a/src/include/btmem.h b/src/include/btmem.h
index 02819237c13..ae29dc68003 100644
--- a/src/include/btmem.h
+++ b/src/include/btmem.h
@@ -437,24 +437,10 @@ struct __wt_page {
 				uint32_t deleted_entries;
 				WT_REF	**index;
 			} * volatile __index;	/* Collated children */
-
-			/*
-			 * When splitting to deepen the tree, track the number
-			 * of entries in the newly created parent, and how many
-			 * subsequent splits follow the initial set of entries.
-			 * If future splits into the page are generally after
-			 * the initial set of items, perform future deepening
-			 * splits in this page to optimize for an append-style
-			 * workload.
-			 */
-			uint32_t deepen_split_append;
-			uint32_t deepen_split_last;
 		} intl;
 #undef	pg_intl_recno
 #define	pg_intl_recno			u.intl.recno
 #define	pg_intl_parent_ref		u.intl.parent_ref
-#define	pg_intl_deepen_split_append	u.intl.deepen_split_append
-#define	pg_intl_deepen_split_last	u.intl.deepen_split_last
 
 	/*
 	 * Macros to copy/set the index because the name is obscured to ensure
@@ -581,7 +567,8 @@ struct __wt_page {
 #define	WT_PAGE_EVICT_LRU	0x08	/* Page is on the LRU queue */
 #define	WT_PAGE_OVERFLOW_KEYS	0x10	/* Page has overflow keys */
 #define	WT_PAGE_SPLIT_INSERT	0x20	/* A leaf page was split for append */
-#define	WT_PAGE_UPDATE_IGNORE	0x40	/* Ignore updates on page discard */
+#define	WT_PAGE_SPLIT_BLOCK	0x40	/* Split blocking eviction and splits */
+#define	WT_PAGE_UPDATE_IGNORE	0x80	/* Ignore updates on page discard */
 	uint8_t flags_atomic;		/* Atomic flags, use F_*_ATOMIC */
 
 	uint8_t unused[2];		/* Unused padding */
diff --git a/src/include/btree.i b/src/include/btree.i
index 23e212eb772..a92d52e784a 100644
--- a/src/include/btree.i
+++ b/src/include/btree.i
@@ -1101,16 +1101,17 @@ __wt_page_can_evict(WT_SESSION_IMPL *session,
 		return (false);
 
 	/*
-	 * If the tree was deepened, there's a requirement that newly created
-	 * internal pages not be evicted until all threads are known to have
-	 * exited the original page index array, because evicting an internal
-	 * page discards its WT_REF array, and a thread traversing the original
-	 * page index array might see a freed WT_REF.  During the split we set
-	 * a transaction value, once that's globally visible, we know we can
-	 * evict the created page.
+	 * If a split created new internal pages, those newly created internal
+	 * pages cannot be evicted until all threads are known to have exited
+	 * the original parent page's index, because evicting an internal page
+	 * discards its WT_REF array, and a thread traversing the original
+	 * parent page index might see a freed WT_REF. During the split we set
+	 * a transaction value, we can evict the created page as soon as that
+	 * transaction value is globally visible.
 	 */
 	if (check_splits && WT_PAGE_IS_INTERNAL(page) &&
-	    !__wt_txn_visible_all(session, mod->mod_split_txn))
+	    (F_ISSET_ATOMIC(page, WT_PAGE_SPLIT_BLOCK) ||
+	    !__wt_txn_visible_all(session, mod->mod_split_txn)))
 		return (false);
 
 	/*
@@ -1374,3 +1375,34 @@ __wt_btree_lsm_over_size(WT_SESSION_IMPL *session, uint64_t maxsize)
 
 	return (child->memory_footprint > maxsize);
 }
+
+/*
+ * __wt_split_intl_race --
+ *	Return if we raced with an internal page split when descending the tree.
+ */
+static inline bool
+__wt_split_intl_race(
+    WT_SESSION_IMPL *session, WT_PAGE *parent, WT_PAGE_INDEX *saved_pindex)
+{
+	WT_PAGE_INDEX *pindex;
+
+	/*
+	 * A place to hang this comment...
+	 *
+	 * There's a page-split race when we walk the tree: if we're splitting
+	 * an internal page into its parent, we update the parent's page index
+	 * and then update the page being split, and it's not an atomic update.
+	 * A thread could read the parent page's original page index, and then
+	 * read the page's replacement index. Because internal page splits work
+	 * by replacing the original page with the initial part of the original
+	 * page, the result of this race is we will have a key that's past the
+	 * end of the current page, and the parent's page index will have moved.
+	 *
+	 * It's also possible a thread could read the parent page's replacement
+	 * page index, and then read the page's original index. Because internal
+	 * splits work by truncating the original page, the original page's old
+	 * content is compatible, this isn't a problem and we ignore this race.
+	 */
+	WT_INTL_INDEX_GET(session, parent, pindex);
+	return (pindex != saved_pindex);
+}
diff --git a/src/include/connection.h b/src/include/connection.h
index 35a83d7c50f..3e8d3705373 100644
--- a/src/include/connection.h
+++ b/src/include/connection.h
@@ -365,13 +365,13 @@ struct __wt_connection_impl {
 
 	WT_SESSION_IMPL *meta_ckpt_session;/* Metadata checkpoint session */
 
-	WT_SESSION_IMPL *sweep_session;	/* Handle sweep session */
-	wt_thread_t	 sweep_tid;	/* Handle sweep thread */
-	int		 sweep_tid_set;	/* Handle sweep thread set */
-	WT_CONDVAR	*sweep_cond;	/* Handle sweep wait mutex */
-	time_t		 sweep_idle_time;/* Handle sweep idle time */
-	time_t		 sweep_interval;/* Handle sweep interval */
-	u_int		 sweep_handles_min;/* Handle sweep minimum open */
+	WT_SESSION_IMPL *sweep_session;	   /* Handle sweep session */
+	wt_thread_t	 sweep_tid;	   /* Handle sweep thread */
+	int		 sweep_tid_set;	   /* Handle sweep thread set */
+	WT_CONDVAR      *sweep_cond;	   /* Handle sweep wait mutex */
+	uint64_t         sweep_idle_time;  /* Handle sweep idle time */
+	uint64_t         sweep_interval;   /* Handle sweep interval */
+	uint64_t         sweep_handles_min;/* Handle sweep minimum open */
 
 	/*
 	 * Shared lookaside lock, session and cursor, used by threads accessing
diff --git a/src/include/extern.h b/src/include/extern.h
index 032b94b7040..a6ccc526f8c 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -155,9 +155,9 @@ extern void __wt_split_stash_discard(WT_SESSION_IMPL *session);
 extern void __wt_split_stash_discard_all( WT_SESSION_IMPL *session_safe, WT_SESSION_IMPL *session);
 extern int __wt_multi_to_ref(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi, WT_REF **refp, size_t *incrp);
 extern int __wt_split_insert(WT_SESSION_IMPL *session, WT_REF *ref);
+extern int __wt_split_multi(WT_SESSION_IMPL *session, WT_REF *ref, int closing);
 extern int __wt_split_reverse(WT_SESSION_IMPL *session, WT_REF *ref);
 extern int __wt_split_rewrite(WT_SESSION_IMPL *session, WT_REF *ref);
-extern int __wt_split_multi(WT_SESSION_IMPL *session, WT_REF *ref, int closing);
 extern int __wt_btree_stat_init(WT_SESSION_IMPL *session, WT_CURSOR_STAT *cst);
 extern int __wt_cache_op(WT_SESSION_IMPL *session, WT_CKPT *ckptbase, WT_CACHE_OP op);
 extern int __wt_upgrade(WT_SESSION_IMPL *session, const char *cfg[]);
@@ -523,7 +523,6 @@ extern uint64_t __wt_strtouq(const char *nptr, char **endptr, int base);
 extern int __wt_thread_create(WT_SESSION_IMPL *session, wt_thread_t *tidret, WT_THREAD_CALLBACK(*func)(void *), void *arg);
 extern int __wt_thread_join(WT_SESSION_IMPL *session, wt_thread_t tid);
 extern void __wt_thread_id(char *buf, size_t buflen);
-extern int __wt_seconds(WT_SESSION_IMPL *session, time_t *timep);
 extern int __wt_epoch(WT_SESSION_IMPL *session, struct timespec *tsp);
 extern void __wt_yield(void);
 extern int __wt_ext_struct_pack(WT_EXTENSION_API *wt_api, WT_SESSION *wt_session, void *buffer, size_t size, const char *fmt, ...);
diff --git a/src/include/misc.h b/src/include/misc.h
index eca77214b47..e542baec642 100644
--- a/src/include/misc.h
+++ b/src/include/misc.h
@@ -13,6 +13,7 @@
 #define	WT_UNUSED(var)		(void)(var)
 
 /* Basic constants. */
+#define	WT_THOUSAND	(1000)
 #define	WT_MILLION	(1000000)
 #define	WT_BILLION	(1000000000)
 
diff --git a/src/include/misc.i b/src/include/misc.i
index 80096d0cf72..75068706b70 100644
--- a/src/include/misc.i
+++ b/src/include/misc.i
@@ -30,6 +30,22 @@ __wt_strdup(WT_SESSION_IMPL *session, const char *str, void *retp)
 }
 
 /*
+ * __wt_seconds --
+ *	Return the seconds since the Epoch.
+ */
+static inline int
+__wt_seconds(WT_SESSION_IMPL *session, time_t *timep)
+{
+	struct timespec t;
+
+	WT_RET(__wt_epoch(session, &t));
+
+	*timep = t.tv_sec;
+
+	return (0);
+}
+
+/*
  * __wt_verbose --
  * 	Verbose message.
  */
diff --git a/src/include/mutex.i b/src/include/mutex.i
index 843c4ad9350..7eb042dd79f 100644
--- a/src/include/mutex.i
+++ b/src/include/mutex.i
@@ -18,7 +18,7 @@
 
 /* Default to spinning 1000 times before yielding. */
 #ifndef WT_SPIN_COUNT
-#define	WT_SPIN_COUNT 1000
+#define	WT_SPIN_COUNT WT_THOUSAND
 #endif
 
 /*
@@ -300,7 +300,7 @@ __wt_fair_lock(WT_SESSION_IMPL *session, WT_FAIR_LOCK *lock)
 		 * situation happens if there are more threads than cores in the
 		 * system and we're thrashing on shared resources.
 		 */
-		if (++pause_cnt < 1000)
+		if (++pause_cnt < WT_THOUSAND)
 			WT_PAUSE();
 		else
 			__wt_sleep(0, 10);
diff --git a/src/include/os.h b/src/include/os.h
index 4ba588111b8..d135fd9eb1f 100644
--- a/src/include/os.h
+++ b/src/include/os.h
@@ -65,9 +65,16 @@ typedef enum {
 	}								\
 } while (0)
 
-#define	WT_TIMEDIFF(end, begin)						\
-	(1000000000 * (uint64_t)((end).tv_sec - (begin).tv_sec) +	\
+#define	WT_TIMEDIFF_NS(end, begin)					\
+	(WT_BILLION * (uint64_t)((end).tv_sec - (begin).tv_sec) +	\
 	    (uint64_t)(end).tv_nsec - (uint64_t)(begin).tv_nsec)
+#define	WT_TIMEDIFF_US(end, begin)					\
+	(WT_TIMEDIFF_NS((end), (begin)) / WT_THOUSAND)
+#define	WT_TIMEDIFF_MS(end, begin)					\
+	(WT_TIMEDIFF_NS((end), (begin)) / WT_MILLION)
+#define	WT_TIMEDIFF_SEC(end, begin)					\
+	(WT_TIMEDIFF_NS((end), (begin)) / WT_BILLION)
+
 #define	WT_TIMECMP(t1, t2)						\
 	((t1).tv_sec < (t2).tv_sec ? -1 :				\
 	     (t1).tv_sec == (t2.tv_sec) ?				\
diff --git a/src/include/stat.h b/src/include/stat.h
index 2a8552fded1..0ad872d11da 100644
--- a/src/include/stat.h
+++ b/src/include/stat.h
@@ -272,7 +272,8 @@ struct __wt_connection_stats {
 	int64_t cache_eviction_server_evicting;
 	int64_t cache_eviction_server_not_evicting;
 	int64_t cache_eviction_slow;
-	int64_t cache_eviction_split;
+	int64_t cache_eviction_split_internal;
+	int64_t cache_eviction_split_leaf;
 	int64_t cache_eviction_walk;
 	int64_t cache_eviction_worker_evicting;
 	int64_t cache_inmem_split;
@@ -434,7 +435,8 @@ struct __wt_dsrc_stats {
 	int64_t cache_eviction_fail;
 	int64_t cache_eviction_hazard;
 	int64_t cache_eviction_internal;
-	int64_t cache_eviction_split;
+	int64_t cache_eviction_split_internal;
+	int64_t cache_eviction_split_leaf;
 	int64_t cache_inmem_split;
 	int64_t cache_inmem_splittable;
 	int64_t cache_overflow_value;
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index 8503f5918e9..1b8c345e32b 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -3713,228 +3713,230 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_CONN_CACHE_EVICTION_SERVER_NOT_EVICTING	1043
 /*! cache: eviction server unable to reach eviction goal */
 #define	WT_STAT_CONN_CACHE_EVICTION_SLOW		1044
-/*! cache: pages split during eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT		1045
+/*! cache: internal pages split during eviction */
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL	1045
+/*! cache: leaf pages split during eviction */
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF		1046
 /*! cache: pages walked for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1046
+#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1047
 /*! cache: eviction worker thread evicting pages */
-#define	WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING	1047
+#define	WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING	1048
 /*! cache: in-memory page splits */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1048
+#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1049
 /*! cache: in-memory page passed criteria to be split */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1049
+#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1050
 /*! cache: lookaside table insert calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1050
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1051
 /*! cache: lookaside table remove calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1051
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1052
 /*! cache: percentage overhead */
-#define	WT_STAT_CONN_CACHE_OVERHEAD			1052
+#define	WT_STAT_CONN_CACHE_OVERHEAD			1053
 /*! cache: tracked dirty pages in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1053
+#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1054
 /*! cache: pages currently held in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1054
+#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1055
 /*! cache: pages read into cache */
-#define	WT_STAT_CONN_CACHE_READ				1055
+#define	WT_STAT_CONN_CACHE_READ				1056
 /*! cache: pages read into cache requiring lookaside entries */
-#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1056
+#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1057
 /*! cache: pages written from cache */
-#define	WT_STAT_CONN_CACHE_WRITE			1057
+#define	WT_STAT_CONN_CACHE_WRITE			1058
 /*! cache: page written requiring lookaside records */
-#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1058
+#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1059
 /*! cache: pages written requiring in-memory restoration */
-#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1059
+#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1060
 /*! connection: pthread mutex condition wait calls */
-#define	WT_STAT_CONN_COND_WAIT				1060
+#define	WT_STAT_CONN_COND_WAIT				1061
 /*! cursor: cursor create calls */
-#define	WT_STAT_CONN_CURSOR_CREATE			1061
+#define	WT_STAT_CONN_CURSOR_CREATE			1062
 /*! cursor: cursor insert calls */
-#define	WT_STAT_CONN_CURSOR_INSERT			1062
+#define	WT_STAT_CONN_CURSOR_INSERT			1063
 /*! cursor: cursor next calls */
-#define	WT_STAT_CONN_CURSOR_NEXT			1063
+#define	WT_STAT_CONN_CURSOR_NEXT			1064
 /*! cursor: cursor prev calls */
-#define	WT_STAT_CONN_CURSOR_PREV			1064
+#define	WT_STAT_CONN_CURSOR_PREV			1065
 /*! cursor: cursor remove calls */
-#define	WT_STAT_CONN_CURSOR_REMOVE			1065
+#define	WT_STAT_CONN_CURSOR_REMOVE			1066
 /*! cursor: cursor reset calls */
-#define	WT_STAT_CONN_CURSOR_RESET			1066
+#define	WT_STAT_CONN_CURSOR_RESET			1067
 /*! cursor: cursor restarted searches */
-#define	WT_STAT_CONN_CURSOR_RESTART			1067
+#define	WT_STAT_CONN_CURSOR_RESTART			1068
 /*! cursor: cursor search calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH			1068
+#define	WT_STAT_CONN_CURSOR_SEARCH			1069
 /*! cursor: cursor search near calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1069
+#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1070
 /*! cursor: truncate calls */
-#define	WT_STAT_CONN_CURSOR_TRUNCATE			1070
+#define	WT_STAT_CONN_CURSOR_TRUNCATE			1071
 /*! cursor: cursor update calls */
-#define	WT_STAT_CONN_CURSOR_UPDATE			1071
+#define	WT_STAT_CONN_CURSOR_UPDATE			1072
 /*! data-handle: connection data handles currently active */
-#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1072
+#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1073
 /*! data-handle: session dhandles swept */
-#define	WT_STAT_CONN_DH_SESSION_HANDLES			1073
+#define	WT_STAT_CONN_DH_SESSION_HANDLES			1074
 /*! data-handle: session sweep attempts */
-#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1074
+#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1075
 /*! data-handle: connection sweep dhandles closed */
-#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1075
+#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1076
 /*! data-handle: connection sweep candidate became referenced */
-#define	WT_STAT_CONN_DH_SWEEP_REF			1076
+#define	WT_STAT_CONN_DH_SWEEP_REF			1077
 /*! data-handle: connection sweep dhandles removed from hash list */
-#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1077
+#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1078
 /*! data-handle: connection sweep time-of-death sets */
-#define	WT_STAT_CONN_DH_SWEEP_TOD			1078
+#define	WT_STAT_CONN_DH_SWEEP_TOD			1079
 /*! data-handle: connection sweeps */
-#define	WT_STAT_CONN_DH_SWEEPS				1079
+#define	WT_STAT_CONN_DH_SWEEPS				1080
 /*! connection: files currently open */
-#define	WT_STAT_CONN_FILE_OPEN				1080
+#define	WT_STAT_CONN_FILE_OPEN				1081
 /*! log: total log buffer size */
-#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1081
+#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1082
 /*! log: log bytes of payload data */
-#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1082
+#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1083
 /*! log: log bytes written */
-#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1083
+#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1084
 /*! log: yields waiting for previous log file close */
-#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1084
+#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1085
 /*! log: total size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1085
+#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1086
 /*! log: total in-memory size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1086
+#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1087
 /*! log: log records too small to compress */
-#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1087
+#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1088
 /*! log: log records not compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1088
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1089
 /*! log: log records compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1089
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1090
 /*! log: log flush operations */
-#define	WT_STAT_CONN_LOG_FLUSH				1090
+#define	WT_STAT_CONN_LOG_FLUSH				1091
 /*! log: maximum log file size */
-#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1091
+#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1092
 /*! log: pre-allocated log files prepared */
-#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1092
+#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1093
 /*! log: number of pre-allocated log files to create */
-#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1093
+#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1094
 /*! log: pre-allocated log files not ready and missed */
-#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1094
+#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1095
 /*! log: pre-allocated log files used */
-#define	WT_STAT_CONN_LOG_PREALLOC_USED			1095
+#define	WT_STAT_CONN_LOG_PREALLOC_USED			1096
 /*! log: log release advances write LSN */
-#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1096
+#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1097
 /*! log: records processed by log scan */
-#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1097
+#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1098
 /*! log: log scan records requiring two reads */
-#define	WT_STAT_CONN_LOG_SCAN_REREADS			1098
+#define	WT_STAT_CONN_LOG_SCAN_REREADS			1099
 /*! log: log scan operations */
-#define	WT_STAT_CONN_LOG_SCANS				1099
+#define	WT_STAT_CONN_LOG_SCANS				1100
 /*! log: consolidated slot closures */
-#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1100
+#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1101
 /*! log: written slots coalesced */
-#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1101
+#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1102
 /*! log: logging bytes consolidated */
-#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1102
+#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1103
 /*! log: consolidated slot joins */
-#define	WT_STAT_CONN_LOG_SLOT_JOINS			1103
+#define	WT_STAT_CONN_LOG_SLOT_JOINS			1104
 /*! log: consolidated slot join races */
-#define	WT_STAT_CONN_LOG_SLOT_RACES			1104
+#define	WT_STAT_CONN_LOG_SLOT_RACES			1105
 /*! log: busy returns attempting to switch slots */
-#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1105
+#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1106
 /*! log: consolidated slot join transitions */
-#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1106
+#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1107
 /*! log: consolidated slot unbuffered writes */
-#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1107
+#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1108
 /*! log: log sync operations */
-#define	WT_STAT_CONN_LOG_SYNC				1108
+#define	WT_STAT_CONN_LOG_SYNC				1109
 /*! log: log sync_dir operations */
-#define	WT_STAT_CONN_LOG_SYNC_DIR			1109
+#define	WT_STAT_CONN_LOG_SYNC_DIR			1110
 /*! log: log server thread advances write LSN */
-#define	WT_STAT_CONN_LOG_WRITE_LSN			1110
+#define	WT_STAT_CONN_LOG_WRITE_LSN			1111
 /*! log: log write operations */
-#define	WT_STAT_CONN_LOG_WRITES				1111
+#define	WT_STAT_CONN_LOG_WRITES				1112
 /*! log: log files manually zero-filled */
-#define	WT_STAT_CONN_LOG_ZERO_FILLS			1112
+#define	WT_STAT_CONN_LOG_ZERO_FILLS			1113
 /*! LSM: sleep for LSM checkpoint throttle */
-#define	WT_STAT_CONN_LSM_CHECKPOINT_THROTTLE		1113
+#define	WT_STAT_CONN_LSM_CHECKPOINT_THROTTLE		1114
 /*! LSM: sleep for LSM merge throttle */
-#define	WT_STAT_CONN_LSM_MERGE_THROTTLE			1114
+#define	WT_STAT_CONN_LSM_MERGE_THROTTLE			1115
 /*! LSM: rows merged in an LSM tree */
-#define	WT_STAT_CONN_LSM_ROWS_MERGED			1115
+#define	WT_STAT_CONN_LSM_ROWS_MERGED			1116
 /*! LSM: application work units currently queued */
-#define	WT_STAT_CONN_LSM_WORK_QUEUE_APP			1116
+#define	WT_STAT_CONN_LSM_WORK_QUEUE_APP			1117
 /*! LSM: merge work units currently queued */
-#define	WT_STAT_CONN_LSM_WORK_QUEUE_MANAGER		1117
+#define	WT_STAT_CONN_LSM_WORK_QUEUE_MANAGER		1118
 /*! LSM: tree queue hit maximum */
-#define	WT_STAT_CONN_LSM_WORK_QUEUE_MAX			1118
+#define	WT_STAT_CONN_LSM_WORK_QUEUE_MAX			1119
 /*! LSM: switch work units currently queued */
-#define	WT_STAT_CONN_LSM_WORK_QUEUE_SWITCH		1119
+#define	WT_STAT_CONN_LSM_WORK_QUEUE_SWITCH		1120
 /*! LSM: tree maintenance operations scheduled */
-#define	WT_STAT_CONN_LSM_WORK_UNITS_CREATED		1120
+#define	WT_STAT_CONN_LSM_WORK_UNITS_CREATED		1121
 /*! LSM: tree maintenance operations discarded */
-#define	WT_STAT_CONN_LSM_WORK_UNITS_DISCARDED		1121
+#define	WT_STAT_CONN_LSM_WORK_UNITS_DISCARDED		1122
 /*! LSM: tree maintenance operations executed */
-#define	WT_STAT_CONN_LSM_WORK_UNITS_DONE		1122
+#define	WT_STAT_CONN_LSM_WORK_UNITS_DONE		1123
 /*! connection: memory allocations */
-#define	WT_STAT_CONN_MEMORY_ALLOCATION			1123
+#define	WT_STAT_CONN_MEMORY_ALLOCATION			1124
 /*! connection: memory frees */
-#define	WT_STAT_CONN_MEMORY_FREE			1124
+#define	WT_STAT_CONN_MEMORY_FREE			1125
 /*! connection: memory re-allocations */
-#define	WT_STAT_CONN_MEMORY_GROW			1125
+#define	WT_STAT_CONN_MEMORY_GROW			1126
 /*! thread-yield: page acquire busy blocked */
-#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1126
+#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1127
 /*! thread-yield: page acquire eviction blocked */
-#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1127
+#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1128
 /*! thread-yield: page acquire locked blocked */
-#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1128
+#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1129
 /*! thread-yield: page acquire read blocked */
-#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1129
+#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1130
 /*! thread-yield: page acquire time sleeping (usecs) */
-#define	WT_STAT_CONN_PAGE_SLEEP				1130
+#define	WT_STAT_CONN_PAGE_SLEEP				1131
 /*! connection: total read I/Os */
-#define	WT_STAT_CONN_READ_IO				1131
+#define	WT_STAT_CONN_READ_IO				1132
 /*! reconciliation: pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE			1132
+#define	WT_STAT_CONN_REC_PAGE_DELETE			1133
 /*! reconciliation: page reconciliation calls */
-#define	WT_STAT_CONN_REC_PAGES				1133
+#define	WT_STAT_CONN_REC_PAGES				1134
 /*! reconciliation: page reconciliation calls for eviction */
-#define	WT_STAT_CONN_REC_PAGES_EVICTION			1134
+#define	WT_STAT_CONN_REC_PAGES_EVICTION			1135
 /*! reconciliation: split bytes currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1135
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1136
 /*! reconciliation: split objects currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1136
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1137
 /*! connection: pthread mutex shared lock read-lock calls */
-#define	WT_STAT_CONN_RWLOCK_READ			1137
+#define	WT_STAT_CONN_RWLOCK_READ			1138
 /*! connection: pthread mutex shared lock write-lock calls */
-#define	WT_STAT_CONN_RWLOCK_WRITE			1138
+#define	WT_STAT_CONN_RWLOCK_WRITE			1139
 /*! session: open cursor count */
-#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1139
+#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1140
 /*! session: open session count */
-#define	WT_STAT_CONN_SESSION_OPEN			1140
+#define	WT_STAT_CONN_SESSION_OPEN			1141
 /*! transaction: transaction begins */
-#define	WT_STAT_CONN_TXN_BEGIN				1141
+#define	WT_STAT_CONN_TXN_BEGIN				1142
 /*! transaction: transaction checkpoints */
-#define	WT_STAT_CONN_TXN_CHECKPOINT			1142
+#define	WT_STAT_CONN_TXN_CHECKPOINT			1143
 /*! transaction: transaction checkpoint generation */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1143
+#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1144
 /*! transaction: transaction checkpoint currently running */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1144
+#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1145
 /*! transaction: transaction checkpoint max time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1145
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1146
 /*! transaction: transaction checkpoint min time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1146
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1147
 /*! transaction: transaction checkpoint most recent time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1147
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1148
 /*! transaction: transaction checkpoint total time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1148
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1149
 /*! transaction: transactions committed */
-#define	WT_STAT_CONN_TXN_COMMIT				1149
+#define	WT_STAT_CONN_TXN_COMMIT				1150
 /*! transaction: transaction failures due to cache overflow */
-#define	WT_STAT_CONN_TXN_FAIL_CACHE			1150
+#define	WT_STAT_CONN_TXN_FAIL_CACHE			1151
 /*! transaction: transaction range of IDs currently pinned by a checkpoint */
-#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1151
+#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1152
 /*! transaction: transaction range of IDs currently pinned */
-#define	WT_STAT_CONN_TXN_PINNED_RANGE			1152
+#define	WT_STAT_CONN_TXN_PINNED_RANGE			1153
 /*! transaction: transactions rolled back */
-#define	WT_STAT_CONN_TXN_ROLLBACK			1153
+#define	WT_STAT_CONN_TXN_ROLLBACK			1154
 /*! transaction: transaction sync calls */
-#define	WT_STAT_CONN_TXN_SYNC				1154
+#define	WT_STAT_CONN_TXN_SYNC				1155
 /*! connection: total write I/Os */
-#define	WT_STAT_CONN_WRITE_IO				1155
+#define	WT_STAT_CONN_WRITE_IO				1156
 
 /*!
  * @}
@@ -4030,114 +4032,116 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_DSRC_CACHE_EVICTION_HAZARD		2042
 /*! cache: internal pages evicted */
 #define	WT_STAT_DSRC_CACHE_EVICTION_INTERNAL		2043
-/*! cache: pages split during eviction */
-#define	WT_STAT_DSRC_CACHE_EVICTION_SPLIT		2044
+/*! cache: internal pages split during eviction */
+#define	WT_STAT_DSRC_CACHE_EVICTION_SPLIT_INTERNAL	2044
+/*! cache: leaf pages split during eviction */
+#define	WT_STAT_DSRC_CACHE_EVICTION_SPLIT_LEAF		2045
 /*! cache: in-memory page splits */
-#define	WT_STAT_DSRC_CACHE_INMEM_SPLIT			2045
+#define	WT_STAT_DSRC_CACHE_INMEM_SPLIT			2046
 /*! cache: in-memory page passed criteria to be split */
-#define	WT_STAT_DSRC_CACHE_INMEM_SPLITTABLE		2046
+#define	WT_STAT_DSRC_CACHE_INMEM_SPLITTABLE		2047
 /*! cache: overflow values cached in memory */
-#define	WT_STAT_DSRC_CACHE_OVERFLOW_VALUE		2047
+#define	WT_STAT_DSRC_CACHE_OVERFLOW_VALUE		2048
 /*! cache: pages read into cache */
-#define	WT_STAT_DSRC_CACHE_READ				2048
+#define	WT_STAT_DSRC_CACHE_READ				2049
 /*! cache: pages read into cache requiring lookaside entries */
-#define	WT_STAT_DSRC_CACHE_READ_LOOKASIDE		2049
+#define	WT_STAT_DSRC_CACHE_READ_LOOKASIDE		2050
 /*! cache: overflow pages read into cache */
-#define	WT_STAT_DSRC_CACHE_READ_OVERFLOW		2050
+#define	WT_STAT_DSRC_CACHE_READ_OVERFLOW		2051
 /*! cache: pages written from cache */
-#define	WT_STAT_DSRC_CACHE_WRITE			2051
+#define	WT_STAT_DSRC_CACHE_WRITE			2052
 /*! cache: page written requiring lookaside records */
-#define	WT_STAT_DSRC_CACHE_WRITE_LOOKASIDE		2052
+#define	WT_STAT_DSRC_CACHE_WRITE_LOOKASIDE		2053
 /*! cache: pages written requiring in-memory restoration */
-#define	WT_STAT_DSRC_CACHE_WRITE_RESTORE		2053
+#define	WT_STAT_DSRC_CACHE_WRITE_RESTORE		2054
 /*! compression: raw compression call failed, no additional data available */
-#define	WT_STAT_DSRC_COMPRESS_RAW_FAIL			2054
+#define	WT_STAT_DSRC_COMPRESS_RAW_FAIL			2055
 /*! compression: raw compression call failed, additional data available */
-#define	WT_STAT_DSRC_COMPRESS_RAW_FAIL_TEMPORARY	2055
+#define	WT_STAT_DSRC_COMPRESS_RAW_FAIL_TEMPORARY	2056
 /*! compression: raw compression call succeeded */
-#define	WT_STAT_DSRC_COMPRESS_RAW_OK			2056
+#define	WT_STAT_DSRC_COMPRESS_RAW_OK			2057
 /*! compression: compressed pages read */
-#define	WT_STAT_DSRC_COMPRESS_READ			2057
+#define	WT_STAT_DSRC_COMPRESS_READ			2058
 /*! compression: compressed pages written */
-#define	WT_STAT_DSRC_COMPRESS_WRITE			2058
+#define	WT_STAT_DSRC_COMPRESS_WRITE			2059
 /*! compression: page written failed to compress */
-#define	WT_STAT_DSRC_COMPRESS_WRITE_FAIL		2059
+#define	WT_STAT_DSRC_COMPRESS_WRITE_FAIL		2060
 /*! compression: page written was too small to compress */
-#define	WT_STAT_DSRC_COMPRESS_WRITE_TOO_SMALL		2060
+#define	WT_STAT_DSRC_COMPRESS_WRITE_TOO_SMALL		2061
 /*! cursor: create calls */
-#define	WT_STAT_DSRC_CURSOR_CREATE			2061
+#define	WT_STAT_DSRC_CURSOR_CREATE			2062
 /*! cursor: insert calls */
-#define	WT_STAT_DSRC_CURSOR_INSERT			2062
+#define	WT_STAT_DSRC_CURSOR_INSERT			2063
 /*! cursor: bulk-loaded cursor-insert calls */
-#define	WT_STAT_DSRC_CURSOR_INSERT_BULK			2063
+#define	WT_STAT_DSRC_CURSOR_INSERT_BULK			2064
 /*! cursor: cursor-insert key and value bytes inserted */
-#define	WT_STAT_DSRC_CURSOR_INSERT_BYTES		2064
+#define	WT_STAT_DSRC_CURSOR_INSERT_BYTES		2065
 /*! cursor: next calls */
-#define	WT_STAT_DSRC_CURSOR_NEXT			2065
+#define	WT_STAT_DSRC_CURSOR_NEXT			2066
 /*! cursor: prev calls */
-#define	WT_STAT_DSRC_CURSOR_PREV			2066
+#define	WT_STAT_DSRC_CURSOR_PREV			2067
 /*! cursor: remove calls */
-#define	WT_STAT_DSRC_CURSOR_REMOVE			2067
+#define	WT_STAT_DSRC_CURSOR_REMOVE			2068
 /*! cursor: cursor-remove key bytes removed */
-#define	WT_STAT_DSRC_CURSOR_REMOVE_BYTES		2068
+#define	WT_STAT_DSRC_CURSOR_REMOVE_BYTES		2069
 /*! cursor: reset calls */
-#define	WT_STAT_DSRC_CURSOR_RESET			2069
+#define	WT_STAT_DSRC_CURSOR_RESET			2070
 /*! cursor: restarted searches */
-#define	WT_STAT_DSRC_CURSOR_RESTART			2070
+#define	WT_STAT_DSRC_CURSOR_RESTART			2071
 /*! cursor: search calls */
-#define	WT_STAT_DSRC_CURSOR_SEARCH			2071
+#define	WT_STAT_DSRC_CURSOR_SEARCH			2072
 /*! cursor: search near calls */
-#define	WT_STAT_DSRC_CURSOR_SEARCH_NEAR			2072
+#define	WT_STAT_DSRC_CURSOR_SEARCH_NEAR			2073
 /*! cursor: truncate calls */
-#define	WT_STAT_DSRC_CURSOR_TRUNCATE			2073
+#define	WT_STAT_DSRC_CURSOR_TRUNCATE			2074
 /*! cursor: update calls */
-#define	WT_STAT_DSRC_CURSOR_UPDATE			2074
+#define	WT_STAT_DSRC_CURSOR_UPDATE			2075
 /*! cursor: cursor-update value bytes updated */
-#define	WT_STAT_DSRC_CURSOR_UPDATE_BYTES		2075
+#define	WT_STAT_DSRC_CURSOR_UPDATE_BYTES		2076
 /*! LSM: sleep for LSM checkpoint throttle */
-#define	WT_STAT_DSRC_LSM_CHECKPOINT_THROTTLE		2076
+#define	WT_STAT_DSRC_LSM_CHECKPOINT_THROTTLE		2077
 /*! LSM: chunks in the LSM tree */
-#define	WT_STAT_DSRC_LSM_CHUNK_COUNT			2077
+#define	WT_STAT_DSRC_LSM_CHUNK_COUNT			2078
 /*! LSM: highest merge generation in the LSM tree */
-#define	WT_STAT_DSRC_LSM_GENERATION_MAX			2078
+#define	WT_STAT_DSRC_LSM_GENERATION_MAX			2079
 /*! LSM: queries that could have benefited from a Bloom filter that did
  * not exist */
-#define	WT_STAT_DSRC_LSM_LOOKUP_NO_BLOOM		2079
+#define	WT_STAT_DSRC_LSM_LOOKUP_NO_BLOOM		2080
 /*! LSM: sleep for LSM merge throttle */
-#define	WT_STAT_DSRC_LSM_MERGE_THROTTLE			2080
+#define	WT_STAT_DSRC_LSM_MERGE_THROTTLE			2081
 /*! reconciliation: dictionary matches */
-#define	WT_STAT_DSRC_REC_DICTIONARY			2081
+#define	WT_STAT_DSRC_REC_DICTIONARY			2082
 /*! reconciliation: internal page multi-block writes */
-#define	WT_STAT_DSRC_REC_MULTIBLOCK_INTERNAL		2082
+#define	WT_STAT_DSRC_REC_MULTIBLOCK_INTERNAL		2083
 /*! reconciliation: leaf page multi-block writes */
-#define	WT_STAT_DSRC_REC_MULTIBLOCK_LEAF		2083
+#define	WT_STAT_DSRC_REC_MULTIBLOCK_LEAF		2084
 /*! reconciliation: maximum blocks required for a page */
-#define	WT_STAT_DSRC_REC_MULTIBLOCK_MAX			2084
+#define	WT_STAT_DSRC_REC_MULTIBLOCK_MAX			2085
 /*! reconciliation: internal-page overflow keys */
-#define	WT_STAT_DSRC_REC_OVERFLOW_KEY_INTERNAL		2085
+#define	WT_STAT_DSRC_REC_OVERFLOW_KEY_INTERNAL		2086
 /*! reconciliation: leaf-page overflow keys */
-#define	WT_STAT_DSRC_REC_OVERFLOW_KEY_LEAF		2086
+#define	WT_STAT_DSRC_REC_OVERFLOW_KEY_LEAF		2087
 /*! reconciliation: overflow values written */
-#define	WT_STAT_DSRC_REC_OVERFLOW_VALUE			2087
+#define	WT_STAT_DSRC_REC_OVERFLOW_VALUE			2088
 /*! reconciliation: pages deleted */
-#define	WT_STAT_DSRC_REC_PAGE_DELETE			2088
+#define	WT_STAT_DSRC_REC_PAGE_DELETE			2089
 /*! reconciliation: page checksum matches */
-#define	WT_STAT_DSRC_REC_PAGE_MATCH			2089
+#define	WT_STAT_DSRC_REC_PAGE_MATCH			2090
 /*! reconciliation: page reconciliation calls */
-#define	WT_STAT_DSRC_REC_PAGES				2090
+#define	WT_STAT_DSRC_REC_PAGES				2091
 /*! reconciliation: page reconciliation calls for eviction */
-#define	WT_STAT_DSRC_REC_PAGES_EVICTION			2091
+#define	WT_STAT_DSRC_REC_PAGES_EVICTION			2092
 /*! reconciliation: leaf page key bytes discarded using prefix compression */
-#define	WT_STAT_DSRC_REC_PREFIX_COMPRESSION		2092
+#define	WT_STAT_DSRC_REC_PREFIX_COMPRESSION		2093
 /*! reconciliation: internal page key bytes discarded using suffix
  * compression */
-#define	WT_STAT_DSRC_REC_SUFFIX_COMPRESSION		2093
+#define	WT_STAT_DSRC_REC_SUFFIX_COMPRESSION		2094
 /*! session: object compaction */
-#define	WT_STAT_DSRC_SESSION_COMPACT			2094
+#define	WT_STAT_DSRC_SESSION_COMPACT			2095
 /*! session: open cursor count */
-#define	WT_STAT_DSRC_SESSION_CURSOR_OPEN		2095
+#define	WT_STAT_DSRC_SESSION_CURSOR_OPEN		2096
 /*! transaction: update conflicts */
-#define	WT_STAT_DSRC_TXN_UPDATE_CONFLICT		2096
+#define	WT_STAT_DSRC_TXN_UPDATE_CONFLICT		2097
 /*! @} */
 /*
  * Statistics section: END
diff --git a/src/log/log.c b/src/log/log.c
index 44dc7dc30a7..3106094e7e3 100644
--- a/src/log/log.c
+++ b/src/log/log.c
@@ -1313,7 +1313,7 @@ __wt_log_release(WT_SESSION_IMPL *session, WT_LOGSLOT *slot, bool *freep)
 		if (F_ISSET(session, WT_SESSION_LOCKED_SLOT))
 			__wt_spin_unlock(session, &log->log_slot_lock);
 		WT_ERR(__wt_cond_signal(session, conn->log_wrlsn_cond));
-		if (++yield_count < 1000)
+		if (++yield_count < WT_THOUSAND)
 			__wt_yield();
 		else
 			ret = __wt_cond_wait(session, log->log_write_cond, 200);
diff --git a/src/log/log_slot.c b/src/log/log_slot.c
index b3790412536..255551f99a4 100644
--- a/src/log/log_slot.c
+++ b/src/log/log_slot.c
@@ -380,7 +380,7 @@ __wt_log_slot_join(WT_SESSION_IMPL *session, uint64_t mysize,
 	 * There should almost always be a slot open.
 	 */
 #ifdef	HAVE_DIAGNOSTIC
-	unbuf_force = (++log->write_calls % 1000) == 0;
+	unbuf_force = (++log->write_calls % WT_THOUSAND) == 0;
 #endif
 	for (;;) {
 		WT_BARRIER();
diff --git a/src/lsm/lsm_cursor.c b/src/lsm/lsm_cursor.c
index dbd6a105475..953698476ef 100644
--- a/src/lsm/lsm_cursor.c
+++ b/src/lsm/lsm_cursor.c
@@ -81,7 +81,7 @@ __wt_clsm_await_switch(WT_CURSOR_LSM *clsm)
 	    lsm_tree->nchunks == 0 ||
 	    clsm->dsk_gen == lsm_tree->dsk_gen;
 	    ++waited) {
-		if (waited % 1000 == 0)
+		if (waited % WT_THOUSAND == 0)
 			WT_RET(__wt_lsm_manager_push_entry(
 			    session, WT_LSM_WORK_SWITCH, 0, lsm_tree));
 		__wt_sleep(0, 10);
@@ -1530,6 +1530,10 @@ __wt_clsm_open(WT_SESSION_IMPL *session,
 	if (!WT_PREFIX_MATCH(uri, "lsm:"))
 		return (EINVAL);
 
+	if (F_ISSET(S2C(session), WT_CONN_IN_MEMORY))
+		WT_RET_MSG(session, EINVAL,
+		    "LSM trees not supported by in-memory configurations");
+
 	WT_RET(__wt_config_gets_def(session, cfg, "checkpoint", 0, &cval));
 	if (cval.len != 0)
 		WT_RET_MSG(session, EINVAL,
diff --git a/src/lsm/lsm_manager.c b/src/lsm/lsm_manager.c
index 1c5124c32af..d8cf36f2cc1 100644
--- a/src/lsm/lsm_manager.c
+++ b/src/lsm/lsm_manager.c
@@ -388,8 +388,7 @@ __lsm_manager_run_server(WT_SESSION_IMPL *session)
 				continue;
 			WT_ERR(__wt_epoch(session, &now));
 			pushms = lsm_tree->work_push_ts.tv_sec == 0 ? 0 :
-			    WT_TIMEDIFF(
-			    now, lsm_tree->work_push_ts) / WT_MILLION;
+			    WT_TIMEDIFF_MS(now, lsm_tree->work_push_ts);
 			fillms = 3 * lsm_tree->chunk_fill_ms;
 			if (fillms == 0)
 				fillms = 10000;
diff --git a/src/lsm/lsm_merge.c b/src/lsm/lsm_merge.c
index dd1419fe67d..1a2608803e4 100644
--- a/src/lsm/lsm_merge.c
+++ b/src/lsm/lsm_merge.c
@@ -94,7 +94,7 @@ __lsm_merge_aggressive_update(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
 
 	WT_RET(__wt_epoch(session, &now));
 	msec_since_last_merge =
-	    WT_TIMEDIFF(now, lsm_tree->merge_aggressive_ts) / WT_MILLION;
+	    WT_TIMEDIFF_MS(now, lsm_tree->merge_aggressive_ts);
 
 	/*
 	 * If there is no estimate for how long it's taking to fill chunks
@@ -457,7 +457,7 @@ __wt_lsm_merge(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree, u_int id)
 	cfg[2] = NULL;
 	WT_ERR(__wt_open_cursor(session, chunk->uri, NULL, cfg, &dest));
 
-#define	LSM_MERGE_CHECK_INTERVAL	1000
+#define	LSM_MERGE_CHECK_INTERVAL	WT_THOUSAND
 	for (insert_count = 0; (ret = src->next(src)) == 0; insert_count++) {
 		if (insert_count % LSM_MERGE_CHECK_INTERVAL == 0) {
 			if (!F_ISSET(lsm_tree, WT_LSM_TREE_ACTIVE))
diff --git a/src/lsm/lsm_tree.c b/src/lsm/lsm_tree.c
index 30af051bbcf..0c3642e70e8 100644
--- a/src/lsm/lsm_tree.c
+++ b/src/lsm/lsm_tree.c
@@ -111,7 +111,7 @@ __lsm_tree_close(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
 		 * other schema level operations will return EBUSY, even though
 		 * we're dropping the schema lock here.
 		 */
-		if (i % 1000 == 0) {
+		if (i % WT_THOUSAND == 0) {
 			WT_WITHOUT_LOCKS(session, ret =
 			    __wt_lsm_manager_clear_tree(session, lsm_tree));
 			WT_RET(ret);
@@ -336,6 +336,11 @@ __wt_lsm_tree_create(WT_SESSION_IMPL *session,
 	}
 	WT_RET_NOTFOUND_OK(ret);
 
+	/* In-memory configurations don't make sense for LSM. */
+	if (F_ISSET(S2C(session), WT_CONN_IN_MEMORY))
+		WT_RET_MSG(session, EINVAL,
+		    "LSM trees not supported by in-memory configurations");
+
 	WT_RET(__wt_config_gets(session, cfg, "key_format", &cval));
 	if (WT_STRING_MATCH("r", cval.str, cval.len))
 		WT_RET_MSG(session, EINVAL,
@@ -747,7 +752,7 @@ __wt_lsm_tree_throttle(
 		WT_ASSERT(session,
 		    WT_TIMECMP(last_chunk->create_ts, ondisk->create_ts) >= 0);
 		timediff =
-		    WT_TIMEDIFF(last_chunk->create_ts, ondisk->create_ts);
+		    WT_TIMEDIFF_NS(last_chunk->create_ts, ondisk->create_ts);
 		lsm_tree->ckpt_throttle =
 		    (in_memory - 2) * timediff / (20 * record_count);
 
@@ -783,8 +788,8 @@ __wt_lsm_tree_throttle(
 	}
 
 	/* Put an upper bound of 1s on both throttle calculations. */
-	lsm_tree->ckpt_throttle = WT_MIN(1000000, lsm_tree->ckpt_throttle);
-	lsm_tree->merge_throttle = WT_MIN(1000000, lsm_tree->merge_throttle);
+	lsm_tree->ckpt_throttle = WT_MIN(WT_MILLION, lsm_tree->ckpt_throttle);
+	lsm_tree->merge_throttle = WT_MIN(WT_MILLION, lsm_tree->merge_throttle);
 
 	/*
 	 * Update our estimate of how long each in-memory chunk stays active.
@@ -798,15 +803,16 @@ __wt_lsm_tree_throttle(
 		WT_ASSERT(session, prev_chunk->generation == 0);
 		WT_ASSERT(session, WT_TIMECMP(
 		    last_chunk->create_ts, prev_chunk->create_ts) >= 0);
-		timediff =
-		    WT_TIMEDIFF(last_chunk->create_ts, prev_chunk->create_ts);
+		timediff = WT_TIMEDIFF_NS(
+		    last_chunk->create_ts, prev_chunk->create_ts);
 		WT_ASSERT(session,
 		    WT_TIMECMP(prev_chunk->create_ts, ondisk->create_ts) >= 0);
-		oldtime = WT_TIMEDIFF(prev_chunk->create_ts, ondisk->create_ts);
+		oldtime = WT_TIMEDIFF_NS(
+		    prev_chunk->create_ts, ondisk->create_ts);
 		if (timediff < 10 * oldtime)
 			lsm_tree->chunk_fill_ms =
 			    (3 * lsm_tree->chunk_fill_ms +
-			    timediff / 1000000) / 4;
+			    timediff / WT_MILLION) / 4;
 	}
 }
 
diff --git a/src/os_posix/os_mtx_cond.c b/src/os_posix/os_mtx_cond.c
index fac2c06957d..d5fc86b648b 100644
--- a/src/os_posix/os_mtx_cond.c
+++ b/src/os_posix/os_mtx_cond.c
@@ -76,9 +76,9 @@ __wt_cond_wait_signal(
 	if (usecs > 0) {
 		WT_ERR(__wt_epoch(session, &ts));
 		ts.tv_sec += (time_t)
-		    (((uint64_t)ts.tv_nsec + 1000 * usecs) / WT_BILLION);
+		    (((uint64_t)ts.tv_nsec + WT_THOUSAND * usecs) / WT_BILLION);
 		ts.tv_nsec = (long)
-		    (((uint64_t)ts.tv_nsec + 1000 * usecs) % WT_BILLION);
+		    (((uint64_t)ts.tv_nsec + WT_THOUSAND * usecs) % WT_BILLION);
 		ret = pthread_cond_timedwait(&cond->cond, &cond->mtx, &ts);
 	} else
 		ret = pthread_cond_wait(&cond->cond, &cond->mtx);
diff --git a/src/os_posix/os_mtx_rw.c b/src/os_posix/os_mtx_rw.c
index d47ab197643..46f134feabb 100644
--- a/src/os_posix/os_mtx_rw.c
+++ b/src/os_posix/os_mtx_rw.c
@@ -201,7 +201,7 @@ __wt_readlock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock)
 		 * Don't sleep long when waiting on a read lock, hopefully we're
 		 * waiting on another read thread to increment the reader count.
 		 */
-		if (++pause_cnt < 1000)
+		if (++pause_cnt < WT_THOUSAND)
 			WT_PAUSE();
 		else
 			__wt_sleep(0, 10);
@@ -300,7 +300,7 @@ __wt_writelock(WT_SESSION_IMPL *session, WT_RWLOCK *rwlock)
 		 * situation happens if there are more threads than cores in the
 		 * system and we're thrashing on shared resources.
 		 */
-		if (++pause_cnt < 1000)
+		if (++pause_cnt < WT_THOUSAND)
 			WT_PAUSE();
 		else
 			__wt_sleep(0, 10);
diff --git a/src/os_posix/os_sleep.c b/src/os_posix/os_sleep.c
index f888e51bf7f..4e90edabc53 100644
--- a/src/os_posix/os_sleep.c
+++ b/src/os_posix/os_sleep.c
@@ -17,8 +17,8 @@ __wt_sleep(uint64_t seconds, uint64_t micro_seconds)
 {
 	struct timeval t;
 
-	t.tv_sec = (time_t)(seconds + micro_seconds / 1000000);
-	t.tv_usec = (suseconds_t)(micro_seconds % 1000000);
+	t.tv_sec = (time_t)(seconds + micro_seconds / WT_MILLION);
+	t.tv_usec = (suseconds_t)(micro_seconds % WT_MILLION);
 
 	(void)select(0, NULL, NULL, NULL, &t);
 }
diff --git a/src/os_posix/os_time.c b/src/os_posix/os_time.c
index c52772e77e1..c3052df62e7 100644
--- a/src/os_posix/os_time.c
+++ b/src/os_posix/os_time.c
@@ -9,22 +9,6 @@
 #include "wt_internal.h"
 
 /*
- * __wt_seconds --
- *	Return the seconds since the Epoch.
- */
-int
-__wt_seconds(WT_SESSION_IMPL *session, time_t *timep)
-{
-	struct timespec t;
-
-	WT_RET(__wt_epoch(session, &t));
-
-	*timep = t.tv_sec;
-
-	return (0);
-}
-
-/*
  * __wt_epoch --
  *	Return the time since the Epoch.
  */
@@ -44,7 +28,7 @@ __wt_epoch(WT_SESSION_IMPL *session, struct timespec *tsp)
 	WT_SYSCALL_RETRY(gettimeofday(&v, NULL), ret);
 	if (ret == 0) {
 		tsp->tv_sec = v.tv_sec;
-		tsp->tv_nsec = v.tv_usec * 1000;
+		tsp->tv_nsec = v.tv_usec * WT_THOUSAND;
 		return (0);
 	}
 	WT_RET_MSG(session, ret, "gettimeofday");
diff --git a/src/os_win/os_sleep.c b/src/os_win/os_sleep.c
index 484cf218f26..33e04c1d8a9 100644
--- a/src/os_win/os_sleep.c
+++ b/src/os_win/os_sleep.c
@@ -19,7 +19,7 @@ __wt_sleep(uint64_t seconds, uint64_t micro_seconds)
 	 * If the caller wants a small pause, set to our
 	 * smallest granularity.
 	 */
-	if (seconds == 0 && micro_seconds < 1000)
-		micro_seconds = 1000;
-	Sleep(seconds * 1000 + micro_seconds / 1000);
+	if (seconds == 0 && micro_seconds < WT_THOUSAND)
+		micro_seconds = WT_THOUSAND;
+	Sleep(seconds * WT_THOUSAND + micro_seconds / WT_THOUSAND);
 }
diff --git a/src/os_win/os_time.c b/src/os_win/os_time.c
index c51db118ce1..2292c317a64 100644
--- a/src/os_win/os_time.c
+++ b/src/os_win/os_time.c
@@ -9,22 +9,6 @@
 #include "wt_internal.h"
 
 /*
- * __wt_seconds --
- *	Return the seconds since the Epoch.
- */
-int
-__wt_seconds(WT_SESSION_IMPL *session, time_t *timep)
-{
-	struct timespec t;
-
-	WT_RET(__wt_epoch(session, &t));
-
-	*timep = t.tv_sec;
-
-	return (0);
-}
-
-/*
  * __wt_epoch --
  *	Return the time since the Epoch.
  */
diff --git a/src/reconcile/rec_write.c b/src/reconcile/rec_write.c
index e57e18f4e87..6d53230e9e0 100644
--- a/src/reconcile/rec_write.c
+++ b/src/reconcile/rec_write.c
@@ -960,7 +960,7 @@ __rec_bnd_cleanup(WT_SESSION_IMPL *session, WT_RECONCILE *r, bool destroy)
 	 * than 10,000 boundary structure elements, discard the boundary array
 	 * entirely and start over next time.
 	 */
-	if (destroy || r->bnd_entries > 10 * 1000) {
+	if (destroy || r->bnd_entries > 10 * WT_THOUSAND) {
 		for (bnd = r->bnd, i = 0; i < r->bnd_entries; ++bnd, ++i) {
 			__wt_free(session, bnd->addr.addr);
 			__wt_free(session, bnd->disk_image);
diff --git a/src/session/session_api.c b/src/session/session_api.c
index f1599320675..7d718c38c4f 100644
--- a/src/session/session_api.c
+++ b/src/session/session_api.c
@@ -1010,7 +1010,7 @@ __session_transaction_sync(WT_SESSION *wt_session, const char *config)
 	while (__wt_log_cmp(&session->bg_sync_lsn, &log->sync_lsn) > 0) {
 		WT_ERR(__wt_cond_signal(session, conn->log_file_cond));
 		WT_ERR(__wt_epoch(session, &now));
-		waited_ms = WT_TIMEDIFF(now, start) / WT_MILLION;
+		waited_ms = WT_TIMEDIFF_MS(now, start);
 		if (forever || waited_ms < timeout_ms)
 			/*
 			 * Note, we will wait an increasing amount of time
diff --git a/src/session/session_compact.c b/src/session/session_compact.c
index bd503cd7826..456fcd3ce03 100644
--- a/src/session/session_compact.c
+++ b/src/session/session_compact.c
@@ -133,8 +133,7 @@ __session_compact_check_timeout(
 		return (0);
 
 	WT_RET(__wt_epoch(session, &end));
-	if (session->compact->max_time <
-	    WT_TIMEDIFF(end, begin) / WT_BILLION)
+	if (session->compact->max_time < WT_TIMEDIFF_SEC(end, begin))
 		WT_RET(ETIMEDOUT);
 	return (0);
 }
diff --git a/src/session/session_dhandle.c b/src/session/session_dhandle.c
index ec2f0921ef2..dd5094fb480 100644
--- a/src/session/session_dhandle.c
+++ b/src/session/session_dhandle.c
@@ -390,7 +390,7 @@ __session_dhandle_sweep(WT_SESSION_IMPL *session)
 	 * do it again.
 	 */
 	WT_RET(__wt_seconds(session, &now));
-	if (now - session->last_sweep < conn->sweep_interval)
+	if (difftime(now, session->last_sweep) < conn->sweep_interval)
 		return (0);
 	session->last_sweep = now;
 
@@ -404,7 +404,8 @@ __session_dhandle_sweep(WT_SESSION_IMPL *session)
 		    dhandle->session_inuse == 0 &&
 		    (WT_DHANDLE_INACTIVE(dhandle) ||
 		    (dhandle->timeofdeath != 0 &&
-		    now - dhandle->timeofdeath > conn->sweep_idle_time))) {
+		    difftime(now, dhandle->timeofdeath) >
+		    conn->sweep_idle_time))) {
 			WT_STAT_FAST_CONN_INCR(session, dh_session_handles);
 			WT_ASSERT(session, !WT_IS_METADATA(dhandle));
 			__session_discard_dhandle(session, dhandle_cache);
diff --git a/src/support/err.c b/src/support/err.c
index c4bf4e8946a..de518cbf08b 100644
--- a/src/support/err.c
+++ b/src/support/err.c
@@ -199,7 +199,8 @@ __wt_eventv(WT_SESSION_IMPL *session, bool msg_event, int error,
 		remain = WT_PTRDIFF(end, p);
 		wlen = (size_t)snprintf(p, remain,
 		    "[%" PRIuMAX ":%" PRIuMAX "][%s]",
-		    (uintmax_t)ts.tv_sec, (uintmax_t)ts.tv_nsec / 1000, tid);
+		    (uintmax_t)ts.tv_sec,
+		    (uintmax_t)ts.tv_nsec / WT_THOUSAND, tid);
 		p = wlen >= remain ? end : p + wlen;
 		prefix_cnt = 1;
 	}
diff --git a/src/support/stat.c b/src/support/stat.c
index 7a84a7b39da..82377d843ee 100644
--- a/src/support/stat.c
+++ b/src/support/stat.c
@@ -47,7 +47,8 @@ static const char * const __stats_dsrc_desc[] = {
 	"cache: data source pages selected for eviction unable to be evicted",
 	"cache: hazard pointer blocked page eviction",
 	"cache: internal pages evicted",
-	"cache: pages split during eviction",
+	"cache: internal pages split during eviction",
+	"cache: leaf pages split during eviction",
 	"cache: in-memory page splits",
 	"cache: in-memory page passed criteria to be split",
 	"cache: overflow values cached in memory",
@@ -164,6 +165,8 @@ __wt_stat_dsrc_clear_single(WT_DSRC_STATS *stats)
 	stats->cache_inmem_splittable = 0;
 	stats->cache_inmem_split = 0;
 	stats->cache_eviction_internal = 0;
+	stats->cache_eviction_split_internal = 0;
+	stats->cache_eviction_split_leaf = 0;
 	stats->cache_eviction_dirty = 0;
 	stats->cache_read_overflow = 0;
 	stats->cache_overflow_value = 0;
@@ -171,7 +174,6 @@ __wt_stat_dsrc_clear_single(WT_DSRC_STATS *stats)
 	stats->cache_write_lookaside = 0;
 	stats->cache_read = 0;
 	stats->cache_read_lookaside = 0;
-	stats->cache_eviction_split = 0;
 	stats->cache_write = 0;
 	stats->cache_write_restore = 0;
 	stats->cache_eviction_clean = 0;
@@ -282,6 +284,9 @@ __wt_stat_dsrc_aggregate_single(
 	to->cache_inmem_splittable += from->cache_inmem_splittable;
 	to->cache_inmem_split += from->cache_inmem_split;
 	to->cache_eviction_internal += from->cache_eviction_internal;
+	to->cache_eviction_split_internal +=
+	    from->cache_eviction_split_internal;
+	to->cache_eviction_split_leaf += from->cache_eviction_split_leaf;
 	to->cache_eviction_dirty += from->cache_eviction_dirty;
 	to->cache_read_overflow += from->cache_read_overflow;
 	to->cache_overflow_value += from->cache_overflow_value;
@@ -289,7 +294,6 @@ __wt_stat_dsrc_aggregate_single(
 	to->cache_write_lookaside += from->cache_write_lookaside;
 	to->cache_read += from->cache_read;
 	to->cache_read_lookaside += from->cache_read_lookaside;
-	to->cache_eviction_split += from->cache_eviction_split;
 	to->cache_write += from->cache_write;
 	to->cache_write_restore += from->cache_write_restore;
 	to->cache_eviction_clean += from->cache_eviction_clean;
@@ -410,6 +414,10 @@ __wt_stat_dsrc_aggregate(
 	to->cache_inmem_split += WT_STAT_READ(from, cache_inmem_split);
 	to->cache_eviction_internal +=
 	    WT_STAT_READ(from, cache_eviction_internal);
+	to->cache_eviction_split_internal +=
+	    WT_STAT_READ(from, cache_eviction_split_internal);
+	to->cache_eviction_split_leaf +=
+	    WT_STAT_READ(from, cache_eviction_split_leaf);
 	to->cache_eviction_dirty += WT_STAT_READ(from, cache_eviction_dirty);
 	to->cache_read_overflow += WT_STAT_READ(from, cache_read_overflow);
 	to->cache_overflow_value += WT_STAT_READ(from, cache_overflow_value);
@@ -419,7 +427,6 @@ __wt_stat_dsrc_aggregate(
 	    WT_STAT_READ(from, cache_write_lookaside);
 	to->cache_read += WT_STAT_READ(from, cache_read);
 	to->cache_read_lookaside += WT_STAT_READ(from, cache_read_lookaside);
-	to->cache_eviction_split += WT_STAT_READ(from, cache_eviction_split);
 	to->cache_write += WT_STAT_READ(from, cache_write);
 	to->cache_write_restore += WT_STAT_READ(from, cache_write_restore);
 	to->cache_eviction_clean += WT_STAT_READ(from, cache_eviction_clean);
@@ -533,7 +540,8 @@ static const char * const __stats_connection_desc[] = {
 	"cache: eviction server evicting pages",
 	"cache: eviction server populating queue, but not evicting pages",
 	"cache: eviction server unable to reach eviction goal",
-	"cache: pages split during eviction",
+	"cache: internal pages split during eviction",
+	"cache: leaf pages split during eviction",
 	"cache: pages walked for eviction",
 	"cache: eviction worker thread evicting pages",
 	"cache: in-memory page splits",
@@ -707,6 +715,8 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 	stats->cache_inmem_splittable = 0;
 	stats->cache_inmem_split = 0;
 	stats->cache_eviction_internal = 0;
+	stats->cache_eviction_split_internal = 0;
+	stats->cache_eviction_split_leaf = 0;
 	stats->cache_lookaside_insert = 0;
 	stats->cache_lookaside_remove = 0;
 		/* not clearing cache_bytes_max */
@@ -721,7 +731,6 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 	stats->cache_read = 0;
 	stats->cache_read_lookaside = 0;
 	stats->cache_eviction_fail = 0;
-	stats->cache_eviction_split = 0;
 	stats->cache_eviction_walk = 0;
 	stats->cache_write = 0;
 	stats->cache_write_restore = 0;
@@ -888,6 +897,10 @@ __wt_stat_connection_aggregate(
 	to->cache_inmem_split += WT_STAT_READ(from, cache_inmem_split);
 	to->cache_eviction_internal +=
 	    WT_STAT_READ(from, cache_eviction_internal);
+	to->cache_eviction_split_internal +=
+	    WT_STAT_READ(from, cache_eviction_split_internal);
+	to->cache_eviction_split_leaf +=
+	    WT_STAT_READ(from, cache_eviction_split_leaf);
 	to->cache_lookaside_insert +=
 	    WT_STAT_READ(from, cache_lookaside_insert);
 	to->cache_lookaside_remove +=
@@ -908,7 +921,6 @@ __wt_stat_connection_aggregate(
 	to->cache_read += WT_STAT_READ(from, cache_read);
 	to->cache_read_lookaside += WT_STAT_READ(from, cache_read_lookaside);
 	to->cache_eviction_fail += WT_STAT_READ(from, cache_eviction_fail);
-	to->cache_eviction_split += WT_STAT_READ(from, cache_eviction_split);
 	to->cache_eviction_walk += WT_STAT_READ(from, cache_eviction_walk);
 	to->cache_write += WT_STAT_READ(from, cache_write);
 	to->cache_write_restore += WT_STAT_READ(from, cache_write_restore);
diff --git a/src/txn/txn_ckpt.c b/src/txn/txn_ckpt.c
index 066abc9ed0f..bc1537ca878 100644
--- a/src/txn/txn_ckpt.c
+++ b/src/txn/txn_ckpt.c
@@ -297,7 +297,7 @@ __checkpoint_stats(
 	/*
 	 * Get time diff in microseconds.
 	 */
-	msec = WT_TIMEDIFF(*stop, *start) / WT_MILLION;
+	msec = WT_TIMEDIFF_MS(*stop, *start);
 
 	if (msec > conn->ckpt_time_max)
 		conn->ckpt_time_max = msec;
@@ -327,7 +327,7 @@ __checkpoint_verbose_track(WT_SESSION_IMPL *session,
 	/*
 	 * Get time diff in microseconds.
 	 */
-	msec = WT_TIMEDIFF(stop, *start) / WT_MILLION;
+	msec = WT_TIMEDIFF_MS(stop, *start);
 	WT_RET(__wt_verbose(session,
 	    WT_VERB_CHECKPOINT, "time: %" PRIu64 " us, gen: %" PRIu64
 	    ": Full database checkpoint %s",
diff --git a/test/format/bulk.c b/test/format/bulk.c
index 203043166a4..75a158af741 100644
--- a/test/format/bulk.c
+++ b/test/format/bulk.c
@@ -36,7 +36,8 @@ wts_load(void)
 	WT_ITEM key, value;
 	WT_SESSION *session;
 	uint8_t *keybuf, *valbuf;
-	int is_bulk, ret;
+	bool is_bulk;
+	int ret;
 
 	conn = g.wts_conn;
 	keybuf = valbuf = NULL;
@@ -49,12 +50,23 @@ wts_load(void)
 		    "=============== bulk load start ===============");
 
 	/*
-	 * Avoid bulk load with KVS (there's no bulk load support for a
-	 * data-source); avoid bulk load with a custom collator, because
-	 * the order of insertion will not match the collation order.
+	 * No bulk load with data-sources.
+	 *
+	 * XXX
+	 * No bulk load with in-memory configurations (currently, WiredTiger
+	 * fails in the column-store case unless you specify the key).
+	 *
+	 * No bulk load with custom collators, the order of insertion will not
+	 * match the collation order.
 	 */
-	is_bulk = !g.c_reverse &&
-	    !DATASOURCE("kvsbdb") && !DATASOURCE("helium");
+	is_bulk = true;
+	if (DATASOURCE("kvsbdb") && DATASOURCE("helium"))
+		is_bulk = false;
+	if (g.c_in_memory)
+		is_bulk = false;
+	if (g.c_reverse)
+		is_bulk = false;
+
 	if ((ret = session->open_cursor(session, g.uri, NULL,
 	    is_bulk ? "bulk" : NULL, &cursor)) != 0)
 		die(ret, "session.open_cursor");
diff --git a/test/format/config.c b/test/format/config.c
index 45310bf1dab..b9d0e437765 100644
--- a/test/format/config.c
+++ b/test/format/config.c
@@ -34,6 +34,7 @@ static void	   config_compression(const char *);
 static void	   config_encryption(void);
 static const char *config_file_type(u_int);
 static CONFIG	  *config_find(const char *, size_t);
+static void	   config_in_memory(void);
 static int	   config_is_perm(const char *);
 static void	   config_isolation(void);
 static void	   config_lrt(void);
@@ -56,6 +57,13 @@ config_setup(void)
 	config_clear();
 
 	/*
+	 * Periodically, run in-memory; don't do it on the first run, all our
+	 * smoke tests would hit it.
+	 */
+	if (!config_is_perm("in_memory") && g.run_cnt % 20 == 19)
+		g.c_in_memory = 1;
+
+	/*
 	 * Choose a data source type and a file type: they're interrelated (LSM
 	 * trees are only compatible with row-store) and other items depend on
 	 * them.
@@ -66,8 +74,11 @@ config_setup(void)
 			config_single("data_source=file", 0);
 			break;
 		case 2:
-			config_single("data_source=lsm", 0);
-			break;
+			if (!g.c_in_memory) {
+				config_single("data_source=lsm", 0);
+				break;
+			}
+			/* FALLTHROUGH */
 		case 3:
 			config_single("data_source=table", 0);
 			break;
@@ -147,6 +158,7 @@ config_setup(void)
 	config_compression("compression");
 	config_compression("logging_compression");
 	config_encryption();
+	config_in_memory();
 	config_isolation();
 	config_lrt();
 
@@ -301,6 +313,43 @@ config_encryption(void)
 }
 
 /*
+ * config_in_memory --
+ *	In-memory configuration.
+ */
+static void
+config_in_memory(void)
+{
+	if (g.c_in_memory == 0)
+		return;
+
+	/* Turn off a lot of stuff. */
+	if (!config_is_perm("backups"))
+		g.c_backups = 0;
+	if (!config_is_perm("checkpoints"))
+		g.c_checkpoints = 0;
+	if (!config_is_perm("compression"))
+		g.c_compression = 0;
+	if (!config_is_perm("logging"))
+		g.c_logging = 0;
+	if (!config_is_perm("salvage"))
+		g.c_salvage = 0;
+	if (!config_is_perm("verify"))
+		g.c_verify = 0;
+
+	/*
+	 * Ensure there is 250MB of cache per thread; keep keys/values small,
+	 * overflow items aren't an issue for in-memory configurations and it
+	 * keeps us from overflowing the cache.
+	 */
+	if (!config_is_perm("cache"))
+		g.c_cache = g.c_threads * 250;
+	if (!config_is_perm("key_max"))
+		g.c_value_max = 64;
+	if (!config_is_perm("value_max"))
+		g.c_value_max = 128;
+}
+
+/*
  * config_isolation --
  *	Isolation configuration.
  */
@@ -341,8 +390,8 @@ static void
 config_lrt(void)
 {
 	/*
-	 * The underlying engine doesn't support a lookaside file for
-	 * fixed-length column stores.
+	 * WiredTiger doesn't support a lookaside file for fixed-length column
+	 * stores.
 	 */
 	if (g.type == FIX) {
 		if (config_is_perm("long_running_txn"))
diff --git a/test/format/config.h b/test/format/config.h
index 7574cd38882..30fcf038439 100644
--- a/test/format/config.h
+++ b/test/format/config.h
@@ -70,9 +70,9 @@ static CONFIG c[] = {
 	  "if LSM inserts are throttled",			/* 90% */
 	  C_BOOL, 90, 0, 0, &g.c_auto_throttle, NULL },
 
-	{ "firstfit",
-	  "if allocation is firstfit",				/* 10% */
-	  C_BOOL, 10, 0, 0, &g.c_firstfit, NULL },
+	{ "backups",
+	  "if backups are enabled",				/* 5% */
+	  C_BOOL, 5, 0, 0, &g.c_backups, NULL },
 
 	{ "bitcnt",
 	  "number of bits for fixed-length column-store files",
@@ -146,9 +146,9 @@ static CONFIG c[] = {
 	  "type of store to create (fix | var | row)",
 	  C_IGNORE|C_STRING, 1, 3, 3, NULL, &g.c_file_type },
 
-	{ "backups",
-	  "if backups are enabled",				/* 5% */
-	  C_BOOL, 5, 0, 0, &g.c_backups, NULL },
+	{ "firstfit",
+	  "if allocation is firstfit",				/* 10% */
+	  C_BOOL, 10, 0, 0, &g.c_firstfit, NULL },
 
 	{ "huffman_key",
 	  "if keys are huffman encoded",			/* 20% */
@@ -158,6 +158,10 @@ static CONFIG c[] = {
 	  "if values are huffman encoded",			/* 20% */
 	  C_BOOL, 20, 0, 0, &g.c_huffman_value, NULL },
 
+	{ "in_memory",
+	  "if in-memory configured",
+	  C_IGNORE, 0, 0, 1, &g.c_in_memory, NULL },
+
 	{ "insert_pct",
 	  "percent operations that are inserts",
 	  0x0, 0, 45, 90, &g.c_insert_pct, NULL },
@@ -187,26 +191,26 @@ static CONFIG c[] = {
 	  "minimum size of keys",
 	  0x0, 10, 32, 256, &g.c_key_min, NULL },
 
-	{ "leak_memory",
-	  "if memory should be leaked on close",
-	  C_BOOL, 0, 0, 0, &g.c_leak_memory, NULL },
-
 	{ "leaf_page_max",
 	  "maximum size of Btree leaf nodes",
 	  0x0, 9, 17, 27, &g.c_leaf_page_max, NULL },
 
+	{ "leak_memory",
+	  "if memory should be leaked on close",
+	  C_BOOL, 0, 0, 0, &g.c_leak_memory, NULL },
+
 	{ "logging",
 	  "if logging configured",				/* 30% */
 	  C_BOOL, 30, 0, 0, &g.c_logging, NULL },
 
-	{ "logging_compression",
-	  "type of logging compression " COMPRESSION_LIST,
-	  C_IGNORE|C_STRING, 0, 0, 0, NULL, &g.c_logging_compression },
-
 	{ "logging_archive",
 	  "if log file archival configured",			/* 50% */
 	  C_BOOL, 50, 0, 0, &g.c_logging_archive, NULL },
 
+	{ "logging_compression",
+	  "type of logging compression " COMPRESSION_LIST,
+	  C_IGNORE|C_STRING, 0, 0, 0, NULL, &g.c_logging_compression },
+
 	{ "logging_prealloc",
 	  "if log file pre-allocation configured",		/* 50% */
 	  C_BOOL, 50, 0, 0, &g.c_logging_prealloc, NULL },
diff --git a/test/format/format.h b/test/format/format.h
index 76e8bc5e43c..c996e98ea3e 100644
--- a/test/format/format.h
+++ b/test/format/format.h
@@ -190,6 +190,7 @@ typedef struct {
 	char	*c_file_type;
 	uint32_t c_huffman_key;
 	uint32_t c_huffman_value;
+	uint32_t c_in_memory;
 	uint32_t c_insert_pct;
 	uint32_t c_internal_key_truncation;
 	uint32_t c_intl_page_max;
diff --git a/test/format/wts.c b/test/format/wts.c
index 23823c20184..cab004cc91d 100644
--- a/test/format/wts.c
+++ b/test/format/wts.c
@@ -149,6 +149,10 @@ wts_open(const char *home, int set_api, WT_CONNECTION **connp)
 	p += snprintf(p, REMAIN(p, end), ",error_prefix=\"%s\"", g.progname);
 #endif
 
+	/* In-memory configuration. */
+	if (g.c_in_memory != 0)
+		p += snprintf(p, REMAIN(p, end), ",in_memory=1");
+
 	/* LSM configuration. */
 	if (DATASOURCE("lsm"))
 		p += snprintf(p, REMAIN(p, end),
@@ -455,7 +459,12 @@ wts_dump(const char *tag, int dump_bdb)
 	int ret;
 	char *cmd;
 
-	/* Some data-sources don't support dump through the wt utility. */
+	/*
+	 * In-memory configurations and data-sources don't support dump through
+	 * the wt utility.
+	 */
+	if (g.c_in_memory != 0)
+		return;
 	if (DATASOURCE("helium") || DATASOURCE("kvsbdb"))
 		return;