WT-2902 Track per-tree the efficiency of eviction walks. (#3036)

Some workloads create "deserts" within a tree where no good eviction
candidates can be found (e.g., zipfian distributions, append-only
workloads, etc.).  Rather than walking all the way through such
regions, give up and try in the opposite direction next time.

Also add a statistic for the eviction empty score.

10 files changed, 271 insertions, 221 deletions

diff --git a/dist/api_data.py b/dist/api_data.py
index 44fc935d5d3..0f4506f608c 100644
--- a/dist/api_data.py
+++ b/dist/api_data.py
@@ -402,7 +402,7 @@ connection_runtime_config = [
                 vary depending on the current eviction load''',
                 min=1, max=20),
             ]),
-    Config('eviction_checkpoint_target', '15', r'''
+    Config('eviction_checkpoint_target', '5', r'''
         perform eviction at the beginning of checkpoints to bring the dirty
         content in cache to this level, expressed as a percentage of the total
         cache size.  Ignored if set to zero or \c in_memory is \c true''',
diff --git a/dist/stat_data.py b/dist/stat_data.py
index a050849ad76..5087afa44dc 100644
--- a/dist/stat_data.py
+++ b/dist/stat_data.py
@@ -185,6 +185,7 @@ connection_stats = [
     CacheStat('cache_eviction_clean', 'unmodified pages evicted'),
     CacheStat('cache_eviction_deepen', 'page split during eviction deepened the tree'),
     CacheStat('cache_eviction_dirty', 'modified pages evicted'),
+    CacheStat('cache_eviction_empty_score', 'eviction empty score', 'no_clear,no_scale'),
     CacheStat('cache_eviction_fail', 'pages selected for eviction unable to be evicted'),
     CacheStat('cache_eviction_force', 'pages evicted because they exceeded the in-memory maximum'),
     CacheStat('cache_eviction_force_delete', 'pages evicted because they had chains of deleted items'),
@@ -208,7 +209,8 @@ connection_stats = [
     CacheStat('cache_eviction_split_leaf', 'leaf pages split during eviction'),
     CacheStat('cache_eviction_state', 'eviction state', 'no_clear,no_scale'),
     CacheStat('cache_eviction_walk', 'pages walked for eviction'),
-    CacheStat('cache_eviction_walks_active', 'files with active eviction walks', 'no_clear,no_scale,size'),
+    CacheStat('cache_eviction_walks_abandoned', 'eviction walks abandoned'),
+    CacheStat('cache_eviction_walks_active', 'files with active eviction walks', 'no_clear,no_scale'),
     CacheStat('cache_eviction_walks_started', 'files with new eviction walks started'),
     CacheStat('cache_eviction_worker_evicting', 'eviction worker thread evicting pages'),
     CacheStat('cache_hazard_checks', 'hazard pointer check calls'),
diff --git a/src/config/config_def.c b/src/config/config_def.c
index f231d7fc5d9..0ff2fd379d2 100644
--- a/src/config/config_def.c
+++ b/src/config/config_def.c
@@ -1005,7 +1005,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  "async=(enabled=false,ops_max=1024,threads=2),cache_overhead=8,"
 	  "cache_size=100MB,checkpoint=(log_size=0,wait=0),error_prefix=,"
 	  "eviction=(threads_max=1,threads_min=1),"
-	  "eviction_checkpoint_target=15,eviction_dirty_target=5,"
+	  "eviction_checkpoint_target=5,eviction_dirty_target=5,"
 	  "eviction_dirty_trigger=20,eviction_target=80,eviction_trigger=95"
 	  ",file_manager=(close_handle_minimum=250,close_idle_time=30,"
 	  "close_scan_interval=10),log=(archive=true,prealloc=true,"
@@ -1207,7 +1207,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  "wait=0),checkpoint_sync=true,config_base=true,create=false,"
 	  "direct_io=,encryption=(keyid=,name=,secretkey=),error_prefix=,"
 	  "eviction=(threads_max=1,threads_min=1),"
-	  "eviction_checkpoint_target=15,eviction_dirty_target=5,"
+	  "eviction_checkpoint_target=5,eviction_dirty_target=5,"
 	  "eviction_dirty_trigger=20,eviction_target=80,eviction_trigger=95"
 	  ",exclusive=false,extensions=,file_extend=,"
 	  "file_manager=(close_handle_minimum=250,close_idle_time=30,"
@@ -1230,7 +1230,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  "wait=0),checkpoint_sync=true,config_base=true,create=false,"
 	  "direct_io=,encryption=(keyid=,name=,secretkey=),error_prefix=,"
 	  "eviction=(threads_max=1,threads_min=1),"
-	  "eviction_checkpoint_target=15,eviction_dirty_target=5,"
+	  "eviction_checkpoint_target=5,eviction_dirty_target=5,"
 	  "eviction_dirty_trigger=20,eviction_target=80,eviction_trigger=95"
 	  ",exclusive=false,extensions=,file_extend=,"
 	  "file_manager=(close_handle_minimum=250,close_idle_time=30,"
@@ -1252,7 +1252,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  ",cache_overhead=8,cache_size=100MB,checkpoint=(log_size=0,"
 	  "wait=0),checkpoint_sync=true,direct_io=,encryption=(keyid=,name="
 	  ",secretkey=),error_prefix=,eviction=(threads_max=1,"
-	  "threads_min=1),eviction_checkpoint_target=15,"
+	  "threads_min=1),eviction_checkpoint_target=5,"
 	  "eviction_dirty_target=5,eviction_dirty_trigger=20,"
 	  "eviction_target=80,eviction_trigger=95,extensions=,file_extend=,"
 	  "file_manager=(close_handle_minimum=250,close_idle_time=30,"
@@ -1273,7 +1273,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  ",cache_overhead=8,cache_size=100MB,checkpoint=(log_size=0,"
 	  "wait=0),checkpoint_sync=true,direct_io=,encryption=(keyid=,name="
 	  ",secretkey=),error_prefix=,eviction=(threads_max=1,"
-	  "threads_min=1),eviction_checkpoint_target=15,"
+	  "threads_min=1),eviction_checkpoint_target=5,"
 	  "eviction_dirty_target=5,eviction_dirty_trigger=20,"
 	  "eviction_target=80,eviction_trigger=95,extensions=,file_extend=,"
 	  "file_manager=(close_handle_minimum=250,close_idle_time=30,"
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index 69fff96fef5..c7bd3f0cb17 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -17,24 +17,24 @@ static int  __evict_pass(WT_SESSION_IMPL *);
 static int  __evict_server(WT_SESSION_IMPL *, bool *);
 static int  __evict_walk(WT_SESSION_IMPL *, WT_EVICT_QUEUE *);
 static int  __evict_walk_file(
-    WT_SESSION_IMPL *, WT_EVICT_QUEUE *, u_int, u_int *, bool *);
+    WT_SESSION_IMPL *, WT_EVICT_QUEUE *, u_int, u_int *);
 
 #define	WT_EVICT_HAS_WORKERS(s)				\
 	(S2C(s)->evict_threads.current_threads > 1)
 
 /*
- * __evict_read_gen --
+ * __evict_entry_priority --
  *	Get the adjusted read generation for an eviction entry.
  */
 static inline uint64_t
-__evict_read_gen(const WT_EVICT_ENTRY *entry)
+__evict_entry_priority(WT_SESSION_IMPL *session, WT_REF *ref)
 {
 	WT_BTREE *btree;
 	WT_PAGE *page;
 	uint64_t read_gen;
 
-	btree = entry->btree;
-	page = entry->ref->page;
+	btree = S2BT(session);
+	page = ref->page;
 
 	/* Any page set to the oldest generation should be discarded. */
 	if (page->read_gen == WT_READGEN_OLDEST)
@@ -60,7 +60,14 @@ __evict_read_gen(const WT_EVICT_ENTRY *entry)
 	 * The base read-generation is skewed by the eviction priority.
 	 * Internal pages are also adjusted, we prefer to evict leaf pages.
 	 */
-	read_gen = page->read_gen + btree->evict_priority;
+	if (page->modify != NULL &&
+	    F_ISSET(S2C(session)->cache, WT_CACHE_EVICT_DIRTY) &&
+	    !F_ISSET(S2C(session)->cache, WT_CACHE_EVICT_CLEAN))
+		read_gen = page->modify->update_txn;
+	else
+		read_gen = page->read_gen;
+
+	read_gen += btree->evict_priority;
 	if (WT_PAGE_IS_INTERNAL(page))
 		read_gen += WT_EVICT_INT_SKEW;
 
@@ -327,8 +334,6 @@ __evict_server(WT_SESSION_IMPL *session, bool *did_work)
 		__wt_spin_unlock(session, &conn->dhandle_lock);
 		WT_RET(ret);
 
-		/* Next time we wake up, reverse the sweep direction. */
-		cache->flags ^= WT_CACHE_WALK_REVERSE;
 		cache->pages_evicted = 0;
 	} else if (cache->pages_evicted != cache->pages_evict) {
 		cache->pages_evicted = cache->pages_evict;
@@ -641,7 +646,7 @@ __evict_pass(WT_SESSION_IMPL *session)
  *	Clear a single walk point.
  */
 static int
-__evict_clear_walk(WT_SESSION_IMPL *session)
+__evict_clear_walk(WT_SESSION_IMPL *session, bool count_stat)
 {
 	WT_BTREE *btree;
 	WT_CACHE *cache;
@@ -658,6 +663,9 @@ __evict_clear_walk(WT_SESSION_IMPL *session)
 	if ((ref = btree->evict_ref) == NULL)
 		return (0);
 
+	if (count_stat)
+		WT_STAT_FAST_CONN_INCR(session, cache_eviction_walks_abandoned);
+
 	/*
 	 * Clear evict_ref first, in case releasing it forces eviction (we
 	 * assert we never try to evict the current eviction walk point).
@@ -684,8 +692,8 @@ __evict_clear_all_walks(WT_SESSION_IMPL *session)
 
 	TAILQ_FOREACH(dhandle, &conn->dhqh, q)
 		if (WT_PREFIX_MATCH(dhandle->name, "file:"))
-			WT_WITH_DHANDLE(session,
-			    dhandle, WT_TRET(__evict_clear_walk(session)));
+			WT_WITH_DHANDLE(session, dhandle,
+			    WT_TRET(__evict_clear_walk(session, true)));
 	return (ret);
 }
 
@@ -730,7 +738,7 @@ __wt_evict_file_exclusive_on(WT_SESSION_IMPL *session)
 
 	/* Clear any existing LRU eviction walk for the file. */
 	WT_WITH_PASS_LOCK(session, ret,
-	    ret = __evict_clear_walk(session));
+	    ret = __evict_clear_walk(session, true));
 	(void)__wt_atomic_subv32(&cache->pass_intr, 1);
 	WT_ERR(ret);
 
@@ -843,8 +851,11 @@ __evict_lru_walk(WT_SESSION_IMPL *session)
 	cache = S2C(session)->cache;
 
 	/* Age out the score of how much the queue has been empty recently. */
-	if (cache->evict_empty_score > 0)
+	if (cache->evict_empty_score > 0) {
 		--cache->evict_empty_score;
+		WT_STAT_FAST_CONN_SET(session, cache_eviction_empty_score,
+		    cache->evict_empty_score);
+	}
 
 	/* Fill the next queue (that isn't the urgent queue). */
 	queue = cache->evict_fill_queue;
@@ -894,10 +905,14 @@ __evict_lru_walk(WT_SESSION_IMPL *session)
 	 */
 	if (__evict_queue_empty(queue)) {
 		if (F_ISSET(cache,
-		    WT_CACHE_EVICT_CLEAN_HARD | WT_CACHE_EVICT_DIRTY_HARD))
+		    WT_CACHE_EVICT_CLEAN_HARD | WT_CACHE_EVICT_DIRTY_HARD)) {
 			cache->evict_empty_score = WT_MIN(
 			    cache->evict_empty_score + WT_EVICT_SCORE_BUMP,
 			    WT_EVICT_SCORE_MAX);
+			WT_STAT_FAST_CONN_SET(session,
+			    cache_eviction_empty_score,
+			    cache->evict_empty_score);
+		}
 		WT_STAT_FAST_CONN_INCR(session, cache_eviction_queue_empty);
 	} else
 		WT_STAT_FAST_CONN_INCR(session, cache_eviction_queue_not_empty);
@@ -1014,8 +1029,8 @@ __evict_walk(WT_SESSION_IMPL *session, WT_EVICT_QUEUE *queue)
 	WT_CONNECTION_IMPL *conn;
 	WT_DATA_HANDLE *dhandle;
 	WT_DECL_RET;
-	u_int max_entries, prev_slot, retries, slot, start_slot, spins;
-	bool dhandle_locked, incr, progress;
+	u_int max_entries, retries, slot, start_slot, spins;
+	bool dhandle_locked, incr;
 
 	conn = S2C(session);
 	cache = S2C(session)->cache;
@@ -1121,8 +1136,6 @@ retry:	while (slot < max_entries) {
 		    btree->evict_walk_skips++ < btree->evict_walk_period)
 			continue;
 		btree->evict_walk_skips = 0;
-		prev_slot = slot;
-		progress = false;
 
 		(void)__wt_atomic_addi32(&dhandle->session_inuse, 1);
 		incr = true;
@@ -1145,22 +1158,12 @@ retry:	while (slot < max_entries) {
 				cache->evict_file_next = dhandle;
 				WT_WITH_DHANDLE(session, dhandle, ret =
 				    __evict_walk_file(session, queue,
-				    max_entries, &slot, &progress));
+				    max_entries, &slot));
 				WT_ASSERT(session, session->split_gen == 0);
 			}
 			__wt_spin_unlock(session, &cache->evict_walk_lock);
 			WT_ERR(ret);
 		}
-
-		/*
-		 * If we didn't find any candidates in the file, skip it next
-		 * time.
-		 */
-		if (slot == prev_slot && !progress)
-			btree->evict_walk_period = WT_MIN(
-			    WT_MAX(1, 2 * btree->evict_walk_period), 100);
-		else
-			btree->evict_walk_period = 0;
 	}
 
 	if (incr) {
@@ -1229,7 +1232,7 @@ __evict_push_candidate(WT_SESSION_IMPL *session,
 
 	evict->btree = S2BT(session);
 	evict->ref = ref;
-	evict->score = __evict_read_gen(evict);
+	evict->score = __evict_entry_priority(session, ref);
 
 	/* Adjust for size when doing dirty eviction. */
 	if (F_ISSET(S2C(session)->cache, WT_CACHE_EVICT_DIRTY) &&
@@ -1247,7 +1250,7 @@ __evict_push_candidate(WT_SESSION_IMPL *session,
  */
 static int
 __evict_walk_file(WT_SESSION_IMPL *session,
-    WT_EVICT_QUEUE *queue, u_int max_entries, u_int *slotp, bool *progressp)
+    WT_EVICT_QUEUE *queue, u_int max_entries, u_int *slotp)
 {
 	WT_BTREE *btree;
 	WT_CACHE *cache;
@@ -1259,17 +1262,18 @@ __evict_walk_file(WT_SESSION_IMPL *session,
 	WT_REF *ref;
 	WT_TXN_GLOBAL *txn_global;
 	uint64_t btree_inuse, bytes_per_slot, cache_inuse;
-	uint64_t pages_seen, refs_walked;
+	uint64_t pages_seen, pages_queued, refs_walked;
 	uint32_t remaining_slots, total_slots, walk_flags;
 	uint32_t target_pages_clean, target_pages_dirty, target_pages;
 	int internal_pages, restarts;
-	bool modified;
+	bool give_up, modified, urgent_queued;
 
 	conn = S2C(session);
 	btree = S2BT(session);
 	cache = conn->cache;
-	internal_pages = restarts = 0;
 	txn_global = &conn->txn_global;
+	internal_pages = restarts = 0;
+	give_up = urgent_queued = false;
 
 	/*
 	 * Figure out how many slots to fill from this tree.
@@ -1324,8 +1328,10 @@ __evict_walk_file(WT_SESSION_IMPL *session,
 
 	walk_flags =
 	    WT_READ_CACHE | WT_READ_NO_EVICT | WT_READ_NO_GEN | WT_READ_NO_WAIT;
-	if (F_ISSET(cache, WT_CACHE_WALK_REVERSE))
-		walk_flags |= WT_READ_PREV;
+
+	/* Randomize the walk direction. */
+	if (btree->evict_walk_reverse)
+		FLD_SET(walk_flags, WT_READ_PREV);
 
 	/*
 	 * Get some more eviction candidate pages.
@@ -1339,10 +1345,22 @@ __evict_walk_file(WT_SESSION_IMPL *session,
 	 * Once we hit the page limit, do one more step through the walk in
 	 * case we are appending and only the last page in the file is live.
 	 */
-	for (evict = start, pages_seen = refs_walked = 0;
+	for (evict = start, pages_queued = pages_seen = refs_walked = 0;
 	    evict < end && (ret == 0 || ret == WT_NOTFOUND);
 	    ret = __wt_tree_walk_count(
 	    session, &btree->evict_ref, &refs_walked, walk_flags)) {
+		/*
+		 * Check whether we're finding a good ration of candidates vs
+		 * pages seen.  Some workloads create "deserts" in trees where
+		 * no good eviction candidates can be found.  Abandon the walk
+		 * if we get into that situation.
+		 */
+		give_up = pages_seen > 100 &&
+		    (pages_queued == 0 || (pages_seen / pages_queued) >
+		    (10 * total_slots / target_pages));
+		if (give_up)
+			break;
+
 		if ((ref = btree->evict_ref) == NULL) {
 			if (++restarts == 2)
 				break;
@@ -1382,7 +1400,7 @@ __evict_walk_file(WT_SESSION_IMPL *session,
 			WT_STAT_FAST_CONN_INCR(
 			    session, cache_eviction_pages_queued_oldest);
 			if (__wt_page_evict_urgent(session, ref))
-				*progressp = true;
+				urgent_queued = true;
 			continue;
 		}
 
@@ -1426,6 +1444,7 @@ fast:		/* If the page can't be evicted, give up. */
 		if (!__evict_push_candidate(session, queue, evict, ref))
 			continue;
 		++evict;
+		++pages_queued;
 
 		if (WT_PAGE_IS_INTERNAL(page))
 		    ++internal_pages;
@@ -1441,6 +1460,18 @@ fast:		/* If the page can't be evicted, give up. */
 	    session, cache_eviction_pages_queued, (u_int)(evict - start));
 
 	/*
+	 * If we didn't find any candidates in the file, reverse the direction
+	 * of the walk and skip it next time.
+	 */
+	if (give_up)
+		btree->evict_walk_reverse = !btree->evict_walk_reverse;
+	if (give_up && !urgent_queued)
+		btree->evict_walk_period = WT_MIN(
+		    WT_MAX(1, 2 * btree->evict_walk_period), 100);
+	else if (pages_queued == target_pages)
+		btree->evict_walk_period = 0;
+
+	/*
 	 * If we happen to end up on the root page, clear it.  We have to track
 	 * hazard pointers, and the root page complicates that calculation.
 	 *
@@ -1452,8 +1483,9 @@ fast:		/* If the page can't be evicted, give up. */
 	 * page: we want this page evicted as quickly as possible.
 	 */
 	if ((ref = btree->evict_ref) != NULL) {
-		if (__wt_ref_is_root(ref) || evict == start)
-			WT_RET(__evict_clear_walk(session));
+		/* Give up the walk occasionally. */
+		if (__wt_ref_is_root(ref) || evict == start || give_up)
+			WT_RET(__evict_clear_walk(session, restarts == 0));
 		else if (ref->page->read_gen == WT_READGEN_OLDEST)
 			WT_RET_NOTFOUND_OK(__wt_tree_walk_count(
 			    session, &btree->evict_ref,
diff --git a/src/include/btree.h b/src/include/btree.h
index f1365c6c933..cfaf59e70e1 100644
--- a/src/include/btree.h
+++ b/src/include/btree.h
@@ -140,6 +140,7 @@ struct __wt_btree {
 	u_int	    evict_walk_skips;	/* Number of walks skipped */
 	u_int	    evict_disabled;	/* Eviction disabled count */
 	volatile uint32_t evict_busy;	/* Count of threads in eviction */
+	bool	    evict_walk_reverse;	/* Walk direction */
 
 	enum {
 		WT_CKPT_OFF, WT_CKPT_PREPARE, WT_CKPT_RUNNING
diff --git a/src/include/cache.h b/src/include/cache.h
index 0cb61f01435..515135f26ab 100644
--- a/src/include/cache.h
+++ b/src/include/cache.h
@@ -181,7 +181,6 @@ struct __wt_cache {
 #define	WT_CACHE_EVICT_MASK	  0x0FF
 #define	WT_CACHE_POOL_MANAGER	  0x100 /* The active cache pool manager */
 #define	WT_CACHE_POOL_RUN	  0x200 /* Cache pool thread running */
-#define	WT_CACHE_WALK_REVERSE	  0x400 /* Scan backwards for candidates */
 	uint32_t flags;
 };
 
diff --git a/src/include/stat.h b/src/include/stat.h
index b61c568783b..e9c6d64a850 100644
--- a/src/include/stat.h
+++ b/src/include/stat.h
@@ -286,12 +286,14 @@ struct __wt_connection_stats {
 	int64_t cache_eviction_get_ref_empty;
 	int64_t cache_eviction_get_ref_empty2;
 	int64_t cache_eviction_aggressive_set;
+	int64_t cache_eviction_empty_score;
 	int64_t cache_eviction_queue_empty;
 	int64_t cache_eviction_queue_not_empty;
 	int64_t cache_eviction_server_evicting;
 	int64_t cache_eviction_server_slept;
 	int64_t cache_eviction_slow;
 	int64_t cache_eviction_state;
+	int64_t cache_eviction_walks_abandoned;
 	int64_t cache_eviction_worker_evicting;
 	int64_t cache_eviction_force_fail;
 	int64_t cache_eviction_walks_active;
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index 61a66bd4086..f4763a113f1 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -1812,7 +1812,7 @@ struct __wt_connection {
 	 * of checkpoints to bring the dirty content in cache to this level\,
 	 * expressed as a percentage of the total cache size.  Ignored if set to
 	 * zero or \c in_memory is \c true., an integer between 0 and 99;
-	 * default \c 15.}
+	 * default \c 5.}
 	 * @config{eviction_dirty_target, perform eviction in worker threads
 	 * when the cache contains at least this much dirty content\, expressed
 	 * as a percentage of the total cache size.  Ignored if \c in_memory is
@@ -2278,7 +2278,7 @@ struct __wt_connection {
  * @config{eviction_checkpoint_target, perform eviction at the beginning of
  * checkpoints to bring the dirty content in cache to this level\, expressed as
  * a percentage of the total cache size.  Ignored if set to zero or \c in_memory
- * is \c true., an integer between 0 and 99; default \c 15.}
+ * is \c true., an integer between 0 and 99; default \c 5.}
  * @config{eviction_dirty_target, perform eviction in worker threads when the
  * cache contains at least this much dirty content\, expressed as a percentage
  * of the total cache size.  Ignored if \c in_memory is \c true., an integer
@@ -4294,360 +4294,364 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_CONN_CACHE_EVICTION_GET_REF_EMPTY2	1039
 /*! cache: eviction currently operating in aggressive mode */
 #define	WT_STAT_CONN_CACHE_EVICTION_AGGRESSIVE_SET	1040
+/*! cache: eviction empty score */
+#define	WT_STAT_CONN_CACHE_EVICTION_EMPTY_SCORE		1041
 /*! cache: eviction server candidate queue empty when topping up */
-#define	WT_STAT_CONN_CACHE_EVICTION_QUEUE_EMPTY		1041
+#define	WT_STAT_CONN_CACHE_EVICTION_QUEUE_EMPTY		1042
 /*! cache: eviction server candidate queue not empty when topping up */
-#define	WT_STAT_CONN_CACHE_EVICTION_QUEUE_NOT_EMPTY	1042
+#define	WT_STAT_CONN_CACHE_EVICTION_QUEUE_NOT_EMPTY	1043
 /*! cache: eviction server evicting pages */
-#define	WT_STAT_CONN_CACHE_EVICTION_SERVER_EVICTING	1043
+#define	WT_STAT_CONN_CACHE_EVICTION_SERVER_EVICTING	1044
 /*!
  * cache: eviction server slept, because we did not make progress with
  * eviction
  */
-#define	WT_STAT_CONN_CACHE_EVICTION_SERVER_SLEPT	1044
+#define	WT_STAT_CONN_CACHE_EVICTION_SERVER_SLEPT	1045
 /*! cache: eviction server unable to reach eviction goal */
-#define	WT_STAT_CONN_CACHE_EVICTION_SLOW		1045
+#define	WT_STAT_CONN_CACHE_EVICTION_SLOW		1046
 /*! cache: eviction state */
-#define	WT_STAT_CONN_CACHE_EVICTION_STATE		1046
+#define	WT_STAT_CONN_CACHE_EVICTION_STATE		1047
+/*! cache: eviction walks abandoned */
+#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_ABANDONED	1048
 /*! cache: eviction worker thread evicting pages */
-#define	WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING	1047
+#define	WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING	1049
 /*! cache: failed eviction of pages that exceeded the in-memory maximum */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_FAIL		1048
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_FAIL		1050
 /*! cache: files with active eviction walks */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_ACTIVE	1049
+#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_ACTIVE	1051
 /*! cache: files with new eviction walks started */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_STARTED	1050
+#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_STARTED	1052
 /*! cache: hazard pointer blocked page eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_HAZARD		1051
+#define	WT_STAT_CONN_CACHE_EVICTION_HAZARD		1053
 /*! cache: hazard pointer check calls */
-#define	WT_STAT_CONN_CACHE_HAZARD_CHECKS		1052
+#define	WT_STAT_CONN_CACHE_HAZARD_CHECKS		1054
 /*! cache: hazard pointer check entries walked */
-#define	WT_STAT_CONN_CACHE_HAZARD_WALKS			1053
+#define	WT_STAT_CONN_CACHE_HAZARD_WALKS			1055
 /*! cache: hazard pointer maximum array length */
-#define	WT_STAT_CONN_CACHE_HAZARD_MAX			1054
+#define	WT_STAT_CONN_CACHE_HAZARD_MAX			1056
 /*! cache: in-memory page passed criteria to be split */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1055
+#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1057
 /*! cache: in-memory page splits */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1056
+#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1058
 /*! cache: internal pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_INTERNAL		1057
+#define	WT_STAT_CONN_CACHE_EVICTION_INTERNAL		1059
 /*! cache: internal pages split during eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL	1058
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL	1060
 /*! cache: leaf pages split during eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF		1059
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF		1061
 /*! cache: lookaside table insert calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1060
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1062
 /*! cache: lookaside table remove calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1061
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1063
 /*! cache: maximum bytes configured */
-#define	WT_STAT_CONN_CACHE_BYTES_MAX			1062
+#define	WT_STAT_CONN_CACHE_BYTES_MAX			1064
 /*! cache: maximum page size at eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_MAXIMUM_PAGE_SIZE	1063
+#define	WT_STAT_CONN_CACHE_EVICTION_MAXIMUM_PAGE_SIZE	1065
 /*! cache: modified pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_DIRTY		1064
+#define	WT_STAT_CONN_CACHE_EVICTION_DIRTY		1066
 /*! cache: modified pages evicted by application threads */
-#define	WT_STAT_CONN_CACHE_EVICTION_APP_DIRTY		1065
+#define	WT_STAT_CONN_CACHE_EVICTION_APP_DIRTY		1067
 /*! cache: overflow pages read into cache */
-#define	WT_STAT_CONN_CACHE_READ_OVERFLOW		1066
+#define	WT_STAT_CONN_CACHE_READ_OVERFLOW		1068
 /*! cache: overflow values cached in memory */
-#define	WT_STAT_CONN_CACHE_OVERFLOW_VALUE		1067
+#define	WT_STAT_CONN_CACHE_OVERFLOW_VALUE		1069
 /*! cache: page split during eviction deepened the tree */
-#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1068
+#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1070
 /*! cache: page written requiring lookaside records */
-#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1069
+#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1071
 /*! cache: pages currently held in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1070
+#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1072
 /*! cache: pages evicted because they exceeded the in-memory maximum */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1071
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1073
 /*! cache: pages evicted because they had chains of deleted items */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1072
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1074
 /*! cache: pages evicted by application threads */
-#define	WT_STAT_CONN_CACHE_EVICTION_APP			1073
+#define	WT_STAT_CONN_CACHE_EVICTION_APP			1075
 /*! cache: pages queued for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED	1074
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED	1076
 /*! cache: pages queued for urgent eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_URGENT	1075
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_URGENT	1077
 /*! cache: pages queued for urgent eviction during walk */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST	1076
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST	1078
 /*! cache: pages read into cache */
-#define	WT_STAT_CONN_CACHE_READ				1077
+#define	WT_STAT_CONN_CACHE_READ				1079
 /*! cache: pages read into cache requiring lookaside entries */
-#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1078
+#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1080
 /*! cache: pages requested from the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_REQUESTED		1079
+#define	WT_STAT_CONN_CACHE_PAGES_REQUESTED		1081
 /*! cache: pages seen by eviction walk */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN		1080
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN		1082
 /*! cache: pages selected for eviction unable to be evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1081
+#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1083
 /*! cache: pages walked for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1082
+#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1084
 /*! cache: pages written from cache */
-#define	WT_STAT_CONN_CACHE_WRITE			1083
+#define	WT_STAT_CONN_CACHE_WRITE			1085
 /*! cache: pages written requiring in-memory restoration */
-#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1084
+#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1086
 /*! cache: percentage overhead */
-#define	WT_STAT_CONN_CACHE_OVERHEAD			1085
+#define	WT_STAT_CONN_CACHE_OVERHEAD			1087
 /*! cache: tracked bytes belonging to internal pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1086
+#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1088
 /*! cache: tracked bytes belonging to leaf pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1087
+#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1089
 /*! cache: tracked dirty bytes in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1088
+#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1090
 /*! cache: tracked dirty pages in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1089
+#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1091
 /*! cache: unmodified pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1090
+#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1092
 /*! connection: auto adjusting condition resets */
-#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1091
+#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1093
 /*! connection: auto adjusting condition wait calls */
-#define	WT_STAT_CONN_COND_AUTO_WAIT			1092
+#define	WT_STAT_CONN_COND_AUTO_WAIT			1094
 /*! connection: files currently open */
-#define	WT_STAT_CONN_FILE_OPEN				1093
+#define	WT_STAT_CONN_FILE_OPEN				1095
 /*! connection: memory allocations */
-#define	WT_STAT_CONN_MEMORY_ALLOCATION			1094
+#define	WT_STAT_CONN_MEMORY_ALLOCATION			1096
 /*! connection: memory frees */
-#define	WT_STAT_CONN_MEMORY_FREE			1095
+#define	WT_STAT_CONN_MEMORY_FREE			1097
 /*! connection: memory re-allocations */
-#define	WT_STAT_CONN_MEMORY_GROW			1096
+#define	WT_STAT_CONN_MEMORY_GROW			1098
 /*! connection: pthread mutex condition wait calls */
-#define	WT_STAT_CONN_COND_WAIT				1097
+#define	WT_STAT_CONN_COND_WAIT				1099
 /*! connection: pthread mutex shared lock read-lock calls */
-#define	WT_STAT_CONN_RWLOCK_READ			1098
+#define	WT_STAT_CONN_RWLOCK_READ			1100
 /*! connection: pthread mutex shared lock write-lock calls */
-#define	WT_STAT_CONN_RWLOCK_WRITE			1099
+#define	WT_STAT_CONN_RWLOCK_WRITE			1101
 /*! connection: total fsync I/Os */
-#define	WT_STAT_CONN_FSYNC_IO				1100
+#define	WT_STAT_CONN_FSYNC_IO				1102
 /*! connection: total read I/Os */
-#define	WT_STAT_CONN_READ_IO				1101
+#define	WT_STAT_CONN_READ_IO				1103
 /*! connection: total write I/Os */
-#define	WT_STAT_CONN_WRITE_IO				1102
+#define	WT_STAT_CONN_WRITE_IO				1104
 /*! cursor: cursor create calls */
-#define	WT_STAT_CONN_CURSOR_CREATE			1103
+#define	WT_STAT_CONN_CURSOR_CREATE			1105
 /*! cursor: cursor insert calls */
-#define	WT_STAT_CONN_CURSOR_INSERT			1104
+#define	WT_STAT_CONN_CURSOR_INSERT			1106
 /*! cursor: cursor next calls */
-#define	WT_STAT_CONN_CURSOR_NEXT			1105
+#define	WT_STAT_CONN_CURSOR_NEXT			1107
 /*! cursor: cursor prev calls */
-#define	WT_STAT_CONN_CURSOR_PREV			1106
+#define	WT_STAT_CONN_CURSOR_PREV			1108
 /*! cursor: cursor remove calls */
-#define	WT_STAT_CONN_CURSOR_REMOVE			1107
+#define	WT_STAT_CONN_CURSOR_REMOVE			1109
 /*! cursor: cursor reset calls */
-#define	WT_STAT_CONN_CURSOR_RESET			1108
+#define	WT_STAT_CONN_CURSOR_RESET			1110
 /*! cursor: cursor restarted searches */
-#define	WT_STAT_CONN_CURSOR_RESTART			1109
+#define	WT_STAT_CONN_CURSOR_RESTART			1111
 /*! cursor: cursor search calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH			1110
+#define	WT_STAT_CONN_CURSOR_SEARCH			1112
 /*! cursor: cursor search near calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1111
+#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1113
 /*! cursor: cursor update calls */
-#define	WT_STAT_CONN_CURSOR_UPDATE			1112
+#define	WT_STAT_CONN_CURSOR_UPDATE			1114
 /*! cursor: truncate calls */
-#define	WT_STAT_CONN_CURSOR_TRUNCATE			1113
+#define	WT_STAT_CONN_CURSOR_TRUNCATE			1115
 /*! data-handle: connection data handles currently active */
-#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1114
+#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1116
 /*! data-handle: connection sweep candidate became referenced */
-#define	WT_STAT_CONN_DH_SWEEP_REF			1115
+#define	WT_STAT_CONN_DH_SWEEP_REF			1117
 /*! data-handle: connection sweep dhandles closed */
-#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1116
+#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1118
 /*! data-handle: connection sweep dhandles removed from hash list */
-#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1117
+#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1119
 /*! data-handle: connection sweep time-of-death sets */
-#define	WT_STAT_CONN_DH_SWEEP_TOD			1118
+#define	WT_STAT_CONN_DH_SWEEP_TOD			1120
 /*! data-handle: connection sweeps */
-#define	WT_STAT_CONN_DH_SWEEPS				1119
+#define	WT_STAT_CONN_DH_SWEEPS				1121
 /*! data-handle: session dhandles swept */
-#define	WT_STAT_CONN_DH_SESSION_HANDLES			1120
+#define	WT_STAT_CONN_DH_SESSION_HANDLES			1122
 /*! data-handle: session sweep attempts */
-#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1121
+#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1123
 /*! log: busy returns attempting to switch slots */
-#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1122
+#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1124
 /*! log: consolidated slot closures */
-#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1123
+#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1125
 /*! log: consolidated slot join races */
-#define	WT_STAT_CONN_LOG_SLOT_RACES			1124
+#define	WT_STAT_CONN_LOG_SLOT_RACES			1126
 /*! log: consolidated slot join transitions */
-#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1125
+#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1127
 /*! log: consolidated slot joins */
-#define	WT_STAT_CONN_LOG_SLOT_JOINS			1126
+#define	WT_STAT_CONN_LOG_SLOT_JOINS			1128
 /*! log: consolidated slot unbuffered writes */
-#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1127
+#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1129
 /*! log: log bytes of payload data */
-#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1128
+#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1130
 /*! log: log bytes written */
-#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1129
+#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1131
 /*! log: log files manually zero-filled */
-#define	WT_STAT_CONN_LOG_ZERO_FILLS			1130
+#define	WT_STAT_CONN_LOG_ZERO_FILLS			1132
 /*! log: log flush operations */
-#define	WT_STAT_CONN_LOG_FLUSH				1131
+#define	WT_STAT_CONN_LOG_FLUSH				1133
 /*! log: log force write operations */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE			1132
+#define	WT_STAT_CONN_LOG_FORCE_WRITE			1134
 /*! log: log force write operations skipped */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1133
+#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1135
 /*! log: log records compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1134
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1136
 /*! log: log records not compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1135
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1137
 /*! log: log records too small to compress */
-#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1136
+#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1138
 /*! log: log release advances write LSN */
-#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1137
+#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1139
 /*! log: log scan operations */
-#define	WT_STAT_CONN_LOG_SCANS				1138
+#define	WT_STAT_CONN_LOG_SCANS				1140
 /*! log: log scan records requiring two reads */
-#define	WT_STAT_CONN_LOG_SCAN_REREADS			1139
+#define	WT_STAT_CONN_LOG_SCAN_REREADS			1141
 /*! log: log server thread advances write LSN */
-#define	WT_STAT_CONN_LOG_WRITE_LSN			1140
+#define	WT_STAT_CONN_LOG_WRITE_LSN			1142
 /*! log: log server thread write LSN walk skipped */
-#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1141
+#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1143
 /*! log: log sync operations */
-#define	WT_STAT_CONN_LOG_SYNC				1142
+#define	WT_STAT_CONN_LOG_SYNC				1144
 /*! log: log sync time duration (usecs) */
-#define	WT_STAT_CONN_LOG_SYNC_DURATION			1143
+#define	WT_STAT_CONN_LOG_SYNC_DURATION			1145
 /*! log: log sync_dir operations */
-#define	WT_STAT_CONN_LOG_SYNC_DIR			1144
+#define	WT_STAT_CONN_LOG_SYNC_DIR			1146
 /*! log: log sync_dir time duration (usecs) */
-#define	WT_STAT_CONN_LOG_SYNC_DIR_DURATION		1145
+#define	WT_STAT_CONN_LOG_SYNC_DIR_DURATION		1147
 /*! log: log write operations */
-#define	WT_STAT_CONN_LOG_WRITES				1146
+#define	WT_STAT_CONN_LOG_WRITES				1148
 /*! log: logging bytes consolidated */
-#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1147
+#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1149
 /*! log: maximum log file size */
-#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1148
+#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1150
 /*! log: number of pre-allocated log files to create */
-#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1149
+#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1151
 /*! log: pre-allocated log files not ready and missed */
-#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1150
+#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1152
 /*! log: pre-allocated log files prepared */
-#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1151
+#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1153
 /*! log: pre-allocated log files used */
-#define	WT_STAT_CONN_LOG_PREALLOC_USED			1152
+#define	WT_STAT_CONN_LOG_PREALLOC_USED			1154
 /*! log: records processed by log scan */
-#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1153
+#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1155
 /*! log: total in-memory size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1154
+#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1156
 /*! log: total log buffer size */
-#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1155
+#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1157
 /*! log: total size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1156
+#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1158
 /*! log: written slots coalesced */
-#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1157
+#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1159
 /*! log: yields waiting for previous log file close */
-#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1158
+#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1160
 /*! reconciliation: fast-path pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1159
+#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1161
 /*! reconciliation: page reconciliation calls */
-#define	WT_STAT_CONN_REC_PAGES				1160
+#define	WT_STAT_CONN_REC_PAGES				1162
 /*! reconciliation: page reconciliation calls for eviction */
-#define	WT_STAT_CONN_REC_PAGES_EVICTION			1161
+#define	WT_STAT_CONN_REC_PAGES_EVICTION			1163
 /*! reconciliation: pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE			1162
+#define	WT_STAT_CONN_REC_PAGE_DELETE			1164
 /*! reconciliation: split bytes currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1163
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1165
 /*! reconciliation: split objects currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1164
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1166
 /*! session: open cursor count */
-#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1165
+#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1167
 /*! session: open session count */
-#define	WT_STAT_CONN_SESSION_OPEN			1166
+#define	WT_STAT_CONN_SESSION_OPEN			1168
 /*! session: table compact failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_COMPACT_FAIL		1167
+#define	WT_STAT_CONN_SESSION_TABLE_COMPACT_FAIL		1169
 /*! session: table compact successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_COMPACT_SUCCESS	1168
+#define	WT_STAT_CONN_SESSION_TABLE_COMPACT_SUCCESS	1170
 /*! session: table create failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_CREATE_FAIL		1169
+#define	WT_STAT_CONN_SESSION_TABLE_CREATE_FAIL		1171
 /*! session: table create successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_CREATE_SUCCESS	1170
+#define	WT_STAT_CONN_SESSION_TABLE_CREATE_SUCCESS	1172
 /*! session: table drop failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_DROP_FAIL		1171
+#define	WT_STAT_CONN_SESSION_TABLE_DROP_FAIL		1173
 /*! session: table drop successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_DROP_SUCCESS		1172
+#define	WT_STAT_CONN_SESSION_TABLE_DROP_SUCCESS		1174
 /*! session: table rebalance failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_REBALANCE_FAIL	1173
+#define	WT_STAT_CONN_SESSION_TABLE_REBALANCE_FAIL	1175
 /*! session: table rebalance successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_REBALANCE_SUCCESS	1174
+#define	WT_STAT_CONN_SESSION_TABLE_REBALANCE_SUCCESS	1176
 /*! session: table rename failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_RENAME_FAIL		1175
+#define	WT_STAT_CONN_SESSION_TABLE_RENAME_FAIL		1177
 /*! session: table rename successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_RENAME_SUCCESS	1176
+#define	WT_STAT_CONN_SESSION_TABLE_RENAME_SUCCESS	1178
 /*! session: table salvage failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_SALVAGE_FAIL		1177
+#define	WT_STAT_CONN_SESSION_TABLE_SALVAGE_FAIL		1179
 /*! session: table salvage successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_SALVAGE_SUCCESS	1178
+#define	WT_STAT_CONN_SESSION_TABLE_SALVAGE_SUCCESS	1180
 /*! session: table truncate failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_TRUNCATE_FAIL	1179
+#define	WT_STAT_CONN_SESSION_TABLE_TRUNCATE_FAIL	1181
 /*! session: table truncate successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_TRUNCATE_SUCCESS	1180
+#define	WT_STAT_CONN_SESSION_TABLE_TRUNCATE_SUCCESS	1182
 /*! session: table verify failed calls */
-#define	WT_STAT_CONN_SESSION_TABLE_VERIFY_FAIL		1181
+#define	WT_STAT_CONN_SESSION_TABLE_VERIFY_FAIL		1183
 /*! session: table verify successful calls */
-#define	WT_STAT_CONN_SESSION_TABLE_VERIFY_SUCCESS	1182
+#define	WT_STAT_CONN_SESSION_TABLE_VERIFY_SUCCESS	1184
 /*! thread-state: active filesystem fsync calls */
-#define	WT_STAT_CONN_THREAD_FSYNC_ACTIVE		1183
+#define	WT_STAT_CONN_THREAD_FSYNC_ACTIVE		1185
 /*! thread-state: active filesystem read calls */
-#define	WT_STAT_CONN_THREAD_READ_ACTIVE			1184
+#define	WT_STAT_CONN_THREAD_READ_ACTIVE			1186
 /*! thread-state: active filesystem write calls */
-#define	WT_STAT_CONN_THREAD_WRITE_ACTIVE		1185
+#define	WT_STAT_CONN_THREAD_WRITE_ACTIVE		1187
 /*! thread-yield: page acquire busy blocked */
-#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1186
+#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1188
 /*! thread-yield: page acquire eviction blocked */
-#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1187
+#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1189
 /*! thread-yield: page acquire locked blocked */
-#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1188
+#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1190
 /*! thread-yield: page acquire read blocked */
-#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1189
+#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1191
 /*! thread-yield: page acquire time sleeping (usecs) */
-#define	WT_STAT_CONN_PAGE_SLEEP				1190
+#define	WT_STAT_CONN_PAGE_SLEEP				1192
 /*! transaction: number of named snapshots created */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1191
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1193
 /*! transaction: number of named snapshots dropped */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1192
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1194
 /*! transaction: transaction begins */
-#define	WT_STAT_CONN_TXN_BEGIN				1193
+#define	WT_STAT_CONN_TXN_BEGIN				1195
 /*! transaction: transaction checkpoint currently running */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1194
+#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1196
 /*! transaction: transaction checkpoint generation */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1195
+#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1197
 /*! transaction: transaction checkpoint max time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1196
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1198
 /*! transaction: transaction checkpoint min time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1197
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1199
 /*! transaction: transaction checkpoint most recent time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1198
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1200
 /*! transaction: transaction checkpoint scrub dirty target */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TARGET	1199
+#define	WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TARGET	1201
 /*! transaction: transaction checkpoint scrub time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TIME		1200
+#define	WT_STAT_CONN_TXN_CHECKPOINT_SCRUB_TIME		1202
 /*! transaction: transaction checkpoint total time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1201
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1203
 /*! transaction: transaction checkpoints */
-#define	WT_STAT_CONN_TXN_CHECKPOINT			1202
+#define	WT_STAT_CONN_TXN_CHECKPOINT			1204
 /*! transaction: transaction failures due to cache overflow */
-#define	WT_STAT_CONN_TXN_FAIL_CACHE			1203
+#define	WT_STAT_CONN_TXN_FAIL_CACHE			1205
 /*!
  * transaction: transaction fsync calls for checkpoint after allocating
  * the transaction ID
  */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST		1204
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST		1206
 /*!
  * transaction: transaction fsync duration for checkpoint after
  * allocating the transaction ID (usecs)
  */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST_DURATION	1205
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST_DURATION	1207
 /*! transaction: transaction range of IDs currently pinned */
-#define	WT_STAT_CONN_TXN_PINNED_RANGE			1206
+#define	WT_STAT_CONN_TXN_PINNED_RANGE			1208
 /*! transaction: transaction range of IDs currently pinned by a checkpoint */
-#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1207
+#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1209
 /*!
  * transaction: transaction range of IDs currently pinned by named
  * snapshots
  */
-#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1208
+#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1210
 /*! transaction: transaction sync calls */
-#define	WT_STAT_CONN_TXN_SYNC				1209
+#define	WT_STAT_CONN_TXN_SYNC				1211
 /*! transaction: transactions committed */
-#define	WT_STAT_CONN_TXN_COMMIT				1210
+#define	WT_STAT_CONN_TXN_COMMIT				1212
 /*! transaction: transactions rolled back */
-#define	WT_STAT_CONN_TXN_ROLLBACK			1211
+#define	WT_STAT_CONN_TXN_ROLLBACK			1213
 
 /*!
  * @}
diff --git a/src/support/stat.c b/src/support/stat.c
index 81859ef1ca8..7150223e6cb 100644
--- a/src/support/stat.c
+++ b/src/support/stat.c
@@ -559,12 +559,14 @@ static const char * const __stats_connection_desc[] = {
 	"cache: eviction calls to get a page found queue empty",
 	"cache: eviction calls to get a page found queue empty after locking",
 	"cache: eviction currently operating in aggressive mode",
+	"cache: eviction empty score",
 	"cache: eviction server candidate queue empty when topping up",
 	"cache: eviction server candidate queue not empty when topping up",
 	"cache: eviction server evicting pages",
 	"cache: eviction server slept, because we did not make progress with eviction",
 	"cache: eviction server unable to reach eviction goal",
 	"cache: eviction state",
+	"cache: eviction walks abandoned",
 	"cache: eviction worker thread evicting pages",
 	"cache: failed eviction of pages that exceeded the in-memory maximum",
 	"cache: files with active eviction walks",
@@ -801,12 +803,14 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 	stats->cache_eviction_get_ref_empty = 0;
 	stats->cache_eviction_get_ref_empty2 = 0;
 		/* not clearing cache_eviction_aggressive_set */
+		/* not clearing cache_eviction_empty_score */
 	stats->cache_eviction_queue_empty = 0;
 	stats->cache_eviction_queue_not_empty = 0;
 	stats->cache_eviction_server_evicting = 0;
 	stats->cache_eviction_server_slept = 0;
 	stats->cache_eviction_slow = 0;
 		/* not clearing cache_eviction_state */
+	stats->cache_eviction_walks_abandoned = 0;
 	stats->cache_eviction_worker_evicting = 0;
 	stats->cache_eviction_force_fail = 0;
 		/* not clearing cache_eviction_walks_active */
@@ -1041,6 +1045,8 @@ __wt_stat_connection_aggregate(
 	    WT_STAT_READ(from, cache_eviction_get_ref_empty2);
 	to->cache_eviction_aggressive_set +=
 	    WT_STAT_READ(from, cache_eviction_aggressive_set);
+	to->cache_eviction_empty_score +=
+	    WT_STAT_READ(from, cache_eviction_empty_score);
 	to->cache_eviction_queue_empty +=
 	    WT_STAT_READ(from, cache_eviction_queue_empty);
 	to->cache_eviction_queue_not_empty +=
@@ -1051,6 +1057,8 @@ __wt_stat_connection_aggregate(
 	    WT_STAT_READ(from, cache_eviction_server_slept);
 	to->cache_eviction_slow += WT_STAT_READ(from, cache_eviction_slow);
 	to->cache_eviction_state += WT_STAT_READ(from, cache_eviction_state);
+	to->cache_eviction_walks_abandoned +=
+	    WT_STAT_READ(from, cache_eviction_walks_abandoned);
 	to->cache_eviction_worker_evicting +=
 	    WT_STAT_READ(from, cache_eviction_worker_evicting);
 	to->cache_eviction_force_fail +=
diff --git a/tools/wtstats/stat_data.py b/tools/wtstats/stat_data.py
index 1eb60c9d513..8f47b86a23e 100644
--- a/tools/wtstats/stat_data.py
+++ b/tools/wtstats/stat_data.py
@@ -7,6 +7,7 @@ no_scale_per_second_list = [
     'cache: bytes currently in the cache',
     'cache: bytes not belonging to page images in the cache',
     'cache: eviction currently operating in aggressive mode',
+    'cache: eviction empty score',
     'cache: eviction state',
     'cache: files with active eviction walks',
     'cache: hazard pointer maximum array length',
@@ -103,6 +104,7 @@ no_clear_list = [
     'cache: bytes currently in the cache',
     'cache: bytes not belonging to page images in the cache',
     'cache: eviction currently operating in aggressive mode',
+    'cache: eviction empty score',
     'cache: eviction state',
     'cache: files with active eviction walks',
     'cache: maximum bytes configured',