SERVER-24580 Add more eviction stats to track efficiency. (#2830)

(cherry picked from commit 1f4aaa4490a82cf947afdabbb9214ee5b1850d13)

8 files changed, 208 insertions, 134 deletions

diff --git a/dist/s_string.ok b/dist/s_string.ok
index 06173fe978c..631f2a5c909 100644
--- a/dist/s_string.ok
+++ b/dist/s_string.ok
@@ -1068,6 +1068,7 @@ unescaped
 unicode
 uninstantiated
 unistd
+unlink
 unlinked
 unmap
 unmarshall
diff --git a/dist/stat_data.py b/dist/stat_data.py
index bd951e64999..790cf043357 100644
--- a/dist/stat_data.py
+++ b/dist/stat_data.py
@@ -162,6 +162,7 @@ connection_stats = [
     CacheStat('cache_bytes_write', 'bytes written from cache', 'size'),
     CacheStat('cache_eviction_aggressive_set', 'eviction currently operating in aggressive mode', 'no_clear,no_scale'),
     CacheStat('cache_eviction_app', 'pages evicted by application threads'),
+    CacheStat('cache_eviction_app_dirty', 'modified pages evicted by application threads'),
     CacheStat('cache_eviction_checkpoint', 'checkpoint blocked page eviction'),
     CacheStat('cache_eviction_clean', 'unmodified pages evicted'),
     CacheStat('cache_eviction_deepen', 'page split during eviction deepened the tree'),
@@ -173,6 +174,9 @@ connection_stats = [
     CacheStat('cache_eviction_hazard', 'hazard pointer blocked page eviction'),
     CacheStat('cache_eviction_internal', 'internal pages evicted'),
     CacheStat('cache_eviction_maximum_page_size', 'maximum page size at eviction', 'no_clear,no_scale,size'),
+    CacheStat('cache_eviction_pages_queued', 'pages queued for eviction'),
+    CacheStat('cache_eviction_pages_queued_oldest', 'pages queued for urgent eviction'),
+    CacheStat('cache_eviction_pages_seen', 'pages seen by eviction walk'),
     CacheStat('cache_eviction_queue_empty', 'eviction server candidate queue empty when topping up'),
     CacheStat('cache_eviction_queue_not_empty', 'eviction server candidate queue not empty when topping up'),
     CacheStat('cache_eviction_server_evicting', 'eviction server evicting pages'),
@@ -181,6 +185,8 @@ connection_stats = [
     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_walks_active', 'files with active eviction walks', 'no_clear,no_scale,size'),
+    CacheStat('cache_eviction_walks_started', 'files with new eviction walks started'),
     CacheStat('cache_eviction_worker_evicting', 'eviction worker thread evicting pages'),
     CacheStat('cache_inmem_split', 'in-memory page splits'),
     CacheStat('cache_inmem_splittable', 'in-memory page passed criteria to be split'),
diff --git a/src/conn/conn_cache.c b/src/conn/conn_cache.c
index 9a2c394e9a6..9dfd1cdcbfa 100644
--- a/src/conn/conn_cache.c
+++ b/src/conn/conn_cache.c
@@ -217,6 +217,14 @@ __wt_cache_stats_update(WT_SESSION_IMPL *session)
 	WT_STAT_SET(
 	    session, stats, cache_bytes_overflow, cache->bytes_overflow);
 	WT_STAT_SET(session, stats, cache_bytes_leaf, leaf);
+
+	/*
+	 * The number of files with active walks ~= number of hazard pointers
+	 * in the walk session.  Note: reading without locking.
+	 */
+	if (conn->evict_session != NULL)
+		WT_STAT_SET(session, stats, cache_eviction_walks_active,
+		    conn->evict_session->nhazard);
 }
 
 /*
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index a2bf1d77dd0..0fd3c069eb0 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -1270,7 +1270,7 @@ __evict_walk_file(WT_SESSION_IMPL *session, u_int *slotp)
 	WT_PAGE *page;
 	WT_PAGE_MODIFY *mod;
 	WT_REF *ref;
-	uint64_t pages_walked;
+	uint64_t pages_seen, refs_walked;
 	uint32_t walk_flags;
 	int internal_pages, restarts;
 	bool enough, modified;
@@ -1304,17 +1304,21 @@ __evict_walk_file(WT_SESSION_IMPL *session, u_int *slotp)
 	 * 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_walked = 0;
+	for (evict = start, pages_seen = refs_walked = 0;
 	    evict < end && !enough && (ret == 0 || ret == WT_NOTFOUND);
 	    ret = __wt_tree_walk_count(
-	    session, &btree->evict_ref, &pages_walked, walk_flags)) {
-		enough = pages_walked > cache->evict_max_refs_per_file;
+	    session, &btree->evict_ref, &refs_walked, walk_flags)) {
+		enough = refs_walked > cache->evict_max_refs_per_file;
 		if ((ref = btree->evict_ref) == NULL) {
 			if (++restarts == 2 || enough)
 				break;
+			WT_STAT_FAST_CONN_INCR(
+			    session, cache_eviction_walks_started);
 			continue;
 		}
 
+		++pages_seen;
+
 		/* Ignore root pages entirely. */
 		if (__wt_ref_is_root(ref))
 			continue;
@@ -1342,9 +1346,13 @@ __evict_walk_file(WT_SESSION_IMPL *session, u_int *slotp)
 		}
 
 		/* Pages we no longer need (clean or dirty), are found money. */
+		if (page->read_gen == WT_READGEN_OLDEST) {
+			WT_STAT_FAST_CONN_INCR(
+			    session, cache_eviction_pages_queued_oldest);
+			goto fast;
+		}
 		if (__wt_page_is_empty(page) ||
-		    F_ISSET(session->dhandle, WT_DHANDLE_DEAD) ||
-		    page->read_gen == WT_READGEN_OLDEST)
+		    F_ISSET(session->dhandle, WT_DHANDLE_DEAD))
 			goto fast;
 
 		/* Skip clean pages if appropriate. */
@@ -1410,6 +1418,8 @@ fast:		/* If the page can't be evicted, give up. */
 	WT_RET_NOTFOUND_OK(ret);
 
 	*slotp += (u_int)(evict - start);
+	WT_STAT_FAST_CONN_INCRV(
+	    session, cache_eviction_pages_queued, (u_int)(evict - start));
 
 	/*
 	 * If we happen to end up on the root page, clear it.  We have to track
@@ -1428,10 +1438,11 @@ fast:		/* If the page can't be evicted, give up. */
 		else if (ref->page->read_gen == WT_READGEN_OLDEST)
 			WT_RET_NOTFOUND_OK(__wt_tree_walk_count(
 			    session, &btree->evict_ref,
-			    &pages_walked, walk_flags));
+			    &refs_walked, walk_flags));
 	}
 
-	WT_STAT_FAST_CONN_INCRV(session, cache_eviction_walk, pages_walked);
+	WT_STAT_FAST_CONN_INCRV(session, cache_eviction_walk, refs_walked);
+	WT_STAT_FAST_CONN_INCRV(session, cache_eviction_pages_seen, pages_seen);
 
 	return (0);
 }
@@ -1547,8 +1558,12 @@ __evict_page(WT_SESSION_IMPL *session, bool is_server)
 		else
 			WT_STAT_FAST_CONN_INCR(
 			    session, cache_eviction_worker_evicting);
-	} else
+	} else {
+		if (__wt_page_is_modified(ref->page))
+			WT_STAT_FAST_CONN_INCR(
+			    session, cache_eviction_app_dirty);
 		WT_STAT_FAST_CONN_INCR(session, cache_eviction_app);
+	}
 
 	/*
 	 * In case something goes wrong, don't pick the same set of pages every
diff --git a/src/include/stat.h b/src/include/stat.h
index f9170dc1a79..a72da020766 100644
--- a/src/include/stat.h
+++ b/src/include/stat.h
@@ -269,6 +269,8 @@ struct __wt_connection_stats {
 	int64_t cache_eviction_slow;
 	int64_t cache_eviction_worker_evicting;
 	int64_t cache_eviction_force_fail;
+	int64_t cache_eviction_walks_active;
+	int64_t cache_eviction_walks_started;
 	int64_t cache_eviction_hazard;
 	int64_t cache_inmem_splittable;
 	int64_t cache_inmem_split;
@@ -280,14 +282,18 @@ struct __wt_connection_stats {
 	int64_t cache_bytes_max;
 	int64_t cache_eviction_maximum_page_size;
 	int64_t cache_eviction_dirty;
+	int64_t cache_eviction_app_dirty;
 	int64_t cache_eviction_deepen;
 	int64_t cache_write_lookaside;
 	int64_t cache_pages_inuse;
 	int64_t cache_eviction_force;
 	int64_t cache_eviction_force_delete;
 	int64_t cache_eviction_app;
+	int64_t cache_eviction_pages_queued;
+	int64_t cache_eviction_pages_queued_oldest;
 	int64_t cache_read;
 	int64_t cache_read_lookaside;
+	int64_t cache_eviction_pages_seen;
 	int64_t cache_eviction_fail;
 	int64_t cache_eviction_walk;
 	int64_t cache_write;
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index 5c2efad77e0..60f725b3d3d 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -3787,257 +3787,269 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_CONN_CACHE_EVICTION_WORKER_EVICTING	1040
 /*! cache: failed eviction of pages that exceeded the in-memory maximum */
 #define	WT_STAT_CONN_CACHE_EVICTION_FORCE_FAIL		1041
+/*! cache: files with active eviction walks */
+#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_ACTIVE	1042
+/*! cache: files with new eviction walks started */
+#define	WT_STAT_CONN_CACHE_EVICTION_WALKS_STARTED	1043
 /*! cache: hazard pointer blocked page eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_HAZARD		1042
+#define	WT_STAT_CONN_CACHE_EVICTION_HAZARD		1044
 /*! cache: in-memory page passed criteria to be split */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1043
+#define	WT_STAT_CONN_CACHE_INMEM_SPLITTABLE		1045
 /*! cache: in-memory page splits */
-#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1044
+#define	WT_STAT_CONN_CACHE_INMEM_SPLIT			1046
 /*! cache: internal pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_INTERNAL		1045
+#define	WT_STAT_CONN_CACHE_EVICTION_INTERNAL		1047
 /*! cache: internal pages split during eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL	1046
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_INTERNAL	1048
 /*! cache: leaf pages split during eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF		1047
+#define	WT_STAT_CONN_CACHE_EVICTION_SPLIT_LEAF		1049
 /*! cache: lookaside table insert calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1048
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_INSERT		1050
 /*! cache: lookaside table remove calls */
-#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1049
+#define	WT_STAT_CONN_CACHE_LOOKASIDE_REMOVE		1051
 /*! cache: maximum bytes configured */
-#define	WT_STAT_CONN_CACHE_BYTES_MAX			1050
+#define	WT_STAT_CONN_CACHE_BYTES_MAX			1052
 /*! cache: maximum page size at eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_MAXIMUM_PAGE_SIZE	1051
+#define	WT_STAT_CONN_CACHE_EVICTION_MAXIMUM_PAGE_SIZE	1053
 /*! cache: modified pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_DIRTY		1052
+#define	WT_STAT_CONN_CACHE_EVICTION_DIRTY		1054
+/*! cache: modified pages evicted by application threads */
+#define	WT_STAT_CONN_CACHE_EVICTION_APP_DIRTY		1055
 /*! cache: page split during eviction deepened the tree */
-#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1053
+#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1056
 /*! cache: page written requiring lookaside records */
-#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1054
+#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1057
 /*! cache: pages currently held in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1055
+#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1058
 /*! cache: pages evicted because they exceeded the in-memory maximum */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1056
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1059
 /*! cache: pages evicted because they had chains of deleted items */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1057
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1060
 /*! cache: pages evicted by application threads */
-#define	WT_STAT_CONN_CACHE_EVICTION_APP			1058
+#define	WT_STAT_CONN_CACHE_EVICTION_APP			1061
+/*! cache: pages queued for eviction */
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED	1062
+/*! cache: pages queued for urgent eviction */
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST	1063
 /*! cache: pages read into cache */
-#define	WT_STAT_CONN_CACHE_READ				1059
+#define	WT_STAT_CONN_CACHE_READ				1064
 /*! cache: pages read into cache requiring lookaside entries */
-#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1060
+#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1065
+/*! cache: pages seen by eviction walk */
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN		1066
 /*! cache: pages selected for eviction unable to be evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1061
+#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1067
 /*! cache: pages walked for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1062
+#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1068
 /*! cache: pages written from cache */
-#define	WT_STAT_CONN_CACHE_WRITE			1063
+#define	WT_STAT_CONN_CACHE_WRITE			1069
 /*! cache: pages written requiring in-memory restoration */
-#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1064
+#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1070
 /*! cache: percentage overhead */
-#define	WT_STAT_CONN_CACHE_OVERHEAD			1065
+#define	WT_STAT_CONN_CACHE_OVERHEAD			1071
 /*! cache: tracked bytes belonging to internal pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1066
+#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1072
 /*! cache: tracked bytes belonging to leaf pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1067
+#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1073
 /*! cache: tracked bytes belonging to overflow pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_OVERFLOW		1068
+#define	WT_STAT_CONN_CACHE_BYTES_OVERFLOW		1074
 /*! cache: tracked dirty bytes in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1069
+#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1075
 /*! cache: tracked dirty pages in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1070
+#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1076
 /*! cache: unmodified pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1071
+#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1077
 /*! connection: auto adjusting condition resets */
-#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1072
+#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1078
 /*! connection: auto adjusting condition wait calls */
-#define	WT_STAT_CONN_COND_AUTO_WAIT			1073
+#define	WT_STAT_CONN_COND_AUTO_WAIT			1079
 /*! connection: files currently open */
-#define	WT_STAT_CONN_FILE_OPEN				1074
+#define	WT_STAT_CONN_FILE_OPEN				1080
 /*! connection: memory allocations */
-#define	WT_STAT_CONN_MEMORY_ALLOCATION			1075
+#define	WT_STAT_CONN_MEMORY_ALLOCATION			1081
 /*! connection: memory frees */
-#define	WT_STAT_CONN_MEMORY_FREE			1076
+#define	WT_STAT_CONN_MEMORY_FREE			1082
 /*! connection: memory re-allocations */
-#define	WT_STAT_CONN_MEMORY_GROW			1077
+#define	WT_STAT_CONN_MEMORY_GROW			1083
 /*! connection: pthread mutex condition wait calls */
-#define	WT_STAT_CONN_COND_WAIT				1078
+#define	WT_STAT_CONN_COND_WAIT				1084
 /*! connection: pthread mutex shared lock read-lock calls */
-#define	WT_STAT_CONN_RWLOCK_READ			1079
+#define	WT_STAT_CONN_RWLOCK_READ			1085
 /*! connection: pthread mutex shared lock write-lock calls */
-#define	WT_STAT_CONN_RWLOCK_WRITE			1080
+#define	WT_STAT_CONN_RWLOCK_WRITE			1086
 /*! connection: total read I/Os */
-#define	WT_STAT_CONN_READ_IO				1081
+#define	WT_STAT_CONN_READ_IO				1087
 /*! connection: total write I/Os */
-#define	WT_STAT_CONN_WRITE_IO				1082
+#define	WT_STAT_CONN_WRITE_IO				1088
 /*! cursor: cursor create calls */
-#define	WT_STAT_CONN_CURSOR_CREATE			1083
+#define	WT_STAT_CONN_CURSOR_CREATE			1089
 /*! cursor: cursor insert calls */
-#define	WT_STAT_CONN_CURSOR_INSERT			1084
+#define	WT_STAT_CONN_CURSOR_INSERT			1090
 /*! cursor: cursor next calls */
-#define	WT_STAT_CONN_CURSOR_NEXT			1085
+#define	WT_STAT_CONN_CURSOR_NEXT			1091
 /*! cursor: cursor prev calls */
-#define	WT_STAT_CONN_CURSOR_PREV			1086
+#define	WT_STAT_CONN_CURSOR_PREV			1092
 /*! cursor: cursor remove calls */
-#define	WT_STAT_CONN_CURSOR_REMOVE			1087
+#define	WT_STAT_CONN_CURSOR_REMOVE			1093
 /*! cursor: cursor reset calls */
-#define	WT_STAT_CONN_CURSOR_RESET			1088
+#define	WT_STAT_CONN_CURSOR_RESET			1094
 /*! cursor: cursor restarted searches */
-#define	WT_STAT_CONN_CURSOR_RESTART			1089
+#define	WT_STAT_CONN_CURSOR_RESTART			1095
 /*! cursor: cursor search calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH			1090
+#define	WT_STAT_CONN_CURSOR_SEARCH			1096
 /*! cursor: cursor search near calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1091
+#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1097
 /*! cursor: cursor update calls */
-#define	WT_STAT_CONN_CURSOR_UPDATE			1092
+#define	WT_STAT_CONN_CURSOR_UPDATE			1098
 /*! cursor: truncate calls */
-#define	WT_STAT_CONN_CURSOR_TRUNCATE			1093
+#define	WT_STAT_CONN_CURSOR_TRUNCATE			1099
 /*! data-handle: connection data handles currently active */
-#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1094
+#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1100
 /*! data-handle: connection sweep candidate became referenced */
-#define	WT_STAT_CONN_DH_SWEEP_REF			1095
+#define	WT_STAT_CONN_DH_SWEEP_REF			1101
 /*! data-handle: connection sweep dhandles closed */
-#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1096
+#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1102
 /*! data-handle: connection sweep dhandles removed from hash list */
-#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1097
+#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1103
 /*! data-handle: connection sweep time-of-death sets */
-#define	WT_STAT_CONN_DH_SWEEP_TOD			1098
+#define	WT_STAT_CONN_DH_SWEEP_TOD			1104
 /*! data-handle: connection sweeps */
-#define	WT_STAT_CONN_DH_SWEEPS				1099
+#define	WT_STAT_CONN_DH_SWEEPS				1105
 /*! data-handle: session dhandles swept */
-#define	WT_STAT_CONN_DH_SESSION_HANDLES			1100
+#define	WT_STAT_CONN_DH_SESSION_HANDLES			1106
 /*! data-handle: session sweep attempts */
-#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1101
+#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1107
 /*! log: busy returns attempting to switch slots */
-#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1102
+#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1108
 /*! log: consolidated slot closures */
-#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1103
+#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1109
 /*! log: consolidated slot join races */
-#define	WT_STAT_CONN_LOG_SLOT_RACES			1104
+#define	WT_STAT_CONN_LOG_SLOT_RACES			1110
 /*! log: consolidated slot join transitions */
-#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1105
+#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1111
 /*! log: consolidated slot joins */
-#define	WT_STAT_CONN_LOG_SLOT_JOINS			1106
+#define	WT_STAT_CONN_LOG_SLOT_JOINS			1112
 /*! log: consolidated slot unbuffered writes */
-#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1107
+#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1113
 /*! log: log bytes of payload data */
-#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1108
+#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1114
 /*! log: log bytes written */
-#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1109
+#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1115
 /*! log: log files manually zero-filled */
-#define	WT_STAT_CONN_LOG_ZERO_FILLS			1110
+#define	WT_STAT_CONN_LOG_ZERO_FILLS			1116
 /*! log: log flush operations */
-#define	WT_STAT_CONN_LOG_FLUSH				1111
+#define	WT_STAT_CONN_LOG_FLUSH				1117
 /*! log: log force write operations */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE			1112
+#define	WT_STAT_CONN_LOG_FORCE_WRITE			1118
 /*! log: log force write operations skipped */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1113
+#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1119
 /*! log: log records compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1114
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1120
 /*! log: log records not compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1115
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1121
 /*! log: log records too small to compress */
-#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1116
+#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1122
 /*! log: log release advances write LSN */
-#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1117
+#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1123
 /*! log: log scan operations */
-#define	WT_STAT_CONN_LOG_SCANS				1118
+#define	WT_STAT_CONN_LOG_SCANS				1124
 /*! log: log scan records requiring two reads */
-#define	WT_STAT_CONN_LOG_SCAN_REREADS			1119
+#define	WT_STAT_CONN_LOG_SCAN_REREADS			1125
 /*! log: log server thread advances write LSN */
-#define	WT_STAT_CONN_LOG_WRITE_LSN			1120
+#define	WT_STAT_CONN_LOG_WRITE_LSN			1126
 /*! log: log server thread write LSN walk skipped */
-#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1121
+#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1127
 /*! log: log sync operations */
-#define	WT_STAT_CONN_LOG_SYNC				1122
+#define	WT_STAT_CONN_LOG_SYNC				1128
 /*! log: log sync_dir operations */
-#define	WT_STAT_CONN_LOG_SYNC_DIR			1123
+#define	WT_STAT_CONN_LOG_SYNC_DIR			1129
 /*! log: log write operations */
-#define	WT_STAT_CONN_LOG_WRITES				1124
+#define	WT_STAT_CONN_LOG_WRITES				1130
 /*! log: logging bytes consolidated */
-#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1125
+#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1131
 /*! log: maximum log file size */
-#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1126
+#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1132
 /*! log: number of pre-allocated log files to create */
-#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1127
+#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1133
 /*! log: pre-allocated log files not ready and missed */
-#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1128
+#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1134
 /*! log: pre-allocated log files prepared */
-#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1129
+#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1135
 /*! log: pre-allocated log files used */
-#define	WT_STAT_CONN_LOG_PREALLOC_USED			1130
+#define	WT_STAT_CONN_LOG_PREALLOC_USED			1136
 /*! log: records processed by log scan */
-#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1131
+#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1137
 /*! log: total in-memory size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1132
+#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1138
 /*! log: total log buffer size */
-#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1133
+#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1139
 /*! log: total size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1134
+#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1140
 /*! log: written slots coalesced */
-#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1135
+#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1141
 /*! log: yields waiting for previous log file close */
-#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1136
+#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1142
 /*! reconciliation: fast-path pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1137
+#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1143
 /*! reconciliation: page reconciliation calls */
-#define	WT_STAT_CONN_REC_PAGES				1138
+#define	WT_STAT_CONN_REC_PAGES				1144
 /*! reconciliation: page reconciliation calls for eviction */
-#define	WT_STAT_CONN_REC_PAGES_EVICTION			1139
+#define	WT_STAT_CONN_REC_PAGES_EVICTION			1145
 /*! reconciliation: pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE			1140
+#define	WT_STAT_CONN_REC_PAGE_DELETE			1146
 /*! reconciliation: split bytes currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1141
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1147
 /*! reconciliation: split objects currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1142
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1148
 /*! session: open cursor count */
-#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1143
+#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1149
 /*! session: open session count */
-#define	WT_STAT_CONN_SESSION_OPEN			1144
+#define	WT_STAT_CONN_SESSION_OPEN			1150
 /*! thread-yield: page acquire busy blocked */
-#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1145
+#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1151
 /*! thread-yield: page acquire eviction blocked */
-#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1146
+#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1152
 /*! thread-yield: page acquire locked blocked */
-#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1147
+#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1153
 /*! thread-yield: page acquire read blocked */
-#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1148
+#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1154
 /*! thread-yield: page acquire time sleeping (usecs) */
-#define	WT_STAT_CONN_PAGE_SLEEP				1149
+#define	WT_STAT_CONN_PAGE_SLEEP				1155
 /*! transaction: number of named snapshots created */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1150
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1156
 /*! transaction: number of named snapshots dropped */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1151
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1157
 /*! transaction: transaction begins */
-#define	WT_STAT_CONN_TXN_BEGIN				1152
+#define	WT_STAT_CONN_TXN_BEGIN				1158
 /*! transaction: transaction checkpoint currently running */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1153
+#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1159
 /*! transaction: transaction checkpoint generation */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1154
+#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1160
 /*! transaction: transaction checkpoint max time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1155
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1161
 /*! transaction: transaction checkpoint min time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1156
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1162
 /*! transaction: transaction checkpoint most recent time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1157
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1163
 /*! transaction: transaction checkpoint total time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1158
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1164
 /*! transaction: transaction checkpoints */
-#define	WT_STAT_CONN_TXN_CHECKPOINT			1159
+#define	WT_STAT_CONN_TXN_CHECKPOINT			1165
 /*! transaction: transaction failures due to cache overflow */
-#define	WT_STAT_CONN_TXN_FAIL_CACHE			1160
+#define	WT_STAT_CONN_TXN_FAIL_CACHE			1166
 /*! transaction: transaction range of IDs currently pinned */
-#define	WT_STAT_CONN_TXN_PINNED_RANGE			1161
+#define	WT_STAT_CONN_TXN_PINNED_RANGE			1167
 /*! transaction: transaction range of IDs currently pinned by a checkpoint */
-#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1162
+#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1168
 /*! transaction: transaction range of IDs currently pinned by named
  * snapshots */
-#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1163
+#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1169
 /*! transaction: transaction sync calls */
-#define	WT_STAT_CONN_TXN_SYNC				1164
+#define	WT_STAT_CONN_TXN_SYNC				1170
 /*! transaction: transactions committed */
-#define	WT_STAT_CONN_TXN_COMMIT				1165
+#define	WT_STAT_CONN_TXN_COMMIT				1171
 /*! transaction: transactions rolled back */
-#define	WT_STAT_CONN_TXN_ROLLBACK			1166
+#define	WT_STAT_CONN_TXN_ROLLBACK			1172
 
 /*!
  * @}
diff --git a/src/support/stat.c b/src/support/stat.c
index 2a826eda962..d64915f0250 100644
--- a/src/support/stat.c
+++ b/src/support/stat.c
@@ -551,6 +551,8 @@ static const char * const __stats_connection_desc[] = {
 	"cache: eviction server unable to reach eviction goal",
 	"cache: eviction worker thread evicting pages",
 	"cache: failed eviction of pages that exceeded the in-memory maximum",
+	"cache: files with active eviction walks",
+	"cache: files with new eviction walks started",
 	"cache: hazard pointer blocked page eviction",
 	"cache: in-memory page passed criteria to be split",
 	"cache: in-memory page splits",
@@ -562,14 +564,18 @@ static const char * const __stats_connection_desc[] = {
 	"cache: maximum bytes configured",
 	"cache: maximum page size at eviction",
 	"cache: modified pages evicted",
+	"cache: modified pages evicted by application threads",
 	"cache: page split during eviction deepened the tree",
 	"cache: page written requiring lookaside records",
 	"cache: pages currently held in the cache",
 	"cache: pages evicted because they exceeded the in-memory maximum",
 	"cache: pages evicted because they had chains of deleted items",
 	"cache: pages evicted by application threads",
+	"cache: pages queued for eviction",
+	"cache: pages queued for urgent eviction",
 	"cache: pages read into cache",
 	"cache: pages read into cache requiring lookaside entries",
+	"cache: pages seen by eviction walk",
 	"cache: pages selected for eviction unable to be evicted",
 	"cache: pages walked for eviction",
 	"cache: pages written from cache",
@@ -748,6 +754,8 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 	stats->cache_eviction_slow = 0;
 	stats->cache_eviction_worker_evicting = 0;
 	stats->cache_eviction_force_fail = 0;
+		/* not clearing cache_eviction_walks_active */
+	stats->cache_eviction_walks_started = 0;
 	stats->cache_eviction_hazard = 0;
 	stats->cache_inmem_splittable = 0;
 	stats->cache_inmem_split = 0;
@@ -759,14 +767,18 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 		/* not clearing cache_bytes_max */
 		/* not clearing cache_eviction_maximum_page_size */
 	stats->cache_eviction_dirty = 0;
+	stats->cache_eviction_app_dirty = 0;
 	stats->cache_eviction_deepen = 0;
 	stats->cache_write_lookaside = 0;
 		/* not clearing cache_pages_inuse */
 	stats->cache_eviction_force = 0;
 	stats->cache_eviction_force_delete = 0;
 	stats->cache_eviction_app = 0;
+	stats->cache_eviction_pages_queued = 0;
+	stats->cache_eviction_pages_queued_oldest = 0;
 	stats->cache_read = 0;
 	stats->cache_read_lookaside = 0;
+	stats->cache_eviction_pages_seen = 0;
 	stats->cache_eviction_fail = 0;
 	stats->cache_eviction_walk = 0;
 	stats->cache_write = 0;
@@ -943,6 +955,10 @@ __wt_stat_connection_aggregate(
 	    WT_STAT_READ(from, cache_eviction_worker_evicting);
 	to->cache_eviction_force_fail +=
 	    WT_STAT_READ(from, cache_eviction_force_fail);
+	to->cache_eviction_walks_active +=
+	    WT_STAT_READ(from, cache_eviction_walks_active);
+	to->cache_eviction_walks_started +=
+	    WT_STAT_READ(from, cache_eviction_walks_started);
 	to->cache_eviction_hazard +=
 	    WT_STAT_READ(from, cache_eviction_hazard);
 	to->cache_inmem_splittable +=
@@ -962,6 +978,8 @@ __wt_stat_connection_aggregate(
 	to->cache_eviction_maximum_page_size +=
 	    WT_STAT_READ(from, cache_eviction_maximum_page_size);
 	to->cache_eviction_dirty += WT_STAT_READ(from, cache_eviction_dirty);
+	to->cache_eviction_app_dirty +=
+	    WT_STAT_READ(from, cache_eviction_app_dirty);
 	to->cache_eviction_deepen +=
 	    WT_STAT_READ(from, cache_eviction_deepen);
 	to->cache_write_lookaside +=
@@ -971,8 +989,14 @@ __wt_stat_connection_aggregate(
 	to->cache_eviction_force_delete +=
 	    WT_STAT_READ(from, cache_eviction_force_delete);
 	to->cache_eviction_app += WT_STAT_READ(from, cache_eviction_app);
+	to->cache_eviction_pages_queued +=
+	    WT_STAT_READ(from, cache_eviction_pages_queued);
+	to->cache_eviction_pages_queued_oldest +=
+	    WT_STAT_READ(from, cache_eviction_pages_queued_oldest);
 	to->cache_read += WT_STAT_READ(from, cache_read);
 	to->cache_read_lookaside += WT_STAT_READ(from, cache_read_lookaside);
+	to->cache_eviction_pages_seen +=
+	    WT_STAT_READ(from, cache_eviction_pages_seen);
 	to->cache_eviction_fail += WT_STAT_READ(from, cache_eviction_fail);
 	to->cache_eviction_walk += WT_STAT_READ(from, cache_eviction_walk);
 	to->cache_write += WT_STAT_READ(from, cache_write);
diff --git a/tools/wtstats/stat_data.py b/tools/wtstats/stat_data.py
index c75e4f194dd..05401702083 100644
--- a/tools/wtstats/stat_data.py
+++ b/tools/wtstats/stat_data.py
@@ -5,6 +5,7 @@ no_scale_per_second_list = [
     'async: maximum work queue length',
     'cache: bytes currently in the cache',
     'cache: eviction currently operating in aggressive mode',
+    'cache: files with active eviction walks',
     'cache: maximum bytes configured',
     'cache: maximum page size at eviction',
     'cache: pages currently held in the cache',
@@ -71,6 +72,7 @@ no_clear_list = [
     'async: maximum work queue length',
     'cache: bytes currently in the cache',
     'cache: eviction currently operating in aggressive mode',
+    'cache: files with active eviction walks',
     'cache: maximum bytes configured',
     'cache: maximum page size at eviction',
     'cache: pages currently held in the cache',