WT-2793 Enhance statistics related to overflow values (#2912)

* WT-2793 Remove very long running config.  Rename the one we run.

* Fix overflow stats.  Make 130K overflow test use btree.

* Add line to upgrading doc stating stat field removed.

14 files changed, 173 insertions, 206 deletions

diff --git a/bench/wtperf/runners/overflow-10k-short.wtperf b/bench/wtperf/runners/overflow-10k-short.wtperf
deleted file mode 100644
index 47228079db8..00000000000
--- a/bench/wtperf/runners/overflow-10k-short.wtperf
+++ /dev/null
@@ -1,19 +0,0 @@
-# wtperf options file: simulate riak and a short form of its voxer config.
-# The configuration for the connection and table are from riak and the
-# specification of the data (count, size, threads) is from basho_bench.
-#
-#conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,statistics=(fast,clear),statistics_log=(wait=600)"
-conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,lsm_manager=(worker_thread_max=6)"
-compact=true
-compression="snappy"
-sess_config="isolation=snapshot"
-table_config="internal_page_max=128K,lsm=(bloom_config=(leaf_page_max=8MB),bloom_bit_count=28,bloom_hash_count=19,bloom_oldest=true,chunk_size=100MB),type=lsm,leaf_page_max=16K,os_cache_dirty_max=16MB"
-icount=15000
-key_sz=40
-value_sz=10000
-max_latency=2000
-populate_threads=1
-report_interval=5
-random_value=true
-run_time=300
-threads=((count=10,read=1),(count=10,update=1))
diff --git a/bench/wtperf/runners/overflow-10k.wtperf b/bench/wtperf/runners/overflow-10k.wtperf
index 9b4ed2acaee..5d7eeea9cf2 100644
--- a/bench/wtperf/runners/overflow-10k.wtperf
+++ b/bench/wtperf/runners/overflow-10k.wtperf
@@ -1,9 +1,7 @@
-# wtperf options file: simulate riak and its test1 and test2 configuration
-# The configuration for the connection and table are from riak and the
-# specification of the data (count, size, threads) is from basho_bench.
 #
-#conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,statistics=(fast,clear),statistics_log=(wait=600)"
-conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,lsm_manager=(worker_thread_max=6)"
+# Run with overflow items and LSM.
+#
+conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,lsm_manager=(worker_thread_max=6),statistics=(fast),statistics_log=(wait=10)"
 compact=true
 compression="snappy"
 sess_config="isolation=snapshot"
@@ -13,8 +11,8 @@ key_sz=40
 value_sz=10000
 max_latency=2000
 populate_threads=1
-report_interval=10
+report_interval=5
 random_value=true
-run_time=18000
-sample_interval=10
-threads=((count=20,read=1,update=1))
+run_time=300
+threads=((count=10,read=1),(count=10,update=1))
+warmup=30
diff --git a/bench/wtperf/runners/overflow-130k-short.wtperf b/bench/wtperf/runners/overflow-130k-short.wtperf
deleted file mode 100644
index 83f67062bf8..00000000000
--- a/bench/wtperf/runners/overflow-130k-short.wtperf
+++ /dev/null
@@ -1,19 +0,0 @@
-# wtperf options file: simulate riak and a short form of its voxer config.
-# The configuration for the connection and table are from riak and the
-# specification of the data (count, size, threads) is from basho_bench.
-#
-#conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,statistics=(fast,clear),statistics_log=(wait=600)"
-conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,lsm_manager=(worker_thread_max=6)"
-compact=true
-compression="snappy"
-sess_config="isolation=snapshot"
-table_config="internal_page_max=128K,lsm=(bloom_config=(leaf_page_max=8MB),bloom_bit_count=28,bloom_hash_count=19,bloom_oldest=true,chunk_size=100MB),type=lsm,leaf_page_max=16K,os_cache_dirty_max=16MB"
-icount=15000
-key_sz=40
-value_sz=130000
-max_latency=2000
-populate_threads=1
-report_interval=5
-random_value=true
-run_time=300
-threads=((count=10,read=1),(count=10,update=1))
diff --git a/bench/wtperf/runners/overflow-130k.wtperf b/bench/wtperf/runners/overflow-130k.wtperf
index a3439f0c575..2be01afd08a 100644
--- a/bench/wtperf/runners/overflow-130k.wtperf
+++ b/bench/wtperf/runners/overflow-130k.wtperf
@@ -1,20 +1,18 @@
-# wtperf options file: simulate riak and its test1 and test2 configuration
-# The configuration for the connection and table are from riak and the
-# specification of the data (count, size, threads) is from basho_bench.
 #
-#conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,statistics=(fast,clear),statistics_log=(wait=600)"
-conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,session_max=1024,lsm_manager=(worker_thread_max=6)"
+# Run with very large overflow items and btree.
+#
+conn_config="cache_size=21G,checkpoint_sync=false,mmap=false,statistics=(fast),statistics_log=(wait=10)"
 compact=true
 compression="snappy"
 sess_config="isolation=snapshot"
-table_config="internal_page_max=128K,lsm=(bloom_config=(leaf_page_max=8MB),bloom_bit_count=28,bloom_hash_count=19,bloom_oldest=true,chunk_size=100MB),type=lsm,leaf_page_max=16K,os_cache_dirty_max=16MB"
+table_config="internal_page_max=128K,type=file,leaf_page_max=16K,os_cache_dirty_max=16MB,leaf_value_max=32K"
 icount=15000
 key_sz=40
 value_sz=130000
 max_latency=2000
 populate_threads=1
-report_interval=10
+report_interval=5
 random_value=true
-run_time=18000
-sample_interval=10
-threads=((count=20,read=1,update=1))
+run_time=300
+threads=((count=10,read=1),(count=10,update=1))
+warmup=30
diff --git a/dist/stat_data.py b/dist/stat_data.py
index b7a1caa6701..576a66e981b 100644
--- a/dist/stat_data.py
+++ b/dist/stat_data.py
@@ -175,7 +175,6 @@ connection_stats = [
     CacheStat('cache_bytes_leaf', 'tracked bytes belonging to leaf pages in the cache', 'no_clear,no_scale,size'),
     CacheStat('cache_bytes_max', 'maximum bytes configured', 'no_clear,no_scale,size'),
     CacheStat('cache_bytes_other', 'bytes not belonging to page images in the cache', 'no_clear,no_scale,size'),
-    CacheStat('cache_bytes_overflow', 'tracked bytes belonging to overflow pages in the cache', 'no_clear,no_scale,size'),
     CacheStat('cache_bytes_read', 'bytes read into cache', 'size'),
     CacheStat('cache_bytes_write', 'bytes written from cache', 'size'),
     CacheStat('cache_eviction_aggressive_set', 'eviction currently operating in aggressive mode', 'no_clear,no_scale'),
@@ -218,12 +217,14 @@ connection_stats = [
     CacheStat('cache_inmem_splittable', 'in-memory page passed criteria to be split'),
     CacheStat('cache_lookaside_insert', 'lookaside table insert calls'),
     CacheStat('cache_lookaside_remove', 'lookaside table remove calls'),
+    CacheStat('cache_overflow_value', 'overflow values cached in memory', 'no_scale'),
     CacheStat('cache_overhead', 'percentage overhead', 'no_clear,no_scale'),
     CacheStat('cache_pages_dirty', 'tracked dirty pages in the cache', 'no_clear,no_scale'),
     CacheStat('cache_pages_inuse', 'pages currently held in the cache', 'no_clear,no_scale'),
     CacheStat('cache_pages_requested', 'pages requested from the cache'),
     CacheStat('cache_read', 'pages read into cache'),
     CacheStat('cache_read_lookaside', 'pages read into cache requiring lookaside entries'),
+    CacheStat('cache_read_overflow', 'overflow pages read into cache'),
     CacheStat('cache_write', 'pages written from cache'),
     CacheStat('cache_write_lookaside', 'page written requiring lookaside records'),
     CacheStat('cache_write_restore', 'pages written requiring in-memory restoration'),
diff --git a/src/btree/bt_ovfl.c b/src/btree/bt_ovfl.c
index fbe361e000a..1f080041a23 100644
--- a/src/btree/bt_ovfl.c
+++ b/src/btree/bt_ovfl.c
@@ -33,6 +33,7 @@ __ovfl_read(WT_SESSION_IMPL *session,
 	store->data = WT_PAGE_HEADER_BYTE(btree, dsk);
 	store->size = dsk->u.datalen;
 
+	WT_STAT_FAST_CONN_INCR(session, cache_read_overflow);
 	WT_STAT_FAST_DATA_INCR(session, cache_read_overflow);
 
 	return (0);
@@ -208,6 +209,7 @@ __wt_ovfl_cache(WT_SESSION_IMPL *session,
 	 */
 	if (!visible) {
 		WT_RET(__ovfl_cache(session, page, vpack));
+		WT_STAT_FAST_CONN_INCR(session, cache_overflow_value);
 		WT_STAT_FAST_DATA_INCR(session, cache_overflow_value);
 	}
 
diff --git a/src/conn/conn_cache.c b/src/conn/conn_cache.c
index 4fccac88bc1..960d86f3e13 100644
--- a/src/conn/conn_cache.c
+++ b/src/conn/conn_cache.c
@@ -201,7 +201,7 @@ __wt_cache_stats_update(WT_SESSION_IMPL *session)
 	WT_CACHE *cache;
 	WT_CONNECTION_IMPL *conn;
 	WT_CONNECTION_STATS **stats;
-	uint64_t inuse, leaf, used;
+	uint64_t inuse, leaf;
 
 	conn = S2C(session);
 	cache = conn->cache;
@@ -212,8 +212,8 @@ __wt_cache_stats_update(WT_SESSION_IMPL *session)
 	 * There are races updating the different cache tracking values so
 	 * be paranoid calculating the leaf byte usage.
 	 */
-	used = cache->bytes_overflow + cache->bytes_internal;
-	leaf = inuse > used ? inuse - used : 0;
+	leaf = inuse > cache->bytes_internal ?
+	    inuse - cache->bytes_internal : 0;
 
 	WT_STAT_SET(session, stats, cache_bytes_max, conn->cache_size);
 	WT_STAT_SET(session, stats, cache_bytes_inuse, inuse);
@@ -230,8 +230,6 @@ __wt_cache_stats_update(WT_SESSION_IMPL *session)
 	WT_STAT_SET(session, stats, cache_bytes_leaf, leaf);
 	WT_STAT_SET(
 	    session, stats, cache_bytes_other, __wt_cache_bytes_other(cache));
-	WT_STAT_SET(
-	    session, stats, cache_bytes_overflow, cache->bytes_overflow);
 
 	WT_STAT_SET(session, stats,
 	    cache_eviction_maximum_page_size, cache->evict_max_page_size);
diff --git a/src/docs/upgrading.dox b/src/docs/upgrading.dox
index 4af8482a635..db40f5c2b55 100644
--- a/src/docs/upgrading.dox
+++ b/src/docs/upgrading.dox
@@ -19,6 +19,15 @@ of the path may no longer be specified. Applications depending on the
 ability to set statistics log file names will require modification.
 </dd>
 
+<dt>Deprecated statistics field</dt>
+<dd>
+The connection statistic \c WT_STAT_CONN_CACHE_BYTES_OVERFLOW has been
+removed.  Overflow information is now available in the
+\c WT_STAT_CONN_CACHE_BYTES_OVERFLOW and \c WT_STAT_CONN_CACHE_OVERFLOW_VALUE.
+Applications specifically looking for that statistic will require
+modification.
+</dd>
+
 </dl><hr>
 @section version_280 Upgrading to Version 2.8.0
 <dl>
diff --git a/src/include/btree.i b/src/include/btree.i
index 623ac75c50a..d8676f9ba60 100644
--- a/src/include/btree.i
+++ b/src/include/btree.i
@@ -94,11 +94,9 @@ __wt_cache_page_inmem_incr(WT_SESSION_IMPL *session, WT_PAGE *page, size_t size)
 		(void)__wt_atomic_add64(&cache->bytes_dirty, size);
 		(void)__wt_atomic_addsize(&page->modify->bytes_dirty, size);
 	}
-	/* Track internal and overflow size in cache. */
+	/* Track internal size in cache. */
 	if (WT_PAGE_IS_INTERNAL(page))
 		(void)__wt_atomic_add64(&cache->bytes_internal, size);
-	else if (page->type == WT_PAGE_OVFL)
-		(void)__wt_atomic_add64(&cache->bytes_overflow, size);
 }
 
 /*
@@ -225,13 +223,10 @@ __wt_cache_page_inmem_decr(WT_SESSION_IMPL *session, WT_PAGE *page, size_t size)
 	    session, &page->memory_footprint, size, "WT_PAGE.memory_footprint");
 	if (__wt_page_is_modified(page))
 		__wt_cache_page_byte_dirty_decr(session, page, size);
-	/* Track internal and overflow size in cache. */
+	/* Track internal size in cache. */
 	if (WT_PAGE_IS_INTERNAL(page))
 		__wt_cache_decr_check_uint64(session,
 		    &cache->bytes_internal, size, "WT_CACHE.bytes_internal");
-	else if (page->type == WT_PAGE_OVFL)
-		__wt_cache_decr_check_uint64(session,
-		    &cache->bytes_overflow, size, "WT_CACHE.bytes_overflow");
 }
 
 /*
diff --git a/src/include/cache.h b/src/include/cache.h
index dbc4074330a..b5f09db3732 100644
--- a/src/include/cache.h
+++ b/src/include/cache.h
@@ -82,7 +82,6 @@ struct __wt_cache {
 	uint64_t bytes_inmem;		/* Bytes/pages in memory */
 	uint64_t pages_inmem;
 	uint64_t bytes_internal;	/* Bytes of internal pages */
-	uint64_t bytes_overflow;	/* Bytes of overflow pages */
 	uint64_t bytes_read;		/* Bytes read into memory */
 
 	uint64_t app_waits;		/* User threads waited for cache */
diff --git a/src/include/stat.h b/src/include/stat.h
index 252e6fbb972..d40f1278611 100644
--- a/src/include/stat.h
+++ b/src/include/stat.h
@@ -312,6 +312,8 @@ struct __wt_connection_stats {
 	int64_t cache_eviction_maximum_page_size;
 	int64_t cache_eviction_dirty;
 	int64_t cache_eviction_app_dirty;
+	int64_t cache_read_overflow;
+	int64_t cache_overflow_value;
 	int64_t cache_eviction_deepen;
 	int64_t cache_write_lookaside;
 	int64_t cache_pages_inuse;
@@ -331,7 +333,6 @@ struct __wt_connection_stats {
 	int64_t cache_overhead;
 	int64_t cache_bytes_internal;
 	int64_t cache_bytes_leaf;
-	int64_t cache_bytes_overflow;
 	int64_t cache_bytes_dirty;
 	int64_t cache_pages_dirty;
 	int64_t cache_eviction_clean;
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index 8f1249481eb..5f1754ccffa 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -4322,267 +4322,269 @@ extern int wiredtiger_extension_terminate(WT_CONNECTION *connection);
 #define	WT_STAT_CONN_CACHE_EVICTION_DIRTY		1065
 /*! cache: modified pages evicted by application threads */
 #define	WT_STAT_CONN_CACHE_EVICTION_APP_DIRTY		1066
+/*! cache: overflow pages read into cache */
+#define	WT_STAT_CONN_CACHE_READ_OVERFLOW		1067
+/*! cache: overflow values cached in memory */
+#define	WT_STAT_CONN_CACHE_OVERFLOW_VALUE		1068
 /*! cache: page split during eviction deepened the tree */
-#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1067
+#define	WT_STAT_CONN_CACHE_EVICTION_DEEPEN		1069
 /*! cache: page written requiring lookaside records */
-#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1068
+#define	WT_STAT_CONN_CACHE_WRITE_LOOKASIDE		1070
 /*! cache: pages currently held in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1069
+#define	WT_STAT_CONN_CACHE_PAGES_INUSE			1071
 /*! cache: pages evicted because they exceeded the in-memory maximum */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1070
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE		1072
 /*! cache: pages evicted because they had chains of deleted items */
-#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1071
+#define	WT_STAT_CONN_CACHE_EVICTION_FORCE_DELETE	1073
 /*! cache: pages evicted by application threads */
-#define	WT_STAT_CONN_CACHE_EVICTION_APP			1072
+#define	WT_STAT_CONN_CACHE_EVICTION_APP			1074
 /*! cache: pages queued for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED	1073
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED	1075
 /*! cache: pages queued for urgent eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST	1074
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_QUEUED_OLDEST	1076
 /*! cache: pages read into cache */
-#define	WT_STAT_CONN_CACHE_READ				1075
+#define	WT_STAT_CONN_CACHE_READ				1077
 /*! cache: pages read into cache requiring lookaside entries */
-#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1076
+#define	WT_STAT_CONN_CACHE_READ_LOOKASIDE		1078
 /*! cache: pages requested from the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_REQUESTED		1077
+#define	WT_STAT_CONN_CACHE_PAGES_REQUESTED		1079
 /*! cache: pages seen by eviction walk */
-#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN		1078
+#define	WT_STAT_CONN_CACHE_EVICTION_PAGES_SEEN		1080
 /*! cache: pages selected for eviction unable to be evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1079
+#define	WT_STAT_CONN_CACHE_EVICTION_FAIL		1081
 /*! cache: pages walked for eviction */
-#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1080
+#define	WT_STAT_CONN_CACHE_EVICTION_WALK		1082
 /*! cache: pages written from cache */
-#define	WT_STAT_CONN_CACHE_WRITE			1081
+#define	WT_STAT_CONN_CACHE_WRITE			1083
 /*! cache: pages written requiring in-memory restoration */
-#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1082
+#define	WT_STAT_CONN_CACHE_WRITE_RESTORE		1084
 /*! cache: percentage overhead */
-#define	WT_STAT_CONN_CACHE_OVERHEAD			1083
+#define	WT_STAT_CONN_CACHE_OVERHEAD			1085
 /*! cache: tracked bytes belonging to internal pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1084
+#define	WT_STAT_CONN_CACHE_BYTES_INTERNAL		1086
 /*! cache: tracked bytes belonging to leaf pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1085
-/*! cache: tracked bytes belonging to overflow pages in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_OVERFLOW		1086
+#define	WT_STAT_CONN_CACHE_BYTES_LEAF			1087
 /*! cache: tracked dirty bytes in the cache */
-#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1087
+#define	WT_STAT_CONN_CACHE_BYTES_DIRTY			1088
 /*! cache: tracked dirty pages in the cache */
-#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1088
+#define	WT_STAT_CONN_CACHE_PAGES_DIRTY			1089
 /*! cache: unmodified pages evicted */
-#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1089
+#define	WT_STAT_CONN_CACHE_EVICTION_CLEAN		1090
 /*! connection: auto adjusting condition resets */
-#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1090
+#define	WT_STAT_CONN_COND_AUTO_WAIT_RESET		1091
 /*! connection: auto adjusting condition wait calls */
-#define	WT_STAT_CONN_COND_AUTO_WAIT			1091
+#define	WT_STAT_CONN_COND_AUTO_WAIT			1092
 /*! connection: files currently open */
-#define	WT_STAT_CONN_FILE_OPEN				1092
+#define	WT_STAT_CONN_FILE_OPEN				1093
 /*! connection: memory allocations */
-#define	WT_STAT_CONN_MEMORY_ALLOCATION			1093
+#define	WT_STAT_CONN_MEMORY_ALLOCATION			1094
 /*! connection: memory frees */
-#define	WT_STAT_CONN_MEMORY_FREE			1094
+#define	WT_STAT_CONN_MEMORY_FREE			1095
 /*! connection: memory re-allocations */
-#define	WT_STAT_CONN_MEMORY_GROW			1095
+#define	WT_STAT_CONN_MEMORY_GROW			1096
 /*! connection: pthread mutex condition wait calls */
-#define	WT_STAT_CONN_COND_WAIT				1096
+#define	WT_STAT_CONN_COND_WAIT				1097
 /*! connection: pthread mutex shared lock read-lock calls */
-#define	WT_STAT_CONN_RWLOCK_READ			1097
+#define	WT_STAT_CONN_RWLOCK_READ			1098
 /*! connection: pthread mutex shared lock write-lock calls */
-#define	WT_STAT_CONN_RWLOCK_WRITE			1098
+#define	WT_STAT_CONN_RWLOCK_WRITE			1099
 /*! connection: total fsync I/Os */
-#define	WT_STAT_CONN_FSYNC_IO				1099
+#define	WT_STAT_CONN_FSYNC_IO				1100
 /*! connection: total read I/Os */
-#define	WT_STAT_CONN_READ_IO				1100
+#define	WT_STAT_CONN_READ_IO				1101
 /*! connection: total write I/Os */
-#define	WT_STAT_CONN_WRITE_IO				1101
+#define	WT_STAT_CONN_WRITE_IO				1102
 /*! cursor: cursor create calls */
-#define	WT_STAT_CONN_CURSOR_CREATE			1102
+#define	WT_STAT_CONN_CURSOR_CREATE			1103
 /*! cursor: cursor insert calls */
-#define	WT_STAT_CONN_CURSOR_INSERT			1103
+#define	WT_STAT_CONN_CURSOR_INSERT			1104
 /*! cursor: cursor next calls */
-#define	WT_STAT_CONN_CURSOR_NEXT			1104
+#define	WT_STAT_CONN_CURSOR_NEXT			1105
 /*! cursor: cursor prev calls */
-#define	WT_STAT_CONN_CURSOR_PREV			1105
+#define	WT_STAT_CONN_CURSOR_PREV			1106
 /*! cursor: cursor remove calls */
-#define	WT_STAT_CONN_CURSOR_REMOVE			1106
+#define	WT_STAT_CONN_CURSOR_REMOVE			1107
 /*! cursor: cursor reset calls */
-#define	WT_STAT_CONN_CURSOR_RESET			1107
+#define	WT_STAT_CONN_CURSOR_RESET			1108
 /*! cursor: cursor restarted searches */
-#define	WT_STAT_CONN_CURSOR_RESTART			1108
+#define	WT_STAT_CONN_CURSOR_RESTART			1109
 /*! cursor: cursor search calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH			1109
+#define	WT_STAT_CONN_CURSOR_SEARCH			1110
 /*! cursor: cursor search near calls */
-#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1110
+#define	WT_STAT_CONN_CURSOR_SEARCH_NEAR			1111
 /*! cursor: cursor update calls */
-#define	WT_STAT_CONN_CURSOR_UPDATE			1111
+#define	WT_STAT_CONN_CURSOR_UPDATE			1112
 /*! cursor: truncate calls */
-#define	WT_STAT_CONN_CURSOR_TRUNCATE			1112
+#define	WT_STAT_CONN_CURSOR_TRUNCATE			1113
 /*! data-handle: connection data handles currently active */
-#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1113
+#define	WT_STAT_CONN_DH_CONN_HANDLE_COUNT		1114
 /*! data-handle: connection sweep candidate became referenced */
-#define	WT_STAT_CONN_DH_SWEEP_REF			1114
+#define	WT_STAT_CONN_DH_SWEEP_REF			1115
 /*! data-handle: connection sweep dhandles closed */
-#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1115
+#define	WT_STAT_CONN_DH_SWEEP_CLOSE			1116
 /*! data-handle: connection sweep dhandles removed from hash list */
-#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1116
+#define	WT_STAT_CONN_DH_SWEEP_REMOVE			1117
 /*! data-handle: connection sweep time-of-death sets */
-#define	WT_STAT_CONN_DH_SWEEP_TOD			1117
+#define	WT_STAT_CONN_DH_SWEEP_TOD			1118
 /*! data-handle: connection sweeps */
-#define	WT_STAT_CONN_DH_SWEEPS				1118
+#define	WT_STAT_CONN_DH_SWEEPS				1119
 /*! data-handle: session dhandles swept */
-#define	WT_STAT_CONN_DH_SESSION_HANDLES			1119
+#define	WT_STAT_CONN_DH_SESSION_HANDLES			1120
 /*! data-handle: session sweep attempts */
-#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1120
+#define	WT_STAT_CONN_DH_SESSION_SWEEPS			1121
 /*! log: busy returns attempting to switch slots */
-#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1121
+#define	WT_STAT_CONN_LOG_SLOT_SWITCH_BUSY		1122
 /*! log: consolidated slot closures */
-#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1122
+#define	WT_STAT_CONN_LOG_SLOT_CLOSES			1123
 /*! log: consolidated slot join races */
-#define	WT_STAT_CONN_LOG_SLOT_RACES			1123
+#define	WT_STAT_CONN_LOG_SLOT_RACES			1124
 /*! log: consolidated slot join transitions */
-#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1124
+#define	WT_STAT_CONN_LOG_SLOT_TRANSITIONS		1125
 /*! log: consolidated slot joins */
-#define	WT_STAT_CONN_LOG_SLOT_JOINS			1125
+#define	WT_STAT_CONN_LOG_SLOT_JOINS			1126
 /*! log: consolidated slot unbuffered writes */
-#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1126
+#define	WT_STAT_CONN_LOG_SLOT_UNBUFFERED		1127
 /*! log: log bytes of payload data */
-#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1127
+#define	WT_STAT_CONN_LOG_BYTES_PAYLOAD			1128
 /*! log: log bytes written */
-#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1128
+#define	WT_STAT_CONN_LOG_BYTES_WRITTEN			1129
 /*! log: log files manually zero-filled */
-#define	WT_STAT_CONN_LOG_ZERO_FILLS			1129
+#define	WT_STAT_CONN_LOG_ZERO_FILLS			1130
 /*! log: log flush operations */
-#define	WT_STAT_CONN_LOG_FLUSH				1130
+#define	WT_STAT_CONN_LOG_FLUSH				1131
 /*! log: log force write operations */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE			1131
+#define	WT_STAT_CONN_LOG_FORCE_WRITE			1132
 /*! log: log force write operations skipped */
-#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1132
+#define	WT_STAT_CONN_LOG_FORCE_WRITE_SKIP		1133
 /*! log: log records compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1133
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITES		1134
 /*! log: log records not compressed */
-#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1134
+#define	WT_STAT_CONN_LOG_COMPRESS_WRITE_FAILS		1135
 /*! log: log records too small to compress */
-#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1135
+#define	WT_STAT_CONN_LOG_COMPRESS_SMALL			1136
 /*! log: log release advances write LSN */
-#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1136
+#define	WT_STAT_CONN_LOG_RELEASE_WRITE_LSN		1137
 /*! log: log scan operations */
-#define	WT_STAT_CONN_LOG_SCANS				1137
+#define	WT_STAT_CONN_LOG_SCANS				1138
 /*! log: log scan records requiring two reads */
-#define	WT_STAT_CONN_LOG_SCAN_REREADS			1138
+#define	WT_STAT_CONN_LOG_SCAN_REREADS			1139
 /*! log: log server thread advances write LSN */
-#define	WT_STAT_CONN_LOG_WRITE_LSN			1139
+#define	WT_STAT_CONN_LOG_WRITE_LSN			1140
 /*! log: log server thread write LSN walk skipped */
-#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1140
+#define	WT_STAT_CONN_LOG_WRITE_LSN_SKIP			1141
 /*! log: log sync operations */
-#define	WT_STAT_CONN_LOG_SYNC				1141
+#define	WT_STAT_CONN_LOG_SYNC				1142
 /*! log: log sync time duration (usecs) */
-#define	WT_STAT_CONN_LOG_SYNC_DURATION			1142
+#define	WT_STAT_CONN_LOG_SYNC_DURATION			1143
 /*! log: log sync_dir operations */
-#define	WT_STAT_CONN_LOG_SYNC_DIR			1143
+#define	WT_STAT_CONN_LOG_SYNC_DIR			1144
 /*! log: log sync_dir time duration (usecs) */
-#define	WT_STAT_CONN_LOG_SYNC_DIR_DURATION		1144
+#define	WT_STAT_CONN_LOG_SYNC_DIR_DURATION		1145
 /*! log: log write operations */
-#define	WT_STAT_CONN_LOG_WRITES				1145
+#define	WT_STAT_CONN_LOG_WRITES				1146
 /*! log: logging bytes consolidated */
-#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1146
+#define	WT_STAT_CONN_LOG_SLOT_CONSOLIDATED		1147
 /*! log: maximum log file size */
-#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1147
+#define	WT_STAT_CONN_LOG_MAX_FILESIZE			1148
 /*! log: number of pre-allocated log files to create */
-#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1148
+#define	WT_STAT_CONN_LOG_PREALLOC_MAX			1149
 /*! log: pre-allocated log files not ready and missed */
-#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1149
+#define	WT_STAT_CONN_LOG_PREALLOC_MISSED		1150
 /*! log: pre-allocated log files prepared */
-#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1150
+#define	WT_STAT_CONN_LOG_PREALLOC_FILES			1151
 /*! log: pre-allocated log files used */
-#define	WT_STAT_CONN_LOG_PREALLOC_USED			1151
+#define	WT_STAT_CONN_LOG_PREALLOC_USED			1152
 /*! log: records processed by log scan */
-#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1152
+#define	WT_STAT_CONN_LOG_SCAN_RECORDS			1153
 /*! log: total in-memory size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1153
+#define	WT_STAT_CONN_LOG_COMPRESS_MEM			1154
 /*! log: total log buffer size */
-#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1154
+#define	WT_STAT_CONN_LOG_BUFFER_SIZE			1155
 /*! log: total size of compressed records */
-#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1155
+#define	WT_STAT_CONN_LOG_COMPRESS_LEN			1156
 /*! log: written slots coalesced */
-#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1156
+#define	WT_STAT_CONN_LOG_SLOT_COALESCED			1157
 /*! log: yields waiting for previous log file close */
-#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1157
+#define	WT_STAT_CONN_LOG_CLOSE_YIELDS			1158
 /*! reconciliation: fast-path pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1158
+#define	WT_STAT_CONN_REC_PAGE_DELETE_FAST		1159
 /*! reconciliation: page reconciliation calls */
-#define	WT_STAT_CONN_REC_PAGES				1159
+#define	WT_STAT_CONN_REC_PAGES				1160
 /*! reconciliation: page reconciliation calls for eviction */
-#define	WT_STAT_CONN_REC_PAGES_EVICTION			1160
+#define	WT_STAT_CONN_REC_PAGES_EVICTION			1161
 /*! reconciliation: pages deleted */
-#define	WT_STAT_CONN_REC_PAGE_DELETE			1161
+#define	WT_STAT_CONN_REC_PAGE_DELETE			1162
 /*! reconciliation: split bytes currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1162
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_BYTES		1163
 /*! reconciliation: split objects currently awaiting free */
-#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1163
+#define	WT_STAT_CONN_REC_SPLIT_STASHED_OBJECTS		1164
 /*! session: open cursor count */
-#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1164
+#define	WT_STAT_CONN_SESSION_CURSOR_OPEN		1165
 /*! session: open session count */
-#define	WT_STAT_CONN_SESSION_OPEN			1165
+#define	WT_STAT_CONN_SESSION_OPEN			1166
 /*! thread-state: active filesystem fsync calls */
-#define	WT_STAT_CONN_THREAD_FSYNC_ACTIVE		1166
+#define	WT_STAT_CONN_THREAD_FSYNC_ACTIVE		1167
 /*! thread-state: active filesystem read calls */
-#define	WT_STAT_CONN_THREAD_READ_ACTIVE			1167
+#define	WT_STAT_CONN_THREAD_READ_ACTIVE			1168
 /*! thread-state: active filesystem write calls */
-#define	WT_STAT_CONN_THREAD_WRITE_ACTIVE		1168
+#define	WT_STAT_CONN_THREAD_WRITE_ACTIVE		1169
 /*! thread-yield: page acquire busy blocked */
-#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1169
+#define	WT_STAT_CONN_PAGE_BUSY_BLOCKED			1170
 /*! thread-yield: page acquire eviction blocked */
-#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1170
+#define	WT_STAT_CONN_PAGE_FORCIBLE_EVICT_BLOCKED	1171
 /*! thread-yield: page acquire locked blocked */
-#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1171
+#define	WT_STAT_CONN_PAGE_LOCKED_BLOCKED		1172
 /*! thread-yield: page acquire read blocked */
-#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1172
+#define	WT_STAT_CONN_PAGE_READ_BLOCKED			1173
 /*! thread-yield: page acquire time sleeping (usecs) */
-#define	WT_STAT_CONN_PAGE_SLEEP				1173
+#define	WT_STAT_CONN_PAGE_SLEEP				1174
 /*! transaction: number of named snapshots created */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1174
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_CREATED		1175
 /*! transaction: number of named snapshots dropped */
-#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1175
+#define	WT_STAT_CONN_TXN_SNAPSHOTS_DROPPED		1176
 /*! transaction: transaction begins */
-#define	WT_STAT_CONN_TXN_BEGIN				1176
+#define	WT_STAT_CONN_TXN_BEGIN				1177
 /*! transaction: transaction checkpoint currently running */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1177
+#define	WT_STAT_CONN_TXN_CHECKPOINT_RUNNING		1178
 /*! transaction: transaction checkpoint generation */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1178
+#define	WT_STAT_CONN_TXN_CHECKPOINT_GENERATION		1179
 /*! transaction: transaction checkpoint max time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1179
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MAX		1180
 /*! transaction: transaction checkpoint min time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1180
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_MIN		1181
 /*! transaction: transaction checkpoint most recent time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1181
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_RECENT		1182
 /*! transaction: transaction checkpoint total time (msecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1182
+#define	WT_STAT_CONN_TXN_CHECKPOINT_TIME_TOTAL		1183
 /*! transaction: transaction checkpoints */
-#define	WT_STAT_CONN_TXN_CHECKPOINT			1183
+#define	WT_STAT_CONN_TXN_CHECKPOINT			1184
 /*! transaction: transaction failures due to cache overflow */
-#define	WT_STAT_CONN_TXN_FAIL_CACHE			1184
+#define	WT_STAT_CONN_TXN_FAIL_CACHE			1185
 /*! transaction: transaction fsync calls for checkpoint after allocating
  * the transaction ID */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST		1185
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST		1186
 /*! transaction: transaction fsync calls for checkpoint before allocating
  * the transaction ID */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_PRE		1186
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_PRE		1187
 /*! transaction: transaction fsync duration for checkpoint after
  * allocating the transaction ID (usecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST_DURATION	1187
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_POST_DURATION	1188
 /*! transaction: transaction fsync duration for checkpoint before
  * allocating the transaction ID (usecs) */
-#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_PRE_DURATION	1188
+#define	WT_STAT_CONN_TXN_CHECKPOINT_FSYNC_PRE_DURATION	1189
 /*! transaction: transaction range of IDs currently pinned */
-#define	WT_STAT_CONN_TXN_PINNED_RANGE			1189
+#define	WT_STAT_CONN_TXN_PINNED_RANGE			1190
 /*! transaction: transaction range of IDs currently pinned by a checkpoint */
-#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1190
+#define	WT_STAT_CONN_TXN_PINNED_CHECKPOINT_RANGE	1191
 /*! transaction: transaction range of IDs currently pinned by named
  * snapshots */
-#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1191
+#define	WT_STAT_CONN_TXN_PINNED_SNAPSHOT_RANGE		1192
 /*! transaction: transaction sync calls */
-#define	WT_STAT_CONN_TXN_SYNC				1192
+#define	WT_STAT_CONN_TXN_SYNC				1193
 /*! transaction: transactions committed */
-#define	WT_STAT_CONN_TXN_COMMIT				1193
+#define	WT_STAT_CONN_TXN_COMMIT				1194
 /*! transaction: transactions rolled back */
-#define	WT_STAT_CONN_TXN_ROLLBACK			1194
+#define	WT_STAT_CONN_TXN_ROLLBACK			1195
 
 /*!
  * @}
diff --git a/src/support/stat.c b/src/support/stat.c
index 483d6715a7e..d8d34e051df 100644
--- a/src/support/stat.c
+++ b/src/support/stat.c
@@ -585,6 +585,8 @@ static const char * const __stats_connection_desc[] = {
 	"cache: maximum page size at eviction",
 	"cache: modified pages evicted",
 	"cache: modified pages evicted by application threads",
+	"cache: overflow pages read into cache",
+	"cache: overflow values cached in memory",
 	"cache: page split during eviction deepened the tree",
 	"cache: page written requiring lookaside records",
 	"cache: pages currently held in the cache",
@@ -604,7 +606,6 @@ static const char * const __stats_connection_desc[] = {
 	"cache: percentage overhead",
 	"cache: tracked bytes belonging to internal pages in the cache",
 	"cache: tracked bytes belonging to leaf pages in the cache",
-	"cache: tracked bytes belonging to overflow pages in the cache",
 	"cache: tracked dirty bytes in the cache",
 	"cache: tracked dirty pages in the cache",
 	"cache: unmodified pages evicted",
@@ -810,6 +811,8 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 		/* not clearing cache_eviction_maximum_page_size */
 	stats->cache_eviction_dirty = 0;
 	stats->cache_eviction_app_dirty = 0;
+	stats->cache_read_overflow = 0;
+	stats->cache_overflow_value = 0;
 	stats->cache_eviction_deepen = 0;
 	stats->cache_write_lookaside = 0;
 		/* not clearing cache_pages_inuse */
@@ -829,7 +832,6 @@ __wt_stat_connection_clear_single(WT_CONNECTION_STATS *stats)
 		/* not clearing cache_overhead */
 		/* not clearing cache_bytes_internal */
 		/* not clearing cache_bytes_leaf */
-		/* not clearing cache_bytes_overflow */
 		/* not clearing cache_bytes_dirty */
 		/* not clearing cache_pages_dirty */
 	stats->cache_eviction_clean = 0;
@@ -1053,6 +1055,8 @@ __wt_stat_connection_aggregate(
 	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_read_overflow += WT_STAT_READ(from, cache_read_overflow);
+	to->cache_overflow_value += WT_STAT_READ(from, cache_overflow_value);
 	to->cache_eviction_deepen +=
 	    WT_STAT_READ(from, cache_eviction_deepen);
 	to->cache_write_lookaside +=
@@ -1079,7 +1083,6 @@ __wt_stat_connection_aggregate(
 	to->cache_overhead += WT_STAT_READ(from, cache_overhead);
 	to->cache_bytes_internal += WT_STAT_READ(from, cache_bytes_internal);
 	to->cache_bytes_leaf += WT_STAT_READ(from, cache_bytes_leaf);
-	to->cache_bytes_overflow += WT_STAT_READ(from, cache_bytes_overflow);
 	to->cache_bytes_dirty += WT_STAT_READ(from, cache_bytes_dirty);
 	to->cache_pages_dirty += WT_STAT_READ(from, cache_pages_dirty);
 	to->cache_eviction_clean += WT_STAT_READ(from, cache_eviction_clean);
diff --git a/tools/wtstats/stat_data.py b/tools/wtstats/stat_data.py
index d06f1035adf..f349c319b3c 100644
--- a/tools/wtstats/stat_data.py
+++ b/tools/wtstats/stat_data.py
@@ -11,11 +11,11 @@ no_scale_per_second_list = [
     'cache: hazard pointer maximum array length',
     'cache: maximum bytes configured',
     'cache: maximum page size at eviction',
+    'cache: overflow values cached in memory',
     'cache: pages currently held in the cache',
     'cache: percentage overhead',
     'cache: tracked bytes belonging to internal pages in the cache',
     'cache: tracked bytes belonging to leaf pages in the cache',
-    'cache: tracked bytes belonging to overflow pages in the cache',
     'cache: tracked dirty bytes in the cache',
     'cache: tracked dirty pages in the cache',
     'connection: files currently open',
@@ -88,7 +88,6 @@ no_clear_list = [
     'cache: percentage overhead',
     'cache: tracked bytes belonging to internal pages in the cache',
     'cache: tracked bytes belonging to leaf pages in the cache',
-    'cache: tracked bytes belonging to overflow pages in the cache',
     'cache: tracked dirty bytes in the cache',
     'cache: tracked dirty pages in the cache',
     'connection: files currently open',