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Type:
Improvement
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Resolution: Fixed
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: Cache and Eviction
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Storage Engines, Storage Engines - Transactions
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SE Transactions - 2025-05-23, SE Transactions - 2025-06-06
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5
While investigating WT-11300 I found that we update the stat cache_eviction_target_strategy_dirty when WT_CACHE_EVICT_UPDATES is set which is misleading because there are 2 other cache evict states which is WT_CACHE_EVICT_DIRTY and WT_CACHE_EVICT_CLEAN.
My suggestion is to have a different stat for each cache eviction state, now in WiredTiger we have the below stats.
- cache_eviction_target_strategy_clean -> WT_CACHE_EVICT_CLEAN
- cache_eviction_target_strategy_dirty -> WT_CACHE_EVICT_DIRTY
This ticket is created to introduce a new stat or rename the stat cache_eviction_target_strategy_both_clean_and_dirty to cache_eviction_target_strategy_updates and update the code like below.
diff --git a/src/evict/evict_lru.c b/src/evict/evict_lru.c
index d8906e464..c396b04ee 100644
--- a/src/evict/evict_lru.c
+++ b/src/evict/evict_lru.c
@@ -1825,13 +1825,14 @@ __evict_walk_tree(WT_SESSION_IMPL *session, WT_EVICT_QUEUE *queue, u_int max_ent
* only looking for dirty pages, search the tree for longer.
*/
min_pages = 10 * (uint64_t)target_pages;
- if (!F_ISSET(cache, WT_CACHE_EVICT_DIRTY | WT_CACHE_EVICT_UPDATES))
- WT_STAT_CONN_INCR(session, cache_eviction_target_strategy_clean);
- else if (!F_ISSET(cache, WT_CACHE_EVICT_CLEAN)) {
+ if (F_ISSET(cache, WT_CACHE_EVICT_DIRTY)){
min_pages *= 10;
WT_STAT_CONN_INCR(session, cache_eviction_target_strategy_dirty);
- } else
- WT_STAT_CONN_INCR(session, cache_eviction_target_strategy_both_clean_and_dirty);
+ } else if (F_ISSET(cache, WT_CACHE_EVICT_CLEAN)) {
+ WT_STAT_CONN_INCR(session, cache_eviction_target_strategy_clean);
+ } else if (F_ISSET(cache, WT_CACHE_EVICT_UPDATES))
+ WT_STAT_CONN_INCR(session, cache_eviction_target_strategy_updates);
