Details
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Task
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Status: Closed
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Minor - P4
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Resolution: Duplicate
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None
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None
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None
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None
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Fully Compatible
Description
This is the cache section from db.serverStatus() after running a busy workload for about a few minutes. Note that mongod was started immediately prior to the test.
How can this possibly be true after a few minutes?
"pages evicted by application threads" : 3938125731,
I thought that maybe it counted bytes, which is possible given:
"bytes written from cache" : 4421343996,
But from looking at the code it just counts the number of calls to __wt_evict_lru_page
/*
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* __wt_evict_lru_page --
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* Called by both eviction and application threads to evict a page.
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*/
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int
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__wt_evict_lru_page(WT_SESSION_IMPL *session, int is_app)
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{
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WT_BTREE *btree;
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WT_CACHE *cache;
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WT_DECL_RET;
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WT_PAGE *page;
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WT_REF *ref;
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if (is_app)
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WT_STAT_FAST_CONN_INCR(session, cache_eviction_app);
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"cache" : {
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"tracked dirty bytes in the cache" : 488305732,
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"bytes currently in the cache" : 857590757,
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"maximum bytes configured" : 1073741824,
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"bytes read into cache" : 6992771243,
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"bytes written from cache" : 4421343996,
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"pages evicted by application threads" : 3938125731,
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"checkpoint blocked page eviction" : 3,
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"unmodified pages evicted" : 199580,
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"page split during eviction deepened the tree" : 1,
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"modified pages evicted" : 65810,
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"pages selected for eviction unable to be evicted" : 941,
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"pages evicted because they exceeded the in-memory maximum" : 400,
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"pages evicted because they had chains of deleted items" : 2,
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"failed eviction of pages that exceeded the in-memory maximum" : 0,
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"hazard pointer blocked page eviction" : 20,
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"internal pages evicted" : 0,
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"maximum page size at eviction" : 42848801,
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"eviction server candidate queue empty when topping up" : 1092,
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"eviction server candidate queue not empty when topping up" : 11153,
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"eviction server evicting pages" : 59,
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"eviction server populating queue, but not evicting pages" : 12186,
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"eviction server unable to reach eviction goal" : 0,
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"pages split during eviction" : 3919,
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"pages walked for eviction" : 9457046,
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"in-memory page splits" : 133,
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"tracked dirty pages in the cache" : 7550,
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"pages currently held in the cache" : 14340,
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"pages read into cache" : 279087,
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"pages written from cache" : 221121
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},
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Attachments
Issue Links
- duplicates
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SERVER-17020 Evictions by eviction server threads are reported as evictions by application threads
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- Closed
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