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Type: Bug
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Resolution: Done
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Priority: Major - P3
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Affects Version/s: None
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Component/s: WiredTiger
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None
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Fully Compatible
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ALL
- standalone, 3 GB cache
- 10 GB data set, 10 M x 1 kB documents
- 64 GB memory, SSD (but probably not relevant as data set should be in filesystem cache)
- 100 threads doing random queries over data set, creating high cache pressure
- observe ~1.7x performance regression in 3.2.3 compared to 3.0.9
- A-B: 3.0.9
- B-C: 3.2.3 (same data set)
3.0.9 3.2.3 queries 82 k/s 48 k/s evictions 78 k/s 36 k/s walked 836 k/s 5813 k/s walked/eviction 11 160 mutex calls 0.7 k/s 12 k/s
It appears that a higher rate of pages walked per page evicted could be a significant factor, so possibly this is related to SERVER-22831, where pages walked for eviction also appeared to be a factor? (Note however that ticket requires a replica set, whereas this ticket is for a standalone mongod.)
There is also a much higher rate of mutex calls.
- depends on
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WT-2453 Throughput drop in wtperf evict Jenkins tests
- Closed
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WT-2544 Fix eviction statistics when clear is configured
- Closed
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WT-2545 Investigate eviction tree walk
- Closed
- is related to
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SERVER-22831 Low query rate with heavy cache pressure and an idle collection
- Closed
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WT-2511 Recent WT builds have a large perf regression as thread count increases in read only workloads larger than cache
- Closed