Azat Khuzhin 9e622b5add perf: switch *_log tables to Memory engine (attempt to reduce cache misses) ... trace_log/query_log from performance tests shows (for cases when prewarm query fails with timeout, 15sec) excessive writeTraceInfo() in trace_log and QueryProfilerRuns in query_log, but this is not the root cause of the timeout, but consequence. Also query_log shows that on failures the following profile events has significantly higher values: - PerfLocalMemoryMisses (6.3x more) - PerfLocalMemoryReferences (7x more) - PerfDataTLBMisses (6.9x more) - PerfInstructionTLBMisses (6.4x more) During looking at performance tests logs I noticed that once the prewarm query fails other server (left/right) was merging (MergeTree) something in *_log tables. But, using MergeTree for *_log in performance tests is useless, since anyway environment for performance tests uses ramdrive. And so MergeTree merges just increase overhead. Eventually I expect that this should decrease extra memory referencing and so this should decrease cache/TLB misses. CI: https://clickhouse-test-reports.s3.yandex.net/30886/c504e0c08df7a926bb479a1d297f326f5c48a32f/performance_comparison/report.html#fail1 v2: <partition_by remove="remove"/>		2021-11-04 09:26:46 +03:00
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top_level_domains_lists.xml
user_files.xml
zzz-perf-comparison-tweaks-config.xml	perf: switch *_log tables to Memory engine (attempt to reduce cache misses)	2021-11-04 09:26:46 +03:00