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Type:
Bug
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Resolution: Duplicate
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: None
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Labels:
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Execution Team 2021-01-25, Repl 2021-03-08, Repl 2021-03-22, Repl 2021-04-05, Repl 2022-03-21, Repl 2022-04-04, Repl 2022-04-18, Repl 2022-05-02, Repl 2022-05-16, Repl 2022-05-30, Repl 2022-06-13, Repl 2022-06-27
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(copied to CRM)
A simple workload with a single thread doing updates as fast as possible sees the following:
- 4.2
- primary
- updates: 1200/s
- log flushes: 300/s
- secondary
- batches: 280/s
- log flushes: 300/s
- primary
- 4.4
- primary
- updates: 1250/s
- log flushes: 10/s; much improved in 4.4 due to PM-1274
- seccondary
- batches: 1200/s
- log flushes: 2400/s; much worse in 4.4 than 4.2, and much higher than primary
- primary
This creates a much higher i/o requirement on the secondary in 4.4, and much higher on the secondary than the primary.
Two possible issues:
- Do we need to flush more often on the secondary than the primary?
- Do we need to do 2 flushes per batch?
- depends on
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SERVER-54938 Only flush journal once per batch on secondary oplog application
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- Closed
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SERVER-54939 Investigate secondary batching behavior in v4.4
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- Closed
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- duplicates
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- Closed
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- is documented by
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DOCS-14755 DOCS-14755 Investigate changes in SERVER-53667: High rate of journal flushes on secondary in 4.4
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- Backlog
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- is related to
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- Closed
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- Closed
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- Closed
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- related to
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- Closed
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