Details
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Bug
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Resolution: Fixed
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Major
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5.5.0, 5.5.1, 5.5.2, 5.5.3, 6.0.0, 6.0.1
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None
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Untriaged
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Unknown
Description
Cursor dropping appears to trigger too aggressively for the checkpoint memory condition (see MB-29227).
Adding additional debug logging, we see that the calculation for cursor_dropping_checkpoint_mem_upper_mark bytes value is incorrect - e.g.
261:2019-04-24T12:22:16.042548+01:00 INFO (default) Triggering cursor dropping as checkpoint_memory (388 MB) exceeds cursor_dropping_checkpoint_mem_upper_mark (50%, 0 MB). Attempting to free 877 MB of memory.
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This is attempting to trigger cursor dropping if the checkpoint memory (388 MB) exceeds 50% of the bucket_quota, however it is incorrectly calculating this limit as 0 MB. As such it is always triggering cursor dropping - and moreover is attempting to free more memory than necessary.
Attachments
For Gerrit Dashboard: MB-33918 | ||||||
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# | Subject | Branch | Project | Status | CR | V |
108205,1 | MB-33918: Add log messages for Cursor Dropping triggering | master | kv_engine | Status: ABANDONED | 0 | -1 |
108266,7 | MB-33918: Fix cursor dropping trigger issue | alice | kv_engine | Status: MERGED | +2 | +1 |
108280,6 | MB-33918: Add log messages for Cursor Dropping triggering | alice | kv_engine | Status: MERGED | +2 | +1 |
108432,2 | Merge branch couchbase/alice | master | kv_engine | Status: MERGED | +2 | +1 |
108518,1 | Merge branch couchbase/alice into master | master | kv_engine | Status: MERGED | +2 | +1 |