Details
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Bug
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Resolution: Fixed
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Major
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6.5.1, 6.5.0
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Triaged
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Unknown
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KV Sprint 2020-April
Description
Discovered whilst investigating MB-38012 that we are currently tracking checkpoint memory overhead incorrectly. We appear to track the allocations of the checkpoint_index map, but not of the keys used in them.
Consider the case where we have a large disk checkpoint that is entirely non-resident in the checkpoint (i.e. everything has been expelled) then the keys are a substantial part of this. In the case of MB-38012 we are tracking approx 80 bytes overhead per item, but this does not include the keys which are ~48 bytes. We were tracking 27GB memory overhead in the checkpoint but in reality this is more like 40GB.
Attachments
For Gerrit Dashboard: MB-38173 | ||||||
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# | Subject | Branch | Project | Status | CR | V |
123312,1 | MB-38173: Track key allocations as part of checkpoint overhead | master | kv_engine | Status: ABANDONED | 0 | 0 |
123313,18 | MB-38173: Track key allocations as part of checkpoint overhead | mad-hatter | kv_engine | Status: MERGED | +2 | +1 |
123439,5 | MB-38271: Swap assertions to checks in takeover test | mad-hatter | kv_engine | Status: MERGED | +2 | +1 |
123514,1 | MB-38173: Remove assertions in takeover test and deal with buffer ack | master | kv_engine | Status: ABANDONED | 0 | 0 |
123516,1 | MB-38173: Swap assertions to checks in takeover test | master | kv_engine | Status: ABANDONED | 0 | -1 |
127720,3 | Merge branch 'mad-hatter' | master | kv_engine | Status: MERGED | +2 | +1 |