bulk: perform meta lookup on range cache miss during index backfill #86492
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I'd argue we can release justify it as bug fix in existing functionality |
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Fixes cockroachdb#84290. This commit addresses the sustained slowdown described in cockroachdb#84290 by replacing the call in `SSTBatcher.flushIfNeeded` to `RangeCache.GetCached` with a call to `RangeCache.Lookup`. The former method checks the cache but returns no range descriptor if the cache currently has no overlapping key. This is possible if the descriptor was recently evicted because it was stale. The later method performs a meta lookup if the cache currently has no overlapping key, so it should always return _some_ range descriptor. There's a question of whether we should be logging a warning but proceeding if this meta lookup fails. For now, I've decided not to change that behavior. Release justification: None. Don't merge yet.
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TFTR! Merging on master for now without an immediate backport. Will wait on the backport for a v22.2 patch release. bors r=dt |
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Fixes #84290.
This commit addresses the sustained slowdown described in #84290 by replacing
the call in
SSTBatcher.flushIfNeededtoRangeCache.GetCachedwith a call toRangeCache.Lookup. The former method checks the cache but returns no rangedescriptor if the cache currently has no overlapping key. This is possible if
the descriptor was recently evicted because it was stale. The later method
performs a meta lookup if the cache currently has no overlapping key, so it
should always return some range descriptor.
There's a question of whether we should be logging a warning but proceeding if
this meta lookup fails. For now, I've decided not to change that behavior.
Release justification: None. Don't merge yet.