LUCENE-10078: Enable merge-on-refresh by default. #921
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This gives implementations of `findFullFlushMerges` to `LogMergePolicy` and `TieredMergePolicy` and enables merge-on-refresh with a default timeout of 500ms. The idea behind the 500ms default is that it felt both high-enough to have time to run merges of small segments, and low enough that the freshness of the data wouldn't look badly affected for users who have high refresh rates (e.g. refreshing every second). For `findFullFlushMerges`, `LogMergePolicy` looks at tail segments to see if it can find at least `mergeFactor` flush segments below the min segment size, and `TieredMergePolicy` looks for a merge that has at least `segmentsPerTier` segments where the largest segment of the merge is a flush segment and below the floor size.
s1monw
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Jun 7, 2022
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Good call, I added a warning to javadocs on |
jpountz
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Jun 7, 2022
This gives implementations of `findFullFlushMerges` to `LogMergePolicy` and `TieredMergePolicy` and enables merge-on-refresh with a default timeout of 500ms. The idea behind the 500ms default is that it felt both high-enough to have time to run merges of small segments, and low enough that the freshness of the data wouldn't look badly affected for users who have high refresh rates (e.g. refreshing every second). In both cases, `findFullFlushMerges` delegates to `findMerges` and filters merges whose segments are all below the min/floor size.
This was referenced Jun 10, 2022
shaie
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Jun 22, 2022
This gives implementations of `findFullFlushMerges` to `LogMergePolicy` and `TieredMergePolicy` and enables merge-on-refresh with a default timeout of 500ms. The idea behind the 500ms default is that it felt both high-enough to have time to run merges of small segments, and low enough that the freshness of the data wouldn't look badly affected for users who have high refresh rates (e.g. refreshing every second). In both cases, `findFullFlushMerges` delegates to `findMerges` and filters merges whose segments are all below the min/floor size.
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This gives implementations of
findFullFlushMergestoLogMergePolicyandTieredMergePolicyand enables merge-on-refresh with a default timeout of500ms.
The idea behind the 500ms default is that it felt both high-enough to have time
to run merges of small segments, and low enough that the freshness of the data
wouldn't look badly affected for users who have high refresh rates (e.g.
refreshing every second).
In both cases,
findFullFlushMergesdelegates tofindMergesand filtersmerges whose segments are all below the min/floor size.