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https://issues.apache.org/jira/browse/FLINK-8639?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16371379#comment-16371379
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ASF GitHub Bot commented on FLINK-8639:
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Github user StefanRRichter commented on the issue:
https://github.com/apache/flink/pull/5465
While `128` is maybe already up to 128x better, a scientific approach for
finding the constant would be to try out for very small entries from which
point you have diminishing returns for higher values. Even for pretty large
entries 128 should still be small in total terms. Maybe we can go higher, or
maybe that is already diminishing returns. If you want, you could measure it.
If you don't have the time, then 128 maybe ok for now.
> Fix always need to seek multiple times when iterator RocksDBMapState
> --------------------------------------------------------------------
>
> Key: FLINK-8639
> URL: https://issues.apache.org/jira/browse/FLINK-8639
> Project: Flink
> Issue Type: Improvement
> Components: State Backends, Checkpointing
> Affects Versions: 1.4.0
> Reporter: Sihua Zhou
> Assignee: Sihua Zhou
> Priority: Critical
> Fix For: 1.5.0
>
>
> Currently, almost every time we want to iterator a RocksDBMapState we need to
> do seek at least 2 times (Seek is a poor performance action for rocksdb cause
> it can't use the bloomfilter). This is because `RocksDBMapIterator` use a
> `cacheEntries` to cache the seek values every time and the `cacheEntries`'s
> init size is 1.
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