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https://issues.apache.org/jira/browse/FLINK-24460?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated FLINK-24460:
-----------------------------------
Labels: pull-request-available (was: )
> Rocksdb Iterator Error Handling Improvement
> -------------------------------------------
>
> Key: FLINK-24460
> URL: https://issues.apache.org/jira/browse/FLINK-24460
> Project: Flink
> Issue Type: Improvement
> Components: Runtime / State Backends
> Affects Versions: 1.14.0
> Reporter: Victor Xu
> Priority: Minor
> Labels: pull-request-available
>
> In FLINK-9373, we introduced RocksIteratorWrapper which was a wrapper around
> RocksIterator to check the iterator status for all the methods. At that time,
> it was required because the iterator may pass the blocks or files it had
> difficulties in reading (because of IO errors, data corruptions, or other
> issues) and continue with the next available keys. *The status flag may not
> be OK, even if the iterator is valid.*
> However, the above behaviour changed after
> [3810|https://github.com/facebook/rocksdb/pull/3810] was merged on May 17,
> 2018:
> *- If the iterator is valid, the status() is guaranteed to be OK;*
> *- If the iterator is not valid, there are two possibilities:*
> *1) We have reached the end of the data. And in this case, status() is
> OK;*
> *2) There is an error. In this case, status() is not OK;*
> More information can be found here:
> https://github.com/facebook/rocksdb/wiki/Iterator#error-handling
> Thus, it should be safe to proceed with other operations (e.g. seek, next,
> seekToFirst, seekToLast, seekForPrev, and prev) without checking status().
> And we only need to check the status if the iterator is invalid. After the
> change, there will be less status() native calls and could theoretically
> improve performance.
>
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