[
https://issues.apache.org/jira/browse/FLINK-9373?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16477383#comment-16477383
]
ASF GitHub Bot commented on FLINK-9373:
---------------------------------------
Github user StefanRRichter commented on the issue:
https://github.com/apache/flink/pull/6020
A quick general question: could you observe any performance impact from
calling the `status()` method in the loops. It looks like a native method and I
am not sure that it is inexpensive. Maybe the better idea is to only check
`isValid()` in the loops and check `status()` only once after the loop to
ensure that everything was well and complete. Maybe that is also the reason why
this is split into two methods in the first place. What do you think?
> Fix potential data losing for RocksDBBackend
> --------------------------------------------
>
> Key: FLINK-9373
> URL: https://issues.apache.org/jira/browse/FLINK-9373
> Project: Flink
> Issue Type: Bug
> Components: State Backends, Checkpointing
> Affects Versions: 1.5.0
> Reporter: Sihua Zhou
> Assignee: Sihua Zhou
> Priority: Blocker
> Fix For: 1.5.0
>
>
> Currently, when using RocksIterator we only use the _iterator.isValid()_ to
> check whether we have reached the end of the iterator. But that is not
> enough, if we refer to RocksDB's wiki
> https://github.com/facebook/rocksdb/wiki/Iterator#error-handling we should
> find that even if _iterator.isValid()=true_, there may also exist some
> internal error. A safer way to use the _RocksIterator_ is to always call the
> _iterator.status()_ to check the internal error of _RocksDB_. There is a case
> from user email seems to lost data because of this
> http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Missing-MapState-when-Timer-fires-after-restored-state-td20134.html
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
