GitHub user sihuazhou opened a pull request:
https://github.com/apache/flink/pull/6020
[FLINK-9373][state] Always call RocksIterator.status() to check the
internal error of RocksDB
## What is the purpose of the change
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
errors. A safer way to use the `RocksIterator` is to always call the
`iterator.status()` to check the internal error of RocksDB. There is one 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
(I'm not so sure yet)
## Brief change log
- *Always call RocksIterator.status() to check the internal error of
RocksDB*
## Verifying this change
This change is a trivial rework / code cleanup without any test coverage.
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): (no)
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: (no)
- The serializers: (no)
- The runtime per-record code paths (performance sensitive): (no)
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
- The S3 file system connector: (no)
## Documentation
- Does this pull request introduce a new feature? (no)
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/sihuazhou/flink FLINK-9373
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/6020.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #6020
----
commit b1d531949d521bb7d72cd389dfe72a4a5cf1bfc9
Author: sihuazhou <summerleafs@...>
Date: 2018-05-16T07:47:05Z
Always call RocksIterator.status() to check the internal error of RocksDB
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