[
https://issues.apache.org/jira/browse/FLINK-13072?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16879099#comment-16879099
]
Stefan Richter edited comment on FLINK-13072 at 7/5/19 9:21 AM:
----------------------------------------------------------------
[~zicat] All operators in Flink are assumed to be single-threaded and spawning
up threads in any user function is something that is not supported by the
framework.
The quote from the doc that you present is about the `StateBackend` classes,
which are (misleadingly named) just the factory for the actual backend
implementations like `RocksDBKeyedStateBackend`. So yes, the factory has to be
thread safe, but the backends (i.e. subclasses of `AbstractKeyedStateBackend`)
and other things are not. What you attempt will not work.
was (Author: srichter):
[~zicat] All operators in Flink are assumed to be single-threaded and spawning
up threads in any user function is something that is not supported by the
framework.
The quote from the doc that you present is about the `StateBackend` classes,
which are (misleadingly named) just the factory for the actual backend
implementations like `RocksDBKeyedStateBackend`. So yes, the factory has to be
thread safe, but the backends and other things are not. What you attempt will
not work.
> RocksDBStateBachend is not thread safe and data loss silently
> -------------------------------------------------------------
>
> Key: FLINK-13072
> URL: https://issues.apache.org/jira/browse/FLINK-13072
> Project: Flink
> Issue Type: Bug
> Components: Runtime / State Backends
> Affects Versions: 1.8.0, 1.8.1
> Reporter: lynn1.zhang
> Priority: Blocker
> Attachments: flink-demo.zip, image-2019-07-03-17-04-17-253.png
>
>
> I create 2 mapstates in one operator, then create 2 threads in apply method,
> each thread operate each map state(the operator is same), the expect result
> is that 2 state have the same result but not. I upload the code, please help
> to try it.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
