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https://issues.apache.org/jira/browse/FLINK-10343?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16614767#comment-16614767
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Andrey Zagrebin commented on FLINK-10343:
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Hi [~aitozi]!
if you use the heap state backend, the state is already manipulated only in
memory between checkpoints, so not sure why one would need more caching on top.
RocksDb backend is used when state does not fit into memory so it cannot be
cached there either. In general both state backends are already basically a
local cache for a running job between checkpoints.
> Expose setCurrentKey method to streamRuntimeContext
> ---------------------------------------------------
>
> Key: FLINK-10343
> URL: https://issues.apache.org/jira/browse/FLINK-10343
> Project: Flink
> Issue Type: Improvement
> Components: Streaming
> Affects Versions: 1.7.0
> Reporter: aitozi
> Assignee: aitozi
> Priority: Major
> Fix For: 1.7.0
>
>
> when we use reducing state / aggregating keyed state and so on , we have to
> read value from state backend and update the value with userFunction and then
> put back to state backend. If we can just cache certain data in heap with a
> map, and update once in snapshot method with
> {code:java}
> snapshot() {
> for(Map.Entry<String, String> entry : map.entrySet()){
> setCurrentKey(entry.getKey());
> valueState.update(entry.getValue()); // put value back to state backend
> }}
> {code}
> we just have to expose the setCurrentKey to userFunction and the will enable
> the ability to cache partitial keyedState in memory by userself.
> what's your opinion [[email protected]] [~azagrebin] ?
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