[ 
https://issues.apache.org/jira/browse/FLINK-32130?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Feifan Wang closed FLINK-32130.
-------------------------------
    Resolution: Duplicate

duplicate to FLINK-29913

> previous checkpoint will be broke by the subsequent incremental checkpoint
> --------------------------------------------------------------------------
>
>                 Key: FLINK-32130
>                 URL: https://issues.apache.org/jira/browse/FLINK-32130
>             Project: Flink
>          Issue Type: Bug
>          Components: Runtime / Checkpointing
>            Reporter: Feifan Wang
>            Priority: Major
>
> Currently, _SharedStateRegistryImpl_ will discard old one while register new 
> state to same key:
> {code:java}
> // Old entry is not in a confirmed checkpoint yet, and the new one differs.
> // This might result from (omitted KG range here for simplicity):
> // 1. Flink recovers from a failure using a checkpoint 1
> // 2. State Backend is initialized to UID xyz and a set of SST: { 01.sst }
> // 3. JM triggers checkpoint 2
> // 4. TM sends handle: "xyz-002.sst"; JM registers it under "xyz-002.sst"
> // 5. TM crashes; everything is repeated from (2)
> // 6. TM recovers from CP 1 again: backend UID "xyz", SST { 01.sst }
> // 7. JM triggers checkpoint 3
> // 8. TM sends NEW state "xyz-002.sst"
> // 9. JM discards it as duplicate
> // 10. checkpoint completes, but a wrong SST file is used
> // So we use a new entry and discard the old one:
> LOG.info(
>         "Duplicated registration under key {} of a new state: {}. "
>                 + "This might happen during the task failover if state 
> backend creates different states with the same key before and after the 
> failure. "
>                 + "Discarding the OLD state and keeping the NEW one which is 
> included into a completed checkpoint",
>         registrationKey,
>         newHandle);
> scheduledStateDeletion = entry.stateHandle;
> entry.stateHandle = newHandle; {code}
> But if _execution.checkpointing.max-concurrent-checkpoints_ > 1, the 
> following case will fail (take _RocksDBStateBackend_ as an example):
>  # cp1 trigger: 1.sst be uploaded to file-1, and register <1.sst,file-1>, cp1 
> reference file-1
>  # cp1 is not yet complete, cp2 trigger: 1.sst be uploaded to file-2, and try 
> register <1.sst,file-2>. SharedStateRegistry discard file-1
>  # cp1 completed and cp2 failed, but the cp1 is broken (file-1 has be deleted)
> I add a test to reproduce the problem ( 
> [pr-22606|https://github.com/apache/flink/pull/22606] ).
> I think we should allow register multi state object to same key, WDYT 
> [~pnowojski], [~roman]  ?



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

Reply via email to