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https://issues.apache.org/jira/browse/HDDS-2372?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16968264#comment-16968264
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Marton Elek commented on HDDS-2372:
-----------------------------------
I had a long conversation with [~shashikant] and He helped me a lot to
understood the problem (thanks here, again). Here are our proposals:
[Problem 1]: race condition between read (read the statemachine data to send it
to the followers) and commit
This can be solved using a a second read attempt after throwing the exception.
[Problem 2]: race condition between writeStateMachineData and
readStateMachineData (the statemachine data write might not be finished when we
start to read back the data (in case of missing cache entry).
This can be fixed with checking the size of the data and compare it with the
length which is part of the chunk write request.
[Problem 3] race condition between close container / write chunk / read chunk :
write chunk may be declined because the container is closed, in this case the
read chunk error should be ignored silently instead of throwing an exception
for ratis. This can be done with using the bcsid. If it's newer than the
term/index of the close container, the request can be safely ignored.
> Datanode pipeline is failing with NoSuchFileException
> -----------------------------------------------------
>
> Key: HDDS-2372
> URL: https://issues.apache.org/jira/browse/HDDS-2372
> Project: Hadoop Distributed Data Store
> Issue Type: Bug
> Reporter: Marton Elek
> Assignee: Shashikant Banerjee
> Priority: Critical
>
> Found it on a k8s based test cluster using a simple 3 node cluster and
> HDDS-2327 freon test. After a while the StateMachine become unhealthy after
> this error:
> {code:java}
> datanode-0 datanode java.util.concurrent.ExecutionException:
> java.util.concurrent.ExecutionException:
> org.apache.hadoop.hdds.scm.container.common.helpers.StorageContainerException:
> java.nio.file.NoSuchFileException:
> /data/storage/hdds/2a77fab9-9dc5-4f73-9501-b5347ac6145c/current/containerDir0/1/chunks/gGYYgiTTeg_testdata_chunk_13931.tmp.2.20830
> {code}
> Can be reproduced.
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