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https://issues.apache.org/jira/browse/HDFS-12256?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Chen Liang updated HDFS-12256:
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Attachment: HDFS-12256-HDFS-7240.001.patch
A closer look shows that, the active flag seems unnecessary since:
1. active is set to false if and only if when containerData is null. Similarly
for active = true
2. both active flag and containerData are final variable and thus set in
constructor and never change.
Because of these 2, checking active flag is equivalent of checking
containerData is null or not. So did two things in v001 patch:
1. remove the active flag
2. since it is possible we store a null containerData in ContainerStatus, there
are a couple places that need to check if {{ContainerStatus#getContainer}}
returns a null before proceeding.
> Ozone : handle inactive containers on DataNode
> ----------------------------------------------
>
> Key: HDFS-12256
> URL: https://issues.apache.org/jira/browse/HDFS-12256
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Reporter: Chen Liang
> Assignee: Chen Liang
> Labels: ozoneMerge, tocheck
> Attachments: HDFS-12256-HDFS-7240.001.patch
>
>
> When a container gets created, corresponding metadata gets added to
> {{ContainerManagerImpl#containerMap}}. What {{containerMap}} stores is a
> containerName to {{ContainerStatus}} instance map. When datanode starts, it
> also loads this map from disk file metadata. As long as the containerName is
> found in this map, it is considered an existing container.
> An issue we saw was that, occasionally, when the container creation on
> datanode fails, the metadata of the failed container may still get added to
> {{containerMap}}, with active flag set to false. But currently such
> containers are not being handled, containers with active=false are just
> treated as normal containers. Then when someone tries to write to this
> container, fails can happen.
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