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https://issues.apache.org/jira/browse/YARN-2229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14071853#comment-14071853
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Tsuyoshi OZAWA commented on YARN-2229:
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Thanks for the comments, Jian, Zhijie and Sid.
{quote}
For example, ContainerTokenIdentifier serializes a long (getContainerId()) at
RM side, but deserializes a int (getId()) at NM side. In this case, I'm afraid
it's going to be wrong
{quote}
If we think the backward compatibility as first priority, we can choose the
first design I proposed as Sid mentioned. This design choice looks reasonable
to me. [~jianhe], what do you think? We discussed that we should avoid
introducing new field to ContinerId class. In my opinion, this reason is weaker
than the backward compatibility.
{quote}
ConverterUtils is a separate consideration. It is marked as @private - but is
used in MapReduce for example (and also in Tez). Looks like the toString method
isn't being changed either, whcih means to ConverterUtils method would continue
to work.
{quote}
I'm thinking to suffix the epoch at the end of container id. I'll work with old
jar which includes old {{ConverterUtils#toContainerId}}. YARN-2182 is the JIRA
to address the change of {{ConverterUtils#toContainerId}}.
> ContainerId can overflow with RM restart
> ----------------------------------------
>
> Key: YARN-2229
> URL: https://issues.apache.org/jira/browse/YARN-2229
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: resourcemanager
> Reporter: Tsuyoshi OZAWA
> Assignee: Tsuyoshi OZAWA
> Attachments: YARN-2229.1.patch, YARN-2229.10.patch,
> YARN-2229.10.patch, YARN-2229.2.patch, YARN-2229.2.patch, YARN-2229.3.patch,
> YARN-2229.4.patch, YARN-2229.5.patch, YARN-2229.6.patch, YARN-2229.7.patch,
> YARN-2229.8.patch, YARN-2229.9.patch
>
>
> On YARN-2052, we changed containerId format: upper 10 bits are for epoch,
> lower 22 bits are for sequence number of Ids. This is for preserving
> semantics of {{ContainerId#getId()}}, {{ContainerId#toString()}},
> {{ContainerId#compareTo()}}, {{ContainerId#equals}}, and
> {{ConverterUtils#toContainerId}}. One concern is epoch can overflow after RM
> restarts 1024 times.
> To avoid the problem, its better to make containerId long. We need to define
> the new format of container Id with preserving backward compatibility on this
> JIRA.
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