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https://issues.apache.org/jira/browse/YARN-3727?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14935330#comment-14935330
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Jason Lowe commented on YARN-3727:
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I think the approach is a reasonable workaround to catch cases where we leak a
local resource and want to avoid failing a new localization.
Could you update the patch to trunk?
> For better error recovery, check if the directory exists before using it for
> localization.
> ------------------------------------------------------------------------------------------
>
> Key: YARN-3727
> URL: https://issues.apache.org/jira/browse/YARN-3727
> Project: Hadoop YARN
> Issue Type: Improvement
> Components: nodemanager
> Affects Versions: 2.7.0
> Reporter: zhihai xu
> Assignee: zhihai xu
> Attachments: YARN-3727.000.patch
>
>
> For better error recovery, check if the directory exists before using it for
> localization.
> We saw the following localization failure happened due to existing cache
> directories.
> {code}
> 2015-05-11 18:59:59,756 INFO
> org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService:
> DEBUG: FAILED { hdfs://XXXX/XXXXX/libjars/1234.jar, 1431395961545, FILE,
> null }, Rename cannot overwrite non empty destination directory
> /XXXX/8/yarn/nm/usercache/XXXX/filecache/21637
> 2015-05-11 18:59:59,756 INFO
> org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.LocalizedResource:
> Resource
> hdfs://XXXX/XXXXX/libjars/1234.jar(->/XXXX/8/yarn/nm/usercache/XXXX/filecache/21637/1234.jar)
> transitioned from DOWNLOADING to FAILED
> {code}
> The real cause for this failure may be disk failure, LevelDB operation
> failure for {{startResourceLocalization}}/{{finishResourceLocalization}} or
> others.
> I wonder whether we can add error recovery code to avoid the localization
> failure by not using the existing cache directories for localization.
> The exception happened at {{files.rename(dst_work, destDirPath,
> Rename.OVERWRITE)}} in FSDownload#call. Based on the following code, after
> the exception, the existing cache directory used by {{LocalizedResource}}
> will be deleted.
> {code}
> try {
> .........
> files.rename(dst_work, destDirPath, Rename.OVERWRITE);
> } catch (Exception e) {
> try {
> files.delete(destDirPath, true);
> } catch (IOException ignore) {
> }
> throw e;
> } finally {
> {code}
> Since the conflicting local directory will be deleted after localization
> failure,
> I think it will be better to check if the directory exists before using it
> for localization to avoid the localization failure.
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