[YARN-6319] race condition between deleting app dir and deleting container dir

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: nodemanager
• Assignee: Hong Zhiguo
• Reporter: Hong Zhiguo
• Created: 10/Mar/17 08:24
• Updated: 17/Mar/17 17:46

Description

Last container (on one node) of one app complete

--> triggers async deletion of container dir (container cleanup)

--> triggers async deletion of app dir (app cleanup)

For LCE, deletion is done by container-executor. The "app cleanup" lists sub-dir (step 1), and then unlink items one by one(step 2). If a file is deleted by "container cleanup" between step 1 and step2, it'll report below error and breaks the deletion.

ContainerExecutor: Couldn't delete file $LOCAL/usercache/$USER/appcache/application_1481785469354_353539/container_1481785469354_353539_01_000028/$FILE - No such file or directory

This app dir then escape the cleanup. And that's why we always have many app dirs left there.

solution 1: just ignore the error without breaking in container-executor.c::delete_path()
solution 2: use a lock to serialize the cleanup of same app dir.
solution 3: backoff and retry on error

Comments are welcome.