[jira] [Created] (HDFS-13112) Token expiration edits may cause log corruption or deadlock

["Daryn Sharp (JIRA)" <ji...@apache.org>]

Daryn Sharp created HDFS-13112:
----------------------------------

             Summary: Token expiration edits may cause log corruption or deadlock
                 Key: HDFS-13112
                 URL: https://issues.apache.org/jira/browse/HDFS-13112
             Project: Hadoop HDFS
          Issue Type: Bug
          Components: namenode
    Affects Versions: 0.23.8, 2.1.0-beta
            Reporter: Daryn Sharp
            Assignee: Daryn Sharp


HDFS-4477 specifically did not acquire the fsn lock during token cancellation based on the belief that edit logs are thread-safe.  However, log rolling is not thread-safe.  Failure to externally synchronize on the fsn lock during a roll will cause problems.

For sync edit logging, it may cause corruption by interspersing edits with the end/start segment edits.  Async edit logging may encounter a deadlock if the log queue overflows.  Luckily, losing the race is extremely rare.  In ~5 years, we've never encountered it.  However, HDFS-13051 lost the race with async edits.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-dev-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-dev-help@hadoop.apache.org