[jira] [Created] (HDFS-6019) Standby NN might not checkpoint when processing the rolling upgrade marker

["Haohui Mai (JIRA)" <ji...@apache.org>]

Haohui Mai created HDFS-6019:
--------------------------------

             Summary: Standby NN might not checkpoint when processing the rolling upgrade marker
                 Key: HDFS-6019
                 URL: https://issues.apache.org/jira/browse/HDFS-6019
             Project: Hadoop HDFS
          Issue Type: Sub-task
            Reporter: Haohui Mai
            Assignee: Haohui Mai


{{FsEditlogLoader}} will call {{FSNameSystem#triggerRollbackCheckpoint()}} when processing the rollback marker, which looks like the following:

{code}
void triggerRollbackCheckpoint() {
  if (standbyCheckpointer != null) {
    standbyCheckpointer.triggerRollbackCheckpoint();
  }
}
{code}

There is a race condition where {{standbyCheckpointer}} can be {{null}}, because in the constructor of the {{NameNode}}, the {{initialize()}} method eventually starts the edit log tailer, but the standby checkpointer is created in {{HAState#enterState()}}. Therefore, the checkpointer might not be able to checkpoint when it sees the marker.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)