[HDFS-3693] QJM: JNStorage should read its storage info even before a writer becomes active

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: QuorumJournalManager (HDFS-3077)
• Fix Version/s: QuorumJournalManager (HDFS-3077)
• Target Version/s: QuorumJournalManager (HDFS-3077)
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 20/Jul/12 00:49
• Updated: 25/Jul/12 21:47
• Resolved: 25/Jul/12 21:47

Description

In order for QJM to work with HA, the standby needs to be able to read from a JournalNode even when no active has written to it. In the current code, it reads the StorageInfo only when newEpoch() is called. But, that's only called when a writer becomes active. This causes the SBN to fail at startup since the JN thinks its storage info is uninitialized.