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Jitendra Nath Pandey commented on HDFS-1975: -------------------------------------------- {quote} Im not sure the tailer will work as is. What happens if you open an inprogress input stream with this? As I understand it, you'll end up with lastTxnId in the middle of the segment. {quote} It will be fixed if FileJournalManager doesn't return in-progress segments. The stand by will lag a bit, but upon a failover, it will catch up. Need to evaluate the impact on number of stored datanode messages. {quote} In FSEditLog, check the states before transitioning them. {quote} initJournals checks the state. Do you mean I should rather check the state in initJournalsForRead/Write? > HA: Support for sharing the namenode state from active to standby. > ------------------------------------------------------------------ > > Key: HDFS-1975 > URL: https://issues.apache.org/jira/browse/HDFS-1975 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: name-node > Reporter: Suresh Srinivas > Assignee: Jitendra Nath Pandey > Attachments: HDFS-1975-HA.2.patch, HDFS-1975-HA.patch, hdfs-1975.txt, > hdfs-1975.txt > > > To enable hot standby namenode, the standby node must have current > information for - namenode state (image + edits) and block location > information. This jira addresses keeping the namenode state current in the > standby node. To do this, the proposed solution in this jira is to use a > shared storage to store the namenode state. > Note one could also build an alternative solution by augmenting the backup > node. A seperate jira could explore this. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira