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https://issues.apache.org/jira/browse/HDFS-8298?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14521912#comment-14521912
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Jing Zhao commented on HDFS-8298:
---------------------------------
Thanks for reporting this, Hari. Currently the active NN updates its memory
state before writing the editlog, thus in case that it cannot successfully
persist the editlog to JNs, there is no way to undo the changes that have
already been applied. If this NN chooses to go to standby state and the other
NN continues to serve as active, these two NNs will have inconsistent state.
> HA: NameNode should not shut down completely without quorum, doesn't recover
> from temporary network outages
> -----------------------------------------------------------------------------------------------------------
>
> Key: HDFS-8298
> URL: https://issues.apache.org/jira/browse/HDFS-8298
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: ha, HDFS, namenode, qjm
> Affects Versions: 2.6.0
> Environment: HDP 2.2
> Reporter: Hari Sekhon
>
> In an HDFS HA setup if there is a temporary problem with contacting journal
> nodes (eg. network interruption), the NameNode shuts down entirely, when it
> should instead go in to a standby mode so that it can stay online and retry
> to achieve quorum later.
> If both NameNodes shut themselves off like this then even after the temporary
> network outage is resolved, the entire cluster remains offline indefinitely
> until operator intervention, whereas it could have self-repaired after
> re-contacting the journalnodes and re-achieving quorum.
> {code}2015-04-15 15:59:26,900 FATAL namenode.FSEditLog
> (JournalSet.java:mapJournalsAndReportErrors(398)) - Error: flush failed for
> required journal (JournalAndStre
> am(mgr=QJM to [<ip>:8485, <ip>:8485, <ip>:8485], stream=QuorumOutputStream
> starting at txid 54270281))
> java.io.IOException: Interrupted waiting 20000ms for a quorum of nodes to
> respond.
> at
> org.apache.hadoop.hdfs.qjournal.client.AsyncLoggerSet.waitForWriteQuorum(AsyncLoggerSet.java:134)
> at
> org.apache.hadoop.hdfs.qjournal.client.QuorumOutputStream.flushAndSync(QuorumOutputStream.java:107)
> at
> org.apache.hadoop.hdfs.server.namenode.EditLogOutputStream.flush(EditLogOutputStream.java:113)
> at
> org.apache.hadoop.hdfs.server.namenode.EditLogOutputStream.flush(EditLogOutputStream.java:107)
> at
> org.apache.hadoop.hdfs.server.namenode.JournalSet$JournalSetOutputStream$8.apply(JournalSet.java:533)
> at
> org.apache.hadoop.hdfs.server.namenode.JournalSet.mapJournalsAndReportErrors(JournalSet.java:393)
> at
> org.apache.hadoop.hdfs.server.namenode.JournalSet.access$100(JournalSet.java:57)
> at
> org.apache.hadoop.hdfs.server.namenode.JournalSet$JournalSetOutputStream.flush(JournalSet.java:529)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLog.logSync(FSEditLog.java:639)
> at
> org.apache.hadoop.hdfs.server.namenode.LeaseManager$Monitor.run(LeaseManager.java:388)
> at java.lang.Thread.run(Thread.java:745)
> 2015-04-15 15:59:26,901 WARN client.QuorumJournalManager
> (QuorumOutputStream.java:abort(72)) - Aborting QuorumOutputStream starting at
> txid 54270281
> 2015-04-15 15:59:26,904 INFO util.ExitUtil (ExitUtil.java:terminate(124)) -
> Exiting with status 1
> 2015-04-15 15:59:27,001 INFO namenode.NameNode (StringUtils.java:run(659)) -
> SHUTDOWN_MSG:
> /************************************************************
> SHUTDOWN_MSG: Shutting down NameNode at <custom_scrubbed>/<ip>
> ************************************************************/{code}
> Hari Sekhon
> http://www.linkedin.com/in/harisekhon
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