[
https://issues.apache.org/jira/browse/HDFS-13596?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16910853#comment-16910853
]
Wei-Chiu Chuang commented on HDFS-13596:
----------------------------------------
Given how much test this patch has been going through, I think the patch is
ready to go.
I think it would make sense to update the "HDFS Rolling Upgrade" doc to call
out the limitation of the approach -- if I understand the patch correctly,
until HDFS finalizes upgrade, it won’t accept any erasure coding operations.
Additionally, NameNode does not write out ec information in edit log, and does
not check point with ec information in the new fsimage.
Additionally, what [~Malygin] and [~ferhui] found, that downgrade from 3.3.0 to
2.7.x can not complete successfully without reverting the commit "Fix potential
FSImage corruption." Have folks tried rolling upgrade/downgrade between 2.8.x
and 3.x? Does that work without reverting that commit? That commit is a
critical fix and it is not acceptable to revert it for many users.
> NN restart fails after RollingUpgrade from 2.x to 3.x
> -----------------------------------------------------
>
> Key: HDFS-13596
> URL: https://issues.apache.org/jira/browse/HDFS-13596
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs
> Reporter: Hanisha Koneru
> Assignee: Fei Hui
> Priority: Blocker
> Attachments: HDFS-13596.001.patch, HDFS-13596.002.patch,
> HDFS-13596.003.patch, HDFS-13596.004.patch, HDFS-13596.005.patch,
> HDFS-13596.006.patch, HDFS-13596.007.patch, HDFS-13596.008.patch,
> HDFS-13596.009.patch
>
>
> After rollingUpgrade NN from 2.x and 3.x, if the NN is restarted, it fails
> while replaying edit logs.
> * After NN is started with rollingUpgrade, the layoutVersion written to
> editLogs (before finalizing the upgrade) is the pre-upgrade layout version
> (so as to support downgrade).
> * When writing transactions to log, NN writes as per the current layout
> version. In 3.x, erasureCoding bits are added to the editLog transactions.
> * So any edit log written after the upgrade and before finalizing the
> upgrade will have the old layout version but the new format of transactions.
> * When NN is restarted and the edit logs are replayed, the NN reads the old
> layout version from the editLog file. When parsing the transactions, it
> assumes that the transactions are also from the previous layout and hence
> skips parsing the erasureCoding bits.
> * This cascades into reading the wrong set of bits for other fields and
> leads to NN shutting down.
> Sample error output:
> {code:java}
> java.lang.IllegalArgumentException: Invalid clientId - length is 0 expected
> length 16
> at com.google.common.base.Preconditions.checkArgument(Preconditions.java:88)
> at org.apache.hadoop.ipc.RetryCache$CacheEntry.<init>(RetryCache.java:74)
> at org.apache.hadoop.ipc.RetryCache$CacheEntry.<init>(RetryCache.java:86)
> at
> org.apache.hadoop.ipc.RetryCache$CacheEntryWithPayload.<init>(RetryCache.java:163)
> at
> org.apache.hadoop.ipc.RetryCache.addCacheEntryWithPayload(RetryCache.java:322)
> at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.addCacheEntryWithPayload(FSNamesystem.java:960)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.applyEditLogOp(FSEditLogLoader.java:397)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:249)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:158)
> at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:888)
> at
> org.apache.hadoop.hdfs.server.namenode.FSImage.loadFSImage(FSImage.java:745)
> at
> org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:323)
> at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1086)
> at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:714)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:632)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:694)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:937)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:910)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1643)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1710)
> 2018-05-17 19:10:06,522 WARN
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Encountered exception
> loading fsimage
> java.io.IOException: java.lang.IllegalStateException: Cannot skip to less
> than the current value (=16389), where newValue=16388
> at
> org.apache.hadoop.hdfs.server.namenode.FSDirectory.resetLastInodeId(FSDirectory.java:1945)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:298)
> at
> org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:158)
> at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:888)
> at
> org.apache.hadoop.hdfs.server.namenode.FSImage.loadFSImage(FSImage.java:745)
> at
> org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:323)
> at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1086)
> at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:714)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:632)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:694)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:937)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:910)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1643)
> at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1710)
> Caused by: java.lang.IllegalStateException: Cannot skip to less than the
> current value (=16389), where newValue=16388
> at org.apache.hadoop.util.SequentialNumber.skipTo(SequentialNumber.java:58)
> at
> org.apache.hadoop.hdfs.server.namenode.FSDirectory.resetLastInodeId(FSDirectory.java:1943)
> {code}
--
This message was sent by Atlassian Jira
(v8.3.2#803003)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
