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Giri commented on HDFS-5074: ---------------------------- The namenode log is: 2013-09-26 10:44:41,914 FATAL org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer: Unknown error encountered while tailing edits. Shutting down standby NN. java.io.IOException: There appears to be a gap in the edit log. We expected txid 26, but got txid 5400. at org.apache.hadoop.hdfs.server.namenode.MetaRecoveryContext.editLogLoaderPrompt(MetaRecoveryContext.java:94) at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadEditRecords(FSEditLogLoader.java:183) at org.apache.hadoop.hdfs.server.namenode.FSEditLogLoader.loadFSEdits(FSEditLogLoader.java:111) at org.apache.hadoop.hdfs.server.namenode.FSImage.loadEdits(FSImage.java:733) at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer.doTailEdits(EditLogTailer.java:227) at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.doWork(EditLogTailer.java:321) at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.access$200(EditLogTailer.java:279) at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread$1.run(EditLogTailer.java:296) at org.apache.hadoop.security.SecurityUtil.doAsLoginUserOrFatal(SecurityUtil.java:456) at org.apache.hadoop.hdfs.server.namenode.ha.EditLogTailer$EditLogTailerThread.run(EditLogTailer.java:292) 2013-09-26 10:44:41,917 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1 > Allow starting up from an fsimage checkpoint in the middle of a segment > ----------------------------------------------------------------------- > > Key: HDFS-5074 > URL: https://issues.apache.org/jira/browse/HDFS-5074 > Project: Hadoop HDFS > Issue Type: Bug > Components: ha, namenode > Affects Versions: 3.0.0, 2.1.0-beta > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Attachments: hdfs-5074.txt > > > We've seen the following behavior a couple times: > - SBN is running and somehow encounters an error in the middle of replaying > an edit log in the tailer (eg the JN it's reading from crashes) > - SBN successfully has processed half of the edits in the segment it was > reading. > - SBN saves a checkpoint, which now falls in the middle of a segment, and > then restarts > Upon restart, the SBN will load this checkpoint which falls in the middle of > a segment. {{selectInputStreams}} then fails when the SBN requests a > mid-segment txid. > We should handle this case by downloading the right segment and > fast-forwarding to the correct txid. -- This message was sent by Atlassian JIRA (v6.1#6144)