Major Description
We saw the following error in JournalNodes a few times before.
2016-09-22 12:44:24,505 WARN org.apache.hadoop.hdfs.server.namenode.FSImage: Caught exception after scanning through 0 ops from /data/1/dfs/current/ed its_inprogress_0000000000000661942 while determining its valid length. Position was 761856 java.io.IOException: Can't scan a pre-transactional edit log. at org.apache.hadoop.hdfs.server.namenode.FSEditLogOp$LegacyReader.scanOp(FSEditLogOp.java:4592) at org.apache.hadoop.hdfs.server.namenode.EditLogFileInputStream.scanNextOp(EditLogFileInputStream.java:245) at org.apache.hadoop.hdfs.server.namenode.EditLogFileInputStream.scanEditLog(EditLogFileInputStream.java:355) at org.apache.hadoop.hdfs.server.namenode.FileJournalManager$EditLogFile.scanLog(FileJournalManager.java:551) at org.apache.hadoop.hdfs.qjournal.server.Journal.scanStorageForLatestEdits(Journal.java:193) at org.apache.hadoop.hdfs.qjournal.server.Journal.<init>(Journal.java:153) at org.apache.hadoop.hdfs.qjournal.server.JournalNode.getOrCreateJournal(JournalNode.java:90)
The edit file was corrupt, and one possible culprit of this error is a full disk. The JournalNode can't recovered and must be resync manually from other JournalNodes.