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Weiwei Yang commented on HDFS-12638: ------------------------------------ Hi [~shv] I don't think what you suggested could fix this. Please see attachment [^OphanBlocksAfterTruncateDelete.jpg]. We are hinting the NPE because inode is removed but the block {{blk_1073741825}} was left over (created during copy-on-truncate), then if we look for INode by the block bcID {{16387}}, we get a {{null}}. What you suggested seems still be operating on deleted block {{blk_1073741826}}, I tried and it did not resolve this problem. Please take a look and let me know if I have any place wrong. Thanks. > NameNode exits due to ReplicationMonitor thread received Runtime exception in > ReplicationWork#chooseTargets > ----------------------------------------------------------------------------------------------------------- > > Key: HDFS-12638 > URL: https://issues.apache.org/jira/browse/HDFS-12638 > Project: Hadoop HDFS > Issue Type: Bug > Components: hdfs > Affects Versions: 2.8.2 > Reporter: Jiandan Yang > Attachments: HDFS-12638-branch-2.8.2.001.patch, > OphanBlocksAfterTruncateDelete.jpg > > > Active NamNode exit due to NPE, I can confirm that the BlockCollection passed > in when creating ReplicationWork is null, but I do not know why > BlockCollection is null, By view history I found > [HDFS-9754|https://issues.apache.org/jira/browse/HDFS-9754] remove judging > whether BlockCollection is null. > NN logs are as following: > {code:java} > 2017-10-11 16:29:06,161 ERROR [ReplicationMonitor] > org.apache.hadoop.hdfs.server.blockmanagement.BlockManager: > ReplicationMonitor thread received Runtime exception. > java.lang.NullPointerException > at > org.apache.hadoop.hdfs.server.blockmanagement.ReplicationWork.chooseTargets(ReplicationWork.java:55) > at > org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.computeReplicationWorkForBlocks(BlockManager.java:1532) > at > org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.computeReplicationWork(BlockManager.java:1491) > at > org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.computeDatanodeWork(BlockManager.java:3792) > at > org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$ReplicationMonitor.run(BlockManager.java:3744) > at java.lang.Thread.run(Thread.java:834) > {code} -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org