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Arpit Agarwal updated HDFS-7066: -------------------------------- Affects Version/s: (was: 2.5.1) HDFS-6581 > LazyWriter#evictBlocks misses a null check for replicaState > ----------------------------------------------------------- > > Key: HDFS-7066 > URL: https://issues.apache.org/jira/browse/HDFS-7066 > Project: Hadoop HDFS > Issue Type: Bug > Components: datanode > Affects Versions: HDFS-6581 > Reporter: Xiaoyu Yao > Assignee: Xiaoyu Yao > Priority: Minor > Fix For: HDFS-6581 > > Attachments: HDFS-7066.0.patch > > > LazyWriter#evictBlocks (added for HDFS-6581) misses a null check for > replicaState. As a result, there are many NPEs in the debug log under certain > conditions. > {code} > 2014-09-15 14:27:10,820 DEBUG impl.FsDatasetImpl > (FsDatasetImpl.java:evictBlocks(2335)) - Evicting block null > 2014-09-15 14:27:10,821 WARN impl.FsDatasetImpl > (FsDatasetImpl.java:run(2409)) - Ignoring exception in LazyWriter: > java.lang.NullPointerException > at > org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl$LazyWriter.evictBlocks(FsDatasetImpl.java:2343) > at > org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl$LazyWriter.run(FsDatasetImpl.java:2396) > at java.lang.Thread.run(Thread.java:745) > {code} > The proposed fix is to break if there is no candidate available to evict. > {code} > while (iterations++ < MAX_BLOCK_EVICTIONS_PER_ITERATION && > transientFreeSpaceBelowThreshold()) { > LazyWriteReplicaTracker.ReplicaState replicaState = > lazyWriteReplicaTracker.getNextCandidateForEviction(); > ++++++++++++++++++++ > if (replicaState == null) { > break; > } > ++++++++++++++++++++ > if (LOG.isDebugEnabled()) { > LOG.debug("Evicting block " + replicaState); > } > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)