[HDFS-3332] NullPointerException in DN when directoryscanner is trying to report bad blocks

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha1
• Fix Version/s: 2.0.0-alpha
• Component/s: datanode

Environment

HDFS

• Hadoop Flags: Reviewed
• Assignee: amith
• Reporter: amith
• Created: 27/Apr/12 04:42
• Updated: 12/May/16 18:14
• Resolved: 03/May/12 19:18

Description

There is 1 NN and 1 DN (NN is started with HA conf)
I corrupted 1 block and found

2012-04-27 09:59:01,214 INFO  datanode.DataNode (BPServiceActor.java:blockReport(401)) - BlockReport of 2 blocks took 0 msec to generate and 5 msecs for RPC and NN processing
2012-04-27 09:59:01,214 INFO  datanode.DataNode (BPServiceActor.java:blockReport(420)) - sent block report, processed command:org.apache.hadoop.hdfs.server.protocol.FinalizeCommand@3b756db3
2012-04-27 09:59:01,726 INFO  datanode.DirectoryScanner (DirectoryScanner.java:scan(390)) - BlockPool BP-2087868617-10.18.40.95-1335500488012 Total blocks: 2, missing metadata files:0, missing block files:0, missing blocks in memory:0, mismatched blocks:1
2012-04-27 09:59:01,727 WARN  impl.FsDatasetImpl (FsDatasetImpl.java:checkAndUpdate(1366)) - Updating size of block -4466699320171028643 from 1024 to 1034
2012-04-27 09:59:01,727 WARN  impl.FsDatasetImpl (FsDatasetImpl.java:checkAndUpdate(1374)) - Reporting the block blk_-4466699320171028643_1004 as corrupt due to length mismatch
2012-04-27 09:59:01,728 DEBUG ipc.Client (Client.java:sendParam(807)) - IPC Client (1957050620) connection to /10.18.40.95:8020 from root sending #257
2012-04-27 09:59:01,730 DEBUG ipc.Client (Client.java:receiveResponse(848)) - IPC Client (1957050620) connection to /10.18.40.95:8020 from root got value #257
2012-04-27 09:59:01,730 DEBUG ipc.ProtobufRpcEngine (ProtobufRpcEngine.java:invoke(193)) - Call: reportBadBlocks 2
2012-04-27 09:59:01,731 ERROR datanode.DirectoryScanner (DirectoryScanner.java:run(288)) - Exception during DirectoryScanner execution - will continue next cycle
java.lang.NullPointerException
	at org.apache.hadoop.hdfs.protocol.DatanodeID.<init>(DatanodeID.java:66)
	at org.apache.hadoop.hdfs.protocol.DatanodeInfo.<init>(DatanodeInfo.java:87)
	at org.apache.hadoop.hdfs.server.datanode.BPServiceActor.reportBadBlocks(BPServiceActor.java:238)
	at org.apache.hadoop.hdfs.server.datanode.BPOfferService.reportBadBlocks(BPOfferService.java:187)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.reportBadBlocks(DataNode.java:559)
	at org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.checkAndUpdate(FsDatasetImpl.java:1377)
	at org.apache.hadoop.hdfs.server.datanode.DirectoryScanner.reconcile(DirectoryScanner.java:318)
	at org.apache.hadoop.hdfs.server.datanode.DirectoryScanner.run(DirectoryScanner.java:284)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
	at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:181)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:205)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)

Here when Directory scanner is trying to report badblock we got a NPE.