Hello.
I can see that if data node receives some IO error, this can cause
checkDir storm.
What I mean:
1) any error produces DataNode.checkDiskError call
2) this call locks volume:
java.lang.Thread.State: RUNNABLE
at java.io.UnixFileSystem.getBooleanAttributes0(Native Method)
at
java.io.UnixFileSystem.getBooleanAttributes(UnixFileSystem.java:228)
at java.io.File.exists(File.java:733)
at
org.apache.hadoop.util.DiskChecker.mkdirsWithExistsCheck(DiskChecker.java:65)
at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:86)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSDir.checkDirTree(FSDataset.java:228)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSDir.checkDirTree(FSDataset.java:232)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSDir.checkDirTree(FSDataset.java:232)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSDir.checkDirTree(FSDataset.java:232)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSVolume.checkDirs(FSDataset.java:414)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSVolumeSet.checkDirs(FSDataset.java:617)
- locked <0x000000080a8faec0> (a
org.apache.hadoop.hdfs.server.datanode.FSDataset$FSVolumeSet)
at
org.apache.hadoop.hdfs.server.datanode.FSDataset.checkDataDir(FSDataset.java:1681)
at
org.apache.hadoop.hdfs.server.datanode.DataNode.checkDiskError(DataNode.java:745)
at
org.apache.hadoop.hdfs.server.datanode.DataNode.checkDiskError(DataNode.java:735)
at
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.close(BlockReceiver.java:202)
at org.apache.hadoop.io.IOUtils.cleanup(IOUtils.java:151)
at org.apache.hadoop.io.IOUtils.closeStream(IOUtils.java:167)
at
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.receiveBlock(BlockReceiver.java:646)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.opWriteBlock(DataXceiver.java:352)
at
org.apache.hadoop.hdfs.protocol.DataTransferProtocol$Receiver.opWriteBlock(DataTransferProtocol.java:390)
at
org.apache.hadoop.hdfs.protocol.DataTransferProtocol$Receiver.processOp(DataTransferProtocol.java:331)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:111)
at java.lang.Thread.run(Thread.java:619)
3) This produces timeouts on other calls, e.g.
2011-06-17 17:35:03,922 WARN
org.apache.hadoop.hdfs.server.datanode.DataNode: checkDiskError: exception:
java.io.InterruptedIOException
at java.io.FileOutputStream.writeBytes(Native Method)
at java.io.FileOutputStream.write(FileOutputStream.java:260)
at
java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
at
java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
at java.io.DataOutputStream.flush(DataOutputStream.java:106)
at
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.close(BlockReceiver.java:183)
at org.apache.hadoop.io.IOUtils.cleanup(IOUtils.java:151)
at org.apache.hadoop.io.IOUtils.closeStream(IOUtils.java:167)
at
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.receiveBlock(BlockReceiver.java:646)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.opWriteBlock(DataXceiver.java:352)
at
org.apache.hadoop.hdfs.protocol.DataTransferProtocol$Receiver.opWriteBlock(DataTransferProtocol.java:390)
at
org.apache.hadoop.hdfs.protocol.DataTransferProtocol$Receiver.processOp(DataTransferProtocol.java:331)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:111)
at java.lang.Thread.run(Thread.java:619)
4) This, in turn, produces more "dir check calls".
5) All the cluster works very slow because of half-working node.
Best regards, Vitalii Tymchyshyn
