zhouyingchao created HDFS-7999:
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Summary: DN Hearbeat is blocked by waiting FsDatasetImpl lock
Key: HDFS-7999
URL: https://issues.apache.org/jira/browse/HDFS-7999
Project: Hadoop HDFS
Issue Type: Bug
Affects Versions: 2.6.0
Reporter: zhouyingchao
I'm using 2.6.0 and noticed that sometime DN's heartbeat were delayed for very
long time, say more than 100 seconds. I get the jstack twice and looks like
they are all blocked (at getStorageReport) by dataset lock, and which is held
by a thread that is calling createTemporary, which again is blocked to wait
earlier incarnation writer to exit.
The heartbeat thread stack:
java.lang.Thread.State: BLOCKED (on object monitor)
at
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsVolumeImpl.getDfsUsed(FsVolumeImpl.java:152)
- waiting to lock <0x00000007b01428c0> (a
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl)
at
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.getStorageReports(FsDatasetImpl.java:144)
- locked <0x00000007b0140ed0> (a java.lang.Object)
at
org.apache.hadoop.hdfs.server.datanode.BPServiceActor.sendHeartBeat(BPServiceActor.java:575)
at
org.apache.hadoop.hdfs.server.datanode.BPServiceActor.offerService(BPServiceActor.java:680)
at
org.apache.hadoop.hdfs.server.datanode.BPServiceActor.run(BPServiceActor.java:850)
at java.lang.Thread.run(Thread.java:662)
The DataXceiver thread holds the dataset lock:
"DataXceiver for client at XXXXX" daemon prio=10 tid=0x00007f14041e6480
nid=0x52bc in Object.wait() [0x00007f11d78f7000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at java.lang.Thread.join(Thread.java:1194)
locked <0x00000007a33b85d8> (a org.apache.hadoop.util.Daemon)
at
org.apache.hadoop.hdfs.server.datanode.ReplicaInPipeline.stopWriter(ReplicaInPipeline.java:183)
at
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.createTemporary(FsDatasetImpl.java:1231)
locked <0x00000007b01428c0> (a
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl)
at
org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetImpl.createTemporary(FsDatasetImpl.java:114)
at
org.apache.hadoop.hdfs.server.datanode.BlockReceiver.<init>(BlockReceiver.java:179)
at
org.apache.hadoop.hdfs.server.datanode.DataXceiver.writeBlock(DataXceiver.java:615)
at
org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.opWriteBlock(Receiver.java:137)
at
org.apache.hadoop.hdfs.protocol.datatransfer.Receiver.processOp(Receiver.java:74)
at org.apache.hadoop.hdfs.server.datanode.DataXceiver.run(DataXceiver.java:235)
at java.lang.Thread.run(Thread.java:662)
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