Qi created FLINK-12426:
--------------------------
Summary: TM occasionally hang in deploying state
Key: FLINK-12426
URL: https://issues.apache.org/jira/browse/FLINK-12426
Project: Flink
Issue Type: Bug
Reporter: Qi
Hi all,
We use Flink batch and start thousands of jobs per day. Occasionally we
observed some stuck jobs, due to some TM hang in “DEPLOYING” state.
It seems that the TM is calling BlobClient to download jars from JM/BlobServer.
Under hood it’s calling Socket.connect() and then Socket.read() to retrieve
results.
These jobs usually have many TM slots (1~2k). We checked the TM log and dumped
the TM thread. It indeed hung on socket read to download jar from Blob server.
We're using Flink 1.5 but this may also affect later versions since related
code are not changed much. We've tried to add socket timeout in BlobClient, but
still no luck.
————————
TM log
————————
...
INFO org.apache.flink.runtime.taskexecutor.TaskExecutor - Received task
DataSource (at createInput(ExecutionEnvironment.java:548) (our.code))
(184/2000). INFO org.apache.flink.runtime.taskmanager.Task - DataSource (at
createInput(ExecutionEnvironment.java:548) (our.code)) (184/2000) switched from
CREATED to DEPLOYING. INFO org.apache.flink.runtime.taskmanager.Task - Creating
FileSystem stream leak safety net for task DataSource (at
createInput(ExecutionEnvironment.java:548) (our.code)) (184/2000) [DEPLOYING]
INFO org.apache.flink.runtime.taskmanager.Task - Loading JAR files for task
DataSource (at createInput(ExecutionEnvironment.java:548) (our.code))
(184/2000) [DEPLOYING]. INFO org.apache.flink.runtime.blob.BlobClient -
Downloading
19e65c0caa41f264f9ffe4ca2a48a434/p-3ecd6341bf97d5512b14c93f6c9f51f682b6db26-37d5e69d156ee00a924c1ebff0c0d280
from some-host-ip-port
{color:#222222}no more logs...{color}
————————
TM thread dump:
————————
_"DataSource (at createInput(ExecutionEnvironment.java:548) (our.code))
(1999/2000)" #72 prio=5 os_prio=0 tid=0x00007fb9a1521000 nid=0xa0994 runnable
[0x00007fb97cfbf000]_
_java.lang.Thread.State: RUNNABLE_
_at java.net.SocketInputStream.socketRead0(Native Method)_
_at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)_
_at java.net.SocketInputStream.read(SocketInputStream.java:171)_
_at java.net.SocketInputStream.read(SocketInputStream.java:141)_
_at
org.apache.flink.runtime.blob.BlobInputStream.read(BlobInputStream.java:152)_
_at
org.apache.flink.runtime.blob.BlobInputStream.read(BlobInputStream.java:140)_
_at
org.apache.flink.runtime.blob.BlobClient.downloadFromBlobServer(BlobClient.java:170)_
_at
org.apache.flink.runtime.blob.AbstractBlobCache.getFileInternal(AbstractBlobCache.java:181)_
_at
org.apache.flink.runtime.blob.PermanentBlobCache.getFile(PermanentBlobCache.java:206)_
_at
org.apache.flink.runtime.execution.librarycache.BlobLibraryCacheManager.registerTask(BlobLibraryCacheManager.java:120)_
_- locked <0x000000078ab60ba8> (a java.lang.Object)_
_at
org.apache.flink.runtime.taskmanager.Task.createUserCodeClassloader(Task.java:893)_
_at org.apache.flink.runtime.taskmanager.Task.run(Task.java:585)_
_at java.lang.Thread.run(Thread.java:748)_
_————————_
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
