Haibo Sun created FLINK-12547: --------------------------------- Summary: Deadlock when the task thread downloads jars using BlobClient Key: FLINK-12547 URL: https://issues.apache.org/jira/browse/FLINK-12547 Project: Flink Issue Type: Bug Components: Runtime / Operators Affects Versions: 1.8.0 Reporter: Haibo Sun Assignee: Haibo Sun
The jstack is as follows (this jstack is from an old Flink version, but the master branch has the same problem). {code:java} "Source: Custom Source (76/400)" #68 prio=5 os_prio=0 tid=0x00007f8139cd3000 nid=0xe2 runnable [0x00007f80da5fd000] 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:170) 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:164) 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 <0x000000062cf2a188> (a java.lang.Object) at org.apache.flink.runtime.taskmanager.Task.createUserCodeClassloader(Task.java:968) at org.apache.flink.runtime.taskmanager.Task.run(Task.java:604) at java.lang.Thread.run(Thread.java:834) Locked ownable synchronizers: - None {code} The reason is that SO_TIMEOUT is not set in the socket connection of the blob client. When the network packet loss seriously due to the high CPU load of the machine, the blob client connection fails to perceive that the server has been disconnected, which results in blocking in the native method. -- This message was sent by Atlassian JIRA (v7.6.3#76005)