slfan1989 opened a new pull request, #4438:
URL: https://github.com/apache/hadoop/pull/4438

   JIRA:HDFS-16631. Enable dfs.datanode.lockmanager.trace In Test.
   
   In Jira [HDFS-16600](https://issues.apache.org/jira/browse/HDFS-16600). Fix 
deadlock on DataNode side. We discussed the issue of deadlock, this is a very 
meaningful discussion, I was reading the log and found the following:
   
   ```
   2022-05-27 07:39:47,890 [Listener at localhost/36941] WARN 
datanode.DataSetLockManager (DataSetLockManager.java:lockLeakCheck(261)) -
    not open lock leak check func.
   ```
   
   Looking at the code, I found that there is such a parameter:
   ```
   <property>
       <name>dfs.datanode.lockmanager.trace</name>
       <value>false</value>
       <description>
         If this is true, after shut down datanode lock Manager will print all 
leak
         thread that not release by lock Manager. Only used for test or trace 
dead lock
         problem. In produce default set false, because it's have little 
performance loss.
       </description>
     </property> 
   ```
   
   I think this parameter should be added in the test environment, so that if 
there is a DN deadlock, the cause can be quickly located.
   
   If my understanding is correct, if a thread needs both read locks and write 
locks, if this parameter is true, relevant thread information can be printed.
   
   
   


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to