You are viewing a plain text version of this content. The canonical link for it is here.
Posted to hdfs-issues@hadoop.apache.org by "Xiaoqiao He (Jira)" <ji...@apache.org> on 2020/03/05 08:51:00 UTC

[jira] [Commented] (HDFS-15113) Missing IBR when NameNode restart if open processCommand async feature

    [ https://issues.apache.org/jira/browse/HDFS-15113?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17051909#comment-17051909 ] 

Xiaoqiao He commented on HDFS-15113:
------------------------------------

Sorry for late response due to long time vacation.
submit v004 and try to add unit test to cover this case. Please give another review. cc [~elgoiri],[~weichiu],[~brahmareddy]. Thanks all.

> Missing IBR when NameNode restart if open processCommand async feature
> ----------------------------------------------------------------------
>
>                 Key: HDFS-15113
>                 URL: https://issues.apache.org/jira/browse/HDFS-15113
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: datanode
>            Reporter: Xiaoqiao He
>            Assignee: Xiaoqiao He
>            Priority: Blocker
>         Attachments: HDFS-15113.001.patch, HDFS-15113.002.patch, HDFS-15113.003.patch, HDFS-15113.004.patch
>
>
> Recently, I meet one case that NameNode missing block after restart which is related with HDFS-14997.
> a. during NameNode restart, it will return command `DNA_REGISTER` to DataNode when receive some RPC request from DataNode.
> b. when DataNode receive `DNA_REGISTER` command, it will run #reRegister async.
> {code:java}
>   void reRegister() throws IOException {
>     if (shouldRun()) {
>       // re-retrieve namespace info to make sure that, if the NN
>       // was restarted, we still match its version (HDFS-2120)
>       NamespaceInfo nsInfo = retrieveNamespaceInfo();
>       // and re-register
>       register(nsInfo);
>       scheduler.scheduleHeartbeat();
>       // HDFS-9917,Standby NN IBR can be very huge if standby namenode is down
>       // for sometime.
>       if (state == HAServiceState.STANDBY || state == HAServiceState.OBSERVER) {
>         ibrManager.clearIBRs();
>       }
>     }
>   }
> {code}
> c. As we know, #register will trigger BR immediately.
> d. because #reRegister run async, so we could not make sure which one run first between send FBR and clear IBR. If clean IBR run first, it will be OK. But if send FBR first then clear IBR, it will missing some blocks received between these two time point until next FBR.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org