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https://issues.apache.org/jira/browse/HDFS-16115?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Daniel Ma updated HDFS-16115:
-----------------------------
Description:
It is an improvement issue. Actually the issue has two sub issues:
1- BPServerActor thread handle commands from NameNode in aysnchronous way (
CommandProcessThread handle commands ), so if there are any exceptions or
errors happen in thread CommandProcessthread resulting the thread fails and
stop, of which BPServiceActor cannot aware and still keep putting commands from
namenode into queues waiting to be handled by CommandProcessThread, actually
CommandProcessThread was dead already.
2-the second sub issue is based on the first one, if CommandProcessThread was
dead owing to some non-fatal errors like "can not create native thread" which
is caused by too many threads existed on the node, this kind of problem should
be given much torlerance instead of simply shudown the thread and never recover
automatically, because the non-fatal errors mentioned above probably can be
recovered soon by itself,
currently, Datanode BPServiceActor cannot turn to normal even when the
non-fatal error was eliminated.
Therefor, in this patch, two things was be done:
1-Add retry mechanism in BPServiceActor thread and CommandProcessThread thread
which is 5 by default and configurable;
2-Add a monitor periodical thread in BPOfferService, if a BPServiceActor thread
is dead owing to too many times non-fatal error, it should not be simply
remove from BPServviceActor lists stored in BPOfferService, instead, the
monitor thread will periodically try to start these special dead BPService
Actor thread.
was:
It is an improvement issue. Actually the issue has two sub issues:
1- BPServerActor thread handle commands from NameNode in aysnchronous way (
CommandProcessThread handle commands ), so if there are any exceptions or
errors happen in thread CommandProcessthread resulting the thread fails and
stop, of which BPServiceActor cannot aware and still keep putting commands from
namenode into queues waiting to be handled by CommandProcessThread, actually
CommandProcessThread was dead already.
2-the second sub issue is based on the first one, if CommandProcessThread was
dead owing to some non-fatal errors like "can not create native thread" which
is caused by too many threads existed on the node, this kind of problem should
be given much torlerance instead of simply shudown the thread and never recover
automatically, because the non-fatal errors mentioned above probably can be
recovered soon by itself,
currently, Datanode BPServiceActor cannot turn to normal even when the
non-fatal error was eliminated.
> Asynchronously handle BPServiceActor command mechanism may result in
> BPServiceActor never fails even CommandProcessingThread is closed with fatal
> error.
> --------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-16115
> URL: https://issues.apache.org/jira/browse/HDFS-16115
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: datanode
> Affects Versions: 3.3.1
> Reporter: Daniel Ma
> Priority: Critical
> Fix For: 3.3.1
>
> Attachments: 0001-HDFS-16115.patch
>
>
> It is an improvement issue. Actually the issue has two sub issues:
> 1- BPServerActor thread handle commands from NameNode in aysnchronous way (
> CommandProcessThread handle commands ), so if there are any exceptions or
> errors happen in thread CommandProcessthread resulting the thread fails and
> stop, of which BPServiceActor cannot aware and still keep putting commands
> from namenode into queues waiting to be handled by CommandProcessThread,
> actually CommandProcessThread was dead already.
> 2-the second sub issue is based on the first one, if CommandProcessThread was
> dead owing to some non-fatal errors like "can not create native thread" which
> is caused by too many threads existed on the node, this kind of problem
> should be given much torlerance instead of simply shudown the thread and
> never recover automatically, because the non-fatal errors mentioned above
> probably can be recovered soon by itself,
> currently, Datanode BPServiceActor cannot turn to normal even when the
> non-fatal error was eliminated.
> Therefor, in this patch, two things was be done:
> 1-Add retry mechanism in BPServiceActor thread and CommandProcessThread
> thread which is 5 by default and configurable;
> 2-Add a monitor periodical thread in BPOfferService, if a BPServiceActor
> thread is dead owing to too many times non-fatal error, it should not be
> simply remove from BPServviceActor lists stored in BPOfferService, instead,
> the monitor thread will periodically try to start these special dead
> BPService Actor thread.
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