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Posted to dev@zookeeper.apache.org by "Flavio Paiva Junqueira (JIRA)" <ji...@apache.org> on 2008/10/05 13:18:44 UTC

[jira] Created: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Leader and followers increase cpu utilization upon loss of a follower
---------------------------------------------------------------------

                 Key: ZOOKEEPER-158
                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
             Project: Zookeeper
          Issue Type: Improvement
          Components: quorum
            Reporter: Flavio Paiva Junqueira
            Priority: Minor


In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Flavio Paiva Junqueira (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12748323#action_12748323 ] 

Flavio Paiva Junqueira commented on ZOOKEEPER-158:
--------------------------------------------------

Is this the same issue as ZOOKEEPER-427?

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>             Fix For: 3.3.0
>
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Patrick Hunt (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642341#action_12642341 ] 

Patrick Hunt commented on ZOOKEEPER-158:
----------------------------------------

re logs remember that you can increase the logging level from the default INFO to DEBUG or TRACE by editing the log4j config file.

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Updated: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
     [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mahadev konar updated ZOOKEEPER-158:
------------------------------------

    Fix Version/s: 3.3.0

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>             Fix For: 3.3.0
>
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642335#action_12642335 ] 

Mahadev konar commented on ZOOKEEPER-158:
-----------------------------------------

i dont see anything in the logs that would help us identify the problem. how much was the substantial increase in the cpu utilitization ? the logs of the leader should help.... 


> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Assigned: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
     [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mahadev konar reassigned ZOOKEEPER-158:
---------------------------------------

    Assignee: Mahadev konar

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642340#action_12642340 ] 

Mahadev konar commented on ZOOKEEPER-158:
-----------------------------------------

well if its easy to reproduce then we should be able to just attach a profiler to the nodes.... i will try this out with a profiler and post the results ... 

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Updated: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Flavio Paiva Junqueira (JIRA)" <ji...@apache.org>.
     [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Flavio Paiva Junqueira updated ZOOKEEPER-158:
---------------------------------------------

    Attachment: dead-follower.tar.gz

Attaching logs provided by Stu Hood (copying from JIRA 157).

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Flavio Paiva Junqueira (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642345#action_12642345 ] 

Flavio Paiva Junqueira commented on ZOOKEEPER-158:
--------------------------------------------------

I think that profiling is a great idea in this case.

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Resolved: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
     [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mahadev konar resolved ZOOKEEPER-158.
-------------------------------------

    Resolution: Fixed

this issue was same as ZOOKEEPER-427. closing it as resolved.

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>             Fix For: 3.3.0
>
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Mahadev konar (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12748595#action_12748595 ] 

Mahadev konar commented on ZOOKEEPER-158:
-----------------------------------------

dont know... could be... ill take a look at the logs and see if thats the problem... 

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>             Fix For: 3.3.0
>
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Patrick Hunt (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642346#action_12642346 ] 

Patrick Hunt commented on ZOOKEEPER-158:
----------------------------------------

another interesting thing to try is run with JMX enabled and you can use jconsole to attach to the VM and get some detail about the VM/ZK during the election.


> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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[jira] Commented: (ZOOKEEPER-158) Leader and followers increase cpu utilization upon loss of a follower

Posted by "Flavio Paiva Junqueira (JIRA)" <ji...@apache.org>.
    [ https://issues.apache.org/jira/browse/ZOOKEEPER-158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12642339#action_12642339 ] 

Flavio Paiva Junqueira commented on ZOOKEEPER-158:
--------------------------------------------------

I also observed this issue using top. To recreate it, I have started 3 servers, killed one follower after a leader had been elected, and use top to observe cpu utilization.I'm not sure how we can pinpoint the problem from the logs. 

> Leader and followers increase cpu utilization upon loss of a follower
> ---------------------------------------------------------------------
>
>                 Key: ZOOKEEPER-158
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-158
>             Project: Zookeeper
>          Issue Type: Improvement
>          Components: quorum
>            Reporter: Flavio Paiva Junqueira
>            Assignee: Mahadev konar
>            Priority: Minor
>         Attachments: dead-follower.tar.gz
>
>
> In a set of ZooKeeper servers, when there is a leader operation and supported by a quorum of servers, we have observed that cpu utilization increases substantially once a follower fails or disconnects. Stu Hood provided logs showing this behavior.

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