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Posted to dev@zookeeper.apache.org by "Flavio Junqueira (JIRA)" <ji...@apache.org> on 2010/11/02 23:52:25 UTC
[jira] Commented: (ZOOKEEPER-702) GSoC 2010: Failure Detector Model
[ https://issues.apache.org/jira/browse/ZOOKEEPER-702?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12927657#action_12927657 ]
Flavio Junqueira commented on ZOOKEEPER-702:
--------------------------------------------
Thanks, Abmar. It looks good to me. I have one quick comment, though. Is there any configuration value that could be causing tests to run slower? I have the impression that tests are running slightly slower with your patch. One in particular that called my attention was QuorumZxidSyncTest:
{noformat}
Trunk: [junit] Running org.apache.zookeeper.test.QuorumZxidSyncTest
[junit] Tests run: 2, Failures: 0, Errors: 0, Time elapsed: 94.55 sec
702: [junit] Running org.apache.zookeeper.test.QuorumZxidSyncTest
[junit] Tests run: 2, Failures: 0, Errors: 0, Time elapsed: 139.985 sec
{noformat}
and this seems to be pretty consistent.
> GSoC 2010: Failure Detector Model
> ---------------------------------
>
> Key: ZOOKEEPER-702
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-702
> Project: Zookeeper
> Issue Type: Wish
> Reporter: Henry Robinson
> Assignee: Abmar Barros
> Fix For: 3.4.0
>
> Attachments: bertier-pseudo.txt, bertier-pseudo.txt, chen-pseudo.txt, chen-pseudo.txt, phiaccrual-pseudo.txt, phiaccrual-pseudo.txt, ZOOKEEPER-702-code.patch, ZOOKEEPER-702-doc.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch, ZOOKEEPER-702.patch
>
>
> Failure Detector Module
> Possible Mentor
> Henry Robinson (henry at apache dot org)
> Requirements
> Java, some distributed systems knowledge, comfort implementing distributed systems protocols
> Description
> ZooKeeper servers detects the failure of other servers and clients by counting the number of 'ticks' for which it doesn't get a heartbeat from other machines. This is the 'timeout' method of failure detection and works very well; however it is possible that it is too aggressive and not easily tuned for some more unusual ZooKeeper installations (such as in a wide-area network, or even in a mobile ad-hoc network).
> This project would abstract the notion of failure detection to a dedicated Java module, and implement several failure detectors to compare and contrast their appropriateness for ZooKeeper. For example, Apache Cassandra uses a phi-accrual failure detector (http://ddsg.jaist.ac.jp/pub/HDY+04.pdf) which is much more tunable and has some very interesting properties. This is a great project if you are interested in distributed algorithms, or want to help re-factor some of ZooKeeper's internal code.
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