[jira] Commented: (ZOOKEEPER-136) sync causes hang in all followers of quorum
[ https://issues.apache.org/jira/browse/ZOOKEEPER-136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12636808#action_12636808 ] Hudson commented on ZOOKEEPER-136: -- Integrated in ZooKeeper-trunk #103 (See [http://hudson.zones.apache.org/hudson/job/ZooKeeper-trunk/103/]) .patch > sync causes hang in all followers of quorum > --- > > Key: ZOOKEEPER-136 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-136 > Project: Zookeeper > Issue Type: Bug >Affects Versions: 3.0.0 >Reporter: Patrick Hunt >Assignee: Benjamin Reed > Fix For: 3.0.0 > > Attachments: ZOOKEEPER-136.patch > > > The attached test causes all of the followers of a quorum to hang. Leader > continues to function correctly. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.
[jira] Commented: (ZOOKEEPER-136) sync causes hang in all followers of quorum
[ https://issues.apache.org/jira/browse/ZOOKEEPER-136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12633371#action_12633371 ] Flavio Paiva Junqueira commented on ZOOKEEPER-136: -- This patch is great! It adds a FollowerSyncRequest class to represent in-flight sync operations, and it cleans up a bit the logic on the leader side. Now, there are several modifications related to debugging messages, which don't seem to be always related to the problem is this jira. This is fine, though. I just commented because they make the patch look a lot more complex than it really is. Something I'd like to understand is the functionality of matchSyncs. Why do we need a boolean flag to decide whether to process or not? Is this to differentiate the processing of sync on a leader and on a follower? In any case, it is probably a good idea to insert a comment explaining. The comment that leads the code of SyncTest.java seems to be copied from elsewhere. Should we remove it and replace with a more representative comment? > sync causes hang in all followers of quorum > --- > > Key: ZOOKEEPER-136 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-136 > Project: Zookeeper > Issue Type: Bug >Affects Versions: 3.0.0 >Reporter: Patrick Hunt >Assignee: Benjamin Reed > Fix For: 3.0.0 > > Attachments: ZOOKEEPER-136.patch > > > The attached test causes all of the followers of a quorum to hang. Leader > continues to function correctly. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.
[jira] Commented: (ZOOKEEPER-136) sync causes hang in all followers of quorum
[ https://issues.apache.org/jira/browse/ZOOKEEPER-136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12628979#action_12628979 ] Benjamin Reed commented on ZOOKEEPER-136: - There are two problems in the code. First, the pendingSyncs hashtable assumes there will only be one pending request for a change operation. This is not a valid assumption. The syncHandler also assumes a single outstanding request for a given session since it removes the session handler from the table. I think a fix needs to get rid of both hashtables since it is very hard to do reliably. Instead we should attach information to Request to hang triggers to a list of SyncRequests. We should also tuck away the FollowerHandle to talk to in a sync specific subclass of Request. I tried doing the above and it worked out pretty well from a code understandability sense, but I still working on making test cases pass. > sync causes hang in all followers of quorum > --- > > Key: ZOOKEEPER-136 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-136 > Project: Zookeeper > Issue Type: Bug >Affects Versions: 3.0.0 >Reporter: Patrick Hunt >Assignee: Patrick Hunt > Fix For: 3.0.0 > > Attachments: log_ZOOKEEPER-136.txt, testfails_ZOOKEEPER-136.patch > > > The attached test causes all of the followers of a quorum to hang. Leader > continues to function correctly. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.
