[jira] Assigned: (ZOOKEEPER-417) stray message problem when changing servers

["Patrick Hunt (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/ZOOKEEPER-417?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Patrick Hunt reassigned ZOOKEEPER-417:
--------------------------------------

    Assignee: Benjamin Reed

> stray message problem when changing servers
> -------------------------------------------
>
>                 Key: ZOOKEEPER-417
>                 URL: https://issues.apache.org/jira/browse/ZOOKEEPER-417
>             Project: Zookeeper
>          Issue Type: Bug
>            Reporter: Benjamin Reed
>            Assignee: Benjamin Reed
>            Priority: Blocker
>             Fix For: 3.2.0
>
>
> There is  a possibility for stray messages from a previous connection to violate ordering and generally cause problems. Here is a scenario: we have a client, C, two followers, F1 and F2, and a leader, L. The client is connected to F1, which is a slow follower. C sends setData("/a", "1") to F1 and then loses the connection, so C reconnects to F2 and sends setData("/a", "2").  it is possible, if F1 is slow enough and the setData("/a", "1") got onto the network before the connection break, for F1 to forward the setData("/a", "1") to L after F2 forwards setData("/a", "2").
> to fix this, the leader should keep track of which follower last registered a session for a client and drop any requests from followers for clients for whom they do not have a registration. 

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.