[jira] [Commented] (CURATOR-439) CuratorFrameworkState STARTED, but ZookeeperClient not connected

["Alex Rankin (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CURATOR-439?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16445867#comment-16445867 ] 

Alex Rankin commented on CURATOR-439:
-------------------------------------

Updating the status to major. After a network outage we saw the Curator status was STARTED, but the Zookeeper client was not connected. This resulted in an outage and forced us to bounce the applications.

> CuratorFrameworkState STARTED, but ZookeeperClient not connected
> ----------------------------------------------------------------
>
>                 Key: CURATOR-439
>                 URL: https://issues.apache.org/jira/browse/CURATOR-439
>             Project: Apache Curator
>          Issue Type: Bug
>          Components: Framework
>    Affects Versions: 3.2.1
>            Reporter: Alex Rankin
>            Priority: Major
>
> I recently ran into an issue on some of our nodes caused by network issues between a service and Zookeeper. I have been unable to recreate them as of yet, but I'm still trying.
> *+Setup+*
> 5x services using Curator 3.2.1 to talk to Zookeeper 3.5.3 cluster (also 5 nodes).
> Network issues caused the services to disconnect from Zookeeper. 
> There's a check in our code to see if the Zookeeper connection is available before sending a request:
> {quote}public boolean isConnected() \{
>     return curatorFramework.getZookeeperClient().isConnected();
> \}
> {quote}
> After the network issues resolved, we noticed that all calls to Zookeeper from 4 of the services were still failing (the fifth was fine). Checking the logs, we saw that {{CuratorFramework.getState()}} was reporting the state as STARTED, but {{curatorFramework.getZookeeperClient().isConnected();}} was returning false. Restarting the service fixed everything, but I want to obviously avoid this issue in future.
> *+Problem+*
> I couldn't find any documentation stating whether the {{CuratorZookeeperClient.isConnected()}} should be used, or if {{CuratorFramework.getState() == CuratorFrameworkState.STARTED}} (the functionality of the deprecated {{CuratorFramework.isConnected()}}) would be the better check, or if these should both be equivalent, and there's a bug that let one be true while the other was false.
> If my own check is wrong, and I shouldn't be using {{CuratorZookeeperClient.isConnected()}}, then I can easily fix that. I wanted to check the expected behaviour before diving too deep into this, in case this is normal and I am just using Curator incorrectly.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)