[jira] [Commented] (ACCUMULO-1454) Need good way to perform a rolling restart of all tablet servers

["Christopher Tubbs (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ACCUMULO-1454?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13664592#comment-13664592 ] 

Christopher Tubbs commented on ACCUMULO-1454:
---------------------------------------------

This shouldn't be too difficult. Essentially, one needs to pause load balancing before each server goes down, and resume when the server comes back.

This could be done with a load balancer that detects that one is in a "rolling-upgrade" state, and is less aggressive about tablet assignment... maybe through a simple timeout delay before assignment.
                
> Need good way to perform a rolling restart of all tablet servers
> ----------------------------------------------------------------
>
>                 Key: ACCUMULO-1454
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-1454
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: tserver
>    Affects Versions: 1.5.0, 1.4.3
>            Reporter: Mike Drob
>
> When needing to change a tserver parameter (e.g. java heap space) across the entire cluster, there is not a graceful way to perform a rolling restart.
> The naive approach of just killing tservers one at a time causes a lot of churn on the cluster as tablets move around and zookeeper tries to maintain current state.
> Potential solutions might be via a fancy fate operation, with coordination by the master. Ideally, the master would know which servers are 'safe' to restart and could minimize overall impact during the operation.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira