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https://issues.apache.org/jira/browse/SOLR-5476?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13895610#comment-13895610
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Mark Miller commented on SOLR-5476:
-----------------------------------
I don't know that that is a great solution either though.
For one, future overseer tasks may have nothing to do with the state delay.
For two, you don't know how long any overseer job will take - you might wait
that delay, but the overseer may be taking 30 seconds or more to run a command
and then when it done it removes a queue item out from the new overseer,
killing the thread. I can't work out how this protects against Overseers
completely from overlapping.
I've thought through a lot of this type of thing, and it just seems like there
are lots of holes that are very hard to fill on this path.
> Overseer Role for nodes
> -----------------------
>
> Key: SOLR-5476
> URL: https://issues.apache.org/jira/browse/SOLR-5476
> Project: Solr
> Issue Type: Sub-task
> Components: SolrCloud
> Reporter: Noble Paul
> Assignee: Noble Paul
> Fix For: 5.0, 4.7
>
> Attachments: SOLR-5476.patch, SOLR-5476.patch, SOLR-5476.patch,
> SOLR-5476.patch, SOLR-5476.patch, SOLR-5476.patch
>
>
> In a very large cluster the Overseer is likely to be overloaded.If the same
> node is a serving a few other shards it can lead to OverSeer getting slowed
> down due to GC pauses , or simply too much of work . If the cluster is
> really large , it is possible to dedicate high end h/w for OverSeers
> It works as a new collection admin command
> command=addrole&role=overseer&node=192.168.1.5:8983_solr
> This results in the creation of a entry in the /roles.json in ZK which would
> look like the following
> {code:javascript}
> {
> "overseer" : ["192.168.1.5:8983_solr"]
> }
> {code}
> If a node is designated for overseer it gets preference over others when
> overseer election takes place. If no designated servers are available another
> random node would become the Overseer.
> Later on, if one of the designated nodes are brought up ,it would take over
> the Overseer role from the current Overseer to become the Overseer of the
> system
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