[
https://issues.apache.org/jira/browse/SOLR-7571?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14570150#comment-14570150
]
Otis Gospodnetic edited comment on SOLR-7571 at 6/3/15 2:25 AM:
----------------------------------------------------------------
[~erickerickson] - Not sure yet, would have to see which numbers you'd end up
having, but I'm guessing you could construct MBean names in such a way that the
name of the leader would be a part of its name (think about parsing, allowed
vs. forbidden chars!) and the metric you want to return would be the MBean
value.
Now that I think about this, you should also probably think about how the size
of Solr response would be affected by more info being added to every response
and how much that would affect the client that has to process this. Providing
this via JMX, which does not stand between client and server on every request,
and is checked independently of search requests, maaaay in some ways be better.
was (Author: otis):
[~erickerickson] - Not sure yet, would have to see which numbers you'd end up
having, but I'm guessing you could construct MBean names in such a way that the
name of the leader would be a part of its name (think about parsing, allowed
vs. forbidden chars!) and the metric you want to return would be the MBean
value.
> Return metrics with update requests to allow clients to self-throttle
> ---------------------------------------------------------------------
>
> Key: SOLR-7571
> URL: https://issues.apache.org/jira/browse/SOLR-7571
> Project: Solr
> Issue Type: Improvement
> Affects Versions: 4.10.3
> Reporter: Erick Erickson
> Assignee: Erick Erickson
>
> I've assigned this to myself to keep track of it, anyone who wants please
> feel free to take this.
> I've recently seen a setup with 10 shards and 4 replicas. The SolrJ client
> (and post.jar for json files for that matter) firehose updates (150 separate
> threads in total) at Solr. Eventually, replicas (not leaders) go into
> recovery and the state cascades and eventually the entire cluster becomes
> unusable. SOLR-5850 delays the behavior, but it still occurs. There are no
> errors in the follower's logs this is leader-initiated-recovery because of a
> timeout.
> I think the root problem is that the client is just sending too many requests
> to the cluster, and ConcurrentUpdateSolrClient/Server (used by the leader to
> distribute update requests to all the followers) (this was observed in Solr
> 4.10.3+). I see thread counts of 500+ when this happens.
> So assuming that this is the root cause, the obvious "cure" is "don't index
> that fast". This is unsatisfactory since "that fast" is variable, the only
> recourse is to set that threshold low enough that the Solr cluster isn't
> being driven as fast is it can be.
> We should provide some mechanism for having the client throttle itself. The
> number of outstanding update threads is one possibility. The client could
> then slow down sending updates to Solr.
> I'm not sure there's a good way to deal with this on the server. Once the
> timeout is encountered, you don't know whether the doc has actually been
> indexed on the follower (actually, in this case it _is_ indexed, it just take
> a while). Ideally we'd just manage it all magically, but an alternative to
> let clients dynamically throttle themselves seems do-able.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
