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https://issues.apache.org/jira/browse/SOLR-5986?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14127767#comment-14127767
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Steve Davids commented on SOLR-5986:
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bq. I think this should be ok, specially considering the intention is to make 
sure that the request is killed and doesn't run forever.
+1, this is a good starting point and can be further refined in the future if 
need be.

I went ahead and opened SOLR-6496 to account for the LBHttpSolrServer's 
continual retries. Also, I am a little concerned that the cursorMark doesn't 
honor the timeAllowed request parameter for some strange reason (the cursorMark 
ticket didn't provide any rational for it), we may want to revisit that 
decision in yet another ticket so people can be confident their cursor mark 
queries won't crash their clusters as well.

Thanks for taking this on Anshum!

> Don't allow runaway queries from harming Solr cluster health or search 
> performance
> ----------------------------------------------------------------------------------
>
>                 Key: SOLR-5986
>                 URL: https://issues.apache.org/jira/browse/SOLR-5986
>             Project: Solr
>          Issue Type: Improvement
>          Components: search
>            Reporter: Steve Davids
>            Assignee: Anshum Gupta
>            Priority: Critical
>             Fix For: 4.10
>
>         Attachments: SOLR-5986.patch, SOLR-5986.patch, SOLR-5986.patch
>
>
> The intent of this ticket is to have all distributed search requests stop 
> wasting CPU cycles on requests that have already timed out or are so 
> complicated that they won't be able to execute. We have come across a case 
> where a nasty wildcard query within a proximity clause was causing the 
> cluster to enumerate terms for hours even though the query timeout was set to 
> minutes. This caused a noticeable slowdown within the system which made us 
> restart the replicas that happened to service that one request, the worst 
> case scenario are users with a relatively low zk timeout value will have 
> nodes start dropping from the cluster due to long GC pauses.
> [~amccurry] Built a mechanism into Apache Blur to help with the issue in 
> BLUR-142 (see commit comment for code, though look at the latest code on the 
> trunk for newer bug fixes).
> Solr should be able to either prevent these problematic queries from running 
> by some heuristic (possibly estimated size of heap usage) or be able to 
> execute a thread interrupt on all query threads once the time threshold is 
> met. This issue mirrors what others have discussed on the mailing list: 
> http://mail-archives.apache.org/mod_mbox/lucene-solr-user/200903.mbox/%3c856ac15f0903272054q2dbdbd19kea3c5ba9e105b...@mail.gmail.com%3E



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