"exceeded limit of maxWarmingSearchers=2" when posting data

[Teruhiko Kurosaka <Ku...@basistech.com>]

I'm trying to stress-test solr (nightly build of 2009-10-12) using JMeter.
I set up JMeter to post pod_other.xml, then hd.xml, then commit.xml that only has a line "<comit/>", 100 times.
Solr instance runs on a multi-core system.

Solr didn't complian when the number of test threads is 1, 2, 3 or 4.

But when I increased the thnumber of test threads to 8, I saw this error
on the console:

SEVERE: org.apache.solr.common.SolrException: Error opening new searcher. exceeded limit of maxWarmingSearchers=2, try again later.


What does this mean? 

Why Solr tries to make warm up searchers when I'm posting documents, not searching?

Do I need to set this maxWarmingSearchers to greater than the number of CPU cores?

Thanks.

T. "Kuro" Kurosaka

Re: "exceeded limit of maxWarmingSearchers=2" when posting data

[Yonik Seeley <ys...@gmail.com>]

2009/10/23 Teruhiko Kurosaka <Ku...@basistech.com>:
> I'm trying to stress-test solr (nightly build of 2009-10-12) using JMeter.
> I set up JMeter to post pod_other.xml, then hd.xml, then commit.xml that only has a line "<comit/>", 100 times.
> Solr instance runs on a multi-core system.
>
> Solr didn't complian when the number of test threads is 1, 2, 3 or 4.
>
> But when I increased the thnumber of test threads to 8, I saw this error
> on the console:
>
> SEVERE: org.apache.solr.common.SolrException: Error opening new searcher. exceeded limit of maxWarmingSearchers=2, try again later.
>
>
> What does this mean?
>
> Why Solr tries to make warm up searchers when I'm posting documents, not searching?

A commit flushes index changes to disk and opens a new index searcher.
 The maxWarmingSearchers limit is just a protection mechanism.

> Do I need to set this maxWarmingSearchers to greater than the number of CPU cores?

No, that's unrelated.  Don't commit so often.
The error is also not a fatal one - the commit fails, but you won't
lose data - you just won't see it until a commit succeeds in opening a
new searcher.

-Yonik
http://www.lucidimagination.com