Solr Profiling

[Rohit <ro...@in-rev.com>]

Hi,

 

My Solr becomes very slow or hangs up at times, we have done almost
everything possible like

.         Giving 16GB memory to JVM

.         Sharding

 

But these help only for X time, i want to profile the server and see whats
going wrong? How can I profile solr remotely?

 

Regards,

Rohit

 

Re: Solr Profiling

[Andre Parodi <an...@gmail.com>]

I guess it could be many things.

Typically an easy one to spot is if you have insufficient heap (i.e. 
your 16Gb) and the jvm is full gc'ing constantly and not freeing up any 
memory and using lots of cpu. This would make solr slow and "hangs up" 
as well during potentially long gc pauses.

add: -XX:+PrintGCDetails -verbose:gc -Xloggc:/var/log/solr-verbose-gc.log

I configure this on all my java apps just in case. You will easily spot 
any gc problems by looking at the verbose log file.

I you are filling the heap and need to find out what is using up all the 
space the you can take a heap dump with jmap 
-dump:format=b,file=heap.bin <pid>. I usually use eclipse memory 
analyser (mat) to inspect the heap. I have found a lucene field cache to 
be a big memory hog.

good luck
andre


On 10/28/2011 02:09 PM, Rohit wrote:
> Hi,
>
>
>
> My Solr becomes very slow or hangs up at times, we have done almost
> everything possible like
>
> .         Giving 16GB memory to JVM
>
> .         Sharding
>
>
>
> But these help only for X time, i want to profile the server and see whats
> going wrong? How can I profile solr remotely?
>
>
>
> Regards,
>
> Rohit
>
>
>
>

Re: Solr Profiling

[Erick Erickson <er...@gmail.com>]

jConsole has been used. What have you tried? A simple
top would give you some info.

But 16G of memory out of how much? It's a mistake to starve
the OS, so make sure you leave some memory for the
OS outside the jvm.

This sounds much like a memory issue, here's an
excellent article on the issues:
http://www.lucidimagination.com/blog/2011/03/27/garbage-collection-bootcamp-1-0/

If none of that helps, could you supply more details?

Best
Erick

On Fri, Oct 28, 2011 at 8:09 AM, Rohit <ro...@in-rev.com> wrote:
> Hi,
>
>
>
> My Solr becomes very slow or hangs up at times, we have done almost
> everything possible like
>
> .         Giving 16GB memory to JVM
>
> .         Sharding
>
>
>
> But these help only for X time, i want to profile the server and see whats
> going wrong? How can I profile solr remotely?
>
>
>
> Regards,
>
> Rohit
>
>
>
>