High response time after being idle

[Odey <ma...@googlemail.com>]

Hello,

I'm running Solr 3.5 on a XAMPP/Tomcat environment. It's working pretty good
for just one exception: when Solr remains idle without handling any requests
for about 5-10 mins the first request sent again will be delayed for a few
seconds. Subsequent requests are lightning-fast as usual. So it seems to me
like something important has been shut down while staying idle and has to be
reloaded.

I'm pretty confused why this is happening since even the first request after
restarting the server is a hundredfold faster then those ominous delayed
requests after being idle. 

I checked my logfiles - but querytime itself is not affected and I couldn't
find any dysfunctionalities or error-messages.

Are there Solr specific preferences which could cause me trouble?

Any help would be appreciated. 

regards,

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Re: High response time after being idle

[Otis Gospodnetic <ot...@yahoo.com>]

Right, I think that's what's happening here.
Google "swapiness" if you are on Linux.

Alternatively, one could add something to prevent the OS from swapping out Solr's process.  Here is how ElasticSearch does it, for example: https://github.com/elasticsearch/elasticsearch/issues/464

Otis 

----
Performance Monitoring SaaS for Solr - http://sematext.com/spm/solr-performance-monitoring/index.html



>________________________________
> From: Erick Erickson <er...@gmail.com>
>To: solr-user@lucene.apache.org 
>Sent: Wednesday, December 28, 2011 5:07 PM
>Subject: Re: High response time after being idle
> 
>What else, if anything, do you have running on the server?
>Because it's possible that pages are being swapped out
>for other processes to use.
>
>Solr itself shouldn't, as far as I know, time out anything so I
>expect you're running into issues with the op system.
>
>Best
>Erick
>
>On Wed, Dec 28, 2011 at 10:25 AM, Gora Mohanty <go...@mimirtech.com> wrote:
>> On Wed, Dec 28, 2011 at 8:52 PM, Odey <ma...@googlemail.com> wrote:
>>> Hello,
>>>
>>> I'm running Solr 3.5 on a XAMPP/Tomcat environment. It's working pretty good
>>> for just one exception: when Solr remains idle without handling any requests
>>> for about 5-10 mins the first request sent again will be delayed for a few
>>> seconds. Subsequent requests are lightning-fast as usual. So it seems to me
>>> like something important has been shut down while staying idle and has to be
>>> reloaded.
>> [...]
>>
>> Is it possible that the system is running out of RAM, and swapping,
>> or is aggressively swapping for some reason?
>>
>> Regards,
>> Gora
>
>
>

Re: High response time after being idle

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

What else, if anything, do you have running on the server?
Because it's possible that pages are being swapped out
for other processes to use.

Solr itself shouldn't, as far as I know, time out anything so I
expect you're running into issues with the op system.

Best
Erick

On Wed, Dec 28, 2011 at 10:25 AM, Gora Mohanty <go...@mimirtech.com> wrote:
> On Wed, Dec 28, 2011 at 8:52 PM, Odey <ma...@googlemail.com> wrote:
>> Hello,
>>
>> I'm running Solr 3.5 on a XAMPP/Tomcat environment. It's working pretty good
>> for just one exception: when Solr remains idle without handling any requests
>> for about 5-10 mins the first request sent again will be delayed for a few
>> seconds. Subsequent requests are lightning-fast as usual. So it seems to me
>> like something important has been shut down while staying idle and has to be
>> reloaded.
> [...]
>
> Is it possible that the system is running out of RAM, and swapping,
> or is aggressively swapping for some reason?
>
> Regards,
> Gora

Re: High response time after being idle

[Chris Hostetter <ho...@fucit.org>]

: Is it possible that the system is running out of RAM, and swapping,
: or is aggressively swapping for some reason?

it doesn't have to be the solr /tomcat process memory getting swapped out 
-- but that's certainly possible -- it could also be that the filesystem 
cache is expunging the disk pages used to hold the index as other 
processes need ram.  So even if your system isn't using any swap, you 
might still see this type of behavior if you are running other processes 
on the same machine and don't have enough free ram available for the 
filesystem cache to keep the index in memory.

check your io stats as well as your swap info.


-Hoss

Re: High response time after being idle

[Gora Mohanty <go...@mimirtech.com>]

On Wed, Dec 28, 2011 at 8:52 PM, Odey <ma...@googlemail.com> wrote:
> Hello,
>
> I'm running Solr 3.5 on a XAMPP/Tomcat environment. It's working pretty good
> for just one exception: when Solr remains idle without handling any requests
> for about 5-10 mins the first request sent again will be delayed for a few
> seconds. Subsequent requests are lightning-fast as usual. So it seems to me
> like something important has been shut down while staying idle and has to be
> reloaded.
[...]

Is it possible that the system is running out of RAM, and swapping,
or is aggressively swapping for some reason?

Regards,
Gora

Re: High response time after being idle

[Odey <ma...@googlemail.com>]

It seems like my operation system was causing me trouble in some way. I
couldn't find what was triggering this issue, but after migrating the whole
project from wamp to lamp it has been resolved and everything is running
smoothly again.

Thank you very much for your help!

Regards,

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