We get at rare times out of memory errors during the day. I know one reason for this is data imports, none are going on. I see in the wiki, document adds have some quirks, not doing that. I don't know to to expect for memory use though.

We had Solr running under Tomcat set to 2G ram. I presume cache size has an effect on memory, that's set to 30,000 for filter, document and queryResult. Have experimented with different sizes for a while, these limits are all lower than we used to have them set to. So, hoping there no sort of memory leak involved.

In any case, some of the messages are:

Exception in thread "http-8080-21" java.lang.OutOfMemoryError: Java heap space
Some look like this:

Exception in thread "http-8080-22" java.lang.NullPointerException
        at java.util.concurrent.ConcurrentLinkedQueue.offer(ConcurrentLinkedQueue.java:273)
...

I presume the null pointer is a result of being out of memory. 

Should Solr possibly need more than 2GB? What else can we tune that might reduce memory usage?

Hi,

Some options:
* Yes, on the slave/search side you can reduce your cache sizes and lower the memory footprint.
* You can also turn off norms in various fields if you don't need that and save memory there.
* You can increase your Xmx

I don't know what version of Solr you have, but look through Lucene/Solr's CHANGES.txt to see if there were any changes that affect memory requirements since your version of Solr.

Otis
----

Sematext :: http://sematext.com/ :: Solr - Lucene - Nutch
Lucene ecosystem search :: http://search-lucene.com/
>________________________________
>From: Steve Fatula <[EMAIL PROTECTED]>
>To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>Sent: Wednesday, November 9, 2011 3:33 PM
>Subject: Out of memory, not during import or updates of the index
>
>We get at rare times out of memory errors during the day. I know one reason for this is data imports, none are going on. I see in the wiki, document adds have some quirks, not doing that. I don't know to to expect for memory use though.
>
>We had Solr running under Tomcat set to 2G ram. I presume cache size has an effect on memory, that's set to 30,000 for filter, document and queryResult. Have experimented with different sizes for a while, these limits are all lower than we used to have them set to. So, hoping there no sort of memory leak involved.
>
>In any case, some of the messages are:
>
>Exception in thread "http-8080-21" java.lang.OutOfMemoryError: Java heap space
>
>
>Some look like this:
>
>Exception in thread "http-8080-22" java.lang.NullPointerException
>        at java.util.concurrent.ConcurrentLinkedQueue.offer(ConcurrentLinkedQueue.java:273)
>...
>
>I presume the null pointer is a result of being out of memory. 
>
>Should Solr possibly need more than 2GB? What else can we tune that might reduce memory usage?
>
>

From: Otis Gospodnetic <[EMAIL PROTECTED]>
>To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>Sent: Wednesday, November 9, 2011 2:51 PM
>Subject: Re: Out of memory, not during import or updates of the index
>
>Hi,
>
>Some options:
>* Yes, on the slave/search side you can reduce your cache sizes and lower the memory footprint.
>* You can also turn off norms in various fields if you don't need that and save memory there.
>* You can increase your Xmx
>
>I don't know what version of Solr you have, but look through Lucene/Solr's CHANGES.txt to see if there were any changes that affect memory requirements since your version of Solr.
>
>
>
>
>
>Using Solr 3.4.0. That changelog actually says it should reduce memory usage for that version. We were on a much older version previously, 1.something.

Norms are off on all fields that it can be turned off on.

I'm just hoping this new version doesn't have any leaks. Does FastLRUCache vs LRUCache make any memory difference?

> Using Solr 3.4.0. That changelog actually says it should reduce memory usage for that version. We were on a much older version previously, 1.something.
> Norms are off on all fields that it can be turned off on.
> I'm just hoping this new version doesn't have any leaks. Does FastLRUCache vs LRUCache make any memory difference?

You can add JVM parameters to better trace the heap usage with
-XX:+PrintGCDetails -verbose:gc -Xloggc:/your/gc/logfile

Graphing that over time may help you see if you are constantly near the
limit, or only at particular times, and try to correlate that to other
operations (insertions, commit, optimize, ...)
--
Andr� Bois-Crettez

Search technology, Kelkoo
http://www.kelkoo.com/

From: Andre Bois-Crettez <[EMAIL PROTECTED]>
>To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>Sent: Thursday, November 10, 2011 7:02 AM
>Subject: Re: Out of memory, not during import or updates of the index
>
>You can add JVM parameters to better trace the heap usage with -XX:+PrintGCDetails -verbose:gc -Xloggc:/your/gc/logfile
>
>Graphing that over time may help you see if you are constantly near the limit, or only at particular times, and try to correlate that to other operations (insertions, commit, optimize, ...)
>
>
>That would be true, except, there are NO insertions, deletions, updates, etc. as that is done in the middle of the night, long before the problem occurs. It is done using the data import manager. Right now, for example, we've raised the limit to 2.5GB and currently, 2GB is free. The only activity is searches, using the http interface, nothing we code in java, etc. So, the only thing consuming memory within Tomcat is solr, the only app.

So, since the caches are all full, and, 2GB of 2.5GB is free, yet, the other day, all 2GB were consumed and out of memory, there is something that consumed that 1.5GB freespace.

I did change the garbage collector today to the parallel one from the default one. Should have been in the first place. Not sure if this will matter or not as far as running out of space. I do have GC log as well (now). There is only one collection every minute or so, and in 11 hours, not one full gc.

How big is your index?

What kind of queries do you tend to see? Do you facet on a lot of fields? Sort on a lot of fields?

Before you get the OOM and are running along nicely, how much RAM is used?

On Nov 9, 2011, at 3:33 PM, Steve Fatula wrote:

> We get at rare times out of memory errors during the day. I know one reason for this is data imports, none are going on. I see in the wiki, document adds have some quirks, not doing that. I don't know to to expect for memory use though.
>
> We had Solr running under Tomcat set to 2G ram. I presume cache size has an effect on memory, that's set to 30,000 for filter, document and queryResult. Have experimented with different sizes for a while, these limits are all lower than we used to have them set to. So, hoping there no sort of memory leak involved.
>
> In any case, some of the messages are:
>
> Exception in thread "http-8080-21" java.lang.OutOfMemoryError: Java heap space
>
>
> Some look like this:
>
> Exception in thread "http-8080-22" java.lang.NullPointerException
>         at java.util.concurrent.ConcurrentLinkedQueue.offer(ConcurrentLinkedQueue.java:273)
> ...
>
> I presume the null pointer is a result of being out of memory.
>
> Should Solr possibly need more than 2GB? What else can we tune that might reduce memory usage?

- Mark Miller
lucidimagination.com

From: Mark Miller <[EMAIL PROTECTED]>
>To: solr-user <[EMAIL PROTECTED]>
>Sent: Thursday, November 10, 2011 3:00 PM
>Subject: Re: Out of memory, not during import or updates of the index
>
>How big is your index?
>
>The total for the data dir is 651M.
>What kind of queries do you tend to see? Do you facet on a lot of fields? Sort on a lot of fields?
>
>If a query is sorted, it's on one field. A fair amount of faceting. Not sure how to answer what kind of queries, various kinds, all dismax. Remember, - 2GB ram was allotted to Solr/Tomcat. Most of the queries run in very small fractions of a second, the longest query we have runs in 140ms. Most are 1ms.
>Before you get the OOM and are running along nicely, how much RAM is used?
>
>I wish I was sitting there just before that happened. Now that we have the GC log, it will be easier to tell I suppose.

Steve,

do you have any custom code in your Solr?
We had out-of-memory errors just because of that, I was using one method to obtain the request which was leaking... had not read javadoc carefully enough. Since then, no leak.

What do you do after the OoME?

paul
Le 9 nov. 2011 à 21:33, Steve Fatula a écrit :

> We get at rare times out of memory errors during the day. I know one reason for this is data imports, none are going on. I see in the wiki, document adds have some quirks, not doing that. I don't know to to expect for memory use though.
>
> We had Solr running under Tomcat set to 2G ram. I presume cache size has an effect on memory, that's set to 30,000 for filter, document and queryResult. Have experimented with different sizes for a while, these limits are all lower than we used to have them set to. So, hoping there no sort of memory leak involved.
>
> In any case, some of the messages are:
>
> Exception in thread "http-8080-21" java.lang.OutOfMemoryError: Java heap space
>
>
> Some look like this:
>
> Exception in thread "http-8080-22" java.lang.NullPointerException
>         at java.util.concurrent.ConcurrentLinkedQueue.offer(ConcurrentLinkedQueue.java:273)
> ...
>
> I presume the null pointer is a result of being out of memory.
>
> Should Solr possibly need more than 2GB? What else can we tune that might reduce memory usage?

From: Paul Libbrecht <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Sent: Thursday, November 10, 2011 7:19 AM
>Subject: Re: Out of memory, not during import or updates of the index
>
>do you have any custom code in your Solr?
>We had out-of-memory errors just because of that, I was using one method to obtain the request which was leaking... had not read javadoc carefully enough. Since then, no leak.
>
>There is no custom code as Solr is called via http. So, only the web interface is used. So, it can't be our code since Solr runs within it's own tomcat instance, and only Solr.