lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From David Spencer <dave-lucene-u...@tropo.com>
Subject Re: Search Performance
Date Fri, 18 Feb 2005 19:00:18 GMT
Noone has mentioned JVM options yet.

[a] -server
[b] -XX:CompileThreshold=1000
[c] Raise the -Xms value if you haven't done so (-Xms...)

I think by default the VM runs with "-client" but -server makes more 
sense for web containers (Tomcat etc).
[b] tells the hotspot compiler to compile methods sooner - you can lower 
the 1000 to, say, '2' makes it compile methods after they've executed 2 
times - I had trouble once lowering this to 1 for some reason




Also, even though you're not supposed to need to do this, I've found it 
helpful to force gc() periodically e.g. every minute via this idiom:

public static long gc()
{
	long bef = mem();
	System.gc();
	sleep( 100);
	System.runFinalization();
	sleep( 100);
	System.gc();
	long aft= mem();
	return aft-bef;
}


Michael Celona wrote:

> What is single handedly the best way to improve search performance?  I have
> an index in the 2G range stored on the local file system of the searcher.
> Under a load test of 5 simultaneous users my average search time is ~4700
> ms.  Under a load test of 10 simultaneous users my average search time is
> ~10000 ms.    I have given the JVM 2G of memory and am a using a dual 3GHz
> Zeons.  Any ideas?  
> 
>  
> 
> Michael
> 
> 


---------------------------------------------------------------------
To unsubscribe, e-mail: lucene-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: lucene-user-help@jakarta.apache.org


Mime
View raw message