We discovered that the kernel was only using 8 CPUs. After recompiling for 16 (8+hyperthreads), it looks like the query rate will settle in around 280-300 qps. Much better, although still quite a bit slower than the opteron.
Peter On 2/22/06, Yonik Seeley <[EMAIL PROTECTED]> wrote: > > Hmmm, not sure what that could be. > You could try using the default FSDir instead of MMapDir to see if the > differences are there. > > Some things that could be different: > - thread scheduling (shouldn't make too much of a difference though) > - synchronization workings > - page replacement policy... how to figure out what pages to swap in > and which to swap out, esp of the memory mapped files. > > You could also try a profiler on both platforms to try and see where > the difference is. > > -Yonik > > On 2/22/06, Peter Keegan <[EMAIL PROTECTED]> wrote: > > I am doing a performance comparison of Lucene on Linux vs Windows. > > > > I have 2 identically configured servers (8-CPUs (real) x 3GHz Xeon > > processors, 64GB RAM). One is running CentOS 4 Linux, the other is > running > > Windows server 2003 Enterprise Edition x64. Both have 64-bit JVMs from > Sun. > > The Lucene server is using MMapDirectory. I'm running the jvm with > > -Xmx16000M. Peak memory usage of the jvm on Linux is about 6GB and 7.8GBon > > windows. > > > > I'm observing query rates of 330 queries/sec on the Wintel server, but > only > > 200 qps on the Linux box. At first, I suspected a network bottleneck, > but > > when I 'short-circuited' Lucene, the query rates were identical. > > > > I suspect that there are some things to be tuned in Linux, but I'm not > sure > > what. Any advice would be appreciated. > > > > Peter > > > > > > > > On 1/30/06, Peter Keegan <[EMAIL PROTECTED]> wrote: > > > > > > I cranked up the dial on my query tester and was able to get the rate > up > > > to 325 qps. Unfortunately, the machine died shortly thereafter (memory > > > errors :-( ) Hopefully, it was just a coincidence. I haven't measured > 64-bit > > > indexing speed, yet. > > > > > > Peter > > > > > > On 1/29/06, Daniel Noll <[EMAIL PROTECTED]> wrote: > > > > > > > > Peter Keegan wrote: > > > > > I tried the AMD64-bit JVM from Sun and with MMapDirectory and I'm > now > > > > > getting 250 queries/sec and excellent cpu utilization (equal > > > > concurrency on > > > > > all cpus)!! Yonik, thanks for the pointer to the 64-bit jvm. I > wasn't > > > > aware > > > > > of it. > > > > > > > > > Wow. That's fast. > > > > > > > > Out of interest, does indexing time speed up much on 64-bit > hardware? > > > > I'm particularly interested in this side of things because for our > own > > > > application, any query response under half a second is good enough, > but > > > > the indexing side could always be faster. :-) > > > > > > > > Daniel > > > > > > > > -- > > > > Daniel Noll > > > > > > > > Nuix Australia Pty Ltd > > > > Suite 79, 89 Jones St, Ultimo NSW 2007, Australia > > > > Phone: (02) 9280 0699 > > > > Fax: (02) 9212 6902 > > > > > > > > This message is intended only for the named recipient. If you are > not > > > > the intended recipient you are notified that disclosing, copying, > > > > distributing or taking any action in reliance on the contents of > this > > > > message or attachment is strictly prohibited. > > > > > > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > >
