Make sure you don't have any empty or bad segments. We had some serious speed issues for a long time until we realized we had some empty segments that had been generated as we tested. Nutch would then sit and spin on these bad segments for a few seconds on every search. Simply deleting the bad segments took search times from >10 seconds to fractions of a second.
g. RP wrote: > I've got 500k urls indexed on an old 700mhz P3 clunker with only 384MB > of RAM at my searches take sub-seconds.... Something is funny here. > I've got my JVM at 64MB for this as well, so be careful as it sounds > like you just caused the box to thrash a bit with swapping. Set the > JVM down to 128MB and see what happens.... > > rp > > Sean Dean wrote: >> It looks like you don't have enough RAM to maintain the quick speeds >> you were seeing when the index was only around 3000 pages. >> >> Nutch scales very well, but the hardware behind it must also. Using >> quick calculations and common sense, if your total system RAM is only >> 512MB and all of that is given to tomcat alone your looking at a >> situation where other system applications and/or parts of Tomcat are >> being executed out of swap memory. This will kill search speed. >> >> My recommendation would be to get more RAM, another 512MB should >> support a 1.5 million page index running at the speeds you >> experienced during your 3000 page trials. If you can get even more, >> then your only helping system (search) performance. >> >> Here are a few other tips, just in case you cant get any more RAM at >> this time: >> >> 1. Make sure your passing "-server" via JAVA_OPTS. >> 2. Disable all non-required system and user applications. >> 3. Download or install the newest stable kernel and recompile without >> all the junk. >> 4. Reduce the size of your index. >> >> >> ----- Original Message ---- >> From: shrinivas patwardhan <[EMAIL PROTECTED]> >> To: [email protected] >> Sent: Friday, December 29, 2006 4:45:41 AM >> Subject: Re: search performance >> >> >> thank you Sean Dean for your quick reply ... >> well i am running nutch on ubuntu 5.01 and jdk1.5 >> there are some apps running in the background but they dont take up that >> much of memory . >> secondly i can understand about the first search .. but the other >> searches >> following it also take time even getting the next 10 pages also takes >> some >> time .. >> so looking at all the issues does it relate to my system on the whole >> .. or >> have i got wrong some where in the indexing process ? >> i just followed the tutorial for nutch -0.7.2 under the section >> whole >> web crawling . >> when i indexed just about 3000 pages (subset of that dmoz index) the >> search >> results were quick ) but now after loading the index file for almost >> 1.5million pages it really dies up >> i use to get a java heap space error in tomcat ,so i fixed it by >> setting the >> >> JAVA_OPTS to Xmx512m >> i guess i have made my self very clear now . so wht do guys think >> must be >> wrong ? >> >> Thanks >> Shrinivas >> > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Nutch-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/nutch-general
