From: Ere M. <ere...@he...> - 2013-09-12 06:26:29
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Luke, a couple of things worth checking: - I once had a horrible situation with RAM being exhausted with no apparent reason, the system slowing to a halt because of swapping etc. Finally found out that /tmp was mounted as a ramdisk, so when enough stuff accumulated in it, it just used up all the memory. - Since your server is virtualized, make sure that the host system is capable of supporting it and doesn't have to use swap. We recently had a case where the host was overprovisioned (if that's the correct term to use) and while there didn't seem to be anything wrong with the virtual server, it just crawled along extremely slowly. Apparently there was also a case where the virtual machines were too aggressively moved from physical machine to another by a load balancer or somesuch. - It has been reported that the G1GC garbage collector would be great with Lucene/Solr. We're now running with it (so far without issues) with the following settings: JAVA_OPTIONS="-server -Xms1G -Xmx16G -XX:+UseG1GC" This garbage collector requires a fairly recent Java runtime (1.7.0_04 or such), so it doesn't work with 1.6 that's still default with e.g. CentOS 6. --Ere 11.9.2013 18.53, Osullivan L. kirjoitti: > Hi Tuan, > > Thanks for this - I've already done some research along this lines, > based on stuff I read here: > > http://cloudinservice.com/tune-apache-performance-using-mpm-prefork-module/ > > The article contains a link to a script which you can run to calculate > the average amount of memory each client is using. > > Our Solr specs seem quite modest compared to yours: > > 374M alphabetical_browse > 60K authority > 1.5G biblio > 19M jetty > 17M lib > 40K reserves > 4.0K solr.xml > 56K stats > 60K website > > When you say the 18GB Solr index fits into Ram, do you mean via the java > server settings in VuFind.sh (-Xmx16384m) or do you calculate this > based on the total amount of Ram available (24GB)? > > Having talked to Demian and read about your experiences, I will > definitely investigate separating the solr server from the web server. > It's not something I can do quickly though owing to University policy > and I think 10 - 12 GB is the most Ram I'm ever going to be given for > one server. With that said, our index is a lot smaller so perhaps 6GB > allocated to Jetty to leave 4GB for the system would be fine? > > Thanks, > > Luke -- Ere Maijala Kansalliskirjasto / The National Library of Finland |