Hi, Tell us more about your deploy. How many documents, and how large? How much RAM? What kind of physical disk system and how is it allocated to the VM? When do you measure - during indexing or during search load? Have you tried to throw more search load on the system? When (how many QPS) does it max out?
In your case it's Tomcat which handles the threading of requests, and Solr is definitely capable of utilizing multi cores. Could it be that you are bound by something else than CPU? Like disk, memory, network or such? -- Jan Høydahl, search solution architect Cominvent AS - www.cominvent.com On 14. sep. 2010, at 04.55, David Crane wrote: > > We are running SOLR 1.4.1 (Lucene 2.9.3) on a 2-CPU Linux host, but it seems > that only 1 CPU is ever being used. It almost seems like something is > single-threading inside the SOLR application. The CPU utilization is very > seldom over 0.9 even under load. > > We are running on virtual Linux hosts and our other apps in the same cluster > are multi-threading w/o issue. Some more info on our stack and versions: > > Linux 2.6.16.33-xenU > Apache 2.2.3 > Tomcat 6.0.16 > Java SE Runtime Environment (build 1.6.0_10-ea-b11) > > Has anyone else noticed this problem? > > Might there be some SOLR config aspect to enable multi-threading that we're > missing? Any suggestions for troubleshooting? > > Judging by SOLR's logs, we do see that multiple requests are processing > simultaneously inside SOLR so we do not believe we're sequentially feeding > requests to SOLR, ie. bottle-necking things outside of SOLR. > > Thanks, > David Crane > -- > View this message in context: > http://lucene.472066.n3.nabble.com/Our-SOLR-instance-seems-to-be-single-threading-and-therefore-not-taking-advantage-of-its-multi-proc-t-tp1470282p1470282.html > Sent from the Solr - User mailing list archive at Nabble.com.