Correction: 0 - 150ms (depends on size of query results; 150ms for non-cached (new) queries returning more than 50K docs).
> -----Original Message----- > From: Fuad Efendi [mailto:f...@efendi.ca] > Sent: September-23-09 11:26 AM > To: solr-user@lucene.apache.org > Subject: RE: Parallel requests to Tomcat > > > I have 0-15ms for 50M (millions docs), Tomcat, 8-CPU: > http://www.tokenizer.org > ================================== > > - something obviously wrong in your case, 130ms is too high. Is it dedicated > server? Disk swapping? Etc. > > > > > -----Original Message----- > > From: Michael [mailto:solrco...@gmail.com] > > Sent: September-23-09 11:17 AM > > To: solr-user@lucene.apache.org; yo...@lucidimagination.com > > Subject: Re: Parallel requests to Tomcat > > > > I'm using a Solr 1.4 nightly from around July. Is that recent enough to > > have the improved reader implementation? > > I'm not sure whether you'd call my operations IO heavy -- each query has > so > > many terms (~50) that even against a 45K document index a query takes > 130ms, > > but the entire index is in a ramfs. > > - Michael > > > > On Tue, Sep 22, 2009 at 8:08 PM, Yonik Seeley > > <yo...@lucidimagination.com>wrote: > > > > > What version of Solr are you using? > > > Solr1.3 and Lucene 2.4 defaulted to an index reader implementation > > > that had to synchronize, so search operations that are IO "heavy" > > > can't proceed in parallel. You shouldn't see this with 1.4 > > > > > > -Yonik > > > http://www.lucidimagination.com > > > > > > > > > > > > On Tue, Sep 22, 2009 at 4:03 PM, Michael <solrco...@gmail.com> wrote: > > > > Hi, > > > > I have a Solr+Tomcat installation on an 8 CPU Linux box, and I just > tried > > > > sending parallel requests to it and measuring response time. I would > > > expect > > > > that it could handle up to 8 parallel requests without significant > > > slowdown > > > > of any individual request. > > > > > > > > Instead, I found that Tomcat is serializing the requests. > > > > > > > > For example, the response time for each of 2 parallel requests is > nearly > > > 2 > > > > times that for a single request, and the time for each of 8 parallel > > > > requests is about 4 times that of a single request. > > > > > > > > I am pretty sure this is a Tomcat issue, for when I started 8 > identical > > > > instances of Solr+Tomcat on the machine (on 8 different ports), I > could > > > send > > > > one request to each in parallel with only a 20% slowdown (compared to > > > 300% > > > > in a single Tomcat.) > > > > > > > > I'm using the stock Tomcat download with minimal configuration > changes, > > > > except that I disabled all logging (in case the logger was blocking > for > > > each > > > > request, serializing them.) I'm giving 2G RAM to each JVM. > > > > > > > > Does anyone more familiar with Tomcat know what's wrong? I can't > imagine > > > > that Tomcat really can't handle parallel requests. > > > > > > > >
