What are your other cache hit rates looking like? Which caches are you using the FastLRUCache on?
-Todd Feak -----Original Message----- From: wojtekpia [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 05, 2008 8:15 AM To: solr-user@lucene.apache.org Subject: Re: Throughput Optimization Yes, I am seeing evictions. I've tried setting my filterCache higher, but then I start getting Out Of Memory exceptions. My filterCache hit ratio is > .99. It looks like I've hit a RAM bound here. I ran a test without faceting. The response times / throughput were both significantly higher, there were no evictions from the filter cache, but I still wasn't getting > 50% CPU utilization. Any thoughts on what physical bound I've hit in this case? Erik Hatcher wrote: > > One quick question.... are you seeing any evictions from your > filterCache? If so, it isn't set large enough to handle the faceting > you're doing. > > Erik > > > On Nov 4, 2008, at 8:01 PM, wojtekpia wrote: > >> >> I've been running load tests over the past week or 2, and I can't >> figure out >> my system's bottle neck that prevents me from increasing throughput. >> First >> I'll describe my Solr setup, then what I've tried to optimize the >> system. >> >> I have 10 million records and 59 fields (all are indexed, 37 are >> stored, 17 >> have termVectors, 33 are multi-valued) which takes about 15GB of >> disk space. >> Most field values are very short (single word or number), and >> usually about >> half the fields have any data at all. I'm running on an 8-core, 64- >> bit, 32GB >> RAM Redhat box. I allocate about 24GB of memory to the java process, >> and my >> filterCache size is 700,000. I'm using a version of Solr between 1.3 >> and the >> current trunk (including the latest SOLR-667 (FastLRUCache) patch), >> and >> Tomcat 6.0. >> >> I'm running a ramp-test, increasing the number of users every few >> minutes. I >> measure the maximum number of requests that Solr can handle per >> second with >> a fixed response time, and call that my throughput. I'd like to see >> a single >> physical resource be maxed out at some point during my test so I >> know it is >> my bottle neck. I generated random queries for my dataset >> representing a >> more or less realistic scenario. The queries include faceting by up >> to 6 >> fields, and quering by up to 8 fields. >> >> I ran a baseline on the un-optimized setup, and saw peak CPU usage >> of about >> 50%, IO usage around 5%, and negligible network traffic. >> Interestingly, the >> CPU peaked when I had 8 concurrent users, and actually dropped down >> to about >> 40% when I increased the users beyond 8. Is that because I have 8 >> cores? >> >> I changed a few settings and observed the effect on throughput: >> >> 1. Increased filterCache size, and throughput increased by about >> 50%, but it >> seems to peak. >> 2. Put the entire index on a RAM disk, and significantly reduced the >> average >> response time, but my throughput didn't change (i.e. even though my >> response >> time was 10X faster, the maximum number of requests I could make per >> second >> didn't increase). This makes no sense to me, unless there is another >> bottle >> neck somewhere. >> 3. Reduced the number of records in my index. The throughput >> increased, but >> the shape of all my graphs stayed the same, and my CPU usage was >> identical. >> >> I have a few questions: >> 1. Can I get more than 50% CPU utilization? >> 2. Why does CPU utilization fall when I make more than 8 concurrent >> requests? >> 3. Is there an obvious bottleneck that I'm missing? >> 4. Does Tomcat have any settings that affect Solr performance? >> >> Any input is greatly appreciated. >> >> -- >> View this message in context: >> http://www.nabble.com/Throughput-Optimization-tp20335132p20335132.html >> Sent from the Solr - User mailing list archive at Nabble.com. > > > -- View this message in context: http://www.nabble.com/Throughput-Optimization-tp20335132p20343425.html Sent from the Solr - User mailing list archive at Nabble.com.
