[EMAIL PROTECTED] escribió: > > We have done some performance measurements, running JetSpeed on RS/6000 > machines with one and with four processors. The 4-way machine's processors > are running about twice as fast as the 1-way's. Surprisingly, performance > seems to increase proportionally with the speed of the processors, but > seems not to improve with the number of processors. Did anybody observe > similar behavior ? Yes. I observed similar behaviour under 2-way with Linux Sun jdk 1.3 Server Hotspot. In my tests, response time grows about 50% between 1 and 2 concurrent requests. From there on, response time growm linearly with the number of concurrent requests. With "perfect" concurrency, time should be the same between 1 and 2 concurrent requests. > > A potential explanation for this behavior might be synchronized statements > in code that is called directly or indirectly from the service-method of a > servlet. Are there known problems in this area ? > I have not identified any such execution path. Potential problem areas are the factories and other singletons, where look up must be performed for components ( getPortlet(), ...) and also the database (I'm using Hypersonic for my tests). Which DB are you using? The logging is a big potential bottleneck, since the threads fight to get a lock on the logger stream. We are logging maybe 20 lines (=20 locks) per request. Do you have profiling data? The profiler does not work under linux hotspot :( -- -------------------------------------------------------------- To subscribe: [EMAIL PROTECTED] To unsubscribe: [EMAIL PROTECTED] Search: <http://www.mail-archive.com/[email protected]/> List Help?: [EMAIL PROTECTED]
