Dave, agreed that 100 threads is a lot, but only if they are all busy. From a unix perspective, the main thing to worry about is that the average queue length in front of the cpu - aka load average - is < 1. As long as this is well below 1 there should not be 'thread thrashing' on a single headed machine, don't you think?
For example, in my experiments on NT we see JRun's VM consuming about 100 threads (because our clients keep their sockets open, but the threads are largely idle). NT and other processes account for an additional 4-500 threads, but CPU utilization is just some 15%. I can monitor page faults as well and they stay at just a couple per second. I'm having a difficult time attributing the thread 'loss' to something else than a bug... Thanks, BenG. [EMAIL PROTECTED] wrote: >Guys, > How many processors do you have running on your system? I do not >believe that this is a JRUN or java issue but a "tread thrashing" >issue. Basically only one thread can run at any exact moment upon a >CPU. By running 100 threads at once, the machine is spending a lot of >resources upon just switching between threads than running them. >Another issue to consider is that NT's thread model is not the best >going. I just got a dual Pentium set up and it provides a little boost, >but not what I had hoped for:( > As for our PRD systems, we use some of the larger SUN systems and >they handle threading very well. After some experience we have found >out that setting more than about 20 threads to a process(not jrun in >particular) provides little benefit due to I/O & other things. This >machine though has 64 processors to utilize. > >Makarand, > It sounds as if you might be upgrading your hardware to a UNIX >system to handle your load. A big perk with JSP's is that your code >won't have to change one bit:) > >Dave > >-----Original Message----- >From: bgroeneveld >Sent: Wednesday, October 03, 2001 6:08 PM >To: jrun-talk >Cc: bgroeneveld >Subject: Re: JRun does not responds after 100 threads > > >Makarand, I have seen similar behavior. I think there may be a JRun >problem. If I setup a threadpool of 50 with an idle thread timeout of >60, then after a fresh jrun startup and no activity NT perfmon shows >the threadpool gets cleaned up. Or if I send a burst of 100 persistent >connections, then after 60s the threadcount goes from 150 to 100. > >I am going to try an experiment with the IBM jvm later this week to >make sure this isn't VM related. > >I've had best performance leaving the threadpool at 1, even thought >that's not what's desired, my server/VM lives much longer that way. >I'm assuming that changing the threadpool causes a fault inside JRun. >Anyone know more? > >BenG. > >JOGALEKAR,MAKARAND (HP-Boise,ex1) wrote: > >>Hello, >> >>We are having lot of problems with JRun 3.0 or Jrun3.1, >>If we get high volume and the thread count goes beyond 100, it does not >>respond. >> >>We are just using servlets with Netscape Exterprise server 3.6 with >> >EJB's at > >>all. >> >>We have disabled the EJB option for performance and also tried >> >different > >>options >>by setting initial thread count to 50 with maximum thread count to >> >500..but > >>nothing works.. >> >>Any help ?? >> >>Thanks, >>-Makarand >> > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Structure your ColdFusion code with Fusebox. Get the official book at http://www.fusionauthority.com/bkinfo.cfm Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
