If you set the java -classic option you will not be running green threads In this scenario. The java vm is managing the threads. Another thing worth looking at is the file descriptor limit. If the os is set to low it can limit the number of http session you have open. This has happened to me when using weblogic.
Hope that is somewhat useful. Will -----Original Message----- From: Ben Groeneveld [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 04, 2001 5:59 PM To: JRun-Talk Subject: Re: JRun does not responds after 100 threads More to ponder...I repeated this run on my laptop now booted in redhat 6.2. I change the JRun web server min threads from 1 to 50, and change the idle thread timeout from 300 to 60s. Now I fire up the JRun 3.1 default server. I check gtop, and I see jrun having 95 processes (a linux thread is practically a process). 60 seconds later this number drops to 46. Hmm. That doesn't seem right. It should be threads beyond the pool of 50 that get killed. Ok, so now I set the min threads back to 1, restart, and JRun default has 44 threads. Now all these threads are idle, none are vying for CPU. I have a hard time accepting this as thread-thrashing or NT vs unix. These are the exact same results I see on NT for JRun 3.0 sp2. I think the thread pool's not working, or I don't understand these parameters. What am I missing? Thanks, BenG. Haseltine, Celeste wrote: >Dave, > >You made an excellent point regarding "thread thrashing". Although I don't >know if "thread thrashing" is completely responsible for the behavior that >Ben is experiencing, it can certainly contribute. If my memory serves me >correctly, the NT and 2000 threading scheduler is based on a "preemptive" >model, vs a Unix operating system's threading scheduler is based on a >"time-slicing" model. The difference being that a time slicing scheduler >will eventually give CPU time to lower priority threads, whereas a >preemptive scheduler may not. It one of many reasons to consider using a >Unix server if you expect to experience heavy traffic/load on your site. > >You can write a simple program to execute a "group" threads and then one by >one, launch another thread within your "group" and watch your performance. >If your performance suddenly deteriorates around 50 or 100 threads, than you >may need to upgrade your machine to include more CPU's. Or, if you are >really anticipating a heavy load/traffic on your server, consider porting to >a Unix server. That's one of the advantages of using JSP's and Java, you >can easily port from one platform to the other if necessary. > >Celeste > > >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] >Sent: Wednesday, October 03, 2001 6:09 PM >To: JRun-Talk >Subject: RE: Re: JRun does not responds after 100 threads > > >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 >> > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Get the mailserver that powers this list at http://www.coolfusion.com Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
