Do you have any native code components? I had a serious problem with "OutOfMemoryError: unable to create new native thread" errors too. They pretty much went away when I ditched the Oracle OCI driver in favor of the thin driver.
BTW, the default linux kernel puts a hard limit of ~1k threads on your processes. A simple java program that does nothing but spawn threads typically tops out around 970-980 threads on linux. From what our ops guys have said, this parameter cannot be changed without recompiling the kernel. Why on earth would you want more than 1000 threads? Surely you don't need that many Ajp/Coyote/whatever processors. Jeff Schnitzer [EMAIL PROTECTED] The Sims Online > -----Original Message----- > From: Ian McFarland [mailto:[EMAIL PROTECTED] > Sent: Wednesday, June 11, 2003 5:05 AM > To: Tomcat List > Cc: Ian McFarland > Subject: OutOfMemoryError under high load > > Hello, > > We're running into the following problem when our Tomcat instances are > under heavy load. > > SEVERE: Caught exception executing > [EMAIL PROTECTED], terminating thread > java.lang.OutOfMemoryError: unable to create new native thread > > The exception is always on thread creation, and correlates a condition > where the process count on the machine suddenly starts to ramp up from > a few hundred to a little above 1000 processes. (Load is fairly > constant during this time, and the condition always expresses itself at > right around the same level of traffic, about 6Mbps of throughput per > server.) There appears to be plenty of heap memory available when this > happens, so that coupled with the thread creation message leads us to > suspect that we're running into an OS tuning problem, instead of > specifically a problem with our app. (A radical rewrite of how our > domain objects are cached, and tuning of various caches to various > sizes, resulted in near identical performance, aside from large > differences in CPU utilization. This seems to further support this > conclusion.) Tuning maxProcessors and a variety of other parameters in > our app seems to have no discernible effect, neither beneficial nor > detrimental, beyond changes in CPU utilization, which always falls in a > band between 10 and 60%, depending on the tuning choices. > > We're currently using Tomcat 4.1.13 under Linux 2.4.17 with Sun JDK > 1.4.1_01. We've tuned all the obvious parameters, (ulimit -n and > /proc/sys/kernel/threads-max, for example,) or at least all the ones we > could think of. I think we're missing something obvious, and the OS is > not letting us spawn more threads. Anyone know what we're doing wrong? > > Thanks in advance, > -Ian McFarland > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
