I've been plugging along with this problem, and I think that the issue is
with the maximum number of threads set by default in Apache - 256. I
monitored the number of processes running during a reboot and found as
follows:
Processes Started | Total
On reboot 37 37
Start Oracle Db 1 18 55
Start Oracle Db 2 14 69
Start Tomcat App 1 41 110
Start Tomcat App 2 35 145
Start Tomcat App 3 36 181
Start Tomcat App 4 37 218
Start Tomcat App 5 36 254
Well, at 254, and only 256, I can see why it was crashing out. The
"OutOfMemoryError" seems a bit of a poor message - the important issue here
seems that I've run out of available processes. And of course, the above
with 5 tomcat engines running, its going to crash as soon as Oracle gets
requests and spawns more processes.
I'm a bit surprised that Tomcat needs so many processes per instance, and
also that the Linux/Apache config is brought to its knees if you hit the
maximum number of processes? Does anyone who runs a number of Internet
applications using JSP have any suggestions here? Seems crazy that I can
only run about 4 (tiny) apps on a server with 512Mb of memory and heaps of
hard drive space!
Next step, I guess, is to look into recompiling Apache with a higher number
of processes specified. Not much fun for a rookie, especially when some
applications are already in service. Aaarrggh!
Any and all suggestions gratefully devoured!
Max Hugen
