Java / Tomcat and file descriptor limits?

Does Java have any synthetic upper limits on the amount of open files a given process can use? I have set the system wide open files limit at 20000 but am still rece开发者_如何学编程iving FD too many open files related errors within tomcat. I've verified that ulimit shows the correct limit of 20000 for the given user.

Basically, does any settings within Tomcat need to be modified?

Appears the tomcat process in question had not been restarted since the ulimit modifications. I didn't think a restart was necessary, but surprisingly a restart fixed the issue.

It's good to configure the system-wide open file limit, but don’t forget that individual users also have limits. Are you on Linux? See /etc/security/limits.conf to assign specific limits per-group, per-user, and default.