Too many open files ( ulimit already changed )

Question

I\'m working on a debian server with tomcat 7 and java 1.7. This is an application that recieves several TCP connections, each TCP connection is an open file by the java pro

Answer 1

Setting higher ulimit maybe completely unnecessary depending on the workload/traffic that the tomcat/httpd handles. Linux creates a file descriptor per socket connection, so if tomcat is configured to use mod_jk/ajp protocol as a connector then you may want to see if the maximum allowed connection is too high or if the connectionTimeout or keepAliveTimeout is too high. These parameters play a huge role in consumption of OS file descriptors. Sometimes it may also be feasible to limit the number of apache httpd/nginx connection if tomcat is fronted by a reverse proxy. I once reduce serverLimit value in httpd to throttle incoming requests during gaterush scenario. All in all adjusting ulimit may not be a viable option since your system may end up consuming however many you throw at it. You will have to come up with a holistic plan to solve this problem.