High CPU Usage and NGINX Hangup

[Igor Sysoev]

On Mar 4, 2014, at 9:07 , loki wrote:

> I am seeing my NGINX server randomly hangup. Multiple worker processes
> utilizing 100% CPU. I see the hangups in strace, but not quite sure what
> would be causing the issue.
> 
> 0.000081 futex(0x7f563c893068, FUTEX_WAIT, 0, NULL) = ? ERESTARTSYS (To be
> restarted)
>    92.011974 --- SIGHUP (Hangup) @ 0 (0) ---
>     0.000069 rt_sigreturn(0x934b9b)    = -1 EINTR (Interrupted system
> call)
>     0.000056 futex(0x7f563c893068, FUTEX_WAIT, 0, NULL) = 0
>   154.792082 futex(0x7f563c893068, FUTEX_WAKE, 1) = 0
> 
> 0.000036 recvmsg(32, 0x7fff134e28b0, 0) = -1 EAGAIN (Resource temporarily
> unavailable)
>     0.000842 epoll_wait(33, {{EPOLLIN, {u32=404296080,
> u64=140007748211088}}}, 512, 54019) = 1
>    49.323010 recvmsg(32, {msg_name(0)=NULL,
> msg_iov(1)=[{"\2\0\0\0\0\0\0\0\261m\0\0\0\0\0\0\5\0\0\0\0\0\0\0\377\377\377\377\0\0\0\0",
> 32}], msg_controllen=0, msg_flags=0}, 0) = 32
>     0.000129 close(23)                 = 0
>     0.002116 recvmsg(32, 0x7fff134e28b0, 0) = -1 EAGAIN (Resource
> temporarily unavailable)
>     0.000837 epoll_wait(33, {{EPOLLIN, {u32=404296080,
> u64=140007748211088}}}, 512, 4695) = 1

nginx does not use mutexes. It seems you run 3rd-party modules.


-- 
Igor Sysoev
http://nginx.com