First of all it kept running out of file handles, so I updated from the latest on ubuntu. Now I see that it's crashed with a register dump:
goroutine 1483734 [IO wait]:
net.runtime_pollWait(0x7ff870182fb8, 0x72, 0xc8200680a0)
net.(*pollDesc).Wait(0xc82ca871e0, 0x72, 0x0, 0x0)
That's the top of the callstack.
Anyone got any ideas whats going on, and why this has only recently started happening?