Are you certain you haven’t capped the memory and all of the GC threads are spinning trying to claim/allocate memory?
> On Oct 25, 2022, at 4:49 PM, Steven Sokol <st...@stevensokol.com> wrote: > > Weird one. I have a go application that, on occasion, will suddenly jump from > some very low CPU usage (1% - 10%) to 400% (4 core system). I run this app at > a heightened priority and it can nearly lock the machine (Pi CM4) up. > > I can kill it with SIGKILL and I'm able to get a stack trace by sending > SIGQUIT. (Here's a gist > <https://gist.github.com/ssokol/b168de8b4546efd9b43a9d6af8538de9> of the > stack trace.) > > The trace would seem to indicate that everything is idle - virtually all the > goroutines are in runtime.gopark. None of them ever get out of it. I've tried > adding a watchdog timer and it locks up along with all the other goroutines, > so it never fires once the runaway event starts. > > The app itself isn't anything special. It listens for data on a set of about > 16 Redis pubsub channels and forwards any data it receives to a very limited > number of clients over UDP. Throughput ranges from 34 - 38 KB/sec, and the > message counts are in the hundreds. Most of the time it eats about 5% of one > core on the CM4. > > I guess this could be an error on my part, but there's nothing in my code > that seems likely to cause this - no obvious place for a multi-threaded tight > loop. I thought for a while that it might be some sort of an issue in Redigo > (golang redis client) but from what that stack trace shows, it looks like all > the redis listeners are happy and healthy and stuck waiting in gopark along > with all the other goroutines. > > Has anyone seen this kind of weird before? > > Thanks, > > -S > > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/5465198d-9a48-4db1-98d5-498922b1ac39n%40googlegroups.com > > <https://groups.google.com/d/msgid/golang-nuts/5465198d-9a48-4db1-98d5-498922b1ac39n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/ECCCFB38-302A-49E0-B594-60B793773E7B%40ix.netcom.com.
