Page 1 of 1

CCR1036-8G-2S+with HIGH CPU load

Posted: Fri Jan 11, 2019 3:29 pm
by ColoCenter
Hi,
I have a CCR1036-8G-2S+ acting as PPPoE server, with at the moment 170 sessions.
I see constantly one CPU having a high load. Randomly this load moves to another CPU. And it gradually increases, and then sometimes drops a bit. This is now happening for a week. See the images:
CPU2.PNG
CPU.PNG
The firmware is Version 6.43.4 (stable), the routerboard version is the same.

Any ideas what might cause this?

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Fri Jan 11, 2019 3:38 pm
by Kindis
Could it we scheduled script. They run in the management process if I remember correctly.

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Fri Jan 11, 2019 4:14 pm
by ColoCenter
I only have one script, that emails me the configuration once a week. Can't imagine that's the problem. Especially since the load shifts to different CPU's multiple times a day.

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sat Jan 12, 2019 10:39 pm
by mac86
Are u doing too much nat or mangle?

Enviado desde mi Moto G (5) mediante Tapatalk


Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sun Jan 13, 2019 7:06 am
by darioferrante
Hi,
Did you verify that the front LCD works correctly? Try however to disable it. Sometimes a failure on the serial interface that manages it generates a CPU overload.

Inviato dal mio HUAWEI MT7-TL10 utilizzando Tapatalk


Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sun Jan 13, 2019 7:14 am
by mducharme
We experienced this previously - a reboot appeared to clear it. I noticed it happens on our router when a user session is "stuck" - sometimes winbox disconnects but the router still thinks the user is logged in, and continues to think so until it is rebooted. I'm not sure if this is the cause or not, but it is correlated.

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sun Jan 13, 2019 12:05 pm
by ColoCenter
The device doesn't do nat'ing or has any magle rules.
I rebooted the device this night, and the CPU load is gone.
I noticed that the memory usage was also gradually increasing since the CPU load appeared.
mem usage.jpeg
Fortunatly it's fixed for now, but not to happy i didn't find a specific cause to prevent it in the future.

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sun Jan 13, 2019 12:37 pm
by CZFan
I am experiencing this on a CCR1036-12G-4S-EM, when I disable SNMP, it goes away so think it is SNMP related.

Have upgraded a couple of versions already since I originally noticed it and currently running 6.43.8 but still the same

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Sun Jan 13, 2019 3:35 pm
by ColoCenter
I read about the disabling SNMP, tried it too, didn't help for me.

This is by the way what the CPU looks like after the reboot. Busy, but normal:
cpu.JPG

Re: CCR1036-8G-2S+with HIGH CPU load

Posted: Mon Jan 14, 2019 1:00 am
by mducharme
I read about the disabling SNMP, tried it too, didn't help for me.

This is by the way what the CPU looks like after the reboot. Busy, but normal:
cpu.JPG
Yes this is exactly what happened to us. In our case it seemed to start when a winbox session terminated abnormally that had a large table open (I think it was the ip routes table). The user session showed as permanently active on the router (under system->users->active users) even though it had disconnected. My guess is that the management CPU was high because it was trying to redraw the table every single time there was a change, even though the user was no longer connected.