Camera falling behind realtime and high zmc CPU usage

ExplodingLemur · Post by **ExplodingLemur** » Thu Sep 27, 2007 4:26 pm

One of my cameras is falling behind realtime...right now anything that happens shows up in ZoneMinder about a minute and a half past the event. This delay seems to increase with time (restarted zoneminder recently, it was at realtime, then shortly after restarting it was up to about 30 seconds behind). The rest of the cameras are working fine. It's not the camera itself, I'm watching the same set of cameras with Axis Camera Station, and that is showing everything in realtime.

Also, possibly related, the zmc process for that camera takes more and more CPU as time goes on, when it starts it's taking about 2x the CPU time as the rest of the zmc processes (about 30% while the other zmc processes are at 12-14% usage), it has grown now to 80-90% (and 3x the memory usage of the other processes). Restarting ZoneMinder doesn't help this. (ZoneMinder 1.22.3, Apache2 2.2.3, Debian Etch).

I have all the cameras set up the same, maximum framerate of 5ps, max alarm framerate 10fps (the cameras are Axis 2100 cameras, capable of 10fps).

Additionally, when looking at the feed for the problematic monitor, the framerate displayed is sometimes 5fps, but usually lower, sometimes as low as around .3fps. The other monitors are able to maintain 5fps when being watched.

Lee Sharp · Post by **Lee Sharp** » Thu Sep 27, 2007 5:55 pm

What happens if you just refresh the web browser?

ExplodingLemur · Post by **ExplodingLemur** » Thu Sep 27, 2007 5:59 pm

It doesn't help at all. The image is still delayed whether I refresh the window, or close and re-open the monitoring window.

I've tried turning off ZM_NETCAM_REGEXPS and setting HTTP 1.0 and then restarting ZoneMinder...the CPU usage of the other zmc processes drop dramatically, but this particular monitor still takes up a significantly larger amount of CPU time. I deleted the monitor and re-created it, and it has the exact same problems. All my cameras have the same firmware versions, I don't know what the problem is... (and I have also power-cycled the problematic cam to see if that's the issue...still wouldn't explain why Axis Camera Station is having no trouble keeping up though).

I found this thread describing what appears to be the same issue I'm having, but without any solution...
http://www.zoneminder.com/forums/viewtopic.php?t=5336

jameswilson · Post by **jameswilson** » Thu Sep 27, 2007 8:06 pm

That was one of mine and it turned out if i recall to be an overheating northbridge. New mobo fixed it

ExplodingLemur · Post by **ExplodingLemur** » Thu Sep 27, 2007 8:45 pm

jameswilson wrote:That was one of mine and it turned out if i recall to be an overheating northbridge. New mobo fixed it

I'm reluctant to suspect the hardware at this point, this box came out of service as part of a MySQL cluster with no problems, and is identical hardware to a number of other machines we have running in a wide variety of roles. Also, if it were hardware-related, I don't think I'd be seeing a problem with only one of the five zmc processes running...

(I just turned on debug level 3 to see what messages ZM might produce)

jameswilson · Post by **jameswilson** » Thu Sep 27, 2007 9:06 pm

ExplodingLemur wrote:
jameswilson wrote:That was one of mine and it turned out if i recall to be an overheating northbridge. New mobo fixed it
I'm reluctant to suspect the hardware at this point, this box came out of service as part of a MySQL cluster with no problems, and is identical hardware to a number of other machines we have running in a wide variety of roles. Also, if it were hardware-related, I don't think I'd be seeing a problem with only one of the five zmc processes running...

(I just turned on debug level 3 to see what messages ZM might produce)

lemur i dont think yours is hardware either, i was getting huge loads (and i mut admit the board i back in service but seems ok now i have a fan on the nb.
I unfortunatly have no idea im afraid. And knowing how zm grabs images from its ring buffer i cant see how this can occur unless its not a zm issue

ExplodingLemur · Post by **ExplodingLemur** » Thu Sep 27, 2007 9:37 pm

Gaah! I turned on debugging...and everything behaved normally.
Turned it off, and everything looks normal still. (restarted ZM after changing the debug settings each time).

Okay...let's try an experiment...4 of the 5 cameras are in the same room, when we shut off the lights the framerates on those cameras drop significantly (to compensate for the low-light conditions). I wonder if the reduced framerate from those is causing weirdness with the 5th camera?

Hmm. Nope...zmc process for the previously problematic camera is still behaving itself. Well, if anyone has any ideas as to what might be going on, I'd love to hear them...I'll keep watching this to see if it happens again.