Large cups systems?

[Bernd Krumböck]

At first I had to update the data.
We migrated another lprng system to cups. This cluster processed 350000 jobs in the last two weeks. No PPD, only raw and interface scripts are used.

> I'd really like to know how you keep such a large configuration stable.  I've got roughly a dozen printers and a couple-hundred users and the whole system seems so flaky that if you sneeze too hard it falls apart.  I find I have to restart the cups service almost daily to keep things running.  I know my physical network is solid.  My configuration is pretty simple, I'm not doing anything fancy.
>

We had problems with some earlier CUPS versions. But we hadn't any problem with stability since 1.2.11.
I recommend you to use 1.2.12 or the latest 1.3.x.

Maybe your problem isn't the CUPS scheduler, maybe it's one of the filters or backends?
How your printers are connected?
Which filters you are using?

Please write down all symptoms before restarting:
lpstat is working?
scheduler use 99% CPU?
Can you stop the scheduler?
You need to use "kill -9"?
...

> So what's the secret?
There is no secret. Only some analyses, a cool head and you sometimes need to be patient.

> More horesepower on my server?
No. Only avoid swapping and a workload of 100%.

> Clustered servers?
Clustering is always a good idea, but has nothing to do with CUPS stability if your hardware and os is working correct.  ;)

> More caffene?  I can live with limited driver capability, most of my users don't even notice, but the stability is a serious issue.  Anything, please, this is frustrating me to no end.
>

We also had problems with stability (e.g. http://www.cups.org/str.php?L1439 and http://www.cups.org/str.php?L2311). So we searched in the CUPS forums and tried the last CUPS version. Without success.
So we started to write down all symptoms. In the last consequence I learned some basics about CUPS source and gnu debugger.

I hope my story isn't frustrating you. If you have no idea how to debug the CUPS sources, then post all informations about your environment and all symptoms to this forum. Maybe someone can fix the problem.

CUPS is still (one of) the best printer scheduler we have ever seen, but it is not bug free.  ;)

regards!
Bernd