CUPS 1.3 - slow response

[angelb]

Hello all.

Continuing with my CUPS 1.3 testing, I've encountered several
performance-related issues on client systems. Consider the
following before the upgrade:

Current clients setup: CUPS 1.2
2700 printer queues
5-7seconds (lpstat -p)

Testing CUPS 1.3 on two AIX 5.2 and two Solaris 10 systems, 4 systems
total.

When CUPS 1.3 is first installed in a client system, once the polling
on the client is completed(as seen from printcap), it took 37minutes
(Solaris client) for the client to display all 2700 printer queues:

Solaris 10: Client running CUPS 1.3 polling CUPS 1.3 server
# timex lpstat -p
real    37m2.83s
user    1m29.07s
sys     0m11.73s

When I stop cupsd for the first time, it creates the remote.cache file,
the lpstat command would then take 15-20seconds:

# ps -ef|grep -i cups
    root 28087     1   4 14:38:29 ?           0:06 /opt/TWWfsw/cups135/sbin/cupsd -c /etc/opt/TWWfsw/cups135/cupsd.conf
    cups 28088 28087   1 14:38:35 ?           0:00 cups-polld cupsserver1 631 3600 631

# timex lpstat -p|wc

real       24.47
user        3.07
sys         0.11
    2707   29777  167898


Solaris 10: Client running CUPS 1.2 polling CUPS 1.3 server
# ps -ef|grep -i cups
    root 27310     1   3 14:36:46 ?           0:05 /opt/TWWfsw/cups1212/sbin/cupsd -c /etc/opt/TWWfsw/cups1212/cupsd.conf
    cups 27388 27310   0 14:36:49 ?           0:00 cups-polld cupsserver1 631 3600 631

# timex lpstat -p|wc
real        5.24
user        2.86
sys         0.09

    2707   29777  167898


AIX 5.2: Client running CUPS 1.3 polling CUPS 1.3 server
# ps -ef|grep -i cups
    root 1532128       1   0 13:48:46      -  0:51 /opt/TWWfsw/cups135/sbin/cupsd -c /etc/opt/TWWfsw/cups135/cupsd.conf
    cups 1994816 1532128   0 13:48:47      -  0:00 cups-polld cupsserver1 631 3600 631

# timex lpstat -p|wc
real 15.41
user 3.84
sys  0.09

    2707   29777  167898



AIX 5.2: Client running CUPS 1.2 polling CUPS 1.3 server
# ps -ef|grep -i cups
    cups 1007656 1126520   0 14:32:12      -  0:00 cups-polld cupsserver1 631 3600 631
    root 1126520       1   1 14:32:10      -  0:06 /opt/TWWfsw/cups1212/sbin/cupsd -c /etc/opt/TWWfsw/cups1212/cupsd.conf

# timex lpstat -p|wc
real 6.95
user 3.35
sys  0.05

    2707   29777  167898


The above finding is true for all systems tested, AIX or Solaris. The
problem appears to be CUPS 1.3 related such that when I start CUPS 1.2
on the client system and polls a CUPS 1.3 server, the response time on
the client goes back to normal, that is, 5-7 seconds to display the
entire list.

The last time I saw the 15-20second response time was in CUPS 1.2.
This is because we have more than 2000 printer queues and the solution
was to set ulimit(default 2000) to 8192 to cupsd which brought the
lpstat response time on the client to 5-7 seconds.


Any suggestion or comments or things to try would be appreciated.

Thanks,
Angel