Performance issues in cups 1.3

[Johan Bernhardsson]

some logs captured with tusc on hp-ux.

http://ryt.nu/select.log.gz    cups 1.2.7 on hpux
http://ryt.nu/poll.log.gz      cups 1.3.3 on hpux
http://ryt.nu/lp.log.gz        lp command cups 1.3.3

/Johan "SmallOne" Bernhardsson


> Okey did some testing during today.
>
> Sent on 24 lp commands at the same time. On to almost identical machines. One with cups 1.3.3 and one with cups 1.2.7.
>
> The one with 1.3.3 took almost 250 seconds before i got a response and the jobs ehere queued.
>
> The one with 1.2.7 took about 3 seconds before i got a repsonse and the jobs where queued.
>
> here are some screenshots fropm Glanceplus watching the cups pid. One with poll and one with select.
>
> http://ryt.nu/select.png
> http://ryt.nu/poll.png
>
> Can anyone confirm this ? Using cups on hpux on parisc ?
>
> /Johan "SmallOne" Bernhardsson
>
>
>
> > The real problem is in the hp-ux clients from what ive seen. They use poll from what ive seen.
> >
> > Ill try to gather some strace output from the servers. And fetch the same from the clients.
> >
> > Ive tried to gather some debug2 logs. But i have to setup a test system for it. As we currently have to many printjobs to get any readable info.
> >
> > /Johan "SmallOne" Bernhardsson
> >
> >
> > > Johan Bernhardsson wrote:
> > > > ...
> > > > When we push alot jobs through a client the load rises quite fast and we get delays.
> > > >
> > > > This seems to have started with the 1.3 release as we didnt have that in 1.2.7 that we ran before. The cpu usage is not the same.
> > > >
> > > > Has anyone else noted anything like this ?
> > >
> > > I haven't, but the scheduler in CUPS 1.3 no longer uses select() when
> > > one of the alternate mechanisms is available - that would mean poll()
> > > or epoll() on RHEL4.
> > >
> > > strace output from cupsd on the servers might be useful in seeing
> > > where the scheduler is spending its time...
> > >
> > > --
> > > ______________________________________________________________________
> > > Michael R Sweet                        Senior Printing System Engineer
> > >
> >
>