remote.cache and polling

[angelb]

Hello all.

When a client's cupsd is refreshed, it writes printers information to remote.cache.

The remote.cache file contains printer informations as shown:

# Remote cache file for CUPS v1.2.4
# Written by cupsd on 2006-11-16 21:32
<Printer ar01 at stldv503>
Type 12374
BrowseTime 1163741126
Info HPLJ4
MakeModel HP LaserJet Series PCL 4/5 CUPS v1.2 on stldv503
Location JON,(BAR-JONS ),LJ4K_JON_TRF , JONABCDC01
DeviceURI ipp://stldv503:631/printers/ar01
State Idle
Accepting Yes
JobSheets none none
Option lease-duration 7200
Option job-sheets none,none
</Printer>
...

If this information is received/written by cupsd, when does the client
ever need the Info, MakeModel, and Location fields?

An application only needs a printer name. An end-user only needs a
printer name and maybe occasional running of lpstat to see printer
status. I've yet to run into a user who will ask information on "Info,
MakeModel, Location". How does one display these info on the client
side?  Anyway, these attributes are essential only on the server side
and should stay there.

So, in any given poll, a client should be receiving only new printer
queue names and/or deleted queues and any status related to the
current state of the printer. If an environment has thousands of
printer queues, this will reduce unecessary network and processing
loads.

This may not be a simple thing to change; I think it will require some
major rewriting of the scheduler...but, it would be a nice.

This is just my observation and still have a lot to learn about CUPS
so if I blew this out of proportion, my apologies... :)

Thanks,
Angel