Details of compression=gzip

[Steve Bergman]

We do a lot of printing over WAN/VPN links. I have a CUPS 1.3.9 server that queues jobs to a CUPS 1.4.8 server, which then sends the jobs to local printers at that location using a combination of lpd: and socket:. I've put compression=gzip in as an argument to ipp: for all the remote printers. Setting LogLevel to debug2, I can see that for most print jobs, I get a line in the log that reports that it compressed the file to xx% of its original size. But for some jobs, I don't get that line. To be clear, even for a single printer, some jobs report the compression statistic and some don't. Does CUPS just not compress files that aren't very compressible? Am I getting all the compression that I can?

Also, is there a way to get compression statistics without setting LogLevel to debug?

Thanks for any information,
Steve Bergman