CUPS Stops Print Queue (should it?)
anonymous at easysw.com
Wed Aug 17 12:38:08 PDT 2005
I was called on to investigate why one of our customer's print queues was intermittently going offline. To make a long story short, the JetDirect backend was returning a negative error status. After trudging through the source code, it became apparent that CUPS will offline a printer if the backend returns a negative status. In all cases, the print job was successfully continued simply by bringing the print queue back online, with no other changes.
I don't understand the philosophy of taking a printer offline after a failure. The source for the backend enters a retry loop if it fails to connect, but once connected, a failure will cause a negative return status, and the scheduler does not retry. The queue is taken offline, and our support staff get calls at inconvenient hours just to go and push the "Start Printer" button on the web console. Meanwhile, the print queue is still accepting jobs, but is not printing anything. Why not retry? The jobs are queueing up anyhow. It seems that the scheduler should keep trying to print.
I am also curious if this behavior (shutting down a print queue) is documented somewhere.
Thanks for the help.
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