Eliminating the dreaded "Database connection error"

Hint: it had nothing to do with the database

I started up the RPM Remote Print Manager® (RPM) user interface one morning, and instead of the usual list of queues and jobs, I saw this instead:

Database connection error

Fortunately, I’m a developer so I didn’t panic right away. Instead, I reached out to my colleagues in technical support. Bryan H gave me a short list of steps, which I’ll list here and explain briefly.

Bryan H [09:10]
it's the UI that recreates config.xml not the service
normally I tell customer to stop the service, stop the UI, rename config.xml, run the UI, start the service

It turns out that the file "config.xml" is one we use both in RPM and the UI. If we can't find the database, or can't open it, this file contains configuration we use to start RPM the best we can and let someone know there is a problem.

Unfortunately, it seems that this file gets clobbered once in a while. I started this blog post earlier, to describe the problem and explain what Bryan says above. Instead, I chose to fix the problem (again, being a developer and all ...)

The Breakdown

First, and most important, neither RPM nor the UI use this file to connect to the database.

Second, if the file does not exist, and you run the UI, then the UI will recreate the file. RPM also recreates the file if it doesn't exist. That's a bit of why we were running into the problem, too many cooks updating the file, occasionally at the same time.

However, the UI knows how to look in the Firebird configuration to get the right database path. RPM does not. That means Bryan H's advice above is solid.

As far as the problem this dialog box is trying to report, we could ignore the error and fix "config.xml" automatically. Basically, we decided to let the user know there was a problem and invite you to contact us for support, just in case.


After taking more care in RPM to not update this file unless necessary, we have stopped seeing this error. Hopefully, that will relieve a moment of panic for everyone who would otherwise run into this difficulty.

If you are running a version of RPM starting at dated 2017-03-08, or more recent, you will have this change available to you. Please contact your salesperson or our technical support staff for more information.