High Fibre Programming

I’m sorry it wasn’t in time for Christmas, I hope everyone managed to have at least a little bit of fun on Christmas day without it – but finally it’s here – version 0.0.4! This version involved the rewriting of the entire logging system for sub-processes, so plenty of testing was needed which wasn’t always compatible with Christmas festivities, (oddly enough).

Download: sourceforge.net/projects/fat-controller/files/

Project web: fat-controller.sourceforge.net

Continuous logging

The main aim for this release was to fully support the “daemonise anything” point of the Fat Controller raison d’etre. Prior to this release, output from sub-processes was collected and then written to the log file only once the process had ended. This was bad for two reasons:

• it only logs output on STDOUT, anything on STDERR is ignored
• no good for long-running daemon processes as nothing is logged until it ends

The Fat Controller now continually monitors STDOUT and STDERR of all sub-processes and immediately writes anything to the log file.

The whole logging system can be re-initialised by sending SIGHUP to The Fat Controller. So if, for example, your log files get deleted due to log rotation, simply send SIGHUP and The Fat Controller will re-open file descriptors to the log files. This can be easily added to your log rotation mechanism.

So, what else is new in v0.0.4? Here’s a brief summary taken from the changelog:

ADDED –run-once
Also to support daemon processes, using the –run-once argument it is possible to tell The Fat Controller to, (cunningly) run a process only once and then end.

ADDED –test-fire
If this argument is specified then The Fat Controller initialises but does not actually run, i.e. it does not daemonise (if it is specified to be in daemonise mode) nor does it run any processes. It is useful combined with the –debug option when testing to check arguments have been correctly read and interpreted.

CHANGED Debug mode
Debug mode is turned on by using the –debug argument when running The Fat Controller. Previously this was added by the init script /etc/init.d/fatcontrollerd if the file fatcontroller.debug was found in the current directory. In addition to turning on debug mode, it also looked for the configuration file in the current directory, and not in /etc/

This has now been substantially simplified. All you need to do to enable debug mode is instead of running the Fat Controller with:

sudo /etc/init.d/fatcontrollerd start

Use:

sudo /etc/init.d/fatcontrollerd debug

My plan is that if no major bugs are found in this release then I will re-release it as v1.0.0 as it will finally be everything that I imagined when I first started this project over a year ago.

I’ve still got plenty more ideas for development and I’m eager to hear any other ideas people may have. Please let me know if you have a great idea or suggestion!

I’ve just about finished the next version of The Fat Controller, v0.0.4. I’ve completely refactored the way it writes output from sub-processes so it needs some careful testing. It would be great if other people could give it a try and do some testing as well, if you’re interested then just leave a comment and I’ll send you the source. Perhaps version 0.0.4 could be ready in time for Christmas – and what better Christmas present than a new version of The Fat Controller?!

Here are the main new features:

Continuous logging
One of the shortcomings of previous versions was that output from sub-processes was only written to the log file once the process had ended. This is of little important for scripts which run quickly, but this is obviously no good for longer scripts or even when used to daemonise a program.

Now, output is written immediately to the log file which means that The Fat Controller can easily be used to daemonise other programs.   One of the issues I sometimes have with Java applications is that there’s not a simple way to run them as a daemon.   With The Fat Controller this is now possible, as well as provide handling should the Java application terminate for whatever reason.

Logging STDERR
In previous versions, only STDOUT from sub-processes was logged.   In v0.0.4 STDERR is also logged and you can specify either a separate log file for STDOUT and STDERR or simply log both into one file.

If you want to impress and amaze your friends and get your hands on the latest version before everyone else then just leave a comment below and I’ll send you the source and you can get testing!