Sunday, August 30th, 2009 ~ 10:09 pm by Mauriat Miranda
As I mentioned previously, I run many sites on my web server. Yesterday I decided to clean up some sites that their owners had neglected or not used. One such site was running Apache Tomcat Java Server, which I did not care to leave running.
Now I, like many users of commercial hosting plans, pay for cPanel/WHM which includes a myriad of options/configurations/settings to do almost everything on the server. Back in 2007, I had used the cPanel Addon to install Tomcat. It was an incredibly easy “1-click Install”. I never checked, but I just assumed it worked. Similarly I thought it would be just as easy to uninstall Tomcat. I clicked “Uninstall” and all went well and I didn’t see any immediate problems. Or so I thought …
Last night the Apache Webserver failed. I did not realize till this morning (6 hours later). After some digging I found that it was because Apache could not find some Tomcat/Java module. So much for a proper uninstall. I did not have time to debug the issue, so what did I do? I simply re-installed Tomcat. I just could not afford any more downtime! … I know, I know: Shame on me!
This incident is like many commonly seen in the Linux world: An all-in-one graphical configuration tool can do wonders, but somewhere due to interaction between components it can causes all sorts of unforeseen problems. The root problem here is that it is incredibly difficult to know all the intricacies and nuances for administrating multiple software systems. Add to that the occasional need to manually edit config files, and you create an unmanageable mess.
Do you remember linuxconf? … Back in the day (pre-2002) Red Hat included a configuration tool called linuxconf which could manage multiple system options using a variety of graphical and non-graphical interfaces. While this worked wonders for novices performing simple tasks (mounting disk partitions, adding users, setting network addresses), it caused all sorts of issues for more complex services (web server, mail server, samba). Unfortunately at that time, there were very few complete comprehensive tools for configuring complex servers. Users who got burned using linuxconf, eventually learned that the only guaranteed way to setup things was to read man pages and documentation, and then editing config files manually.
Redhat did eventually abandon linuxconf with RH8.0. And while many users did complain, ultimately it was a smart decision. Software projects cannot be held accountable if some 3rd-party tool mangled their config files. Even more importantly, how can someone be certain the tool made the change they requested without looking at the config output? You can’t.
Sadly even though I expected cPanel to do its job (considering it is not free), I should have been more careful on a live production server. While I’m not saying that every single “all-in-one” tool is a failure, I am saying that trusting any tool without validation is a very poor choice.