Archive for the ‘Uncategorized’ Category

forget about the environment

May 3, 2009

Maybe this is obvious (and still flammable topic) for most of system administrators, but it worth to say it again.

You should never rely on the environment variables, unless you explicitly specify that in the documentation (which is still bad way in most cases). You script must work if there’s no PATH env. variable, or no EDITOR set, etc. Yes, it may say error to the end user in unresolvable conditions, as `svn ci` do if no EDITOR and no -m specified, but generally it shouldn’t fail.

Not `sh`, but `/bin/sh`, not `cat`, but `/bin/cat`! Remember it and you’ll save a lot of nerves for you and all those people that will use your tools.

Thank you.


My Little Servers Plant

November 14, 2007

Just want to describe the servers set-up I’m using on my current project. In next several posts I’ll tell why things was made some way and not another, and I’ll describe my future plans also.

But for now only the whole system layout:

I have six servers at the moment. Two of them is isolated set-up and runs live installation of the application. They will run it until I’ll get the next release online on new servers set-up.

Remaining four servers:

Two absolutelly same relatively powerfull servers used for web front-end. Almost typical Apache+mod_php installation and nginx reverse-proxy for load-balancing.

One server if dedicated for the MySQL and some background tasks like images processing.

One server (unlike others it is not very powerfull) is now doing absolutely nothing. I’m planning to put system monitoring, logs, backups, staging installation, and maybe some other non-critical stuff there.

All four servers runs under FreeBSD 6.2, shared storage required by application is located on third-party windows server (client’s data-center) and mounted through smb protocol.

Interfaces and Usability

November 13, 2007

There are a lot of UML software, but nothing is better yet than large whiteboard. Why?..