Here's how to give a system administrator a heart attack: the defaultSolaris 9 sendmail configuration apparently allows other machines thatyour Solaris machine thinks are in your local domain to relay throughyou. I say 'apparently' because there's nothing in the sendmail.mc aboutthis, and nothing clear in the generated /etc/mail/sendmail.cf either.

In other fun discoveries, the default sendmail configuration is alsoset up to relay all your mail through a machine called 'mailhost' inyour domain

I'll start by quoting Glyph Lefkowitz from a recent article (okay, recent for my techblog writing):

Metaprogramming is hard, and dress it up however you like, that'swhat using SQL is. Your code is generating other code, andevaluating its results.

Because metaprogramming is so hard, it is almost exclusively theprovince of frameworks, environments and operating systems. For goodreason, too. Whenever code generates other code, there arepotentially very serious mistakes that can get made. [..

If you write a simple threaded program in C on a modern Linux systemand fire it up, you may rapidly notice that you can't have more than acouple hundred threads before you run out of memory. Even if you don't need that many threads, you may discover that your program is using anabsurd amount of (virtual) memory.

(This can also happen in other languages; I know it happens inPython.)

What's eating all the memory is the default NPTL thread stack