Apache’s prefork MPM is a very heavy memory eater. Thirty instances together with PostgreSQL can consume more then 1.5GB of memory. I have already managed the PostgreSQL to become modest. Now the Apache is the target.
Filtering duplicities in XSLT
I had a problem: I needed to find some tags in a subtree without duplicities. The duplicity was determined by a tag’s attribute value. (more…)
MagicDraw – UML tool
Good (meaning many features and userfriendly) and cheap UML modeling tool is a hard candy to find. I need at least following stuff:
- use case, class, activity and sequence diagrams
- not just dummy diagrams but also some semantics
- ability to run under Linux
Memoization
I presume that you know what the memoization is. And if not then you can read about it on wikipedia. I’d like to write about problems that I ran into while implementing memoization in Python.
Function in a function, scope, decorators
When I started using decorators I was confused how it works. I was using decorators like @staticmethod and @classmethod and I didn’t care how it is done. It works. But what about custom decorators? (more…)
Python’s built-in id() and class methods
I found a feature of the built-in function id() that is a little bit unexpected (Python 2.5).
Postfix and DDoS
Last twelve days my SMTP servers were under a continual DDoS. Attack consisted of ~1300000 attempts to deliver a message to random mailboxes under a single domain. Attacks came from ~280000 unique IP addresses. (more…)
mod_python vs. FastCGI
I’m developing webapplications running under mod_python for a long time. I’m not very satisfied with the mod_python performance particularly the first load time so I’m looking for something like an application server – loaded modules will stay “longer” in the memory – application doesn’t need to be completely initialized very often. The FastCGI approach is very close. I ran benchmarks to measure overhead of the FastCGI (mod_fastcgi, mod_fcgid) compared to the mod_python. (more…)
Compression programs comparison
I was wondering how powerful are those simple stream compressors like gzip and bzip2. Test rabbit was a Linux kernel source tree tar-ed into one file which was thrown out to those compression beasts. Simple benchmarks were performed on Mobile AMD Sempron 3100+. (more…)