apache

I've been banging my head against the wall over an error reported in some PHP code I've been writing. For some reason the session would be trashed on the server and on next page load I'd get "Node no longer exists" when I tried to open the session.

It turns out that you can't take a response from a SimpleXML object and store it in a session. You'd think that if you could type "echo $myxml->thisnode" and get a string that it's really a string, but PHP automatically typecasts and converts as needed - except in the case of storing in a session variable.

There's an easy solution. Use explicit typecasting when trying to store an XML result string in a $_SESSION[] variable:

$_SESSION['myinteger'] = (int)$myxml->myinteger;
$_SESSION['mystring'] = (string)$myxml->mystring;

I've always been a PHP guy, but recently I had a little Python web scraper utility I wrote that I wanted a nice interface to, and I didn't feel like writing a complete GTK interface for it, or rewriting it in PHP with CURL.

So, I thought, "Hey, there's these people that run Python on their servers instead of PHP, why don't I try that! It shouldn't be any harder than running PHP, right?"

Wrong. It's not hard, but it brings back memories of my first attempt to get Perl scripts to work properly with Apache.

First, you need to install "libapache2-mod-wsgi". This is the module for Apache that lets you run Python scripts from inside your web server. I know, why doesn't it have the word "Python" in the name? Don't worry - just make sure you don't actually try to use the module that DOES have Python in the name. It's the old and outdated way of doing things.

So, use Synaptic to install the module, or at a console enter:

sudo apt-get install libapache2-mod-wsgi

I was trying to figure out how to write a search engine that could support GamerzCrib forums.

The biggest challenge is that potentially I could be looking at over 10 million posts on the server, and something like 5 million users a month. I've seen vBulletin forums where the search became painfully slow and they had less than a million posts.

After poking around the net, I found Solr, run by the same guys who do Apache web servers. Solr is a Lucene search engine written in Java. It runs as it's own service and accepts updates to the search index, and typically provides XML output as search results, all using http as it's interface.