Archive for May, 2009

PHP SDK for Windows Azure

May 31st, 2009 No comments

Microsoft is embracing the open world, by providing a wrapper or api to interact with their Azure Cloud services platform.

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function getIpBehindProxy

May 19th, 2009 No comments

We were worried, about all the comments on kerala online, being marked as spam by the akismet plugin. When on detailed examination, we found that the basic problem was that wordpress was logging only the immediate downsteam ip as the remote address, well ours was a bit confusing setup, but to handle the traffic we needed it that way.

A search for wordpress behind reverse proxy, landed me to the wordpress support page. In fact the 5th entry on that page is done by Gopka, who is the lead on this project from Saturn.

We started to correct the remote address by overriding the global variable making slight changes to the wp-config, such that we will not accidentally overwrite the changes while upgrading wordpress. Well the code

$list explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);
$_SERVER['REMOTE_ADDR'] = $list[0];

when added to the wp-config, it started to log the first IP, and that would be mostly private IPs if the request was from organisations where internet was shared through proxies or using NAT. The case was same at our office, so we had to find the first public ip from the list of IPs and the code for function getIpBehindProxy was the out come.
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WordPress object caching in file system

May 12th, 2009 No comments

During the past couple of months, since we are maintaining a heavily loaded wordpress implementation, Kerala News Portal for Asianet, distributed across two servers, and having a daily visit of 50K, I was on the hunt for better caching and optimizing techniques. On the move, I happened to read the article by Jeff Starr, written some 15 months ago, and all the associated comments. It was sad to see that the file based cache was removed from wordpress, due to several reasons though.
After reading through this, I saw the official Function Reference for WP Cache, and the eAccelerator for WordPress by NeoSmart Technologies. Reading through the code written by Computer Guru of NeoSmart Technologies, tickled me and I just modified some parts, by pulling out the eaccelerator specific functions, and switching to a file system based store. I am not adding the code as pretty php code. Drop the file into wp-content, create a cache folder in wp-content and chmod folder to 755.
File based object caching for Wordpress (1846)
Recently only I found that this has been outdated with new version of wordpress demanding more of the wrapper functions and capabilities. And this has been brought into the system. Functionally more or less the same, but will work on shared hosting for just object caching.
Object Cache (1001)

Web Spider using php cli

May 7th, 2009 No comments

Purely on academic basis, I had once helped to cook up a web spider, which is used to build site maps. The spider was written in php and uses a couple of reg-exp matches, and finally writes the full sitemap from the start url. The system is assembled using two classes, WebPage and WebSpider. Then to make it similar to linux utilities in the command line environment, some functions were scooped in.
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Categories: Code Snippets Tags: ,

PHP Opcode Caches, switching between

May 6th, 2009 No comments

Opcode Cache

A PHP accelerator is an extension designed to boost the performance of software applications written using the PHP programming language. Most PHP accelerators work by caching the compiled bytecode of PHP scripts to avoid the overhead of parsing and compiling source code on each request (some or all of which may never even be executed). For best performance, caching is to shared memory with direct execution from the shared memory and the minimum of memory copying at runtime. A PHP accelerator typically reduces server load and increases the speed of PHP code anywhere from 2-10 times, depending on factors such as the inherent execution time of the PHP application and the percentage of source code actually executed on a given request. While a code optimizer may even slow down overall performance when used in isolation, it can provide an additional performance boost when coupled with a code cache as the optimization effort is performed just once.
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