On his blog today Gopal Vijayaraghavan has posted about the release of the latest version of the APC sofware (Alternative PHP Cache) - version 3.1.2.

Finally, after nearly a year of work, it's into a release. Some new stuff has sneaked into it undocumented, that people might find interesting - apc.preload_path would be one of them. The backend memory allocation has been re-done - the api part by me and the internals by shire. There's a hell of a lot of new code in there, both rewritten and added. Tons of php4 cruft removed, php5 stuff optimized, made more stable, then less stable, made faster, then applied brakes. Made leak-proof, quake-proof and in general, idiot-proof. So, on & so forth.

To show the difference, he includes a diff of the current version against the previous - 68 files changed, 3255 insertions and 5545 deletions.

Till has written up a nice (long) post about the performance steps he's taken to make his installations of the Zend Framework run even better than they already are.

The other day our servers were overwhelmed with the rising traffic and I started profiling my application through Xdebug.[...] On this project we currently run with 100,000 visitors per day on average, our peak is Sunday night where we get a ton more traffic than usually. [...] Here are a few things, that helped us. Suggestions are in no particular order and I should add that whatever is applicable for my situation, doesn't have to work for you.

His suggestions include using APC for caching, using __autoload, caching of DB queries, and some Apache tweaks to reduce what it has to load/use for each request.

In a recent post to his blog Patrick Allaert takes a look at benchmarking what Zend Platform has to offer against its open source brothers, Xdebug and APC.

The benchmark has been realized on an Intel Core2 Duo CPU T7500 @ 2.20GHz with 2Gb of RAM running Gentoo with a 2.6.25-r7 linux kernel. ab, the Apache Benchmark tool, has been used for the benchmark with 3000 requests and three concurrency modes: -c1, -c5 and -c50 which represents respectively 1, 5 and 50 simultaneous users. The application tested is eZ Publish 4.0.1 with default configuration using the "plain_site" example.

He tested with a number of different PHP installations including a base install of PHP 5.2.6, one including APC, another with APC+Xdebug and others with the Zend Platform. The resulting stats are included as well as a graph showing their relationships to each other. The installs using the bytecode caching came out on top (obviously) with the APC installations being much faster than the accelerated Zend Platform.

Thanks to it being posted on reddit, the traffic to a certain post on Michael Kimsal's blog gave him a crash (literally?) course in high load management on a WordPress blog.

The blog post was voted up on reddit, and the server got slammed. So slammed, in fact, that it was unusable for a few hours while I investigated the problem. I didn't know the post was on reddit, but I knew I was getting some traffic.

He spent some time trying to get the Apache server to finally die off and give him back his machine, at least enough to get a feel for what was going on. Part of his problem was not having APC installed like he thought and the other part - WordPress. While friendly on the outside, it's apparently somewhat lacking on the inside.

On his blog today Michael Kimsal asks a question that hasn't come up much in recent months - with all of the advancements browsers are adding in, why aren't there better hooks for measuring file downloads?

This current tirade stems from implementing a file upload progress meter in PHP5. Yes, PHP5.2 has some hook, and there's a PECL extension. [...] I realize this is partially a PHP issue I'm ranting about, but it's ultimately a hacky workaround to a basic piece of functionality that browsers should support.

He mentions an example where he basically directly asked a member of the IE team about it. It wasn't greeted seriously and still hasn't managed to be included in most of the popular browsers of today.

Brian Shire has posted a new tutorial talking about some of the benefits of caching the functionality of your website (with things like APC, not file or database caching):

Opcode caches save energy, expenses, improve overall user experience on web sites, and it's often one of the simplest optimizations to implement. This article will explain the basics of installing, configuring, and tuning an opcode cache for PHP, the Alternative PHP Cache (APC).

The article focuses on how the APC works and how to get it up and working on your installation (as pulled from the pecl repositories). They look at some of the functions the extension's API includes (like ap_cache_info or ap_store for manual caching) as well as some more advanced topics like locking performance, working with TTL, cache priming and filtering.

Inspired by the nice web interface that the Alternative PHP Cache provides (apc), Harun Yayli decided to hack together his own version for the memcache caching software.

For a long time I was looking for a nice web interface like the apc.php (comes with the apc's source) that displays whole nine yards of stats. [...] Anyways, I decided to rip write my own. Totally based on the original apc.php (I even recycled some functions) and apart from completeness, here is a memcache.php that you can get stats and dump from multiple memcache servers.

Here's the output of his script and he's made the source for it available for download as well.

The New Earth Online has a quick look at one easy method for speeding up your site in a few different ways - caching pages and information with things like Cache_Lite and APC.

As your site traffic grows it takes longer and longer to generate a dynamic page from sending multiple queries to a database. One possible solution to limit queries is to cache the result of each query that is needed, or to have a complete full page cache for your site.

They look at the two ways I mentioned - the Cache_Lite PEAR package and the APC extension (that will soon be included by default in the stable PHP releases). Bits of code are provided for each showing how to get them set up and get them working inside of your application.

In this new post to his blog, Ian Selby talks about a method to "pump up" your web site's performance to give the most to your visitors - the APC cache.

Nothing's cooler than writing a bad-ass site or application and watching it gain popularity and a significant user base. By the same token, nothing's more frustrating that watching your app fall on its face when its running under high load. [...] Before you say, "throw more / better hardware at that mo-fo", why not take a moment and learn about APC: Alternative PHP Cache...

He describes the caching software - what it is and how it can help you and your application - and includes examples using a CacheManger class to store and set values quickly and easily.

Gennady Feldman, in light of some of the recent talk about enhancing the performance of your PHP applications, has written up this new post comparing two of the more favored software packages - APC and Eaccelerator.

Some websites use other technologies like Java and face the exact same problems. There are different variables involved here and the most common one is database. So I thought i would post a couple of articles related to performance and tuning.

This this post of the series focuses on the first of the two - APC - and talks about places it's used and includes some general performance recommendations. These include "Don't try to throw everything at your poor database" and the importance of XDebug.