Blitz is a configurable service that will pound your site with page requests, allowing you to specify the concurrency, timeout, and duration of the onslaught. As it goes about this, it builds statistics and plots them along timelines. You can watch response times, errors and timeouts as it slowly ramps up the number of concurrent users until it reaches the maximum. At the end, it even projects how many hits per day your setup can handle at that rate.

The service has a generous free tier, though they offer paid upgrades for higher concurrency and duration. The free tier offers 250 concurrent users over a one minute rush. (Though if you sign up with this invite link, they will add additional concurrencies to your account.)

I found Blitz very useful when I was trying to squeeze faster response times out of my WordPress setup, tweaking my caching system options and adjusting Nginx and PHP configurations. Since they use the connections at their datacenter, you get more real-world results than if you simply ran Apache Bench locally on the server, or from your residential internet connection. Both tools have their uses, of course, and Blitz is a good one to have in your arsenal.

Its a nice long and informative article, and worth a look if you’re looking to do some performance optimization of web site. (Be sure to look into sprites after you’ve switched to loading JavaScript asynchronously!)

Thinking Async [CSS-Tricks]

One night at a Hackathon a few years ago (see Prime Time Hack), I started my first piece of code transforming PHP into C++. The languages are fairly similar syntactically and C++ drastically outperforms PHP when it comes to both CPU and memory usage. Even PHP itself is written in C. We knew that it was impossible to successfully rewrite an entire codebase of this size by hand, but wondered what would happen if we built a system to do it programmatically.

Interesting, for sure. Imagine using it with WordPress for a high-traffic blog…

HipHop for PHP: Move Fast [Facebook Developer Blog]

But what if you’re running on your own server, be it VPS, dedicated, or something else along those lines? What can you do to squeeze some extra performance out of your high-traffic blog?

Enter W3 Total Cache, a plugin that the infamously slow-loading blog Noupe has recently started using to combat the sluggishness that their constant social media hits cause. It can do a lot of things, including:

• Offloading static content to a CDN, if you have one.
• Minifying and compressing your CSS and JavaScript files, and caching them in memory or disk.
• Caching RSS in memory or disk.
• Ensuring that browsers cache things, such as images, CSS and JavaScript on their end for future page loads.
• Caching database objects in memory.

The plugin’s biggest feature is probably its support of various memory caching systems, such as memcached, APC, and XCache to store things in memory. This makes things very fast. Hard disks are a major bottleneck in servers. If you put frequently requested information in RAM, it can be served a lot faster. Try visiting a page on Noupe. It may load a little slow the first time if the page hadn’t been viewed recently, so you may have to load it again a second time. Things are real fast once they’re in the RAM cache.

I’m thinking of trying it out for myself in the future, once I go through with my plans to move from Apache to NGINX server software, which should free-up a bit of my RAM.