"Curiosity is the very basis of education and if you tell me that curiosity killed the cat, I say only the cat died nobly." - Arnold Edinborough

Yesterday Nginx Inc announced that it had taken $3 million USD in funding. No one deserves this more than Igor Sysoev and it’s hard to believe that Nginx wasn’t commercialized sooner. Well deserved or not, though, whether this funding is good for Nginx or not is up for debate.

To understand the whole aspect of the deal I’ll first cover the worst-case scenario that people might fear happening. I’ll later on cover why this case is unlikely, so please do finish reading before considering me a moron.

The FUD Aspect

Getting funded means a business person has seen potential and decided to invest money to get a return. There’s really no way to deny this, philanthropy simply does not happen in the start-up world unless you’re being funded by your rich but slightly senile aunt. Eventually this business man will want to get a return on his investment and this means the Nginx Inc will have to become profitable. How does an open source project become profitable, though?

  • Going closed source and commercializing the product.
  • Creating a closed source enterprise version to develop alongside open source version.
  • Keeping the core product open and developing commercial extensions of that product.
  • Keeping product open sourced and selling support, training and resources.

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Remember register globals? Remember how you had to code as if it was off, because it might be? Remember how you had to consider the security implications of it being on, because it might be? The might be and might not be is something which has plagued a lot of early PHP features. Register globals is in no way alone in this, in the effort of making things versatile the PHP developers managed to introduce the worst of both worlds and the best of none. At least for code where you can’t guarantee 100% control over the environment your code would be running in.

We see this even today with things such as short open tags. Ever been told you shouldn’t use them? Yeah, that’s primarily because they could be turned off thus leaking your source code into the document. (To a lesser degree it’s also about XML incompatibility)

Today I want to cover a very known feature, which many people don’t often think of as being in the same group as register globals and short open tags. Namely path info. The idea of path info is brilliant enough, it is most often used as a way to have SEO “friendly” URIs in cases where one might not be able to rewrite the URL. In short, you can have a URI like so:

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Lately I’ve been working with a friend on a daily-deal aggregator. The Groupon-like sites are popping up everywhere and the market for aggregators is still fairly unfilled. My project, Alladeals, target the Swedish daily deals market and as such it needs to support Swedish characters. In future it might have to support other languages as well so I decided that UTF8 was the way to go. Since most webpages are encoded in UTF-8 these days it has been fairly painless to actually work with UTF-8 in PHP, that is, until yesterday.

PHP does not natively support UTF-8. This is fairly important to keep in mind when dealing with UTF-8 encoded data in PHP. Usually I’m pretty good at remembering that, however yesterday I happened upon a bug which could easily have gone unnoticed for months if not for some good luck.

The bug manifested itself in the deal titles, the design is not well suited for really long titles so it was decided that it would be best to make sure that the titles did not exceed a length of 140 characters. To cut the the title the following code was used:

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I have previously talked about some of the most common nginx questions; not surprisingly, one such question is how to optimize nginx for high performance. This is not really overly surprising since most of new nginx users are migrating over from Apache and thus are used to having to tune settings and perform voodoo magic to ensure that their servers perform as best as possible.

Well I’ve got some bad news for you, you can’t really optimize nginx very much. There’s no magic settings that will reduce your load by half or make PHP run twice as fast. Thankfully, the good news is that nginx doesn’t require any tuning because it is already optimized out of the box. The biggest optimization happened when you decided to use nginx and ran that apt-get install, yum install or make install. (Please note that repositories are often out of date. The wiki install page usually has a more up-to-date repository)

That said, there’s a lot of options in nginx that affects its behaviour and not all of their defaults values are completely optimized for high traffic situations. We also need to consider the platform that nginx runs on and optimize our OS as there are limitations in place there as well.

So in short, while we cannot optimize the load time of individual connections we can ensure that nginx has the ideal environment optimized for handling high traffic situations. Of course, by high traffic I mean several hundreds of requests per second, the far majority of people don’t need to mess around with this, but if you are curious or want to be prepared then read on.

First of all we need to consider the platform to use as nginx is available on Linux, MacOS, FreeBSD, Solaris, Windows as well as some more esoteric systems. They all implement high performance event based polling methods, sadly, nginx only support 4 of them. I tend to favour FreeBSD out of the four but you should not see huge differences and it’s more important that you are comfortable with your OS of choice than that you get the absolutely most optimized OS.

In case you hadn’t guessed it already then the odd one out is Windows. Nginx on Windows is really not an option for anything you’re going to put into production. Windows has a different way of handling event polling and the nginx author has chosen not to support this; as such it defaults back to using select() which isn’t overly efficient and your performance will suffer quite quickly as a result.

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User EngagementUsually when you browse the internet you get your information and you’re on your way. Sometimes a website isn’t properly constructed and prevents you from getting your information easily, this causes you to become annoyed. Rarely you find something that is so awesome you just have to admire it and the thoughts that have gone into it. Today I found one of those things.

There are a lot of difficult aspects of starting and running a site. You have to consider how to drive traffic, how to rank on search engines, how to convert traffic to paying customers of participating users, and today I saw an ingenious example of how to engage users and encourage participation.

The image on the right is taken from a news post on the NBC Dallas site, it shows the general reader feedback and allows readers to submit their own feedback. The unique aspect is of course how they group the feedback. It’s not a generic 1 to 10 rating, it’s not a “let your voice be heard” sentence, it’s a colourful, graphic and quantified display. I cannot stress enough how awesome this is executed. What they manage to do is immediately quantify the response to an article which encourage users to add their voice.

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This is part two in my caching series. Part one covered the concept behind the full page caching as well as potential problems to keep in mind. This part will focus on implementing the concept in actual PHP code. By the end of this you’ll have a working implementation that can cache full pages and invalidate them intelligently when an update happens.

Requirements

I’ll provide a fully functional framework with the simple application I used to get my benchmark figures. You’ll need the following software to be able to run it.

  • Nginx. I’m not sure which exact version but I generally use and recommend the latest development version.
  • PHP 5.3.0. I recommend at least 5.3.3 so you’ll have PHP-FPM for your fastcgi process management.
  • MySQL
  • Memcached

The Framework

I’ll be referencing the code on github instead of pasting it in this post to keep the size down, so you will probably want to download it.

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