When designing a web application based on PHP, it’s not enough to just fix the problem and project specifications. Server assets such as storage, memory, and number of CPUs contribute to the hosting price. Therefore, when developing a web application, developers should take into account these assets.  The application must run smoothly!

There are three main reasons why performance is critical.

The first one is user experience. If your application takes forever to load, you risk your users switching to rivals or leaving bad reviews that will have a negative impact on the business.

Conversions is the second reason. A faster website means more conversions and more profit.

The third reason is scalability. The more demands your application can handle per moment, the more traffic you’ll have. For illustration, in case your application can handle a single process in 100ms, it implies your application can serve 10 requests per second, so if you will reduce the application processing time to half, your application capacity will double.

There are still some people who can not believe that PHP can be used for big, successful projects, but out there are already many examples of massive sites using PHP.

Firefox: they received more than 10 million downloads as they made the download site 2.2 seconds faster.

Shopzilla: the conversion rate improved by 7–12 percent when the website became 5 seconds faster.

A quick list

Choose the best version of PHP

PHP7 is one of the fastest, if not THE fastest model of PHP out there. Compatibility issues will arise when migrating between these two versions, but the advantages, mainly with the overall performance gain, will outweigh the development price and time for the changes. In our article, you can find more info about the differences between PHP7 and the previous version.

Micro-Optimization

Micro-Optimization represents the minor modifications in your code that improve your software performance. For example, if you are going to use a for-loop, it is usually better to calculate the length in advance.

• Double Quotes (“) vs  Single quotes (‘) – For larger strings or massive iterations, you will notice a significant difference in loops where single quotes run faster than double quotes. This kind of micro-optimization is not needed, but from a performance point of view, it is still good practice to use single and double quotes sensibly wherever the need appears.

XHprof

Because Micro-Optimization is not enough, you can determine exactly which part of our code is slow without the need to guess using a profiling tool called XHProf.

XHprof was developed by Facebook and includes a basic UI for reviewing profile data. XHprof is designed for use in production environments and has a limited impact on performance while still collecting sufficient information to identify performance issues.

Release all resources

Code in PHP needs to be well-framed and there has to be nothing that is not taken care of. We generally see that closing file handler, unsetting massive arrays, closing a curl request or database connections are a few iterations that developers neglect while coding. This results in occupying larger memory for resource maintenance. So, it would be better if all the resources and iterations get released on time.

The unnecessary usage of global variables

If you’re trying to access a global variable, it’s going to be interpreted as a local variable, and it’s going to cost you a lot of money. If you assigned a global variable in your PHP file, a large amount of overhead would definitely be applied. So, restricting the use of global variables to get your PHP performance up and running is suggested.

Use more static methods

Static methods/properties are usually faster than non-static ones. However, if an object is pre-initialized and then a non-static method/property is called persistently on the same object, non-static is faster.

Non-static techniques omit a step of object initialization making them quicker by 20% on average.

Caching

Implementing a caching layer should have an effect on eliminating the load from your server and reducing the amount of time required to retrieve frequently needed data.

Both Memcache and Redis are widely used for caching. However, Redis has some competitive advantages such as synchronizing information to the disk so that data will not be lost when rebooting the server and it has built-in master / slave replication so that redistribution can be increased rapidly.