Configuring Web Systems For Best Performance

Bitrix Site Manager is developed in PHP scripting language and supports PHP4 and PHP5.

The availability of a script execution environment in content management systems allows to create dynamic web projects, easily manage information; analyze the project effectiveness; modify the site content depending on the visitor traffic, etc. It is no doubt that all the modern web projects are developed in a programming language among which PHP is the most popular; many engineers know this language and create sites in it.

Not so long ago HTML projects included only a set of static pages with HTML mark-up tags. The web server read the pages from disk and transferred them via the TCP/IP protocol. This does not require running any additional applications, thus not requiring additional memory or database. This approach is very simple and convenient but not sufficient for modern projects.

PHP (which means Hypertext Preprocessor) is a widely used open source general purpose programming language. PHP has been developed especially for creating web projects; it can be injected in the HTML code.

Note the difference between PHP scripts and applications written in other languages, e.g. Perl or C: we use the HTML code with some PHP commands added instead of creating a program which would build the HTML code using enormous population of API functions designed for HTML generation. The PHP code islands are marked with special initial and final tags allowing the PHP processor to find the beginning and the end of a HTML code section containing the PHP script.

PHP scripts are executed on server side, which is the most important trait that makes it completely different to other scripting languages because most of them run on the client side, e.g. JavaScript. If you run a PHP script on your server, a client would only receive the result of the script execution; it would not be able to know the contents of the script. You can even configure your web server in such a way that HTML files will be processed by the PHP interpreter. Your visitors will never know whether they get plain HTML pages or the result of script execution.

From administrator's point of view, it is very important that the PHP scripts are executed on server side being the interpreted language programs. The latter implies that each time you request a PHP page, the page is processed on the server by a special PHP interpreter: the language syntax, semantics and function calls are verified; and only then the code is executed. Of course, there are some tricks that we can use to avoid the repeated runs. We shall touch this issue later on.

As you can see, PHP sites consume more memory per single web server instance in contrast to common HTML pages. In most cases, web server can start sending a page to a client only after it has been processed by the PHP interpreter. This slows down the page delivery period in comparison with static HTML page.