Credits: Ben Mansell, Stephen Landamore, Daniel Silverstone, Shane Caraveo Building PHP ------------ You must add '--enable-fastcgi' to the configure command on Linux or OSX based systems to get fastcgi support in the php-cgi binary. You also must not use '--enable-discard-path'. Running the FastCGI PHP module ------------------------------ There are two ways to run the resulting 'php' binary after the fastcgi version has been built: 1) Configure your web server to run the PHP binary itself. This is the simplest method, obviously you will have to configure your web server appropriately. Some web servers may also not support this method, or may not be as efficient. 2) Run PHP separately from the web server. In this setup, PHP is started as a separate process entirely from the web server. It will listen on a socket for new FastCGI requests, and deliver PHP pages as appropriate. This is the recommended way of running PHP-FastCGI. To run this way, you must start the PHP binary running by giving it an IP and a port number to listen to on the command line, e.g.: ./php -b 127.0.0.1:8002 The above line is the recommended way of running FastCGI. You usually want the FastCGI server to provide services to the localhost, not everyone on the Internet. If your web server sits on a remote host, you can make FastCGI listen on all interfaces: ./php -b :8002 ./php -b "*:8002" Note that hostnames are not supported. You must also configure your web server to connect to the appropriate port in order to talk to the PHP FastCGI process. The advantage of running PHP in this way is that it entirely separates the web server and PHP process, so that one cannot disrupt the other. It also allows PHP to be on an entirely separate machine from the web server if need be, you could even have several web servers utilising the same running PHP process if required! Using FastCGI PHP with Apache ============================= First of all, you may well ask 'Why?'. After all, Apache already has mod_php. However, there are advantages to running PHP with FastCGI. Separating the PHP code from the web server removes 'bloat' from the main server, and should improve the performance of non-PHP requests. Secondly, having one permanent PHP process as opposed to one per apache process means that shared resources like persistent database connections are used more efficiently. First of all, make sure that the FastCGI module is enabled. You should have a line in your config like: LoadModule fastcgi_module /usr/lib/apache/2.0/mod_fastcgi.so Don't load mod_php, by the way. Make sure it is commented out! #LoadModule php5_module /usr/lib/apache/2.0/libphp5.so Now, we'll create a fcgi-bin directory, just like you would do with normal CGI scripts. You'll need to create a directory somewhere to store your FastCGI binaries. We'll use /space/fcgi-bin/ for this example. Remember to copy the FastCGI-PHP binary in there. (named 'php-cgi') This sets up php to run under mod_fastcgi as a dynamic server. ScriptAlias /fcgi-bin/ /space/fcgi-bin/ Options ExecCGI SetHandler fastcgi-script To setup a specific static configuration for php, you have to use the FastCgiServer configuration for mod_fastcgi. For this, do not use the above configuration, but rather the following. (see mod_fastcgi docs for more configuration information): Alias /fcgi-bin/ /space/fcgi-bin/ FastCgiServer /path/to/php-cgi -processes 5 For either of the above configurations, we need to tell Apache to use the FastCGI binary /fcgi-bin/php to deliver PHP pages. All that is needed is: AddType application/x-httpd-fastphp .php Action application/x-httpd-fastphp /fcgi-bin/php-cgi Now, if you restart Apache, php pages should now be delivered! Using FastCGI PHP with IIS or iPlanet ===================================== FastCGI server plugins are available at www.caraveo.com/fastcgi/ Documentation on these are sparse. iPlanet is not very tested, and no makefile exists yet for unix based iPlanet servers. Security -------- Be sure to run the php binary as an appropriate userid. Also, firewall out the port that PHP is listening on. In addition, you can set the environment variable FCGI_WEB_SERVER_ADDRS to control who can connect to the FastCGI. Set it to a comma separated list of IP addresses, e.g.: export FCGI_WEB_SERVER_ADDRS=199.170.183.28,199.170.183.71 Tuning ------ There are a few tuning parameters that can be tweaked to control the performance of FastCGI PHP. The following are environment variables that can be set before running the PHP binary: PHP_FCGI_CHILDREN (default value: 0) This controls how many child processes the PHP process spawns. When the fastcgi starts, it creates a number of child processes which handle one page request at a time. Value 0 means that PHP willnot start additional processes and main process will handle FastCGI requests by itself. Note that this process may die (because of PHP_FCGI_MAX_REQUESTS) and it willnot respawned automatic. Values 1 and above force PHP start additioanl processes those will handle requests. The main process will restart children in case of their death. So by default, you will be able to handle 1 concurrent PHP page requests. Further requests will be queued. Increasing this number will allow for better concurrency, especially if you have pages that take a significant time to create, or supply a lot of data (e.g. downloading huge files via PHP). On the other hand, having more processes running will use more RAM, and letting too many PHP pages be generated concurrently will mean that each request will be slow. PHP_FCGI_MAX_REQUESTS (default value: 500) This controls how many requests each child process will handle before exitting. When one process exits, another will be created. This tuning is necessary because several PHP functions are known to have memory leaks. If the PHP processes were left around forever, they would be become very inefficient.