Comparison of CGI, FastCGI, PHP-CGI, PHP-FPM, and Spawn-FCGI in PHP environment configuration?

What is CGI

The full name of CGI is "Common Gateway Interface" (Common Gateway Interface). It is a tool for the HTTP server to "talk" with programs on your or other machines. The program must run on the network server.

CGI can be written in any language as long as the language has standard input, output and environment variables. Such as php, perl, tcl, etc.

What is FastCGI

FastCGI is like a long-live CGI. It can be executed all the time. As long as it is activated, it will not take time to fork every time (this is the most criticized fork-and of CGI). -execute mode). It also supports distributed computing, that is, FastCGI programs can be executed on hosts other than the website server and accept requests from other website servers.

FastCGI is a language-independent, scalable architecture CGI open extension. Its main behavior is to keep the CGI interpreter process in memory and thus obtain higher performance. As we all know, repeated loading of the CGI interpreter is the main reason for low CGI performance. If the CGI interpreter remains in memory and accepts FastCGI process manager scheduling, it can provide good performance, scalability, Fail-Over features, etc.

FastCGI and CGI features

1. Like CGI, FastCGI is also language-independent.

　2. In-process applications such as CGI and FastCGI run independently of the core web server, providing a more secure environment than APIs. (APIs link an application's code with the core web server, meaning that an application with a faulty API could damage other applications or the core server; a malicious API's application code could even steal another application. Program or core server key )

3. FastCGI technology currently supports languages: C/C++, Java, Perl, Tcl, Python, SmallTalk, Ruby, etc. Related modules are also available on popular servers such as Apache, ISS, Lighttpd, etc.

　4. Like CGI, FastCGI does not depend on the internal architecture of any web server, so even if server technology changes, FastCGI remains stable.

How FastCGI works
　
　1. Load the FastCGI process manager (IIS ISAPI or Apache Module) when the Web Server starts
　
2. The FastCGI process manager initializes itself, starts multiple CGI interpreter processes (visible multiple php-cgi) and waits for connections from the Web Server.
　
　3. When the client request reaches the Web Server, the FastCGI process manager selects and connects to a CGI interpreter. The Web server sends CGI environment variables and standard input to the FastCGI subprocess php-cgi.
　
　4. After the FastCGI sub-process completes processing, it returns standard output and error information to the Web Server from the same connection. When the FastCGI child process closes the connection, the request is processed. The FastCGI child process then waits for and handles the next connection from the FastCGI process manager (running in the Web Server). In CGI mode, php-cgi exits at this point.
　
In the above case, you can imagine how slow CGI usually is. Every web request to PHP must reparse php.ini, reload all extensions and reinitialize all data structures. With FastCGI, all of this happens only once, when the process starts. An added bonus is that persistent database connections work.

Disadvantages of FastCGI

Because it is multi-process, it consumes more server memory than CGI multi-threading. The PHP-CGI interpreter consumes 7 to 25 megabytes of memory per process. Multiply this number by 50 or 100 to get a large amount of memory.
　
　Nginx 0.8.46+PHP 5.2.14 (FastCGI) server has 30,000 concurrent connections. The 10 Nginx processes opened consume 150M memory (15M*10=150M), and the 64 php-cgi opened The process consumes 1280M of memory (20M*64=1280M), plus the memory consumed by the system itself, the total consumption is less than 2GB of memory. If the server memory is small, you can only open 25 php-cgi processes, so that the total memory consumed by php-cgi is only 500M.

The above data is excerpted from Nginx 0.8.x + PHP 5.2.13 (FastCGI) to build a web server that is ten times better than Apache (version 6)

What is PHP-CGI

PHP-CGI is the FastCGI manager that comes with PHP.
Start PHP-CGI and use the following command:

Copy the code The code is as follows:

php-cgi -b 127.0 .0.1:9000

Disadvantages of PHP-CGI

1. After php-cgi changes the php.ini configuration, you need to restart php-cgi to make the new php-ini take effect. It cannot be restarted smoothly

2. Kill the php-cgi process directly, and php will not be able to run. (PHP-FPM and Spawn-FCGI do not have this problem, the daemon process will smoothly regenerate new child processes.)

　What is PHP-FPM

PHP-FPM is a PHP FastCGI manager, which is only used for PHP and can be downloaded at http://php-fpm.org/download.

PHP-FPM is actually a patch of PHP source code, aiming to integrate FastCGI process management into the PHP package. It must be patched into your PHP source code, and it can be used after compiling and installing PHP.

Now we can download the branch that directly integrates PHP-FPM in the latest PHP 5.3.2 source tree. It is said that the next version will be integrated into the main branch of PHP. Compared with Spawn-FCGI, PHP-FPM has better CPU and memory control, and the former crashes easily and must be monitored with crontab, while PHP-FPM does not have such troubles.

PHP5.3.3 has integrated php-fpm and is no longer a third-party package. PHP-FPM provides a better PHP process management method, which can effectively control memory and processes, and can smoothly reload PHP configuration. It has more advantages than spawn-fcgi, so it is officially included in PHP. PHP-FPM can be turned on by passing the –enable-fpm parameter in ./configure.

Use PHP-FPM to control the FastCGI process of PHP-CGI

Copy the code The code is as follows:

 
/usr/ local/php/sbin/php-fpm{start|stop|quit|restart|reload|logrotate} 

--start starts the fastcgi process of php
--stop forcibly terminates the fastcgi process of php
--quit smoothly terminates php's fastcgi process
--restart restarts php's fastcgi process
--reload smoothly reloads php's php.ini 
--logrotate re-enables the log file

What is Spawn-FCGI

Spawn-FCGI is a universal FastCGI management server. It is part of lighttpd. Many people use Lighttpd's Spawn-FCGI to perform management work in FastCGI mode, but it has many shortcomings. The emergence of PHP-FPM has somewhat alleviated some problems, but PHP-FPM has the disadvantage of having to recompile, which may pose a considerable risk (refer) to some already running environments. It can be used directly in PHP 5.3.3 PHP-FPM.

Spawn-FCGI has now become a separate project, which is more stable and brings convenience to the configuration of many Web sites. Many sites have paired it with nginx to solve dynamic web pages.

The latest lighttpd does not include this piece (http://www.lighttpd.net/search?q=Spawn-FCGI), but it can be found in previous versions. It is included in lighttpd-1.4.15 version (http://www.lighttpd.net/download/lighttpd-1.4.15.tar.gz)

The current download address of Spawn-FCGI is http://redmine.lighttpd.net/projects/spawn-fcgi, and the latest version is http://www.lighttpd.net/download/spawn-fcgi-1.6.3. tar.gz

Note: For the latest Spawn-FCGI, you can search for "Spawn-FCGI" on the lighttpd.net website to find its latest version release address

Now we can use Spawn-FCGI to control the FastCGI process of php-CGI

Copy the code The code is as follows:

/usr/local/bin/spawn-fcgi -a 127.0.0.1 -p 9000 -C 5 -u www-data -g www-data -f /usr/bin/php-CGI

The parameter meaning is as follows:

　-f Specify the executor location of the process that calls FastCGI, and set it according to the PHP installed on the system
　-a bind to the address addr
-p bind to Port port
　-s The path bound to the unix socket path
　-C Specifies the number of FastCGI processes generated, the default is 5 (only for PHP)
　-P Specify the PID file path of the generated process
What identity does -u and -g FastCGI use to run (-u user -g user group). You can use www-data under Ubuntu. Others are configured according to the situation, such as nobody, apache Wait

　PHP-FPM and spawn-CGI comparison test

PHP-FPM is very convenient to use. The configuration is in the PHP-FPM.ini file, and startup and restart can be done from php/sbin/PHP-FPM. What is more convenient is that after modifying php.ini, you can directly use PHP-FPM reload to load it. You can complete the modification and loading of php.ini without killing the process
The results show that using PHP-FPM can significantly improve the performance of PHP. . The CPU recycling speed of the process controlled by PHP-FPM is relatively slow, and the memory is allocated evenly.

The CPU of the process controlled by Spawn-FCGI drops very quickly, and the memory allocation is relatively uneven. Many processes appear to be unallocated, while others are highly occupied. It may be caused by uneven distribution of process tasks. This also leads to a decrease in overall response speed. The reasonable distribution of PHP-FPM leads to the mention of overall response and the average of tasks.

　Comparison of PHP-FPM and Spawn-FCGI functions

　http://php-fpm.org/about/

PHP-FPM and Spawn-FCGI are both process managers that guard php-cgi.

Reference document:

　http://topic.csdn.net/u/20100216/22/5809e272-6f67-4248-bde9-99deeae5215b.html
　http://topic.csdn.net/u/20101015/19/8ae74452 -ec6b-448e-9942-21faeb008cd7.html
　http://club.topsage.com/thread-768488-1-1.html
　http://www.unixaid.info/index.php/productsapp /23-servsf/842-spawn-fcgi
　http://www.fastcgi.com/drupal/node/2
　http://baike.baidu.com/view/641394.htm
　http ://baike.baidu.com/view/32614.htm
　http://blog.yation.com/network/fastcgi/

Comparison of CGI, FastCGI, PHP-CGI, PHP-FPM, and Spawn-FCGI in PHP environment configuration? _PHP Tutorial