PHP optimization, buffering, and Compression

PHP optimization, buffering, and compression-Linux general technology-Linux programming and kernel information. The following is a detailed description. This article provides practical solutions for PHP optimization, buffering, and compression.

As a popular Web programming language, the biggest advantage of PHP is speed. PHP4 is already doing very well in this regard, and you can hardly find a script programming language that is faster than it. However, if your application load is large, and the bandwidth is small, or there are other bottlenecks that affect your server performance, you may wish to try out some prescriptions I have prescribed for you, check whether it is a lab.


I. code optimization

When it comes to code optimization, you may think of neat and clear code, but this article does not mean it here, because if you want to seek speed, you need to adjust the PHP Source Code accordingly. In general, it is to remove unnecessary comments and make the code unreadable. However, this is incredible for a good programmer. Fortunately, Zend Technologies has released the Zend Optimization engine to help you achieve this. It is free now, but you must follow the Zend Optimizer license. This product can optimize the intermediate code generated by the engine.

It is relatively simple to install this engine. After downloading the version of the corresponding platform, uncompress the compressed file and add the following two lines to the php. ini file to restart the Web server.

Zend_optimizer.optimization_level = 15
Zend_extension = "/path/to/ZendOptimizer. so"
Zend_loader.enable = Off

If it is a Win32 platform, it should be:

Zend_optimizer.optimization_level = 15
Zend_extension_ts = "C: \ path \ to \ ZendOptimizer. dll"
Zend_loader.enable = Off

Ah! Not wrong, right? How are three rows? In fact, the third row is optional. Because it seems that turning zend_loader off can improve the speed, it is worth putting the third line in php. ini. Note that you are not using Zend encryption.


Ii. Buffering

If we want to further speed up, we need to consider using the buffer technology. There are some optional solutions, including Zend Cache (test version), APC, Afterburner Cache, and jpCache.

These are all buffer modules. they store the intermediate code generated for the first request to the. php file in the memory of the Web server, and then return the compiled version for future requests. Because this reduces disk read/write and all work in the memory, this process can significantly improve application performance,

There are many ready-made products. Who should I choose?

Zend Cache is a good commercial product. After loading those huge PHP pages for the first time, you will obviously feel the speed improvement and the server will set aside more resources. It is a pity that this product is for silver, but in some cases, you should not be stingy with the silver.

Afterburner Cache is a product of Bware Technologies and is currently in Beta version. It seems to be the same as Zend Cashe, but it cannot achieve the same effect as Zend Cache and cannot work with Zend Optimization engine, but it is free, so I use this module.

APC (Alternative PHP Cache) is another free module released by Community Connect. It seems that it can be used in the production environment.


Iii. Web content Compression

For an increasingly crowded network, saving bandwidth is just like saving water. According to IETF standards, most browsers should support gzip compressed content. In other words, you can send the content compressed with gzip to the browser, and the browser will transparently decompress the data.

Mod_gzip is a free Apache module released by Remote Communications. It compresses static Web content and sends it to browsers. This module is suitable for most static Web pages. Although
Remotecommunications said this module supports all the dynamic content generated by mod_php, mod_perl, and mod, but it still does not seem to work. From the mod_gzip mailing list, it is estimated that this problem can be solved only by 1.3.14.6f.

If you want to compress the dynamic content, you can use class.gzip _ encode. php, a PHP class used at the beginning and end of the script. For the entire website, the function is called in the auto_prepend and auto_append of php. ini. For details, you can read the program of this class. This program is well annotated and the author tells you almost everything. However, before using it, Your PHP should be compiled to support zlib.


For PHP 4.0.4, a new solution is to use ob_gzhandler to achieve the same effect as the above class. Simply Add the following sentence to php. ini:

Output_handler = ob_gzhandler;

This allows PHP to activate the output buffer and compress all output data. If you do not want to compress the output of all the content for any special reason, you can add the following lines to the. htaccess file to compress the files in the corresponding directory.

Php_value output_handler ob_gzhandler

You can also add the following directly in the PHP code:

Ob_start ("ob_gzhandler ");

This compression technology is very effective, but for Netscape Communicator users, because they cannot compress graphic files, it does not seem to end up? Msung stopped? Are you sure you want? IE does not solve this problem when compressing jpeg and gif files.


Conclusion:

Using the technology discussed in this article should improve your website performance, but note the following:

-PHP may not be the cause of the bottleneck. Check other causes (for example, database) carefully)

-You cannot adjust the server performance to the highest level. Therefore, before complaining about php and its buffer, consider whether to upgrade the server or adopt Dynamic Load Balancing Technology (that's a big deal of money ).

-Do not underestimate the content compression. When you see the PHP application speed improvement on your 100 Mb Intranet, do not forget where the modem user complained about your kb HTML page.