Installation and advanced use of PHP APC_PHP tutorial

Because if this thing is called "optional PHP cache", it will easily give people the illusion that it is necessary or not and not very useful.

APC’s homepage is: http://pecl.php.net /package/apc. The current version is 3.0.14, installed through PECL, requires php4.3.0 or higher.

PHP APC installation:
Usually download the source code and compile and install it with phpize. After installation, add
extension=apc.so
to php.ini and that’s it.

Usage of PHP APC:
The use of APC is actually not that important. APC is an optimizer. From the day of installation, it has been silently serving your PHP application in the background. All your PHP code will be Cache. In addition, APC can provide a certain memory cache function. However, this function is not perfect. There are reports that if the write function of APC cache is frequently used, unpredictable errors will occur. If you want to use this function, you can see Look at apc_fetch, apc_store and several other functions related to apc cache. Starting from PHP5.2, APC has introduced a cookie, which solves the problem of the progress bar of large file uploads that has troubled everyone for a long time.

Advanced use of PHP APC

1. Cache period: APC’s cache is divided into two parts: system cache and user data cache.
The system cache is automatically used, which means APC caches PHP The compilation results of the file source code are cached, and then compared with the time stamp when called again. If not expired, the cached code is used to run. The default cache is 3600s (one hour). However, this still wastes a lot of CPU time. Therefore, you can set the system cache in php.ini to never expire (apc.ttl=0). However, if it is set like this, it will be required after running the php code. Restart your web server (such as apache...). The current performance test of APC generally refers to this layer of cache;

The user data cache is read by the user using the apc_store and apc_fetch functions when writing PHP code. For fetching and writing. If the amount is not large, I suggest you use it. If the amount is large, I suggest using memcache will be better. If you want to enjoy the feature of caching large file upload progress brought by APC, you need to set it in php.ini Set apc.rfc1867 to 1, and add a hidden field APC_UPLOAD_PROGRESS to the form. The value of this field can randomly generate a hash to ensure it is unique. For specific examples, please see the link given above.

2 .Status control and analysis: The source code package of PHP APC comes with apc.php; you can upload this file to a directory on the web server and access it with a browser, which will display the current status. We can start from here The table analyzes the current cache status and makes further optimization. apc-info-clublocalhost2.png This is the status of a test site. You can analyze it slowly. This tool will provide many useful tools. For example, you can see which files are frequently used Be included (accessed), which variable in your cache is often read, or frequently updated, etc. Finally, by the way, there are independent reports that the code caching and optimization effect of PHP APC is higher than that of zend optimizer. Even if it is not true Yes, it is open source and free, it is really a pretty good choice

http://www.bkjia.com/PHPjc/446206.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/446206.htmlTechArticleBecause if this thing is called optional PHP cache, it will easily give people the impression that it is optional and not very useful. the illusion. APC's homepage is: http://pecl.php.net /package/apc. The current version is 3.0.1...