Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
litespeed_wiki:php:opcode_cache [2016/06/17 18:45] Jackson Zhang [Opcode caching limitations] |
litespeed_wiki:php:opcode_cache [2016/06/17 18:58] Jackson Zhang [Popular Opcode Caches] |
||
|---|---|---|---|
| Line 9: | Line 9: | ||
| ===== Opcode caching limitations ===== | ===== Opcode caching limitations ===== | ||
| - | - **Opcode caching requires extra RAM.** The RAM limit you set for opcode caching will be automatically partitioned off. You will lose access to this RAM for other uses, so do not allow opcode caching to use too much of your RAM. | + | - **Opcode caching requires extra RAM.** The RAM limit you set for opcode caching will be automatically partitioned off. You will lose access to this RAM for other uses, so do not allow opcode caching to use too much of your RAM. For example, for a plesk user, normally 128M memory was allowed for that account. opcode cache should be set to 32M or lower. We did see out of memory error when opcode cache memory set to 64M. |
| - **Opcode caching requires PHP processes be forked from the same parent process in order to share the cache.** If the parent process is killed, the cache is flushed. This is why opcode caching does not work well with Apache's suPHP -- suPHP starts a new process for each PHP process, causing opcode cache to be flushed almost as soon as it was created. LiteSpeed's [[http://www.litespeedtech.com/products/litespeed-sapi/php/suexec-daemon-mode|suEXEC Daemon mode]] and [[http://www.litespeedtech.com/products/litespeed-sapi/php/suexec-processgroup|suEXEC ProcessGroup]] have been developed for greater use of opcode caching with PHP suEXEC while default suEXEC Worker mode does not. Please [[litespeed_wiki:php:enable_opcode_cache|make a change]] during opcode enabling process. | - **Opcode caching requires PHP processes be forked from the same parent process in order to share the cache.** If the parent process is killed, the cache is flushed. This is why opcode caching does not work well with Apache's suPHP -- suPHP starts a new process for each PHP process, causing opcode cache to be flushed almost as soon as it was created. LiteSpeed's [[http://www.litespeedtech.com/products/litespeed-sapi/php/suexec-daemon-mode|suEXEC Daemon mode]] and [[http://www.litespeedtech.com/products/litespeed-sapi/php/suexec-processgroup|suEXEC ProcessGroup]] have been developed for greater use of opcode caching with PHP suEXEC while default suEXEC Worker mode does not. Please [[litespeed_wiki:php:enable_opcode_cache|make a change]] during opcode enabling process. | ||
| - **Opcode caches can be buggy.** Many users find that choosing an opcode cache is a matter of trial and error -- different opcode caches work better in different setups. | - **Opcode caches can be buggy.** Many users find that choosing an opcode cache is a matter of trial and error -- different opcode caches work better in different setups. | ||
| Line 16: | Line 16: | ||
| ===== Popular Opcode Caches ===== | ===== Popular Opcode Caches ===== | ||
| - | * [[http://xcache.lighttpd.net/|xCache]] -- Actively maintained and supports all PHP versions. | + | |
| - | * [[http://pecl.php.net/package/ZendOpcache|Zend Opcache]] -- Actively maintained and supports PHP 5.2 and up. Starting from PHP 5.5, it is bundled with PHP main source code. | + | * [[http://pecl.php.net/package/ZendOpcache|Zend Opcache]] -- Actively maintained and supports PHP 5.2 and up. Starting from PHP 5.5,including 7.0, it is bundled with PHP main source code. |
| - | * [[litespeed_wiki:php:apc|APC (Alternative Opcode Cache)]] -- Appears to be discontinued. Supports PHP up to version 5.4, but has been reported buggy with PHP 5.4. May be a good solution for PHP 5.3. APC has opcode cache as well as user/variable cache. Since PHP 5.5 and PHP 5.6 are unsupported by APC, xCache or Zend Opcache can be alternatives for op-code cache while APCu could be alternative to APC's user cache. | + | * [[litespeed_wiki:php:apc|APC (Alternative Opcode Cache)]] -- Appears to be discontinued. Supports PHP up to version 5.4, but has been reported buggy with PHP 5.4. May be a good solution for PHP 5.3. APC has opcode cache as well as user/variable cache. Since PHP 5.5 and PHP 5.6 are unsupported by APC, xCache or Zend Opcache can be alternatives for op-code cache while APCu could be alternative to APC's user cache. |
| + | * [[http://xcache.lighttpd.net/|xCache]] -- Actively maintained and supports most PHP versions upto 5.6 but not 7.0. | ||
| * [[http://eaccelerator.net/|eAccelerator]] -- Dead project. Supported PHP 5.4 and earlier. | * [[http://eaccelerator.net/|eAccelerator]] -- Dead project. Supported PHP 5.4 and earlier. | ||
| + | |||
| + | How to enable opcode caches? Please check [[litespeed_wiki:php:enable_opcode_cache|here]]. | ||