Zend Opcache is part of PHP 5.5, however, it's not enabled by default. It's a successor to APC cache--meaning APC cache is never going to be compatible with PHP 5.5 or higher
Opcache is also around 10% faster than APC, and more stable.
However, if you're on PHP 5.3 or PHP 5.4, you can still use ZendOpCache, and it should still be a bit faster than APC
Enable OpCache (part of with PHP 5.5)
vi /usr/local/lib/php.ini
Paste this under your extension_dir
zend_extension=/FULL-PATH-FROM-ABOVE/opcache.so opcache.enable=1 opcache.enable_cli=1 opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.revalidate_freq=60 opcache.fast_shutdown=1
You can also try the below; which I haven't fully tested yet, however, one of our sites Magento would just display a 'white screen of death' when OPcache was enabled--I haven't fully tested the cause, but it definitely has to do with PHP 5.5.8 and OpCache 7.0.2 or 7.0.3-dev
zend_extension=/FULL-PATH-FROM-ABOVE/opcache.so opcache.enable=1 opcache.enable_cli=1 opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.max_wasted_percentage=5 opcache.use_cwd=1 opcache.validate_timestamps=0 opcache.revalidate_freq=60 opcache.fast_shutdown=1
Restart Apache and see if it installed correctly
service httpd restart php -v
You should see something like:
PHP 5.5.8 (cli) (built: Jan 12 2014 20:27:27) Copyright (c) 1997-2013 The PHP Group Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies with Zend OPcache v7.0.3-dev, Copyright (c) 1999-2013, by Zend Technologies
Install Zend OpCache (for PHP 5.3 or 5.4 only)
This url will download the latest version: http://pecl.php.net/get/ZendOpcache
cd /usr/local/src wget http://pecl.php.net/get/ZendOpcache # to get the latest (master) build do the following instead: # wget https://github.com/zendtech/ZendOptimizerPlus/archive/master.zip tar xvfz zendopcache-7.x.x.tgz cd zendopcache-7.x.x phpize whereis php-config # set the path below ./configure --with-php-config=/usr/local/bin/php-config make make install # note the install path because you will use it below vi /usr/local/lib/php.ini
Paste this under your extension_dir
zend_extension=/FULL-PATH-FROM-ABOVE/opcache.so opcache.enable=1 opcache.enable_cli=1 opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.revalidate_freq=60 opcache.fast_shutdown=1
... Or this, which I haven't fully tested--see note above.
zend_extension=/FULL PATH FROM ABOVE/opcache.so opcache.enable=1 opcache.enable_cli=1 opcache.memory_consumption=128 opcache.interned_strings_buffer=8 opcache.max_accelerated_files=4000 opcache.max_wasted_percentage=5 opcache.use_cwd=1 opcache.validate_timestamps=0 opcache.revalidate_freq=60 opcache.fast_shutdown=1
Restart Apache and see if it installed correctly
service httpd restart php -v
You should see something like:
PHP 5.5.8 (cli) (built: Jan 12 2014 20:27:27) Copyright (c) 1997-2013 The PHP Group Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies with Zend OPcache v7.0.3-dev, Copyright (c) 1999-2013, by Zend Technologies
Troubleshooting
After updating to PHP 5.5.8 I started getting zend_mm_heap corrupted and segment fault errors--especially while using drush.
To fix this, simply follow the above instructions for PHP 5.4 to install the latest master version (which at the time of this writing is Zend OPcache v7.0.4-dev)
Afterwards you should see something like this:
PHP 5.5.8 (cli) (built: Jan 21 2014 22:19:07) Copyright (c) 1997-2013 The PHP Group Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2014, by Zend Technologies
UPDATE 2014-01-21
The above still doesn't fix the PHP 5.5.8 error... The solution is to extract the opcache that comes with PHP 5.5.6 and build that:
cd /usr/local/src wget http://us1.php.net/get/php-5.5.6.tar.gz/from/this/mirror tar xvfz php-5.5.6.tar.gz mv php-5.5.6/ext/opcache/ ./ cd opcache/ phpize whereis php-config # set the output path below ./configure --with-php-config=/usr/local/bin/php-config make make install service httpd restart #if you have memcached service memcached restart php -v # If you're feeling adventurous, you can try the above in a single line: wget http://us1.php.net/get/php-5.5.6.tar.gz/from/this/mirror; tar xvfz php-5.5.6.tar.gz; mv php-5.5.6/ext/opcache/ ./; cd opcache/; phpize; ./configure --with-php-config=/usr/local/bin/php-config; make; make install; service httpd restart; service memcached restart; php -v
Should show Zend OPcache v7.0.3-dev -- yes v7.0.3-dev is correct and *is* different than the one that ships with PHP 5.5.7 and PHP 5.5.8
PHP 5.5.8 (cli) (built: Jan 12 2014 20:27:27)
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies
with Zend OPcache v7.0.3-dev, Copyright (c) 1999-2013, by Zend TechnologiesAs noted above, some Magento sites would just display a 'white screen of death' when OPcache was enabled--I have tested install opcache from PHP 5.5.6 and it fixes the problem, but it definitely has to do with PHP 5.5.7 and PHP 5.5.8 ... IF you are still experiencing problems, the solutions is to disable OPcache in your php.ini via 'opcache.enable=0'