How to Speed Up PHP Applications Using OPcache
OPcache is a powerful tool for improving the performance of PHP applications by caching precompiled script bytecode. This reduces the need for PHP to recompile scripts on every request, significantly improving speed and efficiency.
What is OPcache?
OPcache is a built-in PHP extension that caches compiled PHP code in memory, eliminating the need to recompile PHP scripts on each execution.
How OPcache Works:
- Script Compilation: PHP code is compiled into bytecode.
- Caching: Bytecode is stored in shared memory.
- Execution: When a script is requested, the cached version is used instead of recompiling.
Benefits of Using OPcache
- Faster Execution: Eliminates repetitive script compilation.
- Reduced CPU Usage: Compiled code is reused across multiple requests.
- Improved Scalability: Faster response times under heavy traffic.
- Minimal Configuration: Easy to enable and manage.
Enabling OPcache
Step 1: Check OPcache Availability
Run the following command to verify if OPcache is installed:
php -m | grep opcache
Step 2: Enable OPcache
Ensure the following settings are present in your php.ini file:
opcache.enable=1
opcache.memory_consumption=128
opcache.interned_strings_buffer=8
opcache.max_accelerated_files=10000
opcache.validate_timestamps=1
opcache.revalidate_freq=2
Step 3: Restart PHP Service
sudo systemctl restart php-fpm
Tuning OPcache for Better Performance
1. Increase Memory Allocation
Adjust the opcache.memory_consumption setting based on your application size:
opcache.memory_consumption=256
2. Cache More Files
Increase the number of files that OPcache can store:
opcache.max_accelerated_files=20000
3. Reduce Cache Expiry Checks
Set longer cache expiry times for production environments:
opcache.validate_timestamps=0
4. Preloading with PHP 7.4+
Enable preloading for even faster performance:
opcache.preload=/path/to/preload.php
Monitoring OPcache
Use the following tools to monitor OPcache usage:
- OPcache GUI: A web-based GUI for monitoring OPcache statistics.
- PHP Info: Run
phpinfo()and check the OPcache section.
<?php
phpinfo();
?>
Best Practices
- Use OPcache in Production Only: Avoid using OPcache in development to ensure code changes reflect immediately.
- Regularly Clear Cache: Clear cache after code deployments.
- Monitor Cache Usage: Ensure the memory allocation is sufficient.
Helpful Resources
Conclusion
OPcache is a powerful tool for enhancing PHP application performance by caching precompiled code in memory. By enabling and properly tuning OPcache, you can significantly reduce script execution time and improve overall scalability.
