Fine-Tune Your Opcache Configuration to Avoid Caching Suprises

Slides for blog post https://tideways.com/profiler/blog/fine-tune-your-opcache-configuration-to-avoid-caching-suprises

Transcript

1. Opcache Configuration Fine-Tune Your Opcache Configuration to Avoid Caching Suprises Benjamin Eberlei
2. RELEVANT PHP.INI CONFIG ▪ opcache.memory_consumption defaults to 64 (MB) for caching all compiled scripts. ▪ opcache.max_accelerated_files defaults to 2000 cacheable files ▪ opcache.max_wasted_percentage defaults to 5% 2
3. Problem to avoid: Opcache limits reached 3
4. What happens? 1. Opcache attempts to restart when limits are reached 2. If the waste percentage is not reached, no restart is performed. 3. All scripts that are not in Opcache at that time will always stay uncached. 4
5. How to monitor? opcache_get_status(true) returns the relevant metrics. 1. cache_full and opcache hit rate below 99%? Increase memory usage 2. cache_full and num_cached_keys equals max_cached_keys. Increase accelerated files. 5
6. Thank you https://tideways.com/profiler/blog/fine-tune-your-opcache-con figuration-to-avoid-caching-suprises