OPcache Optimization for PHP Applications

OPcache is PHP's built-in bytecode cache. It compiles PHP files once and stores the compiled bytecode in shared memory, eliminating the need to parse and compile on every request. Here's how to configure it properly, with lessons from running DailyWatch in production. How OPcache Works Without OPcache: Request -> Read .php file -> Parse -> Compile to bytecode -> Execute With OPcache: First request: Read .php file -> Parse -> Compile -> Store in shared memory -> Execute Next requests: Load from shared memory -> Execute The parse and compile steps are skipped entirely for cached scripts. Recommended Configuration Add to your php.ini or .user.ini : ; Enable OPcache opcache.enable = 1 opcache.enable_cli = 0 ; Memory allocation opcache.memory_consumption = 128 ; 128MB for bytecode cache opcache.interned_strings_buffer = 16 ; 16MB for interned strings opcache.max_accelerated_files = 10000 ; Max cached scripts ; Revalidation opcache.revalidate_freq = 60 ; Check for file changes every 60s opca