Turning off timestamp validation removes a stat call per file per request, and it means PHP never notices a changed file — so a deploy without a reload serves the previous release indefinitely.
opcache.validate_timestamps=0
opcache.memory_consumption=192
opcache.max_accelerated_files=20000
opcache.interned_strings_buffer=16
; and the deploy step that must exist alongside it:
; systemctl reload php7.3-fpmA reload rather than a restart is what avoids dropping connections. opcache_reset() from a web request clears the cache for one worker only and is not a substitute with fifty of them. max_accelerated_files being too low is the common silent problem — once it is full nothing else is cached and the only report is opcache_get_status(), which nobody checks unless something is already slow.