Yoast is unnecessarily interfering with server-wide caching.
Our small team in a higher-ed support role has been chasing server instability issues related to PHP caching for some time. We manage a LAMP environment, with a mix of WP and other web technologies. We have discovered a compellingly strong coincidence of the instability issues with Yoast updates.
Digging into the plugin code, we find line 328 of wp_seo_main.php performing an opcache_reset() inside a version compare conditional.
Github issue 9315 (https://github.com/Yoast/wordpress-seo/issues/9315) has several users requesting that you change this call to a loop through a file list, running opcache_invalidate() on each of your files. A survey of many other plugins installed in our environment shows that this approach is quite popular, while Yoast is the only plugin in our codebase that uses opcache_reset().
The opcache_invalidate() strategy is rejected because “we’d have to keep a list of files”(!) but as many users pointed out in the discussion on that issue, opcache_resets affect far more than just Yoast or even just WordPress. It imposes a performance cost on all PHP on the server, and violates one of the prime directives of WordPress plugin development. It is not a “play nice with others” programming practice, to say the least.
Please reconsider using opcache_invalidate() instead, or at the very least offering a configuration option that allows disabling the opcache_reset() call.