We are aware that daily some mediawiki servers segfault, for example
php-fpm7.2[18796]: segfault at 5ffddb105c ip 00005575f7234ae3 sp 00007ffd32aad530 error 4 in php-fpm7.2[5575f6f92000+410000]
php-fpm7.2[18795]: segfault at 215 ip 00007f8b49b4d3a9 sp 00007ffd32aad490 error 4 in libmemcached.so.11.0.0[7f8b49b3c000+30000]
It might make sense to use mtail and measure those segfaults, in the future we could potentially alert on this and avoid running into issues when we deploy php extentions and other related updates