What would likely cause directories in /var/run to disappear / not be created on startup? (CentOS 7.3)

Ran into an issue today where Apache would not load because /var/run/httpd was missing. After much hunting to find that cause of the error I was getting ([Tue Jul 25 00:06:31.574386 2017] [auth_digest:error] [pid 6179] (2)No such file or directory: AH01760: failed to initialize shm - all nonce-count checking, one-time nonces, and MD5-sess algorithm disabled). Then I saw that MariaDB was missing its /var/run/mysql directory, and PostgreSQL was missing its directory. What would cause those to not be made on system start-up / saved between reboots? I would not *expect* to need to modify init scripts as suggested in this question . ### Edit: outputs of ls -dl /var/run & ls -dl /run lrwxrwxrwx. 1 root root 6 Dec 15 2015 /var/run -> ../run drwxr-xr-x 25 root root 800 Jul 26 03:40 /run