tail: inotify cannot be used, reverting to polling: Too many open files
Probably you ran out of inotify watches. By default it's an absurdly low 8192.
Check your current value by:
sysctl fs.inotify.max_user_watches
Then change it to something more reasonable by editing /etc/sysctl.conf or a file which it includes, and adding:
fs.inotify.max_user_watches = 524288
(or whatever value) and then running sysctl -p to have it take effect.
You can try increasing fs.inotify.max_user_instances:
sysctl fs.inotify.max_user_instances=512