Alert notification setup assistance

I am running graylog 3.3.8 and was wondering if there is a way to generate an alert to email or http where if the graylog server is failing to process messages and the journal is getting filled up it alerts someone to take a look or do something about it before millions of events get backlogged into the journal?

In general I would hope there would be more ways to get alerted from graylog if something is failing especially internally like if it cant reach elasticsearch or if the server that its on is filling up in disk space.

Thank you

i have that exact problem atm. I have asked on this forum but it seems like no one has encountered it (i had no replies in mot post)
I hade “solved” it by querying the API in a script and trigger a restart when the number of messages is over 500K. It’s of course possible to add functionality to the script to send mail as well

Are you able to provide me with your example script ? I’d really appreciate it. At least it would be something. Im not too familiar with doing API scripts