List of critical error messages (to look for in ES logs)?

Hello all - Is there a list of error phrases or fragments that Elasticsearch logs (in /var/log/elasticsearch/*) that I can monitor for? I'd just like to feed a short list of critical messages to my monitoring agent's (Check-MK in my case) log-watching capability.

I know there are more sophisticated ways of performing this function, but want to keep it simple and use my existing toolset.

If there isn't a list anywhere, I'd like to add my vote to create one.

[I've tried searching for this, but it's a tough thing to come up with the right search terms!]