I'm getting lots of errors in my logs today with messages like:
[OutOfMemoryError[Java heap space]]
I'm guessing the NodeNotConnectedException is probably because the processes are crashing with OOMs?
How do I debug an OutOfMemoryError? Is this ever an expected condition in ES? E.g. because I'm running with too much data compared to the amount of RAM that I have? Or is this always indicative of a bug in ES and perhaps there'd be a chance it would be solved if I upgraded to a newer version? (I'm currently running 1.4.0) Or could this be because I'm running with a river and some of them are unstable? Or are certain queries being run consuming inordinate amounts of memory? I just have no idea where to begin to track this down.