Amazon RDS running out of freeable memory. Should I be worried?
I have an Amazon RDS instance. Freeable Memory has been declining since setup over 1-2 weeks, starting from 15GB of memory down to about 250MB. As it has dropped this low in the last days, it has started to resemble a sawtooth pattern where Freeable Memory drops to this range (250 - 350MB) and then goes back up agin to 500 - 600MB in a sawtooth pattern.
There has not been any notable decline in application quality. However, I am worried that the DB will run out of memory and crash.
Is there a danger that the RDS instance will run out of memory? Is there some setting or parameter I should be looking at to determine if the instance is set up correctly? What is causing this sawtooth pattern?
Freeable memory field is used by MySQL for buffering and caching for it`s own processes. It is normal for the amount of Freeable memory to decrease over time. I wouldn't be worried it kicks old info out as it demands more room.