Why Amazon RDS memory monitor threshold shows me in RED?

Question

Today I have notice that my Amazon RDS instance memory monitor threshold shows me with red line. Here I have attached screen shot for the same.

So, My question is what is that Memory threshold, and why it is crossing limit? Anything wrong with my instance? What is the solution to decrease/control this hike?

Answer 1

The Red line you see is a threshold set by AWS if the RDS is causing that threshold many times then there might be a performance issue that you need to take a look.

MySQL try to use all available memory as needed. However, the limits are defined by RDS' server parameters which you can modify and you may not need to scale up your server.

RDS instances are created with default values for those parameters (the most relevant of them being innodb_buffer_pool_size) to optimize memory usage. In order to see which server variables are applied to your instance, connect to it and execute the "show global variables" command.

It is normal for that number to go up and down as matter of course.

If you are seeing performance issues and you have no more freeable memory, then you should be looking at causes or upgrading to a larger instance.

Those values may not be right for all workloads, but you can adjust them as needed using parameter groups. This document explains how you can use parameter groups:

http://docs.amazonwebservices.com/AmazonRDS/latest/UserGuide/USER_WorkingWithParamGroups.html