How to calculate Redis memory usage

I have an Elasticache Redis instance on AWS and I want to monitor its memory usage and send alerts when it exceeds a certain threshold. The Redis info command provides several memory-related metrics, including

used_memory:3651689760

used_memory_human:3.40G

used_memory_rss:3684122624

used_memory_rss_human:3.43G

used_memory_peak:3704319760

used_memory_peak_human:3.45G

used_memory_peak_perc:98.58%

maxmemory:20975001908

maxmemory_human:19.53G

I would like to calculate the total memory usage of Redis based on these metrics and send an alert when the usage exceeds a specific percentage.

Can anyone provide guidance on how to calculate Redis memory usage based on the info command output?

Thank you in advance for your help!

INFO MEMORY gives you the relevant information about memory related metrics. For finding out the current memory utilization, you can use used_memory_human which in your case is 3.4GB

You can use the following command to find the memory usage:

redis-cli -h 127.0.0.1 -p 6379 INFO MEMORY | grep used_memory_human
used_memory_human:948.84K

There are several ways by which your can implement the alerting on top of this:
You can have a Python or shell script run every 5 minutes or so and trigger and email alert; you can also setup prometheus and alertmanager for the same