Terraform Elasticache alerts

area	metric	comparison operator	threshold	rationale
CPU	CPUUtilization	>	80 %	Queuing theory tells us the latency increases exponentially with utilization. In practice, we see higher latency when utilization exceeds 80% and unacceptable high latency with utilization above 90%
Memory	FreeableMemory	<	64 MB	This number is calculated from our experience with RDS workloads.
Memory	SwapUsage	>	256 MB	Sometimes you can not entirely avoid swapping. But once the database accesses paged memory, it will slow down.