Identify any Amazon ElastiCache nodes that can be upgraded to Reserved Cache Nodes (RCNs) and follow our recommendations for purchasing your RCNs in order to receive a significant discount on the hourly charges. Reserved Nodes/Instances represent an AWS billing concept that enables discounted hourly rates for compute capacity in exchange of reserving a certain amount of compute usage upfront. The cost savings when using Reserved Cache Nodes over On-Demand Cache Nodes are up to 70% when used in steady state (heavy utilization). For example, for a cache.m3.large ElastiCache node (Heavy Utilization Reserved Node) provisioned in the US-East region you can save roughly $87 per month by upgrading it to a Reserved Cache Node for a period of 1 year with partial upfront payment or save $99 per month (as of October 2016) by reserving it for a period of 3 years with upfront payment.
Reserved Cache Nodes represent a good strategy to cut down on Amazon ElastiCache costs but purchasing them without a plan can feel like a risky process. The Cloud Conformity purchasing recommendations outlined in this rule will help you optimize your RCNs spending and save money by using only what you need.
Note: In order to verify the current status of purchased reserved capacity and provide accurate recommendations, Cloud Conformity needs access to the AWS payer account (the account designated to pay the bills) or to AWS individual accounts. The following IAM policy allows Cloud Conformity to view all the reserved ElastiCache nodes available in your account(s):
To verify your current AWS ElastiCache compute capacity and determine if there are any candidates for upgrading to Reserved Cache Nodes (RCNs), perform the following:
To upgrade your On-Demand ElastiCache nodes to Reserved Cache Nodes you need to get informed in order to avoid paying for compute resources that you do not need. To make the RCN purchase based on the right pricing model, the right type at the right time, follow the recommendations outlined below: