Question: How is ElastiCache billed?

Answer

ElastiCache billing depends on several factors such as the cache node type, the number of nodes, the region, and data transfer. The pricing can be broken down into two parts: hourly usage and data transfer in and out of the cache.

Hourly Usage:

ElastiCache charges for every hour the cache nodes are running. This means that even if you are not using the cache, you will still be charged for the time that the nodes are up and running. The pricing for the hourly usage varies based on the cache engine type, node type, and region.

For example, let's say you are using a cache.t2.micro node with Memcached in the US East (N. Virginia) region. The hourly cost would be $0.017, while a cache.r5.large node with Redis in the same region costs $0.19 per hour.

You can find the detailed pricing information for different node types, cache engines, and regions from the AWS ElastiCache pricing page.

Data Transfer:

ElastiCache also charges for data transfer in and out of the cache. This includes all traffic going in and out of the nodes, including requests, responses, and inter-node communication. The pricing for data transfer varies by region and ranges from $0.01 to $0.20 per GB.

Here is an example of how data transfer costs are calculated. Suppose you have a cache.t2.micro node with Redis in the US East (N. Virginia) region, and you transferred 5 GB of data in and 10 GB of data out during the month. The total data transfer cost for the month would be (5 + 10) * $0.12 = $1.80.

It's important to note that data transfer between ElastiCache and other AWS services within the same region is free of charge. However, if you are transferring data between regions or out of AWS, there will be data transfer fees.

In conclusion, ElastiCache billing depends on the cache node type, number of nodes, region, and data transfer. It's essential to understand these factors to estimate the cost accurately and keep an eye on your usage to avoid any unexpected charges.