Question: What are the pricing differences between ElastiCache and running Redis on EC2?

Answer

AWS offers two main ways to run Redis in the cloud: Amazon ElastiCache for Redis or managing your own Redis instances on Amazon EC2. The cost of these services depend on various factors including instance types, data transfer, and additional features.

Amazon ElastiCache for Redis:

Amazon ElastiCache is a fully managed service that simplifies the setup, operation, and scaling of a distributed cache environment on the AWS Cloud.

Pricing Factors:

1. Node Types: Different node types have different prices, which also vary by region. You're charged per hour for each node.
2. Data Transfer: Data transfer IN to Amazon ElastiCache from another AWS service in the same region is free of charge. However, data transfer OUT is charged.
3. Backup Storage: Backups stored are charged based on the amount of backup data retained.
4. Advanced Features: If you use features like encryption, that will add to your costs.

You can check the detailed pricing here.

Running Redis on Amazon EC2:

Running your own Redis instances on EC2 gives you more control but requires more management effort.

Pricing Factors:

1. Instance Types: As with ElastiCache, the hourly rate depends on the instance type and region.
2. Storage: You'll be charged for the EBS volumes used by your EC2 instances.
3. Data Transfer: AWS charges for data transferred "in" and "out" of your EC2 instances.
4. Maintenance & Operation Costs: Unlike ElastiCache, running Redis on EC2 may incur extra costs in terms of time and resources required for maintenance and operations.

You can check the detailed EC2 pricing here.

In summary, while ElastiCache might seem more expensive at first glance, it provides benefits such as automated patching, backups, and high availability that could justify its price. However, if you have the expertise to manage your own Redis cluster and need tight control over its configuration, running Redis on EC2 could be the better choice.