caching.md

Caching

Why

Occasionally we need to cache data, either for a limited amount of time, or for the duration of a user's session.

What

Our OpenShift cluster is peered with our "Data VPC", AKA "Virtual Private Cloud". We have Terraform playbooks that manage the use of Amazon Elasticache to create performant, in-memory distributed caching environments, using the Redis protocol.

How

If you need a new Elasticache instance, accessible to either sandbox or main clusters, submit a pull request to our Data VPC Terraform repositories, respectively:

• Data VPC MAIN
• Data VPC SANDBOX

To gain access to Amazon IAM, you can submit a pull request to the Data VPC IAM Terraform repository:

• Data VPC IAM

Best practices

• Treat this like a cache, not a database. Assume all data is ephemeral and can be wiped at any moment.
• Encrypt any sensitive data using AES-256
• Set an expiry time to live (TTL), to ensure data is purged often

Who

@delivery

References

• Elasticache Docs
• Redis protocol
• Terraform Elasticache Module
• Data VPC MAIN
• Data VPC SANDBOX
• Data VPC IAM