ElastiCache overview¶

• The same way AWS RDS is to get managed Relational Databases
• ElastiCache is to get managed Redis or Memcached
• Caches are in-memory databases with really high performance, low latency
• Helps reduce load off of databases for read intensive workloads
• Helps make your application stateless
• Write Scaling using [[sharding]]
• Read Scaling using [[Read Replica]]s
• Multi AZ with Failover Capability

• AWS takes care of [[OS maintenance]] / [[patching]], optimisations, setup, configuration, monitoring, [[failure recovery]] and [[backups]]

• In-memory data store, sub-millisecond latency

• Must provision an AWS EC2 instance type
• Support for [[Clustering]] (Redis) and [[Multi AZ]], [[Read Replica]]s ([[sharding]])
• Security though IAM, Security Groups, AWS KMS (Key Management Service), [[Redis Auth]]
• [[Backup]] / [[Snapshot]] / [[Point in time restore]] feature
• Managed and Scheduled maintenance
• Monitoring though CloudWatch

• Use case: key/value store, frequent reads, less writes, [[cache]] results for DB queries, store session data for websites, cannot use SQL.

ElastiCache for Solutions Architects¶

• Security

  • Redis support [[Redis AUTH]] (username / password)
  • SSL [[in-flight encryption]] must be enabled and used
  • Memcached supports [[SASL authentication]] (advanced)
  • None of the caches support IAM authentication
  • IAM policies on ElastiCache are only used for AWS API-level security

• Patterns for ElastiCache