AWS ElastiCache

Cache Architectures

• Side cache
  • Most common
  • Independent from datasource
  • Can go out of sync
  • Requires development work
  • Examples
    • Typically used Memcached, Redis
• Write-through/Read-through
  • Integrated with data source (same API)
  • Always in sync
  • Examples
    • DynamoDB Accelerator (DAX)
• Write-behind
  • Integrated with data source
  • Writes happen asynchronously
    • Can go out of sync

Memcached

• Cache Cluster - cache nodes + cache parameters group
• Configuration Endpoint (Auto-discovery)
  • DNS name for an arbitrary cache node
  • Each node maintains the list of all other nodes in the cluster
  • Client (auto-discovery aware) uses this list to create connections
  • Client hashes the key (consistent hashing) and selects the node
  • AWS provides "auto-discovery" clients for .NET, Java, PHP