Section 4 - ElasticCache

Question 1

What is Amazon ElastiCache?

Answer 1

ElastiCache is a fully managed in-memory datastore compatible with Redis or Memcached.

• In-memory datastore
• Compatible with Redis or Memcached engines
• Data can be lost
• Offers high performance and low latency

Question 2

Two types of ElastiCache?

Answer 2

Memcached:

• Great for basic object caching
• Scales horizontally, but there is no persistance, no Multi-AZ or failover.
• a good choice if you want basic caching and you want your caching model to be as simple as possible.

Redis:

• A more sophisticated solution enterprise features like persistance, replication, Multi-AZ and failover.
• Supports sorting and ranking data (e.g. for gaming leaderboards), and complex data types like lists and hashes.

Question 3

ElasticCache scenarios?

Answer 3

• Database under stress:
  
  • heavy reads
  • data does not change frequently