AWS — ElastiCache

What is ElastiCache?

Managed in-memory caching service supporting Redis and Memcached.

Create Redis cluster

aws elasticache create-cache-cluster \
  --cache-cluster-id my-redis \
  --cache-node-type cache.t2.micro \
  --engine redis \
  --num-cache-nodes 1

Create Memcached cluster

aws elasticache create-cache-cluster \
  --cache-cluster-id my-memcached \
  --cache-node-type cache.t2.micro \
  --engine memcached \
  --num-cache-nodes 2

Connect (Python)

import redis

r = redis.Redis(
    host='my-redis.xxxx.cache.amazonaws.com',
    port=6379,
    decode_responses=True
)

r.set('key', 'value')
print(r.get('key'))

Common operations

# Strings
r.set('name', 'John')
r.get('name')
r.incr('counter')

# Hashes
r.hset('user:1', 'name', 'John')
r.hget('user:1', 'name')

# Lists
r.lpush('queue', 'task1')
r.rpop('queue')

# Sets
r.sadd('tags', 'python', 'aws')
r.smembers('tags')

Replication

aws elasticache create-replication-group \
  --replication-group-id my-replication \
  --replication-group-description "My replication" \
  --num-cache-clusters 2

Best practices

1. Use encryption in transit
2. Enable encryption at rest
3. Set up automatic failover
4. Monitor with CloudWatch

Mini Practice

1. Create a Redis cluster
2. Store and retrieve data
3. Use different data types
4. Set up replication

Up Next

Continue with SES - Email Service.