What are the two caching engines supported by AWS ElastiCache?

Redis and Memcached

True or False: Both Redis and Memcached support encryption at rest.

False. Only Redis supports encryption at rest; Memcached does not.

Which ElastiCache engine supports Multi-AZ with automatic failover?
A) Memcached only
B) Redis only
C) Both Redis and Memcached
D) Neither engine

B) Redis only

Fill in the blank: Redis uses a _____ architecture per shard.

Single-threaded

What data structure in Redis is ideal for implementing leaderboards?

Sorted sets

True or False: Memcached supports data persistence across node restarts.

False. Memcached has no persistence; data is lost on restart.

A gaming app needs real-time leaderboards with score updates. Which engine?
A) Memcached
B) Redis
C) Either works equally
D) Neither supports this

B) Redis

What is the maximum number of read replicas per Redis primary node?

5 read replicas

Why would you choose Memcached for simple key-value caching scenarios?

Multi-threaded architecture provides better performance on multi-core systems for simple caching.

True or False: Redis supports pub/sub messaging for real-time communication.

True. Redis provides pub/sub messaging capabilities for real-time applications.

Which feature helps Memcached applications automatically identify cluster nodes?
A) Auto Discovery
B) Multi-AZ
C) Replication
D) Persistence

A) Auto Discovery

Fill in the blank: ElastiCache provides _____ latency for read and write operations.

Sub-millisecond

What happens to Memcached data when a node fails?

Data is lost; Memcached has no replication or backup.

True or False: Redis cluster mode enables horizontal scaling by partitioning data.

True. Cluster mode distributes data across multiple shards for horizontal scaling.

For session storage requiring failure survival, which engine should you choose?
A) Memcached
B) Redis
C) Both work equally
D) Use RDS instead

B) Redis

How many hash slots are distributed across Redis cluster shards?

16,384 hash slots

A compliance requirement mandates encryption at rest. Which engine must you use?

Redis only; Memcached does not support encryption at rest.

True or False: Both Redis and Memcached support encryption in transit.

True. Both engines support TLS encryption for data in transit.

What is the maximum backup retention period for Redis snapshots?
A) 7 days
B) 15 days
C) 35 days
D) 90 days

C) 35 days

Fill in the blank: Memcached uses _____ architecture for better CPU utilization.

Multi-threaded

Which data structures does Redis support beyond simple key-value pairs?

Lists, sets, sorted sets, hashes, bitmaps, hyperloglogs, geospatial indexes

True or False: Redis pub/sub messages are persisted for later delivery.

False. Messages are delivered only to active subscribers at publish time.

An app needs simple caching where data loss is acceptable. Best choice?
A) Redis with Multi-AZ
B) Memcached
C) Redis with backups
D) DynamoDB

B) Memcached

What enables Redis to provide automatic failover capabilities?

Multi-AZ deployment with read replicas

Fill in the blank: Redis snapshots are stored in Amazon _____.

S3

True or False: Memcached supports replication of data across multiple nodes.

False. Memcached has no replication; each node holds unique data.

For real-time chat requiring message broadcasting, which Redis feature works best?
A) Sorted sets
B) Pub/sub
C) Transactions
D) Backups

B) Pub/sub

What is the maximum number of nodes per Redis cluster?

500 nodes per cluster

A scenario requires both read and write scaling. Which Redis configuration?

Cluster mode enabled with multiple shards

True or False: Online resharding allows adding Redis shards without downtime.

True. Online resharding enables shard changes without service interruption.