Redis Cache can be scaled up as required but scaling down is not possible
By default there is no expiration on the assets stored in Redis Cache
Redis Cache can be used as an In-memory Database as well as a Message Queue
Data in Redis Cache is not Encrypted
Data persistence (Premium Tier feature) writes data to Storage Account which is encrypted
Removing Items from Cache
Scheduled Deletion
Set a TTL value for the items
Such items are marked as volatile
Manual Deletion
Manually delete the key that is no longer required
Eviction
Performed automatically by Redis when it is running out of space
volatile-lru: Remove Least Recently Used Keys with TTL
allkeys-lru: Remove LRU Keys even if no TTL
noeviction: Don’t delete even when low on memory
volatile-random: Randomly remove keys that have a TTL value
allkeys-random: Randomly remove any key
volatile-ttl: Remove items that have the shortest TTL remaining
Pricing Tiers
Basic
Low throughput and high latency
No SLA, meant for Development and Testing
53 GBs of storage & up to 20k connected clients
Standard
2 Nodes that are replicated (Primary and Secondary)
99.9% availability
53 GBs of memory and up to 20k connected clients
Premium
Supports Data Persistence
Provides high throughput and low latency
Supports passive geo-replication
Provides 99.95% availability
Up to 120 GB of memory and 40k connected clients
Enterprise
All features of the Premium tier
Support all the features of Redis
Have active geo-replication
Provides 99.999% availability
Up to 100 GB of storage and 200k connected clients
Enterprise Flash
Supports fast non-volatile flash storage
Does not support the other Redis features present in Enterprise
Adds support for up to 1.5 TB of storage
Supports up to 120k connected clients