What is Redis?
Redis (which stands for REmote DIctionary Server) is an open-source, in-memory data structure store. It is used as a database, cache, and message broker. Redis supports a wide range of data structures, such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, and geospatial indexes with radius queries.
Here are some key features and characteristics of Redis:
- n-memory Storage: Redis stores all its data in memory, which allows for very fast read and write operations. This makes it particularly suited for use cases where high-speed access to data is essential, such as caching.
- Persistence: While Redis is an in-memory store, it provides mechanisms to periodically save the data on disk without compromising its high availability. This gives a balance between performance and durability.
- Replication: Redis supports master-slave replication, allowing for data redundancy and higher data availability.
- Partitioning: It supports horizontal partitioning or sharding, which spreads the data across multiple Redis instances.
- Atomic Operations: Redis operations on the complex data types are atomic, which means even if multiple clients are accessing and modifying values simultaneously, Redis will queue and execute them in a sequential manner, ensuring data integrity.
- Extensible through Lua scripting: Redis supports Lua scripting, allowing developers to run their code in the server itself resulting in atomic operations and reduced network round trips.
- High Availability: Using Redis Sentinel, it provides high availability and monitoring.
- Distributed Locks: Redis can be used to implement distributed locks.
- Support for various languages: There are numerous client libraries available for almost every language, which allows easy integration with various applications.
- Pub/Sub Capabilities: Redis has built-in support for message broker capabilities using a publisher/subscriber model.