What are the characteristics of Redis cluster mode?
Characteristics of Redis cluster mode include:
- Data sharding: In a Redis cluster, data is divided into multiple slots with each node responsible for handling a portion of the slots. Keys are distributed to different slots through a hash algorithm, enabling distributed storage of data and load balancing.
- Fault Tolerance: The Redis cluster supports master-slave replication and automatic failover. Each slot has one master node and multiple slave nodes, with the master node handling write operations and the slave nodes handling read operations. In the event of a master node failure, the cluster will automatically elect a new master node from the slave nodes to ensure data availability.
- Inter-node communication: Redis cluster utilizes the Gossip protocol for communication between nodes. Each node communicates by sending and receiving messages to understand the status and topology of other nodes, enabling automatic cluster discovery and dynamic scaling.
- Transparent access for clients: For clients, the usage of Redis cluster and single Redis node is very similar. The client only needs to connect to any node in the cluster, and then the cluster proxy forwards the request to the correct node. This allows for horizontal scaling of the cluster without the need to modify client code.
- High performance: The Redis cluster is designed to achieve high throughput and low latency. By using data sharding and parallel processing, the load can be balanced across multiple nodes, enhancing the system’s concurrent processing capability.
It should be noted that Redis cluster mode may not be suitable for all scenarios. If an application requires very high data consistency, or needs to use complex data structures (such as transactions, Lua scripts, etc.), it is recommended to use single-node Redis or Redis master-slave replication mode.
