Question: What is a Redis Replication Group?

Answer

A Redis Replication Group refers to a group of Redis nodes (servers) that are involved in the replication process. This process involves one primary node and one or more secondary nodes. When changes occur on the primary node (such as write operations), these changes are propagated to the secondary nodes.

In a typical setup, clients read from the secondary nodes and write to the primary node, thereby distributing the load and improving system performance, especially for read intensive workloads.

Here's a basic example of setting up a Redis replication group:

1. Start your primary Redis server, let's say it runs at port 6379:

redis-server --port 6379

2. Then, start a secondary Redis server at a different port, let's say 6380, and set it to replicate the primary:

redis-server --port 6380 --slaveof 127.0.0.1 6379

The command --slaveof configures the secondary server to replicate the primary server located at IP 127.0.0.1 and port 6379.

Remember, the number of secondary servers you can have in a replication group varies and you can add or remove them dynamically based on your requirements.

Note: Replication helps improve data redundancy and availability, but it shouldn't be considered as a replacement for regular backups due to its eventual consistency nature.