Suggest an editImprove this articleRefine the answer for “What does the "master-replica" model mean in Redis?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)The master-replica model (formerly called master-slave) in Redis is a data-replication scheme where the master accepts all write operations, and one or several replicas copy the master's data and can be used for reads. **Key point:** if the master fails, one of the replicas can be promoted to master (manually, or automatically via Redis Sentinel or Redis Cluster), which improves fault tolerance and allows read scaling.Shown above the full answer for quick recall.Answer (EN)ImageThe **master-replica** model (formerly called master-slave) in Redis is a data-replication scheme where: - **Master (the main server)** is the primary node, where all write operations go. - **Replica** is one or several secondary nodes that copy the master's data and can be used for reads. ### How this works: 1. Replicas connect to the master and receive a full copy of its data. 2. After that, the master forwards them a stream of changes (commands), so they stay in sync. 3. Replicas can be used for **reads**, to take load off the master, but **writes** can only go to the master. 4. If the master fails, one of the replicas can be **promoted** to master (manually, or automatically, via Redis Sentinel or Redis Cluster). ### The model's goal: - Improving fault tolerance (data is held on several nodes). - Scaling reads (replicas handle read requests).For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.