Understand the default Redis cluster configuration
The Bitnami Multi-Tier Solution for Redis uses multiple VMs, consisting of 1 master and 2 or more slaves, to provide a horizontally scalable and fault-tolerant deployment. Data automatically replicates from the master node to all slave nodes. In addition to that, every virtual machine includes a Redis Sentinel to ensure high availability. Data persistence is optional and easy to enable.
By default, Redis is set with the configuration below:
- Replication: Master instances can perform read/write operations that are replicated to the slaves nodes to have the data available for read only queries.
- (Optional) Persistence: You can choose between RDB + AOF (with a fsync “every second” policy) persistence or disable it at all. See the Redis official documentation about persistence for further information on this.
- High Availability: This is achieved thanks to Redis Sentinel. In case of failure in the instances, the Sentinels will agree on select a new master/slaves configuration, to keep the deployment working. For more information, refer to the Redis Sentinel Documentation.