How do I upgrade my Amazon ElastiCache for Redis engine version and what is the impact of upgrading?
Upgrade the Redis engine version
- Make a backup of your Redis cluster or replication group. For more information, see Making manual backups.
- Modify the ElastiCache cluster or the replication group and then choose a new engine version.
Note: When upgrading, keep the following in mind:
- When upgrading major engine versions, for example from 5.0.6 to 6.0, you must choose a new parameter group that's compatible with the new engine version.
- If encryption is turned on for your current cluster or replication group, you can't upgrade to an engine version that doesn't support encryption. For example, you can't upgrade from version 3.2.6 to 3.2.10.
- Downgrading to an older engine version after upgrading isn't supported.
Impacts of upgrading
- The ElastiCache for Redis engine upgrade process makes a best effort to retain your existing data and requires successful Redis replication.
- Starting with Redis engine version 5.0.5, you can upgrade your cluster version with minimal downtime. The cluster is available for reads during the entire upgrade. The cluster is available for writes for most of the upgrade duration, except during the failover operation. The failover operation lasts a few seconds.
- You can upgrade your ElastiCache clusters with versions earlier than 5.0.5. The upgrade process is the same but might incur longer failover time during DNS propagation (30s-1m).
- For Redis clusters with Multi-AZ turned on, it's a best practice to schedule engine upgrades during periods of low incoming write traffic. When upgrading to Redis 5.0.6 or higher, the primary cluster continues to be available to service requests during the upgrade process.
- For single node Redis clusters and clusters with Multi-AZ turned off, it's a best practice to make sure that sufficient memory is available to Redis. For more information see, Ensuring that you have enough memory to create a Redis snapshot. For single clusters and clusters with Multi-AZ turned off in any version of Redis, the primary node is unavailable to service requests during the upgrade process.
Upgrading engine versions