Amazon ElastiCache for Redis
ElastiCache for Redis User Guide (API Version 2015-02-02)

Parameter Management

Parameters are grouped together into named parameter groups for easier parameter management. A parameter group represents a combination of specific values for the parameters that are passed to the engine software during startup. These values determine how the engine processes on each node will behave at runtime. The parameter values on a specific parameter group apply to all nodes that are associated with the group, regardless of which cluster they belong to.

To fine-tune your cluster's performance, you can modify some parameter values or change the cluster's parameter group.

Constraints

  • You cannot modify or delete the default parameter groups. If you need custom parameter values, you must create a custom parameter group.

  • If you change a cluster's parameter group, the values for any conditionally modifiable parameter must be the same in both the current and new parameter groups.

  • When you change a cluster's parameters, the change is applied to the cluster either immediately or after the cluster is restarted. This is true whether you change the cluster's parameter group itself or a parameter value within the cluster's parameter group. To determine when a particular parameter change is applied, see the Changes Take Effect column in the tables for Redis Specific Parameters. For information on rebooting a cluster, see Rebooting a Cluster.