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latestOpenAPI 3.0.0Apache 2.0 License2026-07-14130363656.8 KB

Dynamically decreases the number of replicas in a Redis (cluster mode disabled) replication group or the number of replica nodes in one or more node groups (shards) of a Redis (cluster mode enabled) replication group. This operation is performed with no cluster down time.

get/#Action=DecreaseReplicaCount

Query parameters

ReplicationGroupIdstring required

The id of the replication group from which you want to remove replica nodes.

NewReplicaCountinteger
<p>The number of read replica nodes you want at the completion of this operation. For Redis (cluster mode disabled) replication groups, this is the number of replica nodes in the replication group. For Redis (cluster mode enabled) replication groups, this is the number of replica nodes in each of the replication group's node groups.</p> <p>The minimum number of replicas in a shard or replication group is:</p> <ul> <li> <p>Redis (cluster mode disabled)</p> <ul> <li> <p>If Multi-AZ is enabled: 1</p> </li> <li> <p>If Multi-AZ is not enabled: 0</p> </li> </ul> </li> <li> <p>Redis (cluster mode enabled): 0 (though you will not be able to failover to a replica if your primary node fails)</p> </li> </ul>
NodeGroupIdstring required

The 4-digit id for the node group you are configuring. For Redis (cluster mode disabled) replication groups, the node group id is always 0001. To find a Redis (cluster mode enabled)'s node group's (shard's) id, see <a href="https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/shard-find-id.html">Finding a Shard's Id</a>.

NewReplicaCountinteger required
<p>The number of replicas you want in this node group at the end of this operation. The maximum value for <code>NewReplicaCount</code> is 5. The minimum value depends upon the type of Redis replication group you are working with.</p> <p>The minimum number of replicas in a shard or replication group is:</p> <ul> <li> <p>Redis (cluster mode disabled)</p> <ul> <li> <p>If Multi-AZ: 1</p> </li> <li> <p>If Multi-AZ: 0</p> </li> </ul> </li> <li> <p>Redis (cluster mode enabled): 0 (though you will not be able to failover to a replica if your primary node fails)</p> </li> </ul>
PreferredAvailabilityZonesstring[]

A list of <code>PreferredAvailabilityZone</code> strings that specify which availability zones the replication group's nodes are to be in. The nummber of <code>PreferredAvailabilityZone</code> values must equal the value of <code>NewReplicaCount</code> plus 1 to account for the primary node. If this member of <code>ReplicaConfiguration</code> is omitted, ElastiCache for Redis selects the availability zone for each of the replicas.

PreferredOutpostArnsstring[]

The outpost ARNs in which the cache cluster is created.

A list of <code>ConfigureShard</code> objects that can be used to configure each shard in a Redis (cluster mode enabled) replication group. The <code>ConfigureShard</code> has three members: <code>NewReplicaCount</code>, <code>NodeGroupId</code>, and <code>PreferredAvailabilityZones</code>.

ReplicasToRemoveString[]

A list of the node ids to remove from the replication group or node group (shard).

ApplyImmediatelyboolean required

If <code>True</code>, the number of replica nodes is decreased immediately. <code>ApplyImmediately=False</code> is not currently supported.

Action'DecreaseReplicaCount' required
Version'2015-02-02' required

Response

Success