Modifying an ElastiCache cluster - Amazon ElastiCache
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Modifying an ElastiCache cluster

In addition to adding or removing nodes from a cluster, there can be times where you need to make other changes to an existing cluster, such as, adding a security group, changing the maintenance window or a parameter group.

We recommend that you have your maintenance window fall at the time of lowest usage. Thus it might need modification from time to time.

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 section of the Details column in the tables for Memcached specific parameters . For information on rebooting a cluster, see Rebooting a cluster.

To modify a cluster

  1. Sign in to the Amazon Web Services Management Console and open the ElastiCache console at https://console.amazonaws.cn/elasticache/.

  2. From the list in the upper-right corner, choose the Amazon Region where the cluster that you want to modify is located.

  3. In the navigation pane, choose the engine running on the cluster that you want to modify.

    A list of the chosen engine's clusters appears.

  4. In the list of clusters, for the cluster that you want to modify, choose its name.

  5. Choose Actions and then choose Modify.

    The Modify Cluster window appears.

  6. In the Modify Cluster window, make the modifications that you want. Options include:

    • Engine Version Compatibility

    • VPC Security Group(s)

    • Parameter Group

    • Maintenance Window

    • Topic for SNS Notification

    The Apply Immediately box applies only to engine version modifications. To apply changes immediately, choose the Apply Immediately check box. If this box is not chosen, engine version modifications are applied during the next maintenance window. Other modifications, such as changing the maintenance window, are applied immediately.

  7. Choose Modify.

You can modify an existing cluster using the Amazon CLI modify-cache-cluster operation. To modify a cluster's configuration value, specify the cluster's ID, the parameter to change and the parameter's new value. The following example changes the maintenance window for a cluster named my-cluster and applies the change immediately.

Important

You can upgrade to newer engine versions. For more information on doing so, see Engine versions and upgrading . However, you can't downgrade to older engine versions except by deleting the existing cluster and creating it again.

For Linux, OS X, or Unix:

aws elasticache modify-cache-cluster \
    --cache-cluster-id my-cluster \
    --preferred-maintenance-window sun:23:00-mon:02:00

For Windows:

aws elasticache modify-cache-cluster ^
    --cache-cluster-id my-cluster ^
    --preferred-maintenance-window sun:23:00-mon:02:00

The --apply-immediately parameter applies only to modifications in engine version and changing the number of nodes in a cluster. If you want to apply any of these changes immediately, use the --apply-immediately parameter. If you prefer postponing these changes to your next maintenance window, use the --no-apply-immediately parameter. Other modifications, such as changing the maintenance window, are applied immediately.

For more information, see the Amazon CLI for ElastiCache topic modify-cache-cluster.

You can modify an existing cluster using the ElastiCache API ModifyCacheCluster operation. To modify a cluster's configuration value, specify the cluster's ID, the parameter to change and the parameter's new value. The following example changes the maintenance window for a cluster named my-cluster and applies the change immediately.

Important

You can upgrade to newer engine versions. For more information on doing so, see Engine versions and upgrading . However, you can't downgrade to older engine versions except by deleting the existing cluster and creating it again.

Line breaks are added for ease of reading.

https://elasticache.us-west-2.amazonaws.com/
    ?Action=ModifyCacheCluster
    &CacheClusterId=my-cluster
    &PreferredMaintenanceWindow=sun:23:00-mon:02:00
    &SignatureVersion=4
    &SignatureMethod=HmacSHA256
    &Timestamp=20150901T220302Z
    &X-Amz-Algorithm=&AWS;4-HMAC-SHA256
    &X-Amz-Date=20150202T220302Z
    &X-Amz-SignedHeaders=Host
    &X-Amz-Expires=20150901T220302Z
    &X-Amz-Credential=<credential>
    &X-Amz-Signature=<signature>

The ApplyImmediately parameter applies only to modifications in node type, engine version, and changing the number of nodes in a cluster. If you want to apply any of these changes immediately, set the ApplyImmediately parameter to true. If you prefer postponing these changes to your next maintenance window, set the ApplyImmediately parameter to false. Other modifications, such as changing the maintenance window, are applied immediately.

For more information, see the ElastiCache API reference topic ModifyCacheCluster.