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Amazon ElastiCache
API Reference (API Version 2015-02-02)

ModifyCacheCluster

Modifies the settings for a cache cluster. You can use this operation to change one or more cluster configuration parameters by specifying the parameters and the new values.

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

CacheClusterId

The cache cluster identifier. This value is stored as a lowercase string.

Type: String

Required: Yes

ApplyImmediately

If true, this parameter causes the modifications in this request and any pending modifications to be applied, asynchronously and as soon as possible, regardless of the PreferredMaintenanceWindow setting for the cache cluster.

If false, changes to the cache cluster are applied on the next maintenance reboot, or the next failure reboot, whichever occurs first.

Important

If you perform a ModifyCacheCluster before a pending modification is applied, the pending modification is replaced by the newer modification.

Valid values: true | false

Default: false

Type: Boolean

Required: No

AutoMinorVersionUpgrade

This parameter is currently disabled.

Type: Boolean

Required: No

AZMode

Specifies whether the new nodes in this Memcached cache cluster are all created in a single Availability Zone or created across multiple Availability Zones.

Valid values: single-az | cross-az.

This option is only supported for Memcached cache clusters.

Note

You cannot specify single-az if the Memcached cache cluster already has cache nodes in different Availability Zones. If cross-az is specified, existing Memcached nodes remain in their current Availability Zone.

Only newly created nodes are located in different Availability Zones. For instructions on how to move existing Memcached nodes to different Availability Zones, see the Availability Zone Considerations section of Cache Node Considerations for Memcached.

Type: String

Valid Values: single-az | cross-az

Required: No

CacheNodeIdsToRemove.CacheNodeId.N

A list of cache node IDs to be removed. A node ID is a numeric identifier (0001, 0002, etc.). This parameter is only valid when NumCacheNodes is less than the existing number of cache nodes. The number of cache node IDs supplied in this parameter must match the difference between the existing number of cache nodes in the cluster or pending cache nodes, whichever is greater, and the value of NumCacheNodes in the request.

For example: If you have 3 active cache nodes, 7 pending cache nodes, and the number of cache nodes in this ModifyCacheCluser call is 5, you must list 2 (7 - 5) cache node IDs to remove.

Type: array of Strings

Required: No

CacheNodeType

A valid cache node type that you want to scale this cache cluster up to.

Type: String

Required: No

CacheParameterGroupName

The name of the cache parameter group to apply to this cache cluster. This change is asynchronously applied as soon as possible for parameters when the ApplyImmediately parameter is specified as true for this request.

Type: String

Required: No

CacheSecurityGroupNames.CacheSecurityGroupName.N

A list of cache security group names to authorize on this cache cluster. This change is asynchronously applied as soon as possible.

You can use this parameter only with clusters that are created outside of an Amazon Virtual Private Cloud (Amazon VPC).

Constraints: Must contain no more than 255 alphanumeric characters. Must not be "Default".

Type: array of Strings

Required: No

EngineVersion

The upgraded version of the cache engine to be run on the cache nodes.

Important: You can upgrade to a newer engine version (see Selecting a Cache Engine and Version), but you cannot downgrade to an earlier engine version. If you want to use an earlier engine version, you must delete the existing cache cluster and create it anew with the earlier engine version.

Type: String

Required: No

NewAvailabilityZones.PreferredAvailabilityZone.N

The list of Availability Zones where the new Memcached cache nodes are created.

This parameter is only valid when NumCacheNodes in the request is greater than the sum of the number of active cache nodes and the number of cache nodes pending creation (which may be zero). The number of Availability Zones supplied in this list must match the cache nodes being added in this request.

This option is only supported on Memcached clusters.

Scenarios:

  • Scenario 1: You have 3 active nodes and wish to add 2 nodes. Specify NumCacheNodes=5 (3 + 2) and optionally specify two Availability Zones for the two new nodes.

  • Scenario 2: You have 3 active nodes and 2 nodes pending creation (from the scenario 1 call) and want to add 1 more node. Specify NumCacheNodes=6 ((3 + 2) + 1) and optionally specify an Availability Zone for the new node.

  • Scenario 3: You want to cancel all pending operations. Specify NumCacheNodes=3 to cancel all pending operations.

The Availability Zone placement of nodes pending creation cannot be modified. If you wish to cancel any nodes pending creation, add 0 nodes by setting NumCacheNodes to the number of current nodes.

If cross-az is specified, existing Memcached nodes remain in their current Availability Zone. Only newly created nodes can be located in different Availability Zones. For guidance on how to move existing Memcached nodes to different Availability Zones, see the Availability Zone Considerations section of Cache Node Considerations for Memcached.

Impact of new add/remove requests upon pending requests

  • Scenario-1

    • Pending Action: Delete

    • New Request: Delete

    • Result: The new delete, pending or immediate, replaces the pending delete.

  • Scenario-2

    • Pending Action: Delete

    • New Request: Create

    • Result: The new create, pending or immediate, replaces the pending delete.

  • Scenario-3

    • Pending Action: Create

    • New Request: Delete

    • Result: The new delete, pending or immediate, replaces the pending create.

  • Scenario-4

    • Pending Action: Create

    • New Request: Create

    • Result: The new create is added to the pending create.

      Important

      Important: If the new create request is Apply Immediately - Yes, all creates are performed immediately. If the new create request is Apply Immediately - No, all creates are pending.

Type: array of Strings

Required: No

NotificationTopicArn

The Amazon Resource Name (ARN) of the Amazon SNS topic to which notifications are sent.

Note

The Amazon SNS topic owner must be same as the cache cluster owner.

Type: String

Required: No

NotificationTopicStatus

The status of the Amazon SNS notification topic. Notifications are sent only if the status is active.

Valid values: active | inactive

Type: String

Required: No

NumCacheNodes

The number of cache nodes that the cache cluster should have. If the value for NumCacheNodes is greater than the sum of the number of current cache nodes and the number of cache nodes pending creation (which may be zero), more nodes are added. If the value is less than the number of existing cache nodes, nodes are removed. If the value is equal to the number of current cache nodes, any pending add or remove requests are canceled.

If you are removing cache nodes, you must use the CacheNodeIdsToRemove parameter to provide the IDs of the specific cache nodes to remove.

For clusters running Redis, this value must be 1. For clusters running Memcached, this value must be between 1 and 20.

Note

Adding or removing Memcached cache nodes can be applied immediately or as a pending operation (see ApplyImmediately).

A pending operation to modify the number of cache nodes in a cluster during its maintenance window, whether by adding or removing nodes in accordance with the scale out architecture, is not queued. The customer's latest request to add or remove nodes to the cluster overrides any previous pending operations to modify the number of cache nodes in the cluster. For example, a request to remove 2 nodes would override a previous pending operation to remove 3 nodes. Similarly, a request to add 2 nodes would override a previous pending operation to remove 3 nodes and vice versa. As Memcached cache nodes may now be provisioned in different Availability Zones with flexible cache node placement, a request to add nodes does not automatically override a previous pending operation to add nodes. The customer can modify the previous pending operation to add more nodes or explicitly cancel the pending request and retry the new request. To cancel pending operations to modify the number of cache nodes in a cluster, use the ModifyCacheCluster request and set NumCacheNodes equal to the number of cache nodes currently in the cache cluster.

Type: Integer

Required: No

PreferredMaintenanceWindow

Specifies the weekly time range during which maintenance on the cluster is performed. It is specified as a range in the format ddd:hh24:mi-ddd:hh24:mi (24H Clock UTC). The minimum maintenance window is a 60 minute period.

Valid values for ddd are:

  • sun

  • mon

  • tue

  • wed

  • thu

  • fri

  • sat

Example: sun:23:00-mon:01:30

Type: String

Required: No

SecurityGroupIds.SecurityGroupId.N

Specifies the VPC Security Groups associated with the cache cluster.

This parameter can be used only with clusters that are created in an Amazon Virtual Private Cloud (Amazon VPC).

Type: array of Strings

Required: No

SnapshotRetentionLimit

The number of days for which ElastiCache retains automatic cache cluster snapshots before deleting them. For example, if you set SnapshotRetentionLimit to 5, a snapshot that was taken today is retained for 5 days before being deleted.

Note

If the value of SnapshotRetentionLimit is set to zero (0), backups are turned off.

Type: Integer

Required: No

SnapshotWindow

The daily time range (in UTC) during which ElastiCache begins taking a daily snapshot of your cache cluster.

Type: String

Required: No

Response Elements

The following element is returned by the service.

CacheCluster

Contains all of the attributes of a specific cache cluster.

Type: CacheCluster object

Errors

For information about the errors that are common to all actions, see Common Errors.

CacheClusterNotFound

The requested cache cluster ID does not refer to an existing cache cluster.

HTTP Status Code: 404

CacheParameterGroupNotFound

The requested cache parameter group name does not refer to an existing cache parameter group.

HTTP Status Code: 404

CacheSecurityGroupNotFound

The requested cache security group name does not refer to an existing cache security group.

HTTP Status Code: 404

InsufficientCacheClusterCapacity

The requested cache node type is not available in the specified Availability Zone.

HTTP Status Code: 400

InvalidCacheClusterState

The requested cache cluster is not in the available state.

HTTP Status Code: 400

InvalidCacheSecurityGroupState

The current state of the cache security group does not allow deletion.

HTTP Status Code: 400

InvalidParameterCombination

Two or more incompatible parameters were specified.

HTTP Status Code: 400

InvalidParameterValue

The value for a parameter is invalid.

HTTP Status Code: 400

InvalidVPCNetworkStateFault

The VPC network is in an invalid state.

HTTP Status Code: 400

NodeQuotaForClusterExceeded

The request cannot be processed because it would exceed the allowed number of cache nodes in a single cache cluster.

HTTP Status Code: 400

NodeQuotaForCustomerExceeded

The request cannot be processed because it would exceed the allowed number of cache nodes per customer.

HTTP Status Code: 400

Example

Sample Request

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https://elasticache.us-west-2.amazonaws.com/ ?Action=ModifyCacheCluster NumCacheNodes=5 &CacheClusterId=simcoprod01 &ApplyImmediately=true &Version=2015-02-02 &SignatureVersion=4 &SignatureMethod=HmacSHA256 &Timestamp=20150202T192317Z &X-Amz-Credential=<credential>

Sample Response

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<ModifyCacheClusterResponse xmlns="http://elasticache.amazonaws.com/doc/2015-02-02/"> <ModifyCacheClusterResult> <CacheCluster> <CacheParameterGroup> <ParameterApplyStatus>in-sync</ParameterApplyStatus> <CacheParameterGroupName>default.memcached1.4</CacheParameterGroupName> <CacheNodeIdsToReboot/> </CacheParameterGroup> <CacheClusterId>simcoprod01</CacheClusterId> <CacheClusterStatus>available</CacheClusterStatus> <ConfigurationEndpoint> <Port>11211</Port> <Address>simcoprod01.m2st2p.cfg.cache.amazonaws.com</Address> </ConfigurationEndpoint> <CacheNodeType>cache.m1.large</CacheNodeType> <Engine>memcached</Engine> <PendingModifiedValues> <NumCacheNodes>5</NumCacheNodes> </PendingModifiedValues> <PreferredAvailabilityZone>us-west-2b</PreferredAvailabilityZone> <CacheClusterCreateTime>2015-02-02T23:45:20.937Z</CacheClusterCreateTime> <EngineVersion>1.4.5</EngineVersion> <AutoMinorVersionUpgrade>true</AutoMinorVersionUpgrade> <PreferredMaintenanceWindow>fri:04:30-fri:05:30</PreferredMaintenanceWindow> <CacheSecurityGroups> <CacheSecurityGroup> <CacheSecurityGroupName>default</CacheSecurityGroupName> <Status>active</Status> </CacheSecurityGroup> </CacheSecurityGroups> <NumCacheNodes>3</NumCacheNodes> </CacheCluster> </ModifyCacheClusterResult> <ResponseMetadata> <RequestId>d5786c6d-b7fe-11e0-9326-b7275b9d4a6c</RequestId> </ResponseMetadata> </ModifyCacheClusterResponse>

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: