The `AWS::ElastiCache::CacheCluster` type creates an Amazon ElastiCache cache cluster.

CfnCacheCluster

The compute and memory capacity of the nodes in the node group (shard).

The following node types are supported by ElastiCache. Generally speaking, the current generation types provide more memory and computational power at lower cost when compared to their equivalent previous generation counterparts. Changing the CacheNodeType of a Memcached instance is currently not supported. If you need to scale using Memcached, we recommend forcing a replacement update by changing the `LogicalResourceId` of the resource.

- General purpose:

- Current generation:

*M6g node types:* `cache.m6g.large` , `cache.m6g.xlarge` , `cache.m6g.2xlarge` , `cache.m6g.4xlarge` , `cache.m6g.8xlarge` , `cache.m6g.12xlarge` , `cache.m6g.16xlarge` , `cache.m6g.24xlarge`

*M5 node types:* `cache.m5.large` , `cache.m5.xlarge` , `cache.m5.2xlarge` , `cache.m5.4xlarge` , `cache.m5.12xlarge` , `cache.m5.24xlarge`

*M4 node types:* `cache.m4.large` , `cache.m4.xlarge` , `cache.m4.2xlarge` , `cache.m4.4xlarge` , `cache.m4.10xlarge`

*T4g node types:* `cache.t4g.micro` , `cache.t4g.small` , `cache.t4g.medium`

*T3 node types:* `cache.t3.micro` , `cache.t3.small` , `cache.t3.medium`

*T2 node types:* `cache.t2.micro` , `cache.t2.small` , `cache.t2.medium`
- Previous generation: (not recommended)

*T1 node types:* `cache.t1.micro`

*M1 node types:* `cache.m1.small` , `cache.m1.medium` , `cache.m1.large` , `cache.m1.xlarge`

*M3 node types:* `cache.m3.medium` , `cache.m3.large` , `cache.m3.xlarge` , `cache.m3.2xlarge`
- Compute optimized:

- Previous generation: (not recommended)

*C1 node types:* `cache.c1.xlarge`
- Memory optimized:

- Current generation:

*R6gd node types:* `cache.r6gd.xlarge` , `cache.r6gd.2xlarge` , `cache.r6gd.4xlarge` , `cache.r6gd.8xlarge` , `cache.r6gd.12xlarge` , `cache.r6gd.16xlarge`

> The `r6gd` family is available in the following regions: `us-east-2` , `us-east-1` , `us-west-2` , `us-west-1` , `eu-west-1` , `eu-central-1` , `ap-northeast-1` , `ap-southeast-1` , `ap-southeast-2` .

*R6g node types:* `cache.r6g.large` , `cache.r6g.xlarge` , `cache.r6g.2xlarge` , `cache.r6g.4xlarge` , `cache.r6g.8xlarge` , `cache.r6g.12xlarge` , `cache.r6g.16xlarge` , `cache.r6g.24xlarge`

*R5 node types:* `cache.r5.large` , `cache.r5.xlarge` , `cache.r5.2xlarge` , `cache.r5.4xlarge` , `cache.r5.12xlarge` , `cache.r5.24xlarge`

*R4 node types:* `cache.r4.large` , `cache.r4.xlarge` , `cache.r4.2xlarge` , `cache.r4.4xlarge` , `cache.r4.8xlarge` , `cache.r4.16xlarge`
- Previous generation: (not recommended)

*M2 node types:* `cache.m2.xlarge` , `cache.m2.2xlarge` , `cache.m2.4xlarge`

*R3 node types:* `cache.r3.large` , `cache.r3.xlarge` , `cache.r3.2xlarge` , `cache.r3.4xlarge` , `cache.r3.8xlarge`

For region availability, see [Supported Node Types by Region](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/CacheNodes.SupportedTypes.html#CacheNodes.SupportedTypesByRegion)

*Additional node type info*

- All current generation instance types are created in Amazon VPC by default.
- Valkey and Redis OSS append-only files (AOF) are not supported for T1 or T2 instances.
- Valkey and Redis OSS Multi-AZ with automatic failover is not supported on T1 instances.
- Redis OSS configuration variables `appendonly` and `appendfsync` are not supported on Redis OSS version 2.8.22 and later.

cacheNodeType

The name of the cache engine to be used for this cluster.

Valid values for this parameter are: `memcached` | valkey | `redis`

engine

The number of cache nodes that the cache cluster should have.

> However, if the `PreferredAvailabilityZone` and `PreferredAvailabilityZones` properties were not previously specified and you don't specify any new values, an update requires [replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement) .

numCacheNodes

If you are running Valkey 7.2 or later, or Redis OSS engine version 6.0 or later, set this parameter to yes if you want to opt-in to the next minor version upgrade campaign. This parameter is disabled for previous versions.

autoMinorVersionUpgrade

Specifies whether the nodes in this Memcached cluster are created in a single Availability Zone or created across multiple Availability Zones in the cluster's region.

This parameter is only supported for Memcached clusters.

If the `AZMode` and `PreferredAvailabilityZones` are not specified, ElastiCache assumes `single-az` mode.

azMode

The name of the parameter group to associate with this cluster.

If this argument is omitted, the default parameter group for the specified engine is used. You cannot use any parameter group which has `cluster-enabled='yes'` when creating a cluster.

cacheParameterGroupName

A list of security group names to associate with this cluster.

Use this parameter only when you are creating a cluster outside of an Amazon Virtual Private Cloud (Amazon VPC).

cacheSecurityGroupNames

The name of the subnet group to be used for the cluster.

Use this parameter only when you are creating a cluster in an Amazon Virtual Private Cloud (Amazon VPC).

> If you're going to launch your cluster in an Amazon VPC, you need to create a subnet group before you start creating a cluster. For more information, see `[AWS::ElastiCache::SubnetGroup](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticache-subnetgroup.html) .`

cacheSubnetGroupName

A name for the cache cluster.

If you don't specify a name, CloudFormation generates a unique physical ID and uses that ID for the cache cluster. For more information, see [Name Type](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-name.html) .

The name must contain 1 to 50 alphanumeric characters or hyphens. The name must start with a letter and cannot end with a hyphen or contain two consecutive hyphens.

clusterName

The version number of the cache engine to be used for this cluster.

To view the supported cache engine versions, use the DescribeCacheEngineVersions operation.

*Important:* You can upgrade to a newer engine version (see [Selecting a Cache Engine and Version](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/SelectEngine.html#VersionManagement) ), but you cannot downgrade to an earlier engine version. If you want to use an earlier engine version, you must delete the existing cluster or replication group and create it anew with the earlier engine version.

engineVersion

The network type you choose when modifying a cluster, either `ipv4` | `ipv6` .

IPv6 is supported for workloads using Valkey 7.2 and above, Redis OSS engine version 6.2 to 7.1 and Memcached engine version 1.6.6 and above on all instances built on the [Nitro system](https://docs.aws.amazon.com/ec2/nitro/) .

ipDiscovery

Specifies the destination, format and type of the logs.

logDeliveryConfigurations

Must be either `ipv4` | `ipv6` | `dual_stack` .

IPv6 is supported for workloads using Valkey 7.2 and above, Redis OSS engine version 6.2 to 7.1 and Memcached engine version 1.6.6 and above on all instances built on the [Nitro system](https://docs.aws.amazon.com/ec2/nitro/) .

networkType

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

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

notificationTopicArn

The port number on which each of the cache nodes accepts connections.

port

The EC2 Availability Zone in which the cluster is created.

All nodes belonging to this cluster are placed in the preferred Availability Zone. If you want to create your nodes across multiple Availability Zones, use `PreferredAvailabilityZones` .

Default: System chosen Availability Zone.

preferredAvailabilityZone

A list of the Availability Zones in which cache nodes are created.

The order of the zones in the list is not important.

This option is only supported on Memcached.

> If you are creating your cluster in an Amazon VPC (recommended) you can only locate nodes in Availability Zones that are associated with the subnets in the selected subnet group.
>
> The number of Availability Zones listed must equal the value of `NumCacheNodes` .

If you want all the nodes in the same Availability Zone, use `PreferredAvailabilityZone` instead, or repeat the Availability Zone multiple times in the list.

Default: System chosen Availability Zones.

preferredAvailabilityZones

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`

preferredMaintenanceWindow

A single-element string list containing an Amazon Resource Name (ARN) that uniquely identifies a Valkey or Redis OSS RDB snapshot file stored in Amazon S3.

The snapshot file is used to populate the node group (shard). The Amazon S3 object name in the ARN cannot contain any commas.

> This parameter is only valid if the `Engine` parameter is `redis` .

Example of an Amazon S3 ARN: `arn:aws:s3:::my_bucket/snapshot1.rdb`

snapshotArns

The name of a Valkey or Redis OSS snapshot from which to restore data into the new node group (shard).

The snapshot status changes to `restoring` while the new node group (shard) is being created.

> This parameter is only valid if the `Engine` parameter is `redis` .

snapshotName

The number of days for which ElastiCache retains automatic snapshots before deleting them.

For example, if you set `SnapshotRetentionLimit` to 5, a snapshot taken today is retained for 5 days before being deleted.

> This parameter is only valid if the `Engine` parameter is `redis` .

Default: 0 (i.e., automatic backups are disabled for this cache cluster).

snapshotRetentionLimit

The daily time range (in UTC) during which ElastiCache begins taking a daily snapshot of your node group (shard).

Example: `05:00-09:00`

If you do not specify this parameter, ElastiCache automatically chooses an appropriate time range.

> This parameter is only valid if the `Engine` parameter is `redis` .

snapshotWindow

A list of tags to be added to this resource.

transitEncryptionEnabled

One or more VPC security groups associated with the cluster.

Use this parameter only when you are creating a cluster in an Amazon Virtual Private Cloud (Amazon VPC).

vpcSecurityGroupIds

Consists of a primary cluster that accepts writes and an associated secondary cluster that resides in a different Amazon region.

The secondary cluster accepts only reads. The primary cluster automatically replicates updates to the secondary cluster.

- The *GlobalReplicationGroupIdSuffix* represents the name of the Global datastore, which is what you use to associate a secondary cluster.

CfnGlobalReplicationGroup

The replication groups that comprise the Global datastore.

members

Specifies whether a read-only replica is automatically promoted to read/write primary if the existing primary fails.

`AutomaticFailoverEnabled` must be enabled for Valkey or Redis OSS (cluster mode enabled) replication groups.

automaticFailoverEnabled

The cache node type of the Global datastore.

The name of the cache parameter group to use with the Global datastore.

It must be compatible with the major engine version used by the Global datastore.

The ElastiCache engine.

For Valkey or Redis OSS only.

The Elasticache Valkey or Redis OSS engine version.

The number of node groups that comprise the Global Datastore.

globalNodeGroupCount

The optional description of the Global datastore.

globalReplicationGroupDescription

The suffix name of a Global Datastore.

The suffix guarantees uniqueness of the Global Datastore name across multiple regions.

globalReplicationGroupIdSuffix

The Regions that comprise the Global Datastore.

regionalConfigurations

The `AWS::ElastiCache::ParameterGroup` type creates a new cache parameter group.

Cache parameter groups control the parameters for a cache cluster.

CfnParameterGroup

cacheParameterGroupFamily

The description for this cache parameter group.

description

A comma-delimited list of parameter name/value pairs.

For example:

```
"Properties" : { "cas_disabled" : "1", "chunk_size_growth_factor" : "1.02"
}
```

properties

A tag that can be added to an ElastiCache parameter group.

Tags are composed of a Key/Value pair. You can use tags to categorize and track all your parameter groups. A tag with a null Value is permitted.

The `AWS::ElastiCache::ReplicationGroup` resource creates an Amazon ElastiCache (Valkey or Redis OSS) replication group.

A Valkey or Redis OSS (cluster mode disabled) replication group is a collection of cache clusters, where one of the clusters is a primary read-write cluster and the others are read-only replicas.

A Valkey or Redis OSS (cluster mode enabled) cluster is comprised of from 1 to 90 shards (API/CLI: node groups). Each shard has a primary node and up to 5 read-only replica nodes. The configuration can range from 90 shards and 0 replicas to 15 shards and 5 replicas, which is the maximum number or replicas allowed.

The node or shard limit can be increased to a maximum of 500 per cluster if the engine version is Valkey 7.2 or higher, or Redis OSS 5.0.6 or higher. For example, you can choose to configure a 500 node cluster that ranges between 83 shards (one primary and 5 replicas per shard) and 500 shards (single primary and no replicas). Make sure there are enough available IP addresses to accommodate the increase. Common pitfalls include the subnets in the subnet group have too small a CIDR range or the subnets are shared and heavily used by other clusters. For more information, see [Creating a Subnet Group](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/SubnetGroups.Creating.html) . For versions below 5.0.6, the limit is 250 per cluster.

To request a limit increase, see [Amazon Service Limits](https://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html) and choose the limit type *Nodes per cluster per instance type* .

CfnReplicationGroup

A user-created description for the replication group.

replicationGroupDescription

A flag that enables encryption at rest when set to `true` .

*Required:* Only available when creating a replication group in an Amazon VPC using Redis OSS version `3.2.6` or `4.x` onward.

Default: `false`

atRestEncryptionEnabled

*Reserved parameter.* The password used to access a password protected server.

`AuthToken` can be specified only on replication groups where `TransitEncryptionEnabled` is `true` . For more information, see [Authenticating Valkey or Redis OSS users with the AUTH Command](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/auth.html) .

> For HIPAA compliance, you must specify `TransitEncryptionEnabled` as `true` , an `AuthToken` , and a `CacheSubnetGroup` .

Password constraints:

- Must be only printable ASCII characters.
- Must be at least 16 characters and no more than 128 characters in length.
- Nonalphanumeric characters are restricted to (!, &, #, $, ^, <, >, -, ).

For more information, see [AUTH password](https://docs.aws.amazon.com/http://redis.io/commands/AUTH) at http://redis.io/commands/AUTH.

> If ADDING the AuthToken, update requires [Replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement) .

authToken

Specifies whether a read-only replica is automatically promoted to read/write primary if the existing primary fails.

`AutomaticFailoverEnabled` must be enabled for Valkey or Redis OSS (cluster mode enabled) replication groups.

Default: false

If you are running Valkey 7.2 or later, or Redis OSS 6.0 or later, set this parameter to yes if you want to opt-in to the next minor version upgrade campaign. This parameter is disabled for previous versions.

The compute and memory capacity of the nodes in the node group (shard).

The following node types are supported by ElastiCache. Generally speaking, the current generation types provide more memory and computational power at lower cost when compared to their equivalent previous generation counterparts.

- General purpose:

- Current generation:

*M6g node types:* `cache.m6g.large` , `cache.m6g.xlarge` , `cache.m6g.2xlarge` , `cache.m6g.4xlarge` , `cache.m6g.12xlarge` , `cache.m6g.24xlarge`

*M5 node types:* `cache.m5.large` , `cache.m5.xlarge` , `cache.m5.2xlarge` , `cache.m5.4xlarge` , `cache.m5.12xlarge` , `cache.m5.24xlarge`

*M4 node types:* `cache.m4.large` , `cache.m4.xlarge` , `cache.m4.2xlarge` , `cache.m4.4xlarge` , `cache.m4.10xlarge`

*T4g node types:* `cache.t4g.micro` , `cache.t4g.small` , `cache.t4g.medium`

*T3 node types:* `cache.t3.micro` , `cache.t3.small` , `cache.t3.medium`

*T2 node types:* `cache.t2.micro` , `cache.t2.small` , `cache.t2.medium`
- Previous generation: (not recommended)

*T1 node types:* `cache.t1.micro`

*M1 node types:* `cache.m1.small` , `cache.m1.medium` , `cache.m1.large` , `cache.m1.xlarge`

*M3 node types:* `cache.m3.medium` , `cache.m3.large` , `cache.m3.xlarge` , `cache.m3.2xlarge`
- Compute optimized:

- Previous generation: (not recommended)

*C1 node types:* `cache.c1.xlarge`
- Memory optimized:

- Current generation:

*R6gd node types:* `cache.r6gd.xlarge` , `cache.r6gd.2xlarge` , `cache.r6gd.4xlarge` , `cache.r6gd.8xlarge` , `cache.r6gd.12xlarge` , `cache.r6gd.16xlarge`

> The `r6gd` family is available in the following regions: `us-east-2` , `us-east-1` , `us-west-2` , `us-west-1` , `eu-west-1` , `eu-central-1` , `ap-northeast-1` , `ap-southeast-1` , `ap-southeast-2` .

*R6g node types:* `cache.r6g.large` , `cache.r6g.xlarge` , `cache.r6g.2xlarge` , `cache.r6g.4xlarge` , `cache.r6g.12xlarge` , `cache.r6g.24xlarge`

*R5 node types:* `cache.r5.large` , `cache.r5.xlarge` , `cache.r5.2xlarge` , `cache.r5.4xlarge` , `cache.r5.12xlarge` , `cache.r5.24xlarge`

*R4 node types:* `cache.r4.large` , `cache.r4.xlarge` , `cache.r4.2xlarge` , `cache.r4.4xlarge` , `cache.r4.8xlarge` , `cache.r4.16xlarge`
- Previous generation: (not recommended)

*M2 node types:* `cache.m2.xlarge` , `cache.m2.2xlarge` , `cache.m2.4xlarge`

*R3 node types:* `cache.r3.large` , `cache.r3.xlarge` , `cache.r3.2xlarge` , `cache.r3.4xlarge` , `cache.r3.8xlarge`

For region availability, see [Supported Node Types by Amazon Region](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/CacheNodes.SupportedTypes.html#CacheNodes.SupportedTypesByRegion)

The name of the parameter group to associate with this replication group.

If this argument is omitted, the default cache parameter group for the specified engine is used.

If you are running Valkey or Redis OSS version 3.2.4 or later, only one node group (shard), and want to use a default parameter group, we recommend that you specify the parameter group by name.

- To create a Valkey or Redis OSS (cluster mode disabled) replication group, use `CacheParameterGroupName=default.redis3.2` .
- To create a Valkey or Redis OSS (cluster mode enabled) replication group, use `CacheParameterGroupName=default.redis3.2.cluster.on` .

A list of cache security group names to associate with this replication group.

The name of the cache subnet group to be used for the replication group.

> If you're going to launch your cluster in an Amazon VPC, you need to create a subnet group before you start creating a cluster. For more information, see [AWS::ElastiCache::SubnetGroup](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-elasticache-subnetgroup.html) .

The mode can be enabled or disabled.

To change the cluster mode from disabled to enabled, you must first set the cluster mode to compatible. The compatible mode allows your Valkey or Redis OSS clients to connect using both cluster mode enabled and cluster mode disabled. After you migrate all Valkey or Redis OSS clients to use cluster mode enabled, you can then complete cluster mode configuration and set the cluster mode to enabled. For more information, see [Modify cluster mode](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/modify-cluster-mode.html) .

clusterMode

Enables data tiering.

Data tiering is only supported for replication groups using the r6gd node type. This parameter must be set to true when using r6gd nodes. For more information, see [Data tiering](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/data-tiering.html) .

dataTieringEnabled

The name of the cache engine to be used for the clusters in this replication group.

The value must be set to `valkey` or `redis` .

> Upgrading an existing engine from redis to valkey is done through in-place migration, and requires a parameter group.

The version number of the cache engine to be used for the clusters in this replication group.

To view the supported cache engine versions, use the `DescribeCacheEngineVersions` operation.

*Important:* You can upgrade to a newer engine version (see [Selecting a Cache Engine and Version](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/SelectEngine.html#VersionManagement) ) in the *ElastiCache User Guide* , but you cannot downgrade to an earlier engine version. If you want to use an earlier engine version, you must delete the existing cluster or replication group and create it anew with the earlier engine version.

globalReplicationGroupId

The network type you choose when creating a replication group, either `ipv4` | `ipv6` .

IPv6 is supported for workloads using Valkey 7.2 and above, Redis OSS engine version 6.2 to 7.1 or Memcached engine version 1.6.6 and above on all instances built on the [Nitro system](https://docs.aws.amazon.com/ec2/nitro/) .

The ID of the KMS key used to encrypt the disk on the cluster.

kmsKeyId

A flag indicating if you have Multi-AZ enabled to enhance fault tolerance.

For more information, see [Minimizing Downtime: Multi-AZ](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/AutoFailover.html) .

multiAzEnabled

`NodeGroupConfiguration` is a property of the `AWS::ElastiCache::ReplicationGroup` resource that configures an Amazon ElastiCache (ElastiCache) Valkey or Redis OSS cluster node group.

If you set [UseOnlineResharding](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-updatepolicy.html#cfn-attributes-updatepolicy-useonlineresharding) to `true` , you can update `NodeGroupConfiguration` without interruption. When `UseOnlineResharding` is set to `false` , or is not specified, updating `NodeGroupConfiguration` results in [replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement) .

nodeGroupConfiguration

The number of clusters this replication group initially has.

This parameter is not used if there is more than one node group (shard). You should use `ReplicasPerNodeGroup` instead.

If `AutomaticFailoverEnabled` is `true` , the value of this parameter must be at least 2. If `AutomaticFailoverEnabled` is `false` you can omit this parameter (it will default to 1), or you can explicitly set it to a value between 2 and 6.

The maximum permitted value for `NumCacheClusters` is 6 (1 primary plus 5 replicas).

numCacheClusters

An optional parameter that specifies the number of node groups (shards) for this Valkey or Redis OSS (cluster mode enabled) replication group.

For Valkey or Redis OSS (cluster mode disabled) either omit this parameter or set it to 1.

If you set [UseOnlineResharding](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-attribute-updatepolicy.html#cfn-attributes-updatepolicy-useonlineresharding) to `true` , you can update `NumNodeGroups` without interruption. When `UseOnlineResharding` is set to `false` , or is not specified, updating `NumNodeGroups` results in [replacement](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-update-behaviors.html#update-replacement) .

Default: 1

numNodeGroups

The port number on which each member of the replication group accepts connections.

A list of EC2 Availability Zones in which the replication group's clusters are created.

The order of the Availability Zones in the list is the order in which clusters are allocated. The primary cluster is created in the first AZ in the list.

This parameter is not used if there is more than one node group (shard). You should use `NodeGroupConfiguration` instead.

> If you are creating your replication group in an Amazon VPC (recommended), you can only locate clusters in Availability Zones associated with the subnets in the selected subnet group.
>
> The number of Availability Zones listed must equal the value of `NumCacheClusters` .

Default: system chosen Availability Zones.

preferredCacheClusterAZs

The identifier of the cluster that serves as the primary for this replication group.

This cluster must already exist and have a status of `available` .

This parameter is not required if `NumCacheClusters` , `NumNodeGroups` , or `ReplicasPerNodeGroup` is specified.

primaryClusterId

An optional parameter that specifies the number of replica nodes in each node group (shard).

Valid values are 0 to 5.

replicasPerNodeGroup

The replication group identifier. This parameter is stored as a lowercase string.

Constraints:

- A name must contain from 1 to 40 alphanumeric characters or hyphens.
- The first character must be a letter.
- A name cannot end with a hyphen or contain two consecutive hyphens.

replicationGroupId

One or more Amazon VPC security groups associated with this replication group.

Use this parameter only when you are creating a replication group in an Amazon Virtual Private Cloud (Amazon VPC).

securityGroupIds

A list of Amazon Resource Names (ARN) that uniquely identify the Valkey or Redis OSS RDB snapshot files stored in Amazon S3.

The snapshot files are used to populate the new replication group. The Amazon S3 object name in the ARN cannot contain any commas. The new replication group will have the number of node groups (console: shards) specified by the parameter *NumNodeGroups* or the number of node groups configured by *NodeGroupConfiguration* regardless of the number of ARNs specified here.

Example of an Amazon S3 ARN: `arn:aws:s3:::my_bucket/snapshot1.rdb`

The name of a snapshot from which to restore data into the new replication group.

The snapshot status changes to `restoring` while the new replication group is being created.

The number of days for which ElastiCache retains automatic 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.

Default: 0 (i.e., automatic backups are disabled for this cluster).

The cluster ID that is used as the daily snapshot source for the replication group.

This parameter cannot be set for Valkey or Redis OSS (cluster mode enabled) replication groups.

snapshottingClusterId

The daily time range (in UTC) during which ElastiCache begins taking a daily snapshot of your node group (shard).

Example: `05:00-09:00`

If you do not specify this parameter, ElastiCache automatically chooses an appropriate time range.

A list of tags to be added to this resource.

Tags are comma-separated key,value pairs (e.g. Key= `myKey` , Value= `myKeyValue` . You can include multiple tags as shown following: Key= `myKey` , Value= `myKeyValue` Key= `mySecondKey` , Value= `mySecondKeyValue` . Tags on replication groups will be replicated to all nodes.

A flag that enables in-transit encryption when set to `true` .

This parameter is only available when creating a replication group in an Amazon VPC using Valkey version `7.2` and above, Redis OSS version `3.2.6` , or Redis OSS version `4.x` and above, and the cluster is being created in an Amazon VPC.

If you enable in-transit encryption, you must also specify a value for `CacheSubnetGroup` .

> TransitEncryptionEnabled is required when creating a new valkey replication group.

Default: `false`

> For HIPAA compliance, you must specify `TransitEncryptionEnabled` as `true` , an `AuthToken` , and a `CacheSubnetGroup` .

A setting that allows you to migrate your clients to use in-transit encryption, with no downtime.

When setting `TransitEncryptionEnabled` to `true` , you can set your `TransitEncryptionMode` to `preferred` in the same request, to allow both encrypted and unencrypted connections at the same time. Once you migrate all your Valkey or Redis OSS clients to use encrypted connections you can modify the value to `required` to allow encrypted connections only.

Setting `TransitEncryptionMode` to `required` is a two-step process that requires you to first set the `TransitEncryptionMode` to `preferred` , after that you can set `TransitEncryptionMode` to `required` .

This process will not trigger the replacement of the replication group.

transitEncryptionMode

The ID of user group to associate with the replication group.

userGroupIds

The `AWS::ElastiCache::SecurityGroup` resource creates a cache security group.

For more information about cache security groups, go to [CacheSecurityGroups](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/VPCs.html) in the *Amazon ElastiCache User Guide* or go to [CreateCacheSecurityGroup](https://docs.aws.amazon.com/AmazonElastiCache/latest/APIReference/API_CreateCacheSecurityGroup.html) in the *Amazon ElastiCache API Reference Guide* .

For more information, see [CreateCacheSubnetGroup](https://docs.aws.amazon.com/AmazonElastiCache/latest/APIReference/API_CreateCacheSubnetGroup.html) .

CfnSecurityGroup

A description for the cache security group.

A tag that can be added to an ElastiCache security group.

Tags are composed of a Key/Value pair. You can use tags to categorize and track all your security groups. A tag with a null Value is permitted.

The AWS::ElastiCache::SecurityGroupIngress type authorizes ingress to a cache security group from hosts in specified Amazon EC2 security groups.

For more information about ElastiCache security group ingress, go to [AuthorizeCacheSecurityGroupIngress](https://docs.aws.amazon.com/AmazonElastiCache/latest/APIReference/API_AuthorizeCacheSecurityGroupIngress.html) in the *Amazon ElastiCache API Reference Guide* .

> Updates are not supported.

CfnSecurityGroupIngress

The name of the Cache Security Group to authorize.

cacheSecurityGroupName

Name of the EC2 Security Group to include in the authorization.

ec2SecurityGroupName

Specifies the Amazon Account ID of the owner of the EC2 security group specified in the EC2SecurityGroupName property.

The Amazon access key ID is not an acceptable value.

ec2SecurityGroupOwnerId

The resource representing a serverless cache.

CfnServerlessCache

The engine the serverless cache is compatible with.

The unique identifier of the serverless cache.

serverlessCacheName

The cache usage limit for the serverless cache.

cacheUsageLimits

The daily time that a cache snapshot will be created.

Default is NULL, i.e. snapshots will not be created at a specific time on a daily basis. Available for Valkey, Redis OSS and Serverless Memcached only.

dailySnapshotTime

Represents the information required for client programs to connect to a cache node.

This value is read-only.

endpoint

The name of the final snapshot taken of a cache before the cache is deleted.

finalSnapshotName

The ID of the AWS Key Management Service (KMS) key that is used to encrypt data at rest in the serverless cache.

The version number of the engine the serverless cache is compatible with.

majorEngineVersion

readerEndpoint

The IDs of the EC2 security groups associated with the serverless cache.

The ARN of the snapshot from which to restore data into the new cache.

snapshotArnsToRestore

The current setting for the number of serverless cache snapshots the system will retain.

Available for Valkey, Redis OSS and Serverless Memcached only.

If no subnet IDs are given and your VPC is in us-west-1, then ElastiCache will select 2 default subnets across AZs in your VPC.

For all other Regions, if no subnet IDs are given then ElastiCache will select 3 default subnets across AZs in your default VPC.

subnetIds

The identifier of the user group associated with the serverless cache.

Available for Valkey and Redis OSS only. Default is NULL.

userGroupId

Creates a cache subnet group.

For more information about cache subnet groups, go to Cache Subnet Groups in the *Amazon ElastiCache User Guide* or go to [CreateCacheSubnetGroup](https://docs.aws.amazon.com/AmazonElastiCache/latest/APIReference/API_CreateCacheSubnetGroup.html) in the *Amazon ElastiCache API Reference Guide* .

CfnSubnetGroup

The description for the cache subnet group.

The EC2 subnet IDs for the cache subnet group.

The name for the cache subnet group. This value is stored as a lowercase string.

Constraints: Must contain no more than 255 alphanumeric characters or hyphens.

Example: `mysubnetgroup`

A tag that can be added to an ElastiCache subnet group.

Tags are composed of a Key/Value pair. You can use tags to categorize and track all your subnet groups. A tag with a null Value is permitted.

For Valkey 7.2 and onwards, or Redis OSS engine version 6.0 and onwards: Creates user. For more information, see [Using Role Based Access Control (RBAC)](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/Clusters.RBAC.html) .

CfnUser

The current supported values are valkey and redis.

userId

userName

Access permissions string used for this user.

accessString

Specifies the authentication mode to use. Below is an example of the possible JSON values:.

```
{ Passwords: ["*****", "******"] // If Type is password.
}
```

authenticationMode

Indicates a password is not required for this user.

noPasswordRequired

Passwords used for this user.

You can create up to two passwords for each user.

passwords

For Valkey 7.2 and onwards, or Redis OSS 6.0 and onwards: Creates a user group. For more information, see [Using Role Based Access Control (RBAC)](https://docs.aws.amazon.com/AmazonElastiCache/latest/dg/Clusters.RBAC.html).

CfnUserGroup

The list of user IDs that belong to the user group.

A user named `default` must be included.

Amazon ElastiCache

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