def create_replication_group(ReplicationGroupId=None, ReplicationGroupDescription=None, PrimaryClusterId=None, AutomaticFailoverEnabled=None, NumCacheClusters=None, PreferredCacheClusterAZs=None, NumNodeGroups=None, ReplicasPerNodeGroup=None, NodeGroupConfiguration=None, CacheNodeType=None, Engine=None, EngineVersion=None, CacheParameterGroupName=None, CacheSubnetGroupName=None, CacheSecurityGroupNames=None, SecurityGroupIds=None, Tags=None, SnapshotArns=None, SnapshotName=None, PreferredMaintenanceWindow=None, Port=None, NotificationTopicArn=None, AutoMinorVersionUpgrade=None, SnapshotRetentionLimit=None, SnapshotWindow=None, AuthToken=None):
    """
    Creates a Redis (cluster mode disabled) or a Redis (cluster mode enabled) replication group.
    A Redis (cluster mode disabled) replication group is a collection of cache clusters, where one of the cache clusters is a read/write primary and the others are read-only replicas. Writes to the primary are asynchronously propagated to the replicas.
    A Redis (cluster mode enabled) replication group is a collection of 1 to 15 node groups (shards). Each node group (shard) has one read/write primary node and up to 5 read-only replica nodes. Writes to the primary are asynchronously propagated to the replicas. Redis (cluster mode enabled) replication groups partition the data across node groups (shards).
    When a Redis (cluster mode disabled) replication group has been successfully created, you can add one or more read replicas to it, up to a total of 5 read replicas. You cannot alter a Redis (cluster mode enabled) replication group after it has been created. However, if you need to increase or decrease the number of node groups (console: shards), you can avail yourself of ElastiCache for Redis' enhanced backup and restore. For more information, see Restoring From a Backup with Cluster Resizing in the ElastiCache User Guide .
    See also: AWS API Documentation
    
    
    :example: response = client.create_replication_group(
        ReplicationGroupId='string',
        ReplicationGroupDescription='string',
        PrimaryClusterId='string',
        AutomaticFailoverEnabled=True|False,
        NumCacheClusters=123,
        PreferredCacheClusterAZs=[
            'string',
        ],
        NumNodeGroups=123,
        ReplicasPerNodeGroup=123,
        NodeGroupConfiguration=[
            {
                'Slots': 'string',
                'ReplicaCount': 123,
                'PrimaryAvailabilityZone': 'string',
                'ReplicaAvailabilityZones': [
                    'string',
                ]
            },
        ],
        CacheNodeType='string',
        Engine='string',
        EngineVersion='string',
        CacheParameterGroupName='string',
        CacheSubnetGroupName='string',
        CacheSecurityGroupNames=[
            'string',
        ],
        SecurityGroupIds=[
            'string',
        ],
        Tags=[
            {
                'Key': 'string',
                'Value': 'string'
            },
        ],
        SnapshotArns=[
            'string',
        ],
        SnapshotName='string',
        PreferredMaintenanceWindow='string',
        Port=123,
        NotificationTopicArn='string',
        AutoMinorVersionUpgrade=True|False,
        SnapshotRetentionLimit=123,
        SnapshotWindow='string',
        AuthToken='string'
    )
    
    
    :type ReplicationGroupId: string
    :param ReplicationGroupId: [REQUIRED]
            The replication group identifier. This parameter is stored as a lowercase string.
            Constraints:
            A name must contain from 1 to 20 alphanumeric characters or hyphens.
            The first character must be a letter.
            A name cannot end with a hyphen or contain two consecutive hyphens.
            

    :type ReplicationGroupDescription: string
    :param ReplicationGroupDescription: [REQUIRED]
            A user-created description for the replication group.
            

    :type PrimaryClusterId: string
    :param PrimaryClusterId: The identifier of the cache cluster that serves as the primary for this replication group. This cache cluster must already exist and have a status of available .
            This parameter is not required if NumCacheClusters , NumNodeGroups , or ReplicasPerNodeGroup is specified.
            

    :type AutomaticFailoverEnabled: boolean
    :param AutomaticFailoverEnabled: Specifies whether a read-only replica is automatically promoted to read/write primary if the existing primary fails.
            If true , Multi-AZ is enabled for this replication group. If false , Multi-AZ is disabled for this replication group.
            AutomaticFailoverEnabled must be enabled for Redis (cluster mode enabled) replication groups.
            Default: false
            Note
            ElastiCache Multi-AZ replication groups is not supported on:
            Redis versions earlier than 2.8.6.
            Redis (cluster mode disabled): T1 and T2 node types. Redis (cluster mode enabled): T2 node types.
            

    :type NumCacheClusters: integer
    :param NumCacheClusters: 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 (primary plus 5 replicas).
            

    :type PreferredCacheClusterAZs: list
    :param PreferredCacheClusterAZs: A list of EC2 Availability Zones in which the replication group's cache 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.
            Note
            If you are creating your replication group in an Amazon VPC (recommended), you can only locate cache 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.
            (string) --
            

    :type NumNodeGroups: integer
    :param NumNodeGroups: An optional parameter that specifies the number of node groups (shards) for this Redis (cluster mode enabled) replication group. For Redis (cluster mode disabled) either omit this parameter or set it to 1.
            Default: 1
            

    :type ReplicasPerNodeGroup: integer
    :param ReplicasPerNodeGroup: An optional parameter that specifies the number of replica nodes in each node group (shard). Valid values are 0 to 5.

    :type NodeGroupConfiguration: list
    :param NodeGroupConfiguration: A list of node group (shard) configuration options. Each node group (shard) configuration has the following: Slots, PrimaryAvailabilityZone, ReplicaAvailabilityZones, ReplicaCount.
            If you're creating a Redis (cluster mode disabled) or a Redis (cluster mode enabled) replication group, you can use this parameter to individually configure each node group (shard), or you can omit this parameter.
            (dict) --node group (shard) configuration options. Each node group (shard) configuration has the following: Slots , PrimaryAvailabilityZone , ReplicaAvailabilityZones , ReplicaCount .
            Slots (string) --A string that specifies the keyspace for a particular node group. Keyspaces range from 0 to 16,383. The string is in the format startkey-endkey .
            Example: '0-3999'
            ReplicaCount (integer) --The number of read replica nodes in this node group (shard).
            PrimaryAvailabilityZone (string) --The Availability Zone where the primary node of this node group (shard) is launched.
            ReplicaAvailabilityZones (list) --A list of Availability Zones to be used for the read replicas. The number of Availability Zones in this list must match the value of ReplicaCount or ReplicasPerNodeGroup if not specified.
            (string) --
            
            

    :type CacheNodeType: string
    :param CacheNodeType: The compute and memory capacity of the nodes in the node group (shard).
            Valid node types are as follows:
            General purpose:
            Current generation: cache.t2.micro , cache.t2.small , cache.t2.medium , cache.m3.medium , cache.m3.large , cache.m3.xlarge , cache.m3.2xlarge , cache.m4.large , cache.m4.xlarge , cache.m4.2xlarge , cache.m4.4xlarge , cache.m4.10xlarge
            Previous generation: cache.t1.micro , cache.m1.small , cache.m1.medium , cache.m1.large , cache.m1.xlarge
            Compute optimized: cache.c1.xlarge
            Memory optimized:
            Current generation: cache.r3.large , cache.r3.xlarge , cache.r3.2xlarge , cache.r3.4xlarge , cache.r3.8xlarge
            Previous generation: cache.m2.xlarge , cache.m2.2xlarge , cache.m2.4xlarge
            
            Notes:
            All T2 instances are created in an Amazon Virtual Private Cloud (Amazon VPC).
            Redis backup/restore is not supported for Redis (cluster mode disabled) T1 and T2 instances. Backup/restore is supported on Redis (cluster mode enabled) T2 instances.
            Redis Append-only files (AOF) functionality is not supported for T1 or T2 instances.
            For a complete listing of node types and specifications, see Amazon ElastiCache Product Features and Details and either Cache Node Type-Specific Parameters for Memcached or Cache Node Type-Specific Parameters for Redis .
            

    :type Engine: string
    :param Engine: The name of the cache engine to be used for the cache clusters in this replication group.

    :type EngineVersion: string
    :param EngineVersion: The version number of the cache engine to be used for the cache 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 ) 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 cache cluster or replication group and create it anew with the earlier engine version.
            

    :type CacheParameterGroupName: string
    :param CacheParameterGroupName: 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 Redis 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 Redis (cluster mode disabled) replication group, use CacheParameterGroupName=default.redis3.2 .
            To create a Redis (cluster mode enabled) replication group, use CacheParameterGroupName=default.redis3.2.cluster.on .
            

    :type CacheSubnetGroupName: string
    :param CacheSubnetGroupName: The name of the cache subnet group to be used for the replication group.
            Warning
            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 Subnets and Subnet Groups .
            

    :type CacheSecurityGroupNames: list
    :param CacheSecurityGroupNames: A list of cache security group names to associate with this replication group.
            (string) --
            

    :type SecurityGroupIds: list
    :param SecurityGroupIds: 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).
            (string) --
            

    :type Tags: list
    :param Tags: A list of cost allocation tags to be added to this resource. A tag is a key-value pair. A tag key must be accompanied by a tag value.
            (dict) --A cost allocation Tag that can be added to an ElastiCache cluster or replication group. Tags are composed of a Key/Value pair. A tag with a null Value is permitted.
            Key (string) --The key for the tag. May not be null.
            Value (string) --The tag's value. May be null.
            
            

    :type SnapshotArns: list
    :param SnapshotArns: A list of Amazon Resource Names (ARN) that uniquely identify the Redis 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.
            Note
            This parameter is only valid if the Engine parameter is redis .
            Example of an Amazon S3 ARN: arn:aws:s3:::my_bucket/snapshot1.rdb
            (string) --
            

    :type SnapshotName: string
    :param SnapshotName: 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.
            Note
            This parameter is only valid if the Engine parameter is redis .
            

    :type PreferredMaintenanceWindow: string
    :param PreferredMaintenanceWindow: Specifies the weekly time range during which maintenance on the cache 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:
            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 Port: integer
    :param Port: The port number on which each member of the replication group accepts connections.

    :type NotificationTopicArn: string
    :param NotificationTopicArn: The Amazon Resource Name (ARN) of the Amazon Simple Notification Service (SNS) topic to which notifications are sent.
            Note
            The Amazon SNS topic owner must be the same as the cache cluster owner.
            

    :type AutoMinorVersionUpgrade: boolean
    :param AutoMinorVersionUpgrade: This parameter is currently disabled.

    :type SnapshotRetentionLimit: integer
    :param SnapshotRetentionLimit: 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.
            Note
            This parameter is only valid if the Engine parameter is redis .
            Default: 0 (i.e., automatic backups are disabled for this cache cluster).
            

    :type SnapshotWindow: string
    :param SnapshotWindow: 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.
            Note
            This parameter is only valid if the Engine parameter is redis .
            

    :type AuthToken: string
    :param AuthToken: 
            Reserved parameter. The password used to access a password protected server.
            Password constraints:
            Must be only printable ASCII characters.
            Must be at least 16 characters and no more than 128 characters in length.
            Cannot contain any of the following characters: '/', ''', or '@'.
            For more information, see AUTH password at Redis.
            

    :rtype: dict
    :return: {
        'ReplicationGroup': {
            'ReplicationGroupId': 'string',
            'Description': 'string',
            'Status': 'string',
            'PendingModifiedValues': {
                'PrimaryClusterId': 'string',
                'AutomaticFailoverStatus': 'enabled'|'disabled'
            },
            'MemberClusters': [
                'string',
            ],
            'NodeGroups': [
                {
                    'NodeGroupId': 'string',
                    'Status': 'string',
                    'PrimaryEndpoint': {
                        'Address': 'string',
                        'Port': 123
                    },
                    'Slots': 'string',
                    'NodeGroupMembers': [
                        {
                            'CacheClusterId': 'string',
                            'CacheNodeId': 'string',
                            'ReadEndpoint': {
                                'Address': 'string',
                                'Port': 123
                            },
                            'PreferredAvailabilityZone': 'string',
                            'CurrentRole': 'string'
                        },
                    ]
                },
            ],
            'SnapshottingClusterId': 'string',
            'AutomaticFailover': 'enabled'|'disabled'|'enabling'|'disabling',
            'ConfigurationEndpoint': {
                'Address': 'string',
                'Port': 123
            },
            'SnapshotRetentionLimit': 123,
            'SnapshotWindow': 'string',
            'ClusterEnabled': True|False,
            'CacheNodeType': 'string'
        }
    }
    
    
    :returns: 
    Redis versions earlier than 2.8.6.
    Redis (cluster mode disabled):T1 and T2 cache node types. Redis (cluster mode enabled): T1 node types.
    
    """
    pass