feat(redshift): multi AZ cluster (#29976)

### Issue # (if applicable)

Closes #<issue number here>.

### Reason for this change

AWS CDK cannot configure Redshift multi-AZ cluster.

### Description of changes

Add `multiAz` to `clusterProps`.

### Description of how you validated changes

I've added both unit and integ tests.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: badmintoncryer

packages/@aws-cdk/aws-redshift-alpha/README.md

@@ -556,6 +556,28 @@ const cluster = new Cluster(this, 'Redshift', {
 cluster.addIamRole(role);
 ```
 
+## Multi-AZ
+
+Amazon Redshift supports [multiple Availability Zones (Multi-AZ) deployments]((https://docs.aws.amazon.com/redshift/latest/mgmt/managing-cluster-multi-az.html)) for provisioned RA3 clusters.
+By using Multi-AZ deployments, your Amazon Redshift data warehouse can continue operating in failure scenarios when an unexpected event happens in an Availability Zone.
+
+To create a Multi-AZ cluster, set the `multiAz` property to `true` when creating the cluster.
+
+```ts
+declare const vpc: ec2.IVpc;
+
+new redshift.Cluster(stack, 'Cluster', {
+  masterUser: {
+    masterUsername: 'admin',
+  },
+  vpc, // 3 AZs are required for Multi-AZ
+  nodeType: redshift.NodeType.RA3_XLPLUS, // must be RA3 node type
+  clusterType: redshift.ClusterType.MULTI_NODE, // must be MULTI_NODE
+  numberOfNodes: 2, // must be 2 or more
+  multiAz: true,
+});
+```
+
 ## Resizing
 
 As your data warehousing needs change, it's possible to resize your Redshift cluster. If the cluster was deployed via CDK, 

packages/@aws-cdk/aws-redshift-alpha/lib/cluster.ts

@@ -385,6 +385,13 @@ export interface ClusterProps {
    * @default - false
    */
   readonly enhancedVpcRouting?: boolean;
+
+  /**
+   * Indicating whether Amazon Redshift should deploy the cluster in two Availability Zones.
+   *
+   * @default - false
+   */
+  readonly multiAz?: boolean;
 }
 
 /**
@@ -558,6 +565,17 @@ export class Cluster extends ClusterBase {
       );
     }
 
+    const nodeType = props.nodeType || NodeType.DC2_LARGE;
+
+    if (props.multiAz) {
+      if (!nodeType.startsWith('ra3')) {
+        throw new Error(`Multi-AZ cluster is only supported for RA3 node types, got: ${props.nodeType}`);
+      }
+      if (clusterType === ClusterType.SINGLE_NODE) {
+        throw new Error('Multi-AZ cluster is not supported for `clusterType` single-node');
+      }
+    }
+
     this.cluster = new CfnCluster(this, 'Resource', {
       // Basic
       allowVersionUpgrade: true,
@@ -574,7 +592,7 @@ export class Cluster extends ClusterBase {
         ?? props.masterUser.masterPassword?.unsafeUnwrap()
         ?? 'default',
       preferredMaintenanceWindow: props.preferredMaintenanceWindow,
-      nodeType: props.nodeType || NodeType.DC2_LARGE,
+      nodeType,
       numberOfNodes: nodeCount,
       loggingProperties,
       iamRoles: Lazy.list({ produce: () => this.roles.map(role => role.roleArn) }, { omitEmpty: true }),
@@ -586,6 +604,7 @@ export class Cluster extends ClusterBase {
       classic: props.classicResizing,
       elasticIp: props.elasticIp,
       enhancedVpcRouting: props.enhancedVpcRouting,
+      multiAz: props.multiAz,
     });
 
     this.cluster.applyRemovalPolicy(removalPolicy, {

packages/@aws-cdk/aws-redshift-alpha/test/cluster.test.ts

@@ -4,7 +4,7 @@ import * as iam from 'aws-cdk-lib/aws-iam';
 import * as kms from 'aws-cdk-lib/aws-kms';
 import * as s3 from 'aws-cdk-lib/aws-s3';
 import * as cdk from 'aws-cdk-lib';
-import { Cluster, ClusterParameterGroup, ClusterSubnetGroup, ClusterType } from '../lib';
+import { Cluster, ClusterParameterGroup, ClusterSubnetGroup, ClusterType, NodeType } from '../lib';
 import { CfnCluster } from 'aws-cdk-lib/aws-redshift';
 
 let stack: cdk.Stack;
@@ -614,6 +614,67 @@ test('elastic ip address', () => {
   });
 });
 
+describe('multi AZ cluster', () => {
+  test('create a multi AZ cluster', () => {
+    // WHEN
+    new Cluster(stack, 'Redshift', {
+      masterUser: {
+        masterUsername: 'admin',
+        masterPassword: cdk.SecretValue.unsafePlainText('tooshort'),
+      },
+      vpc,
+      nodeType: NodeType.RA3_XLPLUS,
+      multiAz: true,
+    });
+
+    // THEN
+    Template.fromStack(stack).hasResourceProperties('AWS::Redshift::Cluster', {
+      AllowVersionUpgrade: true,
+      MasterUsername: 'admin',
+      MasterUserPassword: 'tooshort',
+      ClusterType: 'multi-node',
+      AutomatedSnapshotRetentionPeriod: 1,
+      Encrypted: true,
+      NumberOfNodes: 2,
+      NodeType: 'ra3.xlplus',
+      DBName: 'default_db',
+      PubliclyAccessible: false,
+      ClusterSubnetGroupName: { Ref: 'RedshiftSubnetsDFE70E0A' },
+      VpcSecurityGroupIds: [
+        { 'Fn::GetAtt': ['RedshiftSecurityGroup796D74A7', 'GroupId'] },
+      ],
+      MultiAZ: true,
+    });
+  });
+
+  test('throw error for invalid node type', () => {
+    expect(() => {
+      new Cluster(stack, 'Redshift', {
+        masterUser: {
+          masterUsername: 'admin',
+        },
+        vpc,
+        nodeType: NodeType.DS2_XLARGE,
+        multiAz: true,
+      });
+    }).toThrow('Multi-AZ cluster is only supported for RA3 node types, got: ds2.xlarge');
+  });
+
+  test('throw error for single node cluster', () => {
+    expect(() => {
+      new Cluster(stack, 'Redshift', {
+        masterUser: {
+          masterUsername: 'admin',
+        },
+        vpc,
+        nodeType: NodeType.RA3_XLPLUS,
+        multiAz: true,
+        clusterType: ClusterType.SINGLE_NODE,
+      });
+    }).toThrow('Multi-AZ cluster is not supported for `clusterType` single-node');
+  });
+});
+
 describe('reboot for Parameter Changes', () => {
   test('throw error for cluster without parameter group', () => {
     // Given