chore(opensearchservice): t3 instance type does not support Multi-AZ with standby feature

packages/aws-cdk-lib/aws-opensearchservice/lib/domain.ts

@@ -1827,6 +1827,10 @@ export class Domain extends DomainBase implements IDomain, ec2.IConnectable {
       }
     }
 
+    if (isSomeInstanceType('t3') && multiAzWithStandbyEnabled) {
+      throw new Error('T3 instance types does not support Multi-AZ with standby feature.');
+    }
+
     const offPeakWindowEnabled = props.offPeakWindowEnabled ?? props.offPeakWindowStart !== undefined;
     if (offPeakWindowEnabled) {
       this.validateWindowStartTime(props.offPeakWindowStart);

packages/aws-cdk-lib/aws-opensearchservice/test/domain.test.ts

@@ -408,6 +408,27 @@ each([testedOpenSearchVersions]).test('can specify multiAZWithStandbyEnabled in
   });
 });
 
+each([testedOpenSearchVersions]).test('multiAZWithStandbyEnabled: true throws with t3 instance type (data node)', (engineVersion) => {
+  expect(() => new Domain(stack, 'Domain', {
+    version: engineVersion,
+    capacity: {
+      dataNodeInstanceType: 't3.medium.search',
+      multiAzWithStandbyEnabled: true,
+    },
+  })).toThrow(/T3 instance types does not support Multi-AZ with standby feature\./);
+});
+
+each([testedOpenSearchVersions]).test('multiAZWithStandbyEnabled: true throws with t3 instance type (master node)', (engineVersion) => {
+  expect(() => new Domain(stack, 'Domain', {
+    version: engineVersion,
+    capacity: {
+      masterNodeInstanceType: 't3.medium.search',
+      masterNodes: 1,
+      multiAzWithStandbyEnabled: true,
+    },
+  })).toThrow(/T3 instance types does not support Multi-AZ with standby feature\./);
+});
+
 each([testedOpenSearchVersions]).test('ENABLE_OPENSEARCH_MULTIAZ_WITH_STANDBY set multiAZWithStandbyEnabled value', (engineVersion) => {
   const stackWithFlag = new Stack(app, 'StackWithFlag', {
     env: { account: '1234', region: 'testregion' },