fix(rds): readers not always be created after the writer

packages/aws-cdk-lib/aws-rds/lib/cluster.ts

@@ -772,6 +772,8 @@ abstract class DatabaseClusterNew extends DatabaseClusterBase {
  subnetGroup: this.subnetGroup,
  });
  readers.push(clusterInstance);
+ // this makes sure the readers would always be created after the writer
+ clusterInstance.node.addDependency(writer);
 
  if (clusterInstance.tier < 2) {
  this.validateReaderInstance(writer, clusterInstance);

packages/aws-cdk-lib/aws-rds/test/cluster.test.ts

@@ -554,6 +554,42 @@ describe('cluster new api', () => {
  PromotionTier: 0,
  });
  });
+
+ test('readers always to be created after the writer', () => {
+ // GIVEN
+ const stack = testStack();
+ const vpc = new ec2.Vpc(stack, 'VPC');
+
+ // WHEN
+ new DatabaseCluster(stack, 'Database', {
+ engine: DatabaseClusterEngine.AURORA,
+ vpc,
+ vpcSubnets: vpc.selectSubnets({ subnetType: ec2.SubnetType.PUBLIC }),
+ writer: ClusterInstance.serverlessV2('writer'),
+ readers: [
+ ClusterInstance.serverlessV2('reader1', { instanceIdentifier: 'reader1' }),
+ ClusterInstance.serverlessV2('reader2', { instanceIdentifier: 'reader2' }),
+ ],
+ });
+
+ // THEN
+ const template = Template.fromStack(stack);
+ Array.isArray(template);
+ // reader1 should depend on the writer
+ template.hasResource('AWS::RDS::DBInstance', {
+ Properties: {
+ DBInstanceIdentifier: 'reader1',
+ },
+ DependsOn: Match.arrayWith(['Databasewriter2462CC03']),
+ });
+ // reader2 should depend on the writer
+ template.hasResource('AWS::RDS::DBInstance', {
+ Properties: {
+ DBInstanceIdentifier: 'reader2',
+ },
+ DependsOn: Match.arrayWith(['Databasewriter2462CC03']),
+ });
+ });
  });
 
  describe('instanceIdentifiers', () => {