Hey all, I am trying to set up an RDS alarm for the following configuration as such:

const instance = new aws.rds.Instance(instanceName, {
    allocatedStorage,
    // This is the availability zone of the subnet.
    // For db.t3.micro instances, you can only use us-west-2a or us-west-2b.
    availabilityZone: 'us-west-2a',
    dbSubnetGroupName: subnetGroup.name,
    engine: 'postgres',
    // 15.2 is the newest version supported on RDS as of now.
    // <https://docs.aws.amazon.com/AmazonRDS/latest/PostgreSQLReleaseNotes/postgresql-versions.html#postgresql-versions-version14>
    engineVersion: '15.2',
    allowMajorVersionUpgrade: true,
    instanceClass: instanceType,
    // <https://aws.amazon.com/about-aws/whats-new/2018/09/amazon-rds-now-provides-database-deletion-protection/>
    deletionProtection,
    applyImmediately: true,
    skipFinalSnapshot,
    backupRetentionPeriod,
    backupWindow: '00:00-01:00',
    maintenanceWindow: 'sun:03:00-sun:04:00',
    finalSnapshotIdentifier: `${instanceName}-final-snapshot-${Date.now()}`,
    password: dbPassword,
    username: dbUsername,
    vpcSecurityGroupIds: [securityGroup.id],
    tags: {
      Name: instanceName,
      Stack: stackName,
    },
  });

  const sharedCoreStackRef = new pulumi.StackReference("yoz/shared-core/shared-core");
  const alarmTopicArn = sharedCoreStackRef.requireOutput('alarmTopicArn');

  // TODO: Consider adding alarms for IOPS & throughput
  
  new aws.cloudwatch.MetricAlarm(`${stackName}-cpu-alarm`, {
      comparisonOperator: "GreaterThanOrEqualToThreshold",
      evaluationPeriods: 2,
      metricName: "CPUUtilization",
      namespace: "AWS/RDS",
      period: 120,
      statistic: "Average",
      threshold: 75,
      alarmDescription: "Monitors CPU utilization",
      dimensions: {
        DBInstanceIdentifier: instance.dbName,
      },
      alarmActions: [alarmTopicArn]
  });

  new aws.cloudwatch.MetricAlarm(`${stackName}-connections-alarm`, {
      comparisonOperator: "GreaterThanOrEqualToThreshold",
      evaluationPeriods: 2,
      metricName: "DatabaseConnections",
      namespace: "AWS/RDS",
      period: 120,
      statistic: "Average",
      threshold: Math.round(maxDatabaseConnections * 0.75),
      alarmDescription: "Monitors database connections",
      dimensions: {
        DBInstanceIdentifier: instance.dbName,
      },
      alarmActions: [alarmTopicArn]
  });

  new aws.cloudwatch.MetricAlarm(`${stackName}-disk-alarm`, {
      comparisonOperator: "LessThanOrEqualToThreshold",
      evaluationPeriods: 2,
      metricName: "FreeStorageSpace",
      namespace: "AWS/RDS",
      period: 120,
      statistic: "Average",
      threshold: Math.round((allocatedStorage ** 9) * 0.25),
      alarmDescription: "Monitors free storage space left",
      dimensions: {
        DBInstanceIdentifier: instance.dbName,
      },
      alarmActions: [alarmTopicArn]
  });

  new aws.cloudwatch.MetricAlarm(`${stackName}-memory-alarm`, {
      comparisonOperator: "LessThanOrEqualToThreshold",
      evaluationPeriods: 2,
      metricName: "FreeableMemory",
      namespace: "AWS/RDS",
      period: 120,
      statistic: "Average",
      threshold: Math.round((allocatedMemory ** 9) * 0.15),
      alarmDescription: "Monitors free memory left",
      dimensions: {
        DBInstanceIdentifier: instance.dbName,
      },
      alarmActions: [alarmTopicArn]
  });