Get rds replica lag metric value

get_aws_rds_replica_lag.py

def get_cloudwatch_replica_lag(rds_id, start_time, end_time)
    local_timezone = pytz.timezone('Asia/Shanghai')
    cloudwatch = boto3.client('cloudwatch')
    start_time_with_tz = local_timezone.localize(start_time)
    end_time_with_tz = local_timezone.localize(end_time)
    values = cloudwatch.get_metric_statistics(Namespace='AWS/RDS',
                                              MetricName='ReplicaLag',
                                              Dimensions=[dict(Name='DBInstanceIdentifier', Value=rds_id)],
                                              StartTime=start_time_with_tz,
                                              EndTime=end_time_with_tz,
                                              Period=60,
                                              Statistics=['Maximum'],
                                              Unit='Seconds').get('Datapoints')
    return values