AWS: Getting 400 Bad Request error from AmazonCloudWatch.GetMetricStatistics()

Question

I'm having a little trouble using AmazonCloudWatch to fetch CPU Utilization. When I try to use AmazonCloudWatch.GetMetricStatistics(), I get this for an exception message:

Exception of type 'Amazon.CloudWatch.AmazonCloudWatchException' was thrown.

And this for an inner exception:

{"The remote server returned an error: (400) Bad Request."}

Here is the code I'm using to make the call:

public static String getCPUStats(String Endpoint, String InstanceID) 
    {
        try
        {
            AmazonCloudWatchConfig cloudConfig = new AmazonCloudWatchConfig();
            cloudConfig.ServiceURL = Endpoint;

            string AWSAccessKey = Sql.ToString(appConfig["AWSAccessKey"]);
            string AWSSecretKey = Sql.ToString(appConfig["AWSSecretKey"]);

            AmazonCloudWatch client = AWSClientFactory.CreateAmazonCloudWatchClient(AWSAccessKey, AWSSecretKey, cloudConfig);

            GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
            request.Dimensions.Add(new Dimension { Name = "InstanceId", Value = InstanceID });
            request.StartTime = DateTime.UtcNow.AddMinutes(-5);
            request.EndTime = DateTime.UtcNow;
            request.Namespace = "AWS/EC2";
            request.Statistics.Add("Maximum");
            request.Statistics.Add("Average");
            request.MetricName = "CPUUtilization";
            request.Period = 60;

            GetMetricStatisticsResponse r = client.GetMetricStatistics(request);

            if (r.GetMetricStatisticsResult.Datapoints.Count > 0)
            {
                Datapoint dataPoint = r.GetMetricStatisticsResult.Datapoints[0];
                return "CPU maximum load: " + dataPoint.Maximum;

            }

            return "No data available.";
        }
        catch (Exception ex)
        {
            return ex.Message;
        }
    }

Some side notes - the access key, secret access key, and endpoint work fine for creating an AmazonEC2Client, so I'm pretty sure the problem isn't there.

I've done quite a bit of googling and poring over the documentation, but haven't been successful in solving this. Any ideas? Thanks so much!

Answer 1

Unfortunately, we weren't able to figure this one out - we ended up deciding to use Microsoft Azure instead of Amazon Web Services :(

Answer 2

I think you can only request one Statistics at a time. So try removing either request.Statistics.Add("Maximum"); or request.Statistics.Add("Average");