# Getting Metrics from CloudWatch
<a name="examples-cloudwatch-get-metrics"></a>

## Prerequisites
<a name="codeExamplePrereq"></a>

Before you begin, we recommend you read [Getting started using the AWS SDK for C\$1\$1](getting-started.md). 

Download the example code and build the solution as described in [Getting started on code examples](getting-started-code-examples.md). 

To run the examples, the user profile your code uses to make the requests must have proper permissions in AWS (for the service and the action). For more information, see [Providing AWS credentials](credentials.md).

## Listing Metrics
<a name="listing-metrics"></a>

To list CloudWatch metrics, create a [ListMetricsRequest](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_list_metrics_request.html) and call the CloudWatchClient’s `ListMetrics` function. You can use the `ListMetricsRequest` to filter the returned metrics by namespace, metric name, or dimensions.

**Note**  
A list of metrics and dimensions that are posted by AWS services can be found within the [Amazon CloudWatch Metrics and Dimensions Reference](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CW_Support_For_AWS.html) in the Amazon CloudWatch User Guide.

 **Includes** 

```
#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/ListMetricsRequest.h>
#include <aws/monitoring/model/ListMetricsResult.h>
#include <iomanip>
#include <iostream>
```

 **Code** 

```
        Aws::CloudWatch::CloudWatchClient cw;
        Aws::CloudWatch::Model::ListMetricsRequest request;

        if (argc > 1)
        {
            request.SetMetricName(argv[1]);
        }

        if (argc > 2)
        {
            request.SetNamespace(argv[2]);
        }

        bool done = false;
        bool header = false;
        while (!done)
        {
            auto outcome = cw.ListMetrics(request);
            if (!outcome.IsSuccess())
            {
                std::cout << "Failed to list CloudWatch metrics:" <<
                    outcome.GetError().GetMessage() << std::endl;
                break;
            }

            if (!header)
            {
                std::cout << std::left << std::setw(48) << "MetricName" <<
                    std::setw(32) << "Namespace" << "DimensionNameValuePairs" <<
                    std::endl;
                header = true;
            }

            const auto &metrics = outcome.GetResult().GetMetrics();
            for (const auto &metric : metrics)
            {
                std::cout << std::left << std::setw(48) <<
                    metric.GetMetricName() << std::setw(32) <<
                    metric.GetNamespace();
                const auto &dimensions = metric.GetDimensions();
                for (auto iter = dimensions.cbegin();
                    iter != dimensions.cend(); ++iter)
                {
                    const auto &dimkv = *iter;
                    std::cout << dimkv.GetName() << " = " << dimkv.GetValue();
                    if (iter + 1 != dimensions.cend())
                    {
                        std::cout << ", ";
                    }
                }
                std::cout << std::endl;
            }

            const auto &next_token = outcome.GetResult().GetNextToken();
            request.SetNextToken(next_token);
            done = next_token.empty();
        }
```

The metrics are returned in a [ListMetricsResult](https://docs.aws.amazon.com/sdk-for-cpp/latest/api/aws-cpp-sdk-monitoring/html/class_aws_1_1_cloud_watch_1_1_model_1_1_list_metrics_result.html) by calling its `GetMetrics` function. The results may be *paged*. To retrieve the next batch of results, call `SetNextToken` on the original request object with the return value of the `ListMetricsResult` object’s `GetNextToken` function, and pass the modified request object back to another call to `ListMetrics`.

See the [complete example](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cloudwatch/list_metrics.cpp).

## More Information
<a name="more-information"></a>
+  [ListMetrics](https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/ListMetrics.html) in the Amazon CloudWatch API Reference.