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Using Alarm Actions in CloudWatch

Using CloudWatch alarm actions, you can create alarms that perform actions such as automatically stopping, terminating, rebooting, or recovering Amazon EC2 instances.

Alarm actions can be added to an alarm by using the PutMetricAlarmRequest’s SetAlarmActions function when creating an alarm.

Prerequisites

Before you begin, we recommend you read Getting started using the Amazon SDK for C++.

Download the example code and build the solution as described in Get started on code examples.

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

Enable Alarm Actions

To enable alarm actions for a CloudWatch alarm, call the CloudWatchClient’s EnableAlarmActions with a EnableAlarmActionsRequest containing one or more names of alarms whose actions you want to enable.

Includes

#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/EnableAlarmActionsRequest.h>
#include <aws/monitoring/model/PutMetricAlarmRequest.h>
#include <iostream>

Code

    Aws::CloudWatch::CloudWatchClient cw;
    Aws::CloudWatch::Model::PutMetricAlarmRequest request;
    request.SetAlarmName(alarm_name);
    request.SetComparisonOperator(
        Aws::CloudWatch::Model::ComparisonOperator::GreaterThanThreshold);
    request.SetEvaluationPeriods(1);
    request.SetMetricName("CPUUtilization");
    request.SetNamespace("AWS/EC2");
    request.SetPeriod(60);
    request.SetStatistic(Aws::CloudWatch::Model::Statistic::Average);
    request.SetThreshold(70.0);
    request.SetActionsEnabled(false);
    request.SetAlarmDescription("Alarm when server CPU exceeds 70%");
    request.SetUnit(Aws::CloudWatch::Model::StandardUnit::Seconds);
    request.AddAlarmActions(actionArn);

    Aws::CloudWatch::Model::Dimension dimension;
    dimension.SetName("InstanceId");
    dimension.SetValue(instanceId);
    request.AddDimensions(dimension);

    auto outcome = cw.PutMetricAlarm(request);
    if (!outcome.IsSuccess())
    {
        std::cout << "Failed to create CloudWatch alarm:" <<
            outcome.GetError().GetMessage() << std::endl;
        return;
    }

    Aws::CloudWatch::Model::EnableAlarmActionsRequest enable_request;
    enable_request.AddAlarmNames(alarm_name);

    auto enable_outcome = cw.EnableAlarmActions(enable_request);
    if (!enable_outcome.IsSuccess())
    {
        std::cout << "Failed to enable alarm actions:" <<
            enable_outcome.GetError().GetMessage() << std::endl;
        return;
    }

    std::cout << "Successfully created alarm " << alarm_name <<
        " and enabled actions on it." << std::endl;

See the complete example.

Disable Alarm Actions

To disable alarm actions for a CloudWatch alarm, call the CloudWatchClient’s DisableAlarmActions with a DisableAlarmActionsRequest containing one or more names of alarms whose actions you want to disable.

Includes

#include <aws/core/Aws.h>
#include <aws/monitoring/CloudWatchClient.h>
#include <aws/monitoring/model/DisableAlarmActionsRequest.h>
#include <iostream>

Code

        Aws::CloudWatch::CloudWatchClient cw;

        Aws::CloudWatch::Model::DisableAlarmActionsRequest disableAlarmActionsRequest;
        disableAlarmActionsRequest.AddAlarmNames(alarm_name);

        auto disableAlarmActionsOutcome = cw.DisableAlarmActions(disableAlarmActionsRequest);
        if (!disableAlarmActionsOutcome.IsSuccess())
        {
            std::cout << "Failed to disable actions for alarm " << alarm_name <<
                ": " << disableAlarmActionsOutcome.GetError().GetMessage() <<
                std::endl;
        }
        else
        {
            std::cout << "Successfully disabled actions for alarm " <<
                alarm_name << std::endl;
        }

See the complete example.

More Information