Use MonitorInstances with an Amazon SDK or CLI

    Aws::EC2::EC2Client ec2Client(clientConfiguration);
    Aws::EC2::Model::MonitorInstancesRequest request;
    request.AddInstanceIds(instanceId);
    request.SetDryRun(true);

    auto dry_run_outcome = ec2Client.MonitorInstances(request);
    if (dry_run_outcome.IsSuccess()) {
        std::cerr
                << "Failed dry run to enable monitoring on instance. A dry run should trigger an error."
                <<
                std::endl;
        return false;
    }
    else if (dry_run_outcome.GetError().GetErrorType()
             != Aws::EC2::EC2Errors::DRY_RUN_OPERATION) {
        std::cerr << "Failed dry run to enable monitoring on instance " <<
                  instanceId << ": " << dry_run_outcome.GetError().GetMessage() <<
                  std::endl;
        return false;
    }

    request.SetDryRun(false);
    auto monitorInstancesOutcome = ec2Client.MonitorInstances(request);
    if (!monitorInstancesOutcome.IsSuccess()) {
        std::cerr << "Failed to enable monitoring on instance " <<
                  instanceId << ": " <<
                  monitorInstancesOutcome.GetError().GetMessage() << std::endl;
    }
    else {
        std::cout << "Successfully enabled monitoring on instance " <<
                  instanceId << std::endl;
    }

To enable detailed monitoring for an instance

This example command enables detailed monitoring for the specified instance.

Command:

aws ec2 monitor-instances --instance-ids i-1234567890abcdef0

Output:

{
  "InstanceMonitorings": [
      {
          "InstanceId": "i-1234567890abcdef0",
          "Monitoring": {
              "State": "pending"
          }
      }
  ]
}

import { MonitorInstancesCommand } from "@aws-sdk/client-ec2";

import { client } from "../libs/client.js";

// Turn on detailed monitoring for the selected instance.
// By default, metrics are sent to Amazon CloudWatch every 5 minutes.
// For a cost you can enable detailed monitoring which sends metrics every minute.
export const main = async () => {
  const command = new MonitorInstancesCommand({
    InstanceIds: ["INSTANCE_ID"],
  });

  try {
    const { InstanceMonitorings } = await client.send(command);
    const instancesBeingMonitored = InstanceMonitorings.map(
      (im) =>
        ` • Detailed monitoring state for ${im.InstanceId} is ${im.Monitoring.State}.`,
    );
    console.log("Monitoring status:");
    console.log(instancesBeingMonitored.join("\n"));
  } catch (err) {
    console.error(err);
  }
};

Example 1: This example enables detailed monitoring for the specified instance.

Start-EC2InstanceMonitoring -InstanceId i-12345678

Output:

InstanceId    Monitoring
----------    ----------
i-12345678    Amazon.EC2.Model.Monitoring

    DATA lt_instance_ids TYPE /aws1/cl_ec2instidstringlist_w=>tt_instanceidstringlist.
    APPEND NEW /aws1/cl_ec2instidstringlist_w( iv_value = iv_instance_id ) TO lt_instance_ids.

    "Perform dry run"
    TRY.
        " DryRun is set to true. This checks for the required permissions to monitor the instance without actually making the request. "
        lo_ec2->monitorinstances(
          it_instanceids = lt_instance_ids
          iv_dryrun = abap_true
        ).
      CATCH /aws1/cx_rt_service_generic INTO DATA(lo_exception).
        " If the error code returned is `DryRunOperation`, then you have the required permissions to monitor this instance. "
        IF lo_exception->av_err_code = 'DryRunOperation'.
          MESSAGE 'Dry run to enable detailed monitoring completed.' TYPE 'I'.
          " DryRun is set to false to enable detailed monitoring. "
          lo_ec2->monitorinstances(
            it_instanceids = lt_instance_ids
            iv_dryrun = abap_false
          ).
          MESSAGE 'Detailed monitoring enabled.' TYPE 'I'.
          " If the error code returned is `UnauthorizedOperation`, then you don't have the required permissions to monitor this instance. "
        ELSEIF lo_exception->av_err_code = 'UnauthorizedOperation'.
          MESSAGE 'Dry run to enable detailed monitoring failed. User does not have the permissions to monitor the instance.' TYPE 'E'.
        ELSE.
          DATA(lv_error) = |"{ lo_exception->av_err_code }" - { lo_exception->av_err_msg }|.
          MESSAGE lv_error TYPE 'E'.
        ENDIF.
    ENDTRY.