CloudWatch metrics for your Gateway Load Balancer - Elastic Load Balancing

CloudWatch metrics for your Gateway Load Balancer

Elastic Load Balancing publishes data points to Amazon CloudWatch for your Gateway Load Balancers and your targets. CloudWatch enables you to retrieve statistics about those data points as an ordered set of time-series data, known as metrics. Think of a metric as a variable to monitor, and the data points as the values of that variable over time. For example, you can monitor the total number of healthy targets for a Gateway Load Balancer over a specified time period. Each data point has an associated time stamp and an optional unit of measurement.

You can use metrics to verify that your system is performing as expected. For example, you can create a CloudWatch alarm to monitor a specified metric and initiate an action (such as sending a notification to an email address) if the metric goes outside of what you consider an acceptable range.

Elastic Load Balancing reports metrics to CloudWatch only when requests are flowing through the Gateway Load Balancer. If there are requests flowing, Elastic Load Balancing measures and sends its metrics in 60-second intervals. If there are no requests flowing or no data for a metric, the metric is not reported.

For more information, see the Amazon CloudWatch User Guide.

Gateway Load Balancer metrics

The AWS/GatewayELB namespace includes the following metrics.

Metric Description
ActiveFlowCount

The total number of concurrent flows (or connections) from clients to targets.

Reporting criteria: There is a nonzero value

Statistics: The most useful statistics are Average, Maximum, and Minimum.

Dimensions

  • LoadBalancer

  • AvailabilityZone, LoadBalancer

ConsumedLCUs

The number of load balancer capacity units (LCU) used by your load balancer. You pay for the number of LCUs that you use per hour. For more information, see Elastic Load Balancing Pricing.

Reporting criteria: Always reported

Statistics: All

Dimensions

  • LoadBalancer

HealthyHostCount

The number of targets that are considered healthy.

Reporting criteria: Reported if health checks are enabled

Statistics: The most useful statistics are Maximum and Minimum.

Dimensions

  • LoadBalancer, TargetGroup

  • AvailabilityZone, LoadBalancer, TargetGroup

NewFlowCount

The total number of new flows (or connections) established from clients to targets in the time period.

Reporting criteria: There is a nonzero value

Statistics: The most useful statistic is Sum.

Dimensions

  • LoadBalancer

  • AvailabilityZone, LoadBalancer

ProcessedBytes

The total number of bytes processed by the load balancer. This count includes traffic to and from targets, but not health check traffic.

Reporting criteria: There is a nonzero value

Statistics: The most useful statistic is Sum.

Dimensions

  • LoadBalancer

  • AvailabilityZone, LoadBalancer

UnHealthyHostCount

The number of targets that are considered unhealthy.

Reporting criteria: Reported if health checks are enabled

Statistics: The most useful statistics are Maximum and Minimum.

Dimensions

  • LoadBalancer, TargetGroup

  • AvailabilityZone, LoadBalancer, TargetGroup

Metric dimensions for Gateway Load Balancers

To filter the metrics for your Gateway Load Balancer, use the following dimensions.

Dimension Description
AvailabilityZone

Filters the metric data by Availability Zone.

LoadBalancer

Filters the metric data by Gateway Load Balancer. Specify the Gateway Load Balancer as follows: gateway/load-balancer-name/1234567890123456 (the final portion of the ARN).

TargetGroup

Filters the metric data by target group. Specify the target group as follows: targetgroup/target-group-name/1234567890123456 (the final portion of the target group ARN).

View CloudWatch metrics for your Gateway Load Balancer

You can view the CloudWatch metrics for your Gateway Load Balancers by using the Amazon EC2 console. These metrics are displayed as monitoring graphs. The monitoring graphs show data points if the Gateway Load Balancer is active and receiving requests.

Alternatively, you can view metrics for your Gateway Load Balancer using the CloudWatch console.

To view metrics using the Amazon EC2 console

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. To view metrics filtered by target group, do the following:

    1. In the navigation pane, choose Target Groups.

    2. Select your target group and choose Monitoring.

    3. (Optional) To filter the results by time, select a time range from Showing data for.

    4. To get a larger view of a single metric, select its graph.

  3. To view metrics filtered by Gateway Load Balancer, do the following:

    1. In the navigation pane, choose Load Balancers.

    2. Select your Gateway Load Balancer and choose Monitoring.

    3. (Optional) To filter the results by time, select a time range from Showing data for.

    4. To get a larger view of a single metric, select its graph.

To view metrics using the CloudWatch console

  1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

  2. In the navigation pane, choose Metrics.

  3. Select the GatewayELB namespace.

  4. (Optional) To view a metric across all dimensions, enter its name in the search field.

To view metrics using the AWS CLI

Use the following list-metrics command to list the available metrics:

aws cloudwatch list-metrics --namespace AWS/GatewayELB

To get the statistics for a metric using the AWS CLI

Use the following get-metric-statistics command get statistics for the specified metric and dimension. Note that CloudWatch treats each unique combination of dimensions as a separate metric. You can't retrieve statistics using combinations of dimensions that were not specially published. You must specify the same dimensions that were used when the metrics were created.

aws cloudwatch get-metric-statistics --namespace AWS/GatewayELB \ --metric-name UnHealthyHostCount --statistics Average --period 3600 \ --dimensions Name=LoadBalancer,Value=net/my-load-balancer/50dc6c495c0c9188 \ Name=TargetGroup,Value=targetgroup/my-targets/73e2d6bc24d8a067 \ --start-time 2017-04-18T00:00:00Z --end-time 2017-04-21T00:00:00Z

The following is example output.

{ "Datapoints": [ { "Timestamp": "2020-12-18T22:00:00Z", "Average": 0.0, "Unit": "Count" }, { "Timestamp": "2020-12-18T04:00:00Z", "Average": 0.0, "Unit": "Count" }, ... ], "Label": "UnHealthyHostCount" }