Elastic Load Balancing (ELB)

Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and Lambda functions.

aws.elb.BackendConnectionErrors

The number of errors encountered by the load balancer while attempting to connect to your application.

For high error counts, look for network related issues or check that your servers are operating correctly. The ELB is having problems connecting to them.

For more information, refer to the Elastic Load Balancing documentation.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HealthyHostCount

A count of the number of healthy instances that are bound to the load balancer.

Hosts are declared healthy if they meet the threshold for the number of consecutive health checks that are successful. Hosts that have failed more health checks than the value of the unhealthy threshold are considered unhealthy. If cross-zone is enabled, the count of the number of healthy instances is calculated for all Availability Zones.

For more information, refer to the Elastic Load Balancing documentation.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_Backend_2XX

The count of the number of HTTP 2XX response codes generated by back-end instances. This metric does not include any response codes generated by the load balancer.

The 2XX class status codes represent successful actions (e.g., 200-OK, 201-Created, 202-Accepted, 203-Non-Authoritative Info).

For more information, refer to the Elastic Load Balancing documentation.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_Backend_3XX

The count of the number of HTTP 3XX response codes generated by back-end instances. This metric does not include any response codes generated by the load balancer.

The 3XX class status code indicates that the user agent requires action (e.g., 301-Moved Permanently, 302-Found, 305-Use Proxy, 307-Temporary Redirect).

For more information, refer to the Elastic Load Balancing documentation.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_Backend_4XX

The count of the number of HTTP 4XX response codes generated by back-end instances. This metric does not include any response codes generated by the load balancer. For more information, refer to the Elastic Load Balancing documentation.

The 4XX class status code represents client errors (e.g., 400-Bad Request, 401-Unauthorized, 403-Forbidden, 404-Not Found).

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_Backend_5XX

The count of the number of HTTP 5XX response codes generated by back-end instances. This metric does not include any response codes generated by the load balancer. For more information, refer to the Elastic Load Balancing documentation.

The 5XX class status code represents back-end server errors e.g., 500-Internal Server Error, 501-Not implemented, 503-Service Unavailable).

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_ELB_4XX

The count of the number of HTTP 4XX client error codes generated by the load balancer when the listener is configured to use HTTP or HTTPS protocols. For more information, refer to the Elastic Load Balancing documentation.

Client errors are generated when a request is malformed or is incomplete.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.HTTPCode_ELB_5XX

The count of the number of HTTP 5XX server error codes generated by the load balancer when the listener is configured to use HTTP or HTTPS protocols. This metric does not include any responses generated by back-end instances.For more information, refer to the Elastic Load Balancing documentation.

The metric is reported if there are no back-end instances that are healthy or registered to the load balancer, or if the request rate exceeds the capacity of the instances or the load balancers.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.Latency

A measurement of the time backend requests require to process. For more information, refer to the Elastic Load Balancing documentation.

Latency metrics from the ELB are good indicators of the overall performance of your application.

MetadataDescription
Metric TypeCounter
Value TyperelativeTime
Segment ByCloudProvider
Default Time AggregationAverage
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationAverage
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.RequestCount

The number of requests handled by the load balancer. For more information, refer to the Elastic Load Balancing documentation.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.SpilloverCount

A count of the total number of requests that were rejected due to the queue being full. For more information, refer to the Elastic Load Balancing documentation.

Positive numbers indicate some requests are not being forwarded to any server. Clients are not notified that their request was dropped.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.SurgeQueueLength

A count of the total number of requests that are pending submission to a registered instance. For more information, refer to the Elastic Load Balancing documentation.

Positive numbers indicate clients are waiting for their requests to be forwarded to a server for processing.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max

aws.elb.UnHealthyHostCount

The count of the number of unhealthy instances that are bound to the load balancer. For more information, refer to the Elastic Load Balancing documentation.

Hosts are declared healthy if they meet the threshold for the number of consecutive health checks that are successful. Hosts that have failed more health checks than the value of the unhealthy threshold are considered unhealthy.

MetadataDescription
Metric TypeCounter
Value TypeInteger
Segment ByCloudProvider
Default Time AggregationRate
Available Time Aggregation FormatsAvg, Rate, Sum, Min, Max
Default Group AggregationSum
Available Group Aggregation FormatsAvg, Sum, Min, Max