Elastic Load Balancing (ELB)

Overview

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

Setup

Installation

If you haven’t already, first set up the AWS CloudWatch integration. No additional steps are needed for installation.

Configuration

On the AWS CloudWatch integration page, ensure that the ELB service is selected for metric collection.

Metrics

Application Load Balancer

Name Description
ActiveConnectionCount
(count)
The total number of concurrent TCP connections active from clients
to the load balancer and from the load balancer to targets.
ClientTLSNegotiationErrorCount
(count)
The number of TLS connections initiated by the client that did not
establish a session with the load balancer.
ConsumedLCUs
(count)
The number of load balancer capacity units (LCU) used by your load
balancer.
HealthyHostCount
(count)
The number of client-side errors captured.
HTTPCode_ELB_4XX_Count
(count)
The number of HTTP 4XX client error codes that originate from the
load balancer
HTTPCode_ELB_5XX_Count
(count)
The number of HTTP 5XX client error codes that originate from the
load balancer
HTTPCode_Target_2XX_Count
(count)
The number of HTTP response codes generated by the targets.
HTTPCode_Target_3XX_Count
(count)
The number of HTTP response codes generated by the targets.
HTTPCode_Target_4XX_Count
(count)
The number of HTTP response codes generated by the targets.
HTTPCode_Target_5XX_Count
(count)
The number of HTTP response codes generated by the targets.
IPv6ProcessedBytes
(bytes)
The total number of bytes processed by the load balancer over IPv6.
IPv6RequestCount
(bytes)
The number of IPv6 requests received by the load balancer.
NewConnectionCount
(count)
The total number of new TCP connections established from clients to
the load balancer and from the load balancer to targets.
ProcessedBytes
(bytes)
The total number of bytes processed by the load balancer over IPv4
and IPv6.
RejectedConnectionCount
(count)
The number of connections that were rejected because the load
balancer had reached its maximum number of connections.
RequestCount
(count)
The number of requests received by the load balancer. This includes
requests over IPv4 and IPv6.
RequestCountPerTarget
(count)
The average number of requests received by each target in a target
group.
RuleEvaluations
(count)
The number of rules processed by the load balancer given a request
rate averaged over an hour.
TargetConnectionErrorCount
(count)
The number of connections that were not successfully established
between the load balancer and target.
TargetResponseTime
(seconds)
The time elapsed, in seconds, after the request leaves the load
balancer until a response from the target is received.
TargetTLSNegotiationErrorCount
(count)
The number of TLS connections initiated by the load balancer that
did not establish a session with the target.
UnHealthyHostCount
(count)
The number of targets that are considered unhealthy.

Network Load Balancer

Name Description
ActiveFlowCount
(count)
The total number of concurrent TCP flows (or connections) from
clients to targets. This metric includes only the connections in
the ESTABLISHED state. TCP connections are not terminated at the
load balancer, so a client opening a TCP connection to a target
counts as a single flow.
ConsumedLCUs
(count)
The number of load balancer capacity units (LCU) used by your load
balancer.
HealthyHostCount
(count)
The number of targets that are considered healthy.
NewFlowCount
(count)
The total number of new TCP flows (or connections) established from
clients to targets in the time period.
ProcessedBytes
(bytes)
The total number of bytes processed by the load balancer, including
TCP/IP headers.
TCP_Client_Reset_Count
(count)
The total number of reset (RST) packets sent from a client to a
target.
TCP_ELB_Reset_Count
(count)
The total number of reset (RST) packets generated by the load
balancer.
TCP_Target_Reset_Count
(count)
The total number of reset (RST) packets sent from a target to a
client.
UnHealthyHostCount
(count)
The number of targets that are considered unhealthy.

Classic Load Balancer

Name Description
BackendConnectionErrors
(count)
The number of connections that were not successfully established
between the load balancer and the registered instances. Because the
load balancer retries the connection when there are errors, this
count can exceed the request rate.
HealthyHostCount
(count)
The number of healthy instances registered with your load balancer.
HTTPCode_Backend_2XX
(count)
The number of HTTP response codes generated by registered instances
HTTPCode_Backend_3XX
(count)
The number of HTTP response codes generated by registered instances
HTTPCode_Backend_4XX
(count)
The number of HTTP response codes generated by registered instances
HTTPCode_Backend_5XX
(count)
The number of HTTP response codes generated by registered instances
HTTPCode_ELB_4XX
(count)
The number of HTTP 4XX client error codes generated by the load
balancer.
HTTPCode_ELB_5XX
(count)
The number of HTTP 5XX client error codes generated by the load
balancer.
Latency
(seconds)
[HTTP listener] The total time elapsed, in seconds, from the time
the load balancer sent the request to a registered instance until
the instance started to send the response headers.

[TCP listener] The total time elapsed, in seconds, for the load
balancer to successfully establish a connection to a registered
instance.
RequestCount
(count)
The number of requests completed or connections made during the
specified interval (1 or 5 minutes).

[HTTP listener] The number of requests received and routed,
including HTTP error responses from the registered instances.

[TCP listener] The number of connections made to the registered
instances.
SpilloverCount
(count)
The total number of requests that were rejected because the surge
queue is full.

[HTTP listener] The load balancer returns an HTTP 503 error code.

[TCP listener] The load balancer closes the connection.
SurgeQueueLength
(count)
The total number of requests that are pending routing.
UnHealthyHostCount
(count)
The number of unhealthy instances registered with your load
balancer.

Available Tags

Name Description
awsaccount AWS account associated with the metrics
az Availability zone of the load balancer
name Name of the load balancer
region Name of the region

Note

We retrieve up to 25 custom tags created on your ELB instances. To use the custom tags, copy the curated dashboard and use the dynamic tags feature.