All Products
Search
Document Center

Server Load Balancer:ALB monitoring metrics

Last Updated:Oct 27, 2025

If requests to your Application Load Balancer (ALB) instance time out or cause network issues such as throttling, you can check the monitoring metrics of the ALB instance to troubleshoot errors and evaluate its load and performance. This topic describes the monitoring metrics for ALB.

Background information

When you call the CloudMonitor API, you must provide the ALB Namespace, Period, MetricName, and Dimensions.

  • The Namespace is acs_alb.

  • The default value of Period is 60 seconds. The value can be any multiple of 60.

  • Dimensions is a JSON string. For example, [{"loadBalancerId":"alb-t93aj3yndojot5****"}]. The loadBalancerId in Dimensions is the ID of the ALB instance.

ALB monitoring metrics

Metrics that you can view in the console or using an API or SDK

  • In the MetricName column of the following tables, metrics that do not have the DualStack_ prefix do not distinguish between IPv4 and IPv6 metrics. These metrics indicate the total values for an ALB instance.

    • For an IPv4 instance, a metric without the DualStack_ prefix indicates the IPv4 metric for the ALB instance.

    • For a dual-stack instance, a metric without the DualStack_ prefix indicates the sum of the IPv4 and IPv6 metrics for the ALB instance.

  • In the MetricName column of the following tables, metrics that have the DualStack_ prefix display separate metrics for IPv4 and IPv6.

    • For an IPv4 instance, the IPv6 value of a metric with the DualStack_ prefix is 0.0. The IPv4 value is the actual metric for the ALB instance.

    • For a dual-stack instance, a metric with the DualStack_ prefix displays separate values for the IPv4 and IPv6 metrics of the ALB instance.

In the following tables, a hyphen (-) indicates that the metric does not have a DualStack_ version and does not provide separate views for IPv4 and IPv6 metrics.

Instance metrics

Instance connection metrics

Metric

Description

MetricName

Dimensions

Statistics

Active connections of the ALB instance

The number of TCP connections in the ESTABLISHED state on the ALB instance. Unit: Count

LoadBalancerActiveConnection

DualStack_LoadBalancerActiveConnection

userId, loadBalancerId

Value

Inactive connections of the ALB instance

The number of TCP connections that are not in the ESTABLISHED state and all UDP connections on the ALB instance. Unit: Count

LoadBalancerInactiveConnection

DualStack_LoadBalancerInactiveConnection

userId, loadBalancerId

Value

Maximum concurrent connections of the ALB instance

The total number of TCP and UDP connections that are processed by the ALB instance. Unit: Count

LoadBalancerMaxConnection

DualStack_LoadBalancerMaxConnection

userId, loadBalancerId

Value

Backend TLS handshake failures per second of the ALB instance

The number of times per second that the ALB instance fails to establish TLS connections with backend servers. Unit: Count/s

LoadBalancerUpstreamTLSNegotiationError

DualStack_LoadBalancerUpstreamTLSNegotiationError

userId, loadBalancerId

Value

New connections per second of the ALB instance

The number of new connections that are established between the ALB instance and backend servers per second. Unit: Count/s

LoadBalancerNewConnection

DualStack_LoadBalancerNewConnection

userId, loadBalancerId

Value

Dropped connections per second of the ALB instance

The number of connection requests that are dropped by the ALB instance per second. Unit: Count/s

LoadBalancerRejectedConnection

DualStack_LoadBalancerRejectedConnection

userId, loadBalancerId

Value

Backend connection failures per second of the ALB instance

The number of times per second that the ALB instance fails to connect to backend servers. Unit: Count/s

LoadBalancerUpstreamConnectionError

DualStack_LoadBalancerUpstreamConnectionError

userId, loadBalancerId

Value

TLS handshake failures per second of the ALB instance

The number of failed TLS connections per second between an ALB instance and clients. Unit: Count/s

LoadBalancerClientTLSNegotiationError

DualStack_LoadBalancerClientTLSNegotiationError

userId, loadBalancerId

Value

Instance request monitoring metrics

Metric

Description

MetricName

Dimensions

Statistics

Custom responses per second from the ALB instance

The number of custom responses that are returned by the ALB instance to clients per second. Unit: Count/s

LoadBalancerHTTPFixedResponse

DualStack_LoadBalancerHTTPFixedResponse

userId, loadBalancerId

Value

Redirections per second of the ALB instance

The number of successful redirection operations that are performed by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPRedirect

DualStack_LoadBalancerHTTPRedirect

userId, loadBalancerId

Value

Requests per second of the ALB instance

The total number of requests that are processed by the ALB instance per second. Unit: Count/s

LoadBalancerQPS

DualStack_LoadBalancerQPS

userId, loadBalancerId

Value

Non-sticky requests per second of the ALB instance

The number of new connection requests that are established by the ALB instance per second without using sticky sessions. Unit: Count/s

LoadBalancerNonStickyRequest

DualStack_LoadBalancerNonStickyRequest

userId, loadBalancerId

Value

Backend response time of the ALB instance

The period of time from when the ALB instance establishes a connection with a backend server to when the connection is closed after all data is received. Unit: ms

LoadBalancerUpstreamResponseTime

DualStack_LoadBalancerUpstreamResponseTime

userId, loadBalancerId

Value

Request latency of the ALB instance

The period of time from when the ALB instance receives the first request message to when a response is returned. Unit: ms

LoadBalancerRequestTime

DualStack_LoadBalancerRequestTime

userId, loadBalancerId

Value

Instance bandwidth metrics

Metric

Description

MetricName

Dimensions

Statistics

Outbound bandwidth of the ALB instance

The bandwidth that is consumed when the ALB instance accesses external resources. Unit: bit/s

LoadBalancerOutBits

DualStack_LoadBalancerOutBits

userId, loadBalancerId

Value

Inbound bandwidth of the ALB instance

The bandwidth that is consumed when external resources access the ALB instance. Unit: bit/s

LoadBalancerInBits

DualStack_LoadBalancerInBits

userId, loadBalancerId

Value

Instance status code metrics

Metric

Description

MetricName

Dimensions

Statistics

2XX status codes per second from the ALB instance

The number of 2XX status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode2XX

DualStack_LoadBalancerHTTPCode2XX

userId, loadBalancerId

Value

3XX status codes per second from the ALB instance

The number of 3XX status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode3XX

DualStack_LoadBalancerHTTPCode3XX

userId, loadBalancerId

Value

4XX status codes per second from the ALB instance

The number of 4XX status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode4XX

DualStack_LoadBalancerHTTPCode4XX

userId, loadBalancerId

Value

500 status codes per second from the ALB instance

The number of 500 status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode500

DualStack_LoadBalancerHTTPCode500

userId, loadBalancerId

Value

502 status codes per second from the ALB instance

The number of 502 status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode502

DualStack_LoadBalancerHTTPCode502

userId, loadBalancerId

Value

503 status codes per second from the ALB instance

The number of 503 status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode503

DualStack_LoadBalancerHTTPCode503

userId, loadBalancerId

Value

504 status codes per second from the ALB instance

The number of 504 status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode504

DualStack_LoadBalancerHTTPCode504

userId, loadBalancerId

Value

5XX status codes per second from the ALB instance

The number of 5XX status codes that are returned by the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCode5XX

DualStack_LoadBalancerHTTPCode5XX

userId, loadBalancerId

Value

Instance backend status code metrics

Metric

Description

MetricName

Dimensions

Statistics

Backend 2XX status codes per second of the ALB instance

The number of 2XX status codes that are returned by backend servers to the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCodeUpstream2XX

userId, loadBalancerId

Value

Backend 3XX status codes per second of the ALB instance

The number of 3XX status codes that are returned by backend servers to the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCodeUpstream3XX

userId, loadBalancerId

Value

Backend 4XX status codes per second of the ALB instance

The number of 4XX status codes that are returned by backend servers to the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCodeUpstream4XX

userId, loadBalancerId

Value

Backend 5XX status codes per second of the ALB instance

The number of 5XX status codes that are returned by backend servers to the ALB instance per second. Unit: Count/s

LoadBalancerHTTPCodeUpstream5XX

userId, loadBalancerId

Value

Instance health check metrics

Metric

Description

MetricName

Dimensions

Statistics

Healthy servers of the ALB instance

The number of servers that are in the Normal state based on the health check results of the ALB instance. Unit: Count

LoadBalancerHealthyHostCount

userId, loadBalancerId

Value

Unhealthy servers of the ALB instance

The number of servers that are in the abnormal state based on the health check results of the ALB instance. Unit: Count

LoadBalancerUnHealthyHostCount

userId, loadBalancerId

Value

Instance LCU resource usage metrics

Metric

Description

MetricName

Dimensions

Statistics

LCU usage

The number of LCUs that are used by the ALB instance.

If a resource reservation is in effect and the usage is lower than the reserved LCUs, the value of ConsumedLCUs is 0. If the usage exceeds the reserved LCUs, the value of ConsumedLCUs is greater than 0. Unit: Count

ConsumedLCUs

userId, loadBalancerId

Value

Peak LCUs

The maximum number of LCUs that are used by the ALB instance at a specific point in time. This metric is available only when you use resource reservations. Unit: Count

PeakLCUs

userId, loadBalancerId

Value

Reserved LCUs

The number of LCUs that are reserved for the ALB instance. Unit: Count

ReservedLCUs

userId, loadBalancerId

Value

The instance LCU resource usage metrics are displayed only after you request resource reservations.

Listener metrics

Listener connection metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Listener Active Connection Count

The number of TCP connections in the ESTABLISHED state on the listener port. Unit: Count

ListenerActiveConnection

DualStack_ListenerActiveConnection

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Inactive connections of the listener

The number of TCP connections that are not in the ESTABLISHED state and all UDP connections on the listener port. Unit: Count

ListenerInactiveConnection

DualStack_ListenerInactiveConnection

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Maximum concurrent connections of the listener

The total number of TCP and UDP connections that are processed by the listener port. Unit: Count

ListenerMaxConnection

DualStack_ListenerMaxConnection

userId, loadBalancerId, listenerProtocol, listenerPort

Value

TLS handshake failures per second of the listener

The number of times per second that the listener port fails to establish TLS connections with clients. Unit: Count/s

ListenerClientTLSNegotiationError

DualStack_ListenerClientTLSNegotiationError

userId, loadBalancerId, listenerProtocol, listenerPort

Value

New connections per second of the listener

The number of new connections that are established between the listener port and backend servers per second. Unit: Count/s

ListenerNewConnection

DualStack_ListenerNewConnection

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Dropped connections per second of the listener

The number of connection requests that are dropped by the listener port per second. Unit: Count/s

ListenerRejectedConnection

DualStack_ListenerRejectedConnection

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend connection failures per second of the listener

The number of times per second that the listener port fails to connect to backend servers. Unit: Count/s

ListenerUpstreamConnectionError

DualStack_ListenerUpstreamConnectionError

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend TLS handshake failures per second of the listener

The number of times per second that the listener port fails to establish TLS connections with backend servers. Unit: Count/s

ListenerUpstreamTLSNegotiationError

DualStack_ListenerUpstreamTLSNegotiationError

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener request metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Custom responses per second from the listener

The number of custom responses that are returned by the listener port to clients per second. Unit: Count/s

ListenerHTTPFixedResponse

DualStack_ListenerHTTPFixedResponse

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Redirections per second of the listener

The number of successful redirection operations that are performed by the listener port per second. Unit: Count/s

ListenerHTTPRedirect

DualStack_ListenerHTTPRedirect

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Requests per second of the listener

The total number of requests that are processed by the listener port per second. Unit: Count/s

ListenerQPS

DualStack_ListenerQPS

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Non-sticky requests per second of the listener

The number of new connection requests that are established by the listener port per second without using sticky sessions. Unit: Count/s

ListenerNonStickyRequest

DualStack_ListenerNonStickyRequest

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend response time of the listener

The period of time from when the listener port establishes a connection with a backend server to when the connection is closed after all data is received. Unit: ms

ListenerUpstreamResponseTime

DualStack_ListenerUpstreamResponseTime

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Request latency of the listener

The period of time from when the listener port receives the first request message to when a response is returned. Unit: ms

ListenerRequestTime

DualStack_ListenerRequestTime

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener bandwidth metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Outbound bandwidth of the listener

The volume of outbound HTTP data that is sent by the listener per second. Unit: bit/s

ListenerOutBits

DualStack_ListenerOutBits

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Inbound bandwidth of the listener

The volume of inbound HTTP data that is received by the listener per second. Unit: bit/s

ListenerInBits

DualStack_ListenerInBits

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener status code metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

2XX status codes per second from the listener

The number of 2XX status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode2XX

DualStack_ListenerHTTPCode2XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

3XX status codes per second from the listener

The number of 3XX status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode3XX

DualStack_ListenerHTTPCode3XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

4XX status codes per second from the listener

The number of 4XX status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode4XX

DualStack_ListenerHTTPCode4XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

5XX status codes per second from the listener

The number of 5XX status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode5XX

DualStack_ListenerHTTPCode5XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Monitors 500 items per second

The number of 500 status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode500

DualStack_ListenerHTTPCode500

userId, loadBalancerId, listenerProtocol, listenerPort

Value

502 status codes per second from the listener

The number of 502 status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode502

DualStack_ListenerHTTPCode502

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener events per second: 503

The number of 503 status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode503

DualStack_ListenerHTTPCode503

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener: 504 items per second

The number of 504 status codes that are returned by the listener port per second. Unit: Count/s

ListenerHTTPCode504

DualStack_ListenerHTTPCode504

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener backend status code metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Backend 2XX status codes per second of the listener

The number of 2XX status codes that are returned by backend servers for the listener port per second. Unit: Count/s

ListenerHTTPCodeUpstream2XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend 3XX status codes per second of the listener

The number of 3XX status codes that are returned by backend servers for the listener port per second. Unit: Count/s

ListenerHTTPCodeUpstream3XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend 4XX status codes per second of the listener

The number of 4XX status codes that are returned by backend servers for the listener port per second. Unit: Count/s

ListenerHTTPCodeUpstream4XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Backend 5XX status codes per second of the listener

The number of 5XX status codes that are returned by backend servers for the listener port per second. Unit: Count/s

ListenerHTTPCodeUpstream5XX

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Listener health check metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Healthy servers of the listener

The number of servers that are in the Normal state based on the health check results of the listener port. Unit: Count

ListenerHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Unhealthy servers of the listener

The number of servers that are in the abnormal state based on the health check results of the listener port. Unit: Count

ListenerUnHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort

Value

Forwarding rule connection metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Backend connection failures per second for the forwarding rule

The number of times per second that the forwarding rule fails to connect to backend servers. Unit: Count/s

RuleUpstreamConnectionError

DualStack_RuleUpstreamConnectionError

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Backend TLS handshake failures per second for the forwarding rule

The number of times per second that backend servers fail to establish TLS connections for the forwarding rule. Unit: Count/s

RuleUpstreamTLSNegotiationError

DualStack_RuleUpstreamTLSNegotiationError

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Forwarding rule request metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Non-sticky requests per second for the forwarding rule

The number of new connection requests that are established by the forwarding rule per second without using sticky sessions. Unit: Count/s

RuleNonStickyRequest

DualStack_RuleNonStickyRequest

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Requests per second for the forwarding rule

The total number of requests that are processed by the forwarding rule per second. Unit: Count/s

RuleQPS

DualStack_RuleQPS

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Backend response time for the forwarding rule

The period of time from when the forwarding rule establishes a connection with a backend server to when the connection is closed after all data is received. Unit: ms

RuleUpstreamResponseTime

DualStack_RuleUpstreamResponseTime

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Request latency for the forwarding rule

The period of time from when the forwarding rule receives the first request message to when a response is returned. Unit: ms

RuleRequestTime

DualStack_RuleRequestTime

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Forwarding rule backend status code metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Backend 2XX status codes per second for the forwarding rule

The number of 2XX status codes that are returned by backend servers for the forwarding rule per second. Unit: Count/s

RuleHTTPCodeUpstream2XX

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Backend 3XX status codes per second for the forwarding rule

The number of 3XX status codes that are returned by backend servers for the forwarding rule per second. Unit: Count/s

RuleHTTPCodeUpstream3XX

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Backend 4XX status codes per second for the forwarding rule

The number of 4XX status codes that are returned by backend servers for the forwarding rule per second. Unit: Count/s

RuleHTTPCodeUpstream4XX

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Backend 5XX status codes per second for the forwarding rule

The number of 5XX status codes that are returned by backend servers for the forwarding rule per second. Unit: Count/s

RuleHTTPCodeUpstream5XX

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Forwarding rule health check metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Healthy servers for the forwarding rule

The number of servers that are in the Normal state based on the health check results of the forwarding rule. Unit: Count

RuleHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Unhealthy servers for the forwarding rule

The number of servers that are in the abnormal state based on the health check results of the forwarding rule. Unit: Count

RuleUnHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Server group connection metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Backend connection failures per second for the server group

The number of times per second that the server group fails to connect to backend servers. Unit: Count/s

ServerGroupUpstreamConnectionError

DualStack_ServerGroupUpstreamConnectionError

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Backend TLS handshake failures per second for the server group

The number of times per second that backend servers fail to establish TLS connections for the server group. Unit: Count/s

ServerGroupUpstreamTLSNegotiationError

DualStack_ServerGroupUpstreamTLSNegotiationError

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Server group request metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Non-sticky requests for the server group

The number of new connection requests that are established by the server group per second without using sticky sessions. Unit: Count/s

ServerGroupNonStickyRequest

DualStack_ServerGroupNonStickyRequest

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Requests per second for the server group

The total number of requests that are processed by the server group per second. Unit: Count/s

ServerGroupQPS

DualStack_ServerGroupQPS

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Backend response time of the server group

The period of time from when the server group establishes a connection with a backend server to when the connection is closed after all data is received. Unit: ms

ServerGroupUpstreamResponseTime

DualStack_ServerGroupUpstreamResponseTime

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Request latency of the server group

The period of time from when the server group receives the first request message to when a response is returned. Unit: ms

ServerGroupRequestTime

DualStack_ServerGroupRequestTime

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Server group backend status code metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Backend 2XX status codes per second for the server group

The number of 2XX status codes that are returned by backend servers in the server group per second. Unit: Count/s

ServerGroupHTTPCodeUpstream2XX

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Backend 3XX status codes per second for the server group

The number of 3XX status codes that are returned by backend servers in the server group per second. Unit: Count/s

ServerGroupHTTPCodeUpstream3XX

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Backend 4XX status codes per second for the server group

The number of 4XX status codes that are returned by backend servers in the server group per second. Unit: Count/s

ServerGroupHTTPCodeUpstream4XX

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Backend 5XX status codes per second for the server group

The number of 5XX status codes that are returned by backend servers in the server group per second. Unit: Count/s

ServerGroupHTTPCodeUpstream5XX

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Server group health check metrics (by dimension)

Metric

Description

MetricName

Dimensions

Statistics

Healthy servers in the server group

The number of servers that are in the Normal state based on the health check results of the server group. Unit: Count

ServerGroupHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

Unhealthy servers in the server group

The number of servers that are in the abnormal state based on the health check results of the server group. Unit: Count

ServerGroupUnHealthyHostCount

userId, loadBalancerId, listenerProtocol, listenerPort, serverGroupId

Value

VIP (zone) metrics

By default, upgraded ALB instances support viewing the metrics on the VIP (Zone) tab. Before the upgrade, ALB instances in static IP mode supported this feature, while ALB instances in dynamic IP mode did not.

To create alert rules for the VIP (zone) metrics of an ALB instance, go to the CloudMonitor console. For more information, see Create an alert rule for an ALB metric.

VIP (zone) connection metrics

Metric

Description

MetricName

Dimensions

Statistics

Active connections of the VIP

The number of TCP connections in the ESTABLISHED state for a specific VIP (zone) of the ALB instance. Unit: Count

VipActiveConnection

userId, loadBalancerId,

vip

Value

Inactive connections of the VIP

The number of TCP connections that are not in the ESTABLISHED state for a specific VIP (zone) of the ALB instance. Unit: Count

VipInactiveConnection

userId, loadBalancerId, vip

Value

Maximum concurrent connections of the VIP

The total number of TCP connections that are processed by a specific VIP (zone) of the ALB instance. Unit: Count

VipMaxConnection

userId, loadBalancerId, vip

Value

Backend TLS handshake failures per second of the VIP

The number of times per second that a specific VIP (zone) of the ALB instance fails to establish TLS connections with backend servers. Unit: Count/s

VipUpstreamTLSNegotiationError

userId, loadBalancerId,

vip

Value

New connections per second of the VIP

The number of new connections that are established between a specific VIP (zone) of the ALB instance and backend servers per second. Unit: Count/s

VipNewConnection

userId, loadBalancerId,

vip

Value

Dropped connections per second of the VIP

The number of connection requests that are dropped by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipRejectedConnection

userId, loadBalancerId,

vip

Value

Backend connection failures per second of the VIP

The number of times per second that a specific VIP (zone) of the ALB instance fails to connect to backend servers. Unit: Count/s

VipUpstreamConnectionError

userId, loadBalancerId,

vip

Value

TLS handshake failures per second of the VIP

The number of times per second that a specific VIP (zone) of the ALB instance fails to establish TLS connections with clients. Unit: Count/s

VipClientTLSNegotiationError

userId, loadBalancerId,

vip

Value

VIP (zone) request metrics

Metric

Description

MetricName

Dimensions

Statistics

Custom responses per second from the VIP

The number of custom responses that are returned by a specific VIP (zone) of the ALB instance to clients per second. Unit: Count/s

VipHTTPFixedResponse

userId, loadBalancerId,

vip

Value

Redirections per second of the VIP

The number of successful redirection operations that are performed by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPRedirect

userId, loadBalancerId,

vip

Value

Requests per second of the VIP

The total number of requests that are processed by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipQPS

userId, loadBalancerId,

vip

Value

Non-sticky requests per second of the VIP

The number of new connection requests that are established by a specific VIP (zone) of the ALB instance per second without using sticky sessions. Unit: Count/s

VipNonStickyRequest

userId, loadBalancerId,

vip

Value

Backend response time of the VIP

The period of time from when a specific VIP (zone) of the ALB instance establishes a connection with a backend server to when the connection is closed after all data is received. Unit: ms

VipUpstreamResponseTime

userId, loadBalancerId,

vip

Value

Request latency of the VIP

The period of time from when a specific VIP (zone) of the ALB instance receives the first request message to when a response is returned. Unit: ms

VipRequestTime

userId, loadBalancerId,

vip

Value

VIP (zone) bandwidth metrics

Metric

Description

MetricName

Dimensions

Statistics

Outbound bandwidth of the VIP

The volume of outbound HTTP data that is sent by a specific VIP (zone) of an ALB instance per second. Unit: bit/s

VipOutBits

userId, loadBalancerId,

vip

Value

Inbound bandwidth of the VIP

The volume of inbound HTTP data that is received by a specific VIP (zone) of an ALB instance per second. Unit: bit/s

VipInBits

userId, loadBalancerId,

vip

Value

VIP (zone) status code metrics

Metric

Description

MetricName

Dimensions

Statistics

2XX status codes per second from the VIP

The number of 2XX status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode2XX

userId, loadBalancerId,

vip

Value

3XX status codes per second from the VIP

The number of 3XX status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode3XX

userId, loadBalancerId,

vip

Value

4XX status codes per second from the VIP

The number of 4XX status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode4XX

userId, loadBalancerId,

vip

Value

5XX status codes per second from the VIP

The number of 5XX status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode5XX

userId, loadBalancerId,

vip

Value

500 status codes per second from the VIP

The number of 500 status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode500

userId, loadBalancerId,

vip

Value

502 status codes per second from the VIP

The number of 502 status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode502

userId, loadBalancerId,

vip

Value

VIP: 503 per second

The number of 503 status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode503

userId, loadBalancerId,

vip

Value

VIP connections: 504 per second

The number of 504 status codes that are returned by a specific VIP (zone) of the ALB instance per second. Unit: Count/s

VipHTTPCode504

userId, loadBalancerId,

vip

Value

ALB metrics that can be viewed only using an API or SDK

The metrics in the following table are not displayed in the ALB console. You can query these metrics only using an API or SDK. Each metric represents the total value for an ALB instance, and IPv4 and IPv6 values are not displayed separately.

Forwarding rule metrics

Metric

Description

MetricName

Dimensions

Statistics

Percentage of backend 2XX status codes per second

The percentage of 2XX status codes returned per second by backend servers for the forwarding rule. Unit: %

RuleHTTPCodeUpstream2XXRatio

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Percentage of backend 3XX status codes per second

The percentage of 3XX status codes returned per second by backend servers for the forwarding rule. Unit: %

RuleHTTPCodeUpstream3XXRatio

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Percentage of backend 4XX status codes per second

The percentage of 4XX status codes returned per second by backend servers for the forwarding rule. Unit: %

RuleHTTPCodeUpstream4XXRatio

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

Percentage of backend 5XX status codes per second

The percentage of 5XX status codes returned per second by backend servers for the forwarding rule. Unit: %

RuleHTTPCodeUpstream5XXRatio

userId, loadBalancerId, listenerProtocol, listenerPort, ruleId

Value

References

For information about how to query and analyze monitoring data, see View monitoring information about an ALB instance.