You can query monitoring metrics to assess the status, load, and performance of your Classic Load Balancer (CLB) instance. This helps you troubleshoot issues such as request timeouts and throttling. This topic describes the monitoring metrics for CLB.
Usage notes
To call the CloudMonitor API operations, you need to set the Namespace, Period, MetricName, and Dimensions parameters for your CLB instance as follows:
Set Namespace to
acs_slb_dashboard.Period defaults to 60 (in seconds) and you can also set it to a multiple of 60.
Set Dimensions to a JSON string. Example:
[{"instanceId":"lb-bp1r92vzpemy099f******", "port":"80", "vip":"121.43.**.**"}]. In Dimensions, set the instanceId field to the ID of your CLB instance, the port field to the port of your CLB instance, and the vip field to its service address.
CLB monitoring metrics
Metrics that can be viewed by using the console, API, or SDK
Layer 4 monitoring metrics
Category | Metric | Description | MetricName | Dimensions | Statistics |
Instance connection metrics | New Connections to Instance | The number of new TCP and UDP connections per second on a CLB instance. Unit: Count/s | InstanceNewConnection | instanceId | Average, Minimum, and Maximum |
Connections Dropped on Instance | The number of TCP and UDP connections dropped per second on a CLB instance. Unit: Count/s | InstanceDropConnection | instanceId | Average, Minimum, and Maximum | |
Active Connections to Instance | The number of TCP connections in the ESTABLISHED state on a CLB instance. Unit: Count Note A persistent connection can simultaneously transfer multiple file requests. | InstanceActiveConnection | instanceId | Average, Minimum, and Maximum | |
Inactive Connections to Instance | The number of TCP connections not in the ESTABLISHED state as well as UDP connections on a CLB instance. Unit: Count | InstanceInactiveConnection | instanceId | Average, Minimum, and Maximum | |
Maximum Concurrent Connections to Instance | The number of TCP and UDP connections processed by a CLB instance. Unit: Count | InstanceMaxConnection | instanceId | Average, Minimum, and Maximum | |
Instance bandwidth or traffic metrics | Inbound Traffic to Instance | The TCP and UDP traffic received by a CLB instance. Unit: bit/s | InstanceTrafficRX | instanceId | Average, Minimum, and Maximum |
Outbound Traffic from Instance | The TCP and UDP traffic sent by a CLB instance per second. Unit: bit/s | InstanceTrafficTX | instanceId | Average, Minimum, and Maximum | |
Inbound Packets to Instance | The number of TCP and UDP packets received by a CLB instance per second. Unit: Count/s | InstancePacketRX | instanceId | Average, Minimum, and Maximum | |
Outbound Packets from Instance | The number of TCP and UDP packets sent by a CLB instance per second. Unit: Count/s | InstancePacketTX | instanceId | Average, Minimum, and Maximum | |
Inbound Traffic Dropped on Instance | The TCP and UDP traffic that a CLB instance fails to receive per second. Unit: bit/s | InstanceDropTrafficRX | instanceId | Average, Minimum, and Maximum | |
Outbound Traffic Dropped on Instance | The TCP and UDP traffic that a CLB instance fails to send per second. Unit: bit/s | InstanceDropTrafficTX | instanceId | Average, Minimum, and Maximum | |
Inbound Packets Dropped on Instance | The number of TCP and UDP packets that a CLB instance fails to receive per second. Unit: Count/s | InstanceDropPacketRX | instanceId | Average, Minimum, and Maximum | |
Outbound Packets Dropped on Instance | The number of TCP and UDP packets that a CLB instance fails to send per second. Unit: Count/s | InstanceDropPacketTX | instanceId | Average, Minimum, and Maximum | |
Listener connection metrics | New Connections to Listener | The number of new TCP or UDP connections per second on a listener port. Unit: Count/s | NewConnection | instanceId, port, and vip | Average, Minimum, and Maximum |
Connections Dropped on Listener | The number of TCP or UDP connections dropped per second on a listener port. Unit: Count/s | DropConnection | instanceId, port, and vip | Average, Minimum, and Maximum | |
Active Connections to Listener | The number of TCP connections in the ESTABLISHED state on a listener port. Unit: Count Note A persistent connection can simultaneously transfer multiple file requests. | ActiveConnection | instanceId, port, and vip | Average, Minimum, and Maximum | |
Inactive Connections to Listener | The number of TCP connections not in the ESTABLISHED state or UDP connections on a listener port. Unit: Count | InactiveConnection | instanceId, port, and vip | Average, Minimum, and Maximum | |
Maximum Concurrent Connections to Listener | The number of TCP or UDP connections processed by a listener port. Unit: Count | MaxConnection | instanceId, port, and vip | Average, Minimum, and Maximum | |
Listener bandwidth or traffic metrics | Inbound Traffic to Listener | The TCP or UDP traffic received by a listener port per second. Unit: bit/s | TrafficRXNew | instanceId, port, and vip | Average, Minimum, and Maximum |
Outbound Traffic from Listener | The TCP or UDP traffic sent by a listener port per second. Unit: bit/s | TrafficTXNew | instanceId, port, and vip | Average, Minimum, and Maximum | |
Inbound Packets to Listener | The number of TCP or UDP packets received by a listener port per second. Unit: Count/s | PacketRX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Outbound Packets from Listener | The number of TCP or UDP packets sent by a listener port per second. Unit: Count/s | PacketTX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Inbound Traffic Dropped on Listener | The TCP or UDP traffic that a listener port fails to receive per second. Unit: bit/s | DropTrafficRX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Outbound Traffic Dropped on Listener | The TCP or UDP traffic that a listener port fails to send per second. Unit: bit/s | DropTrafficTX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Inbound Packets Dropped on Listener | The number of TCP or UDP packets that a listener port fails to receive per second. Unit: Count/s | DropPacketRX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Outbound Packets Dropped on Listener | The number of TCP or UDP packets that a listener port fails to send per second. Unit: Count/s | DropPacketTX | instanceId, port, and vip | Average, Minimum, and Maximum | |
Listener health check metrics | Healthy Backend ECS Instances | The number of healthy ECS instances that serve as backend servers for a listener port. | HeathyServerCount | instanceId, port, and vip | Average, Minimum, and Maximum |
Unhealthy ECS Instances | The number of unhealthy ECS instances that serve as backend servers for a listener port. | UnhealthyServerCount | instanceId, port, and vip | Average, Minimum, and Maximum |
Layer 7 monitoring metrics
Category | Metric | Description | MetricName | Dimensions | Statistics |
Instance connection metrics | Response Time of Layer 7 Instance | The time elapsed from when a client sends a request to when it receives a response through the CLB instance. Unit: ms | InstanceRt | instanceId | Average |
UpstreamRT of Layer 7 Instance | The time taken for a CLB instance to forward a request to a backend server and receive a response. Unit: ms | InstanceUpstreamRt | instanceId | Average | |
Instance request metric | QPS of Layer 7 Instance | The number of HTTP or HTTPS requests that a CLB instance processes per second. Unit: Count/s | InstanceQps | instanceId | Average |
Instance status code metrics | 2XX Status Codes of Layer 7 Instance | The number of 2xx (Success) status codes returned from a backend server to a client through the CLB instance per second. Unit: Count/s | InstanceStatusCode2xx | instanceId | Average |
3XX Status Codes of Layer 7 Instance | The number of 3xx (Redirection) status codes returned from a backend server to a client through the CLB instance per second. Unit: Count/s | InstanceStatusCode3xx | instanceId | Average | |
4XX Status Codes of Layer 7 Instance | The number of 4xx (Client Error) status codes returned from a backend server to a client through the CLB instance per second. Unit: Count/s | InstanceStatusCode4xx | instanceId | Average | |
5XX Status Codes of Layer 7 Instance | The number of 5xx (Server Error) status codes returned from a backend server to a client through the CLB instance per second. Unit: Count/s | InstanceStatusCode5xx | instanceId | Average | |
Other Status Codes of Layer 7 Instance | The number of status codes except 2xx, 3xx, 4xx, and 5xx returned from a backend server to a client through the CLB instance per second. Unit: Count/s | InstanceStatusCodeOther | instanceId | Average | |
Backend instance status code metrics | 4XX Status Codes of Layer 7 Instance | The number of 4xx Client Error status codes returned to a CLB instance from the backend server per second. Unit: Count/s | InstanceUpstreamCode4xx | instanceId | Average |
5XX Status Codes of Layer 7 Instance | The number of 5xx Server Error status codes returned to a CLB instance from the backend server per second. Unit: Count/s | InstanceUpstreamCode5xx | instanceId | Average | |
Listener connection metrics | Response Time of Layer 7 Listener | The time taken for the client to send a request to the backend server and receive a response by using a listener port. Unit: ms | Rt | instanceId, port, and vip | Average |
UpstreamRT of Layer 7 Listener | The time taken for a listener port to forward a request to the backend server and receive a response. Unit: ms | UpstreamRt | instanceId, port, and vip | Average | |
Listener request metric | QPS of Layer 7 Listener | The number of HTTP or HTTPS requests that a listener port processes per second. Unit: Count/s | Qps | instanceId, port, and vip | Average |
Listener status code metrics | 2XX Status Codes of Layer 7 Listener | The number of 2xx Success status codes returned to the client from the backend server by using a listener port per second. Unit: Count/s | StatusCode2xx | instanceId, port, and vip | Average |
3XX Status Codes of Layer 7 Listener | The number of 3xx Redirection status codes returned to the client from the backend server by using a listener port per second. Unit: Count/s | StatusCode3xx | instanceId, port, and vip | Average | |
4XX Status Codes of Layer 7 Listener | The number of 4xx Client Error status codes returned to the client from the backend server by using a listener port per second. Unit: Count/s | StatusCode4xx | instanceId, port, and vip | Average | |
5XX Status Codes of Layer 7 Listener | The number of 5xx Server Error status codes returned to the client from the backend server by using a listener port per second. Unit: Count/s | StatusCode5xx | instanceId, port, and vip | Average | |
Other Status Codes of Layer 7 Listener | The number of status codes except 2xx, 3xx, 4xx, and 5xx returned to the client from the backend server by using a listener port per second. Unit: Count/s | StatusCodeOther | instanceId, port, and vip | Average | |
Backend listener status code metrics | 4XX Status Codes of Layer 7 Listener | The number of 4xx Client Error status codes returned to the CLB instance from the backend server by using a listener port per second. Unit: Count/s | UpstreamCode4xx | instanceId, port, and vip | Average |
5XX Status Codes of Layer 7 Listener | The number of 5xx Server Error status codes returned to the CLB instance from the backend server by using a listener port per second. Unit: Count/s | UpstreamCode5xx | instanceId, port, and vip | Average |
Metrics that can be viewed by using the API or SDK
Layer 4 monitoring metrics
Category | Metric | Description | MetricName | Dimensions | Statistics |
Instance connection metrics | Instance connection utilization | The ratio of established connections to the maximum connections for a CLB instance. Unit: % | InstanceMaxConnectionUtilization | instanceId | Average, Maximum, and Minimum |
New instance connection utilization | The ratio of new connections to the maximum allowed new connections for a CLB instance. Unit: % | InstanceNewConnectionUtilization | instanceId | Average, Maximum, and Minimum |
Layer 7 monitoring metrics
Category | Metric | Description | MetricName | Dimensions | Statistics |
Instance request metric | QPS utilization | The ratio of the current QPS to the maximum QPS of the CLB instance. Unit: % | InstanceQpsUtilization | instanceId | Average, Maximum, and Minimum |
FAQ
What is the difference between monitoring data and billing data?
Factor | Monitoring data | Billing data |
Calculation method | Data is sampled by the CLB system at a 1-minute granularity. The CloudMonitor service then aggregates these data points and calculates the average value over a 15-minute interval. The metrics displayed in the monitoring console represent this final average. | Billing data is collected at the same granularity. However, the CLB system aggregates these data points into an hourly sum (total value). This hourly total is then sent to the billing system for invoicing. Therefore, billing data reflects the cumulative total over a period, whereas monitoring data reflects an average. |
Real-timeliness | Monitoring data is provided in near real-time. However, small delays are inherent in the data collection, processing, and display pipeline. This can lead to minor discrepancies when compared with billing data at any given moment. | The billing system is designed to accommodate processing delays of up to 3 hours. For example, usage data from the 01:00-02:00 hour, which would normally be billed before 03:00, could be delayed and processed as late as 05:00. This intentional latency is a key reason for differences between real-time monitoring and final billing data. |
Purpose | To provide operational visibility into the instance's real-time health and performance. It is used to detect anomalies, diagnose issues, and trigger operational responses (e.g., alerts, autoscaling). | To accurately calculate charges based on the actual resources consumed over a billing period. For all financial accounting and invoicing, the billing data is the official source of truth, not the monitoring data. |
References
The monitoring data may be different from the billing data. For more information, see Monitoring data and billing data.
For more information about how to view CLB monitoring data, see View monitoring data of CLB.
For more information about how to configure alert rules for CLB instances, see Configure alert rules.