This document provides you with the information you need to understand Cloud Monitoring for Network Load Balancing.
Network Load Balancing exports key metrics to Monitoring.
Monitoring metrics can be used for the following purposes:
- Evaluate a load balancer's configuration, usage, and performance
- Troubleshoot problems
- Improve resource utilization and user experience
You can create custom dashboards, set up alerts, and query metrics through Monitoring.
Configuring monitoring and alerting using Cloud Console
Refer to Metrics and resource types for a list of collected metrics. Refer to Filters for lists of attributes you can use to filter your results.
Defining Monitoring custom dashboards
You can create custom Monitoring dashboards over Network Load Balancing metrics.
- Go to Monitoring in the Google Cloud Console.
Go to Monitoring - Select Dashboards > Create Dashboard.
- Click Add chart.
- Give the chart a title.
- Select metrics and filters.
You can find Network Load Balancing metrics by searching for theloadbalancing.googleapis.com/l3/externalprefix. - Click Save.
Defining Monitoring alerts
You can define Monitoring alerts over various Network Load Balancing metrics:
- Go to Monitoring in the Google Cloud Console.
Go to Monitoring - Select Alerting > Create a Policy.
- Select resource types and metrics.
You can find Network Load Balancing resource types and metrics by searching forloadbalancing.googleapis.com/l3/externalin the Find resource type and metric field. - Specify a Configuration to set when an alert should be triggered.
- Add Filters if desired.
- Click Save.
Metric reporting frequency and retention
Metrics for the network load balancers are exported to Monitoring in 1-minute granularity batches. Monitoring data is retained for six weeks. The dashboard provides data analysis in default intervals of 1h (one hour), 6h (six hours), 1d (one day), 1w (one week), and 6w (six weeks). You can manually request analysis in any interval from six weeks (6w) to sixty seconds (60s).
Metrics and resource types
Metrics
The following metrics for network load balancers are reported into Monitoring. You can use these metric names when making API requests.
| metric_name | Type | Description |
|---|---|---|
| loadbalancing.googleapis.com/l3/external/ingress_bytes_count | counter | The number of bytes sent from a client to a network load balancer backend. For TCP flows, only bytes in the application stream are counted. Sampled every 60 seconds. After sampling, data is not visible for up to 150 seconds. |
| loadbalancing.googleapis.com/l3/external/ingress_packets_count | counter | The number of packets sent from a client to a network load balancer backend. Sampled every 60 seconds. After sampling, data is not visible for up to 150 seconds. |
| loadbalancing.googleapis.com/l3/external/egress_bytes_count | counter | The number of bytes sent from a network load balancer backend to a client. For TCP flows, only bytes in on the application stream are counted. Sampled every 60 seconds. After sampling, data is not visible for up to 150 seconds. |
| loadbalancing.googleapis.com/l3/external/egress_packets_count | counter | The number of packets sent from a network load balancer backend to a client. Sampled every 60 seconds. After sampling, data is not visible for up to 150 seconds. |
| loadbalancing.googleapis.com/l3/external/rtt_latencies Available only for TCP traffic. |
distribution | A distribution of RTT measured over TCP connections for network load balancer flows. Sampled every 60 seconds. After sampling, data is not visible for up to 150 seconds. |
Resource types
resource.type = tcp_lb_rule or udp_lb_rule
A network load balancer can support either TCP or UDP traffic. You can specify the resource type to limit data to either TCP or UDP load balancers.
Filters
Resource labels
You can restrict your query by resource. You can also group results by these values.
resource.label.<var>label_key</var>:
| label_key | Type | Description |
|---|---|---|
| project | string | The identifier of the Google Cloud project associated with this
resource, such as my-project. |
| load_balancer_name | string | The name of the load balancer. |
| region | string | The region
where the load balancer's backend instance is located:
us-central1, europe-west1,
asia-east1 |
| network_name | string | The VPC network in which the load balancer backend resides. |
| backend_target_type | string | The type of the backend target that handled the connection. Valid values
are BACKEND_SERVICE and TARGET_POOL. |
| backend_target_name | string | The name of the backend target configured for this network load balancer. |
| forwarding_rule_name | string | The name of the forwarding rule used by the client to connect to the network load balancer. |
| forwarding_rule_network_tier | string | The network tier of the forwarding rule. |
| backend_name | string | The name of the backend instance group that handled the connection. Available for backend service-based network load balancers only. |
| backend_type | string | The type of the backend that handled the connection. Available for backend
service-based network load balancers only. The only valid value is
INSTANCE_GROUP. For a target pool-based network load balancer,
the field is set to UNSUPPORTED_FOR_TARGET_POOL. |
| backend_scope | string | The scope of the backend group (name of the zone or region) that handled the connection. |
| backend_scope_type | string | The type of the scope of the backend group that handled the
connection. Valid values are ZONE and REGION. |
| backend_failover_configuration | string | Failover configuration of the backend group that
handled the connection. Valid values are PRIMARY,
BACKUP, or UNKNOWN. |
| backend_subnetwork_name | string | The name of the subnetwork of the instance that received the connection. |
| endpoint_zone | string | Zone of the endpoint (Compute Engine/GKE instance) that handled the connection. |
Metric labels
You can restrict your query by metric label. You can also group results by these values.
metric.label.<var>label_key</var>:
| label_key | Type | Description |
|---|---|---|
| client_country | string | Country of the client which initiated the connection to the network load balancer. |
| client_continent | string | Continent of the client which initiated the connection to the network load balancer. |
Monitoring API requests
You can construct arbitrary queries over the Network Load Balancing metrics using the Monitoring API`s v3 projects.timeSeries.list request. The exact structure of the various definitions follow the generic monitoring filters semantics.
Example API requests
- Get all bytes sent from all network load balancers in the project, during 12:00-12:02 PM UTC on 2019-07-01, with 1m aggregates:
timeSeries.list parameters:
- name: projects/
PROJECT_ID - Filter: resource.type = "tcp_lb_rule" AND metric.name="loadbalancing.googleapis.com/l3/external/egress_bytes_count"
- interval.start_time: 2019-07-01T12:00:00Z
- interval.end_time: 2019-07-01T12:02:00Z
- aggregation.alignmentPeriod: 60s
- aggregation.crossSeriesReducer: REDUCE_SUM
- aggregation.perSeriesAligner: ALIGN_SUM
- Get median RTT measurement over all network load balancers in the project, during 12:19-12:20 PM UTC on 2019-07-01, broken down by client country:
timeSeries.list parameters:
- name: projects/
PROJECT_ID - Filter: resource.type = "tcp_lb_rule" AND metric.name="loadbalancing.googleapis.com/l3/external/rtt_latencies"
- interval.start_time: 2019-07-01T12:19:00Z
- interval.end_time: 2019-07-01T12:20:00Z
- aggregation.alignmentPeriod: 60s
- aggregation.crossSeriesReducer: REDUCE_SUM
- aggregation.groupByFields: metric.label.client_country
- aggregation.perSeriesAligner: ALIGN_PERCENTILE_50
- Get total bytes from a specific network load balancer during 12:19-12:20 PM UTC on 2019-07-01, broken down by endpoint_zone and client continent:
timeSeries.list parameters:
- name: projects/
PROJECT_ID - Filter: resource.type = "tcp_lb_rule" AND resource.label.load_balancer_name = "netlb-bs-1" AND metric.name="loadbalancing.googleapis.com/l3/external/ingress_bytes_count"
- interval.start_time: 2019-07-01T12:19:00Z
- interval.end_time: 2017-07-01T12:20:00Z
- aggregation.alignmentPeriod: 60s
- aggregation.crossSeriesReducer: REDUCE_SUM
- aggregation.groupByFields: metric.label.client_continent
- aggregation.groupByFields: resource.label.endpoint_zone
- aggregation.perSeriesAligner: ALIGN_SUM
What's next
- Read conceptual information about Network Load Balancing
- Set up a network load balancer
- Read about Monitoring Metrics, time series, and resources
- Read about forwarding rules