Using monitoring

TCP Proxy Load Balancing and SSL Proxy Load Balancing export monitoring data to Cloud 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.

In addition to the predefined dashboards in Monitoring, you can create custom dashboards, set up alerts, and query the metrics by using the Cloud Monitoring API.

Viewing Monitoring dashboards

  1. Go to Monitoring in the Google Cloud Console.
    Go to Monitoring
  2. If Resources appears in the navigation pane, select Resources and then select Google Cloud Load Balancers. Otherwise, select Dashboards and then select the dashboard named Google Cloud Load Balancers.
  3. Click the name of your load balancer.

In the left pane, you can see various details for this load balancer. In the right pane, you can see timeseries graphs. To see specific breakdowns, click Breakdowns.

Metric reporting frequency and retention

Metrics for the load balancers are exported to Monitoring in one-minute granularity batches. Monitoring data is retained for six (6) 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 6W to one minute.

Metrics for TCP proxy load balancers and SSL proxy load balancers

The following metrics for TCP proxy load balancers and SSL proxy load balancers are reported into Monitoring.

Metric Name Description
Inbound Traffic tcp_ssl_proxy/ingress_bytes_count The number of bytes sent from external endpoints to configured backends through the proxy (in bytes per sec).
Outbound Traffic tcp_ssl_proxy/egress_bytes_count The number of bytes sent from configured backends to external endpoints through the proxy (in bytes per sec).
Open Connections tcp_ssl_proxy/open_connections The number of connections open at the given sample moment. Samples are taken one minute apart.
New Connections per second tcp_ssl_proxy/new_connections The number of connections that were created (client successfully connected to backend). The counting granularity is per minute, but graphs are adjusted to show per second values. For more information, see the Monitoring documentation.
Closed Connections per second tcp_ssl_proxy/closed_connections The number of connections that were closed. The counting granularity is per minute, but graphs are adjusted to show per second values. For more information, see the Monitoring documentation.
Frontend RTT tcp_ssl_proxy/frontend_tcp_rtt A distribution of the smoothed RTT measured for each connection between client and proxy (measured by the proxy's TCP stack, each time application layer bytes pass from proxy to client).

Filtering dimensions for metrics

Metrics are aggregated for each TCP proxy load balancer and SSL proxy load balancer. Metrics can be further broken down by the following dimensions.

Property Description
BACKEND SCOPE The scope (region or zone) of the instance group that served the connection.
BACKEND ZONE If the instance group was a zonal instance group, the zone of the instance group that served the connection.
BACKEND REGION If the instance group was a regional instance group, the region of the instance group that served the connection.
PROXY CONTINENT Continent of the proxy that terminated the user TCP/SSL connection. (Examples: America, Europe, Asia)
INSTANCE GROUP The name of the instance group that received the user connection.

FORWARDING RULE The name of the forwarding rule used to connect to the proxy.
CLIENT COUNTRY The name of the country of the user.

What's next