Monitor Composite Health

This page shows how to monitor the health of published services that use Composite Health. You can do the following:

Monitor current health states: Check the real-time health state of a published service or an individual backend service.
View logs for health state transitions: Use Cloud Logging to view log entries that record changes in health states for monitored resources.

You monitor published services through their associated composite health checks, and you monitor individual backend services through their associated health sources. Service consumers can view logs for Private Service Connect NEGs that connect to published services that use Composite Health.

Composite Health uses the following states to represent the health of published services and backend services.

Health state	Monitored resource	Description
`HEALTHY`	Health source	The associated backend service is healthy as defined by its health aggregation policy.
	Composite health check	The published service is healthy because each of its associated health sources is healthy.
	Private Service Connect NEG	The associated published service is healthy as defined by the producer's composite health check.
`UNHEALTHY`	Health source	The backend service does not meet the criteria defined by its health aggregation policy.
	Composite health check	The published service is unhealthy because one or more of the associated health sources are unhealthy.
	Private Service Connect NEG	The associated published service is unhealthy as defined by the producer's composite health check; this status can trigger cross-region failover.
`UNKNOWN`	Health source	The health state is not available yet. This is a transient state that occurs when resources are newly created or configured.
	Composite health check	No associated health sources are unhealthy, but one or more health sources are unknown.
	Private Service Connect NEG	The health state of the associated published service is not available yet.

Before you begin

You must configure Composite Health before you can use it to monitor the health of published services.

Required roles

To get the permissions that you need to monitor Composite Health, ask your administrator to grant you the following IAM roles on your project:

Check the health state of health sources or composite health checks: Compute Viewer (roles/compute.viewer)
View Composite Health logging: Logs Viewer (roles/logging.viewer)

For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

Check the health state of a single health source

This section shows how to retrieve the following information about a health source:

The overall health state
The number of healthy endpoints compared to the total number of endpoints in each instance group or NEG that is associated with the health source's backend service

If the health source is associated with the backend service of an internal passthrough Network Load Balancer that has multiple forwarding rules, the health state is calculated independently for each of the load balancer's forwarding rules. In this case, the health state details include a forwardingRule field to identify the forwarding rule that is being evaluated.

Console

In the Google Cloud console, go to the Composite Health page:

Go to Composite Health
Click Health sources.
Click the name of the health source that you want to view.
To view more details, in the Health status section, click the expander arrow next to the backend service that you want to view. If forwarding rules are displayed, click the expander arrow next to a forwarding rule to view the status of the associated backends.

gcloud

Use the gcloud compute health-sources get-health command.

gcloud compute health-sources get-health HEALTH_SOURCE \
    --region=REGION

Replace the following:

HEALTH_SOURCE: the name of the health source
REGION: the region of the health source

API

Send a request to the regionHealthSources.getHealth method.

HTTP method and URL:

GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/regions/REGION/healthSources/HEALTH_SOURCE/getHealth

Replace the following:

PROJECT_ID: the ID of your project
REGION: the region of the health source
HEALTH_SOURCE: the name of the health source

Check the health state of a composite health check

This section shows how to check the health state of a composite health check, including the following information:

The overall health state of the monitored regional published service
The individual health state of each health source that is associated with the composite health check

Console

In the Google Cloud console, go to the Composite Health page:

Go to Composite Health
Click the name of the composite health check that you want to view.
To view more details, in the Health status section, click the expander arrow next to the composite health check that you want to view.

gcloud

Use the gcloud compute composite-health-checks get-health command.

gcloud compute composite-health-checks get-health COMPOSITE_CHECK_NAME \
    --region=REGION

Replace the following:

COMPOSITE_CHECK_NAME: the name of the composite health check
REGION: the region of the composite health check

API

Send a request to the regionCompositeHealthChecks.getHealth method.

HTTP method and URL:

GET https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/regions/REGION/compositeHealthChecks/COMPOSITE_CHECK_NAME/getHealth

Replace the following:

PROJECT_ID: the ID of your project
REGION: the region of the composite health check
COMPOSITE_CHECK_NAME: the name of the composite health check

View Composite Health logs

You can use Cloud Logging to track changes in health states. These logs are generated each time a health state changes (for example, from HEALTHY to UNHEALTHY).

Logging is enabled by default for health sources, composite health checks, and Private Service Connect NEGs that connect to published services that are configured to use Composite Health.

For more information about querying and analyzing log data, see Analyze logs using Logs Explorer and Observability Analytics.

Console

To view Composite Health logs, do the following.

In the Google Cloud console, go to the Logs Explorer page.

Go to Logs Explorer
If you don't see the query editor field in the Query pane, click the Show query toggle.
In the query editor field:
- To view logs for producer resources (health sources and composite health checks), enter the following query:
```
logName="projects/PROJECT_ID/logs/compute.googleapis.com%2Fcompositehealth"
```
- To view logs for consumer resources (Private Service Connect NEGs connected to published services that use composite health checks), enter the following query:
```
logName="projects/PROJECT_ID/logs/compute.googleapis.com%2Fservicehealthchecks"
```
Replace PROJECT_ID with your project ID.
Click Run query.