Quota configuration helps to achieve fairness and budgeting in service usage.

The metric based quota configuration works this way:

• The service configuration defines a set of metrics.
• For API calls, the quota.metric_rules maps methods to metrics with corresponding costs.
• The quota.limits defines limits on the metrics, which will be used for quota checks at runtime.

An example quota configuration in yaml format:

quota: limits:

• name: apiWriteQpsPerProject metric: library.googleapis.com/write_calls unit: "1/min/{project}" # rate limit for consumer projects values: STANDARD: 10000

The metric rules bind all methods to the read_calls metric,

except for the UpdateBook and DeleteBook methods. These two methods

are mapped to the write_calls metric, with the UpdateBook method

consuming at twice rate as the DeleteBook method.

metric_rules:

• selector: "*" metric_costs: library.googleapis.com/read_calls: 1
• selector: google.example.library.v1.LibraryService.UpdateBook metric_costs: library.googleapis.com/write_calls: 2
• selector: google.example.library.v1.LibraryService.DeleteBook metric_costs: library.googleapis.com/write_calls: 1

Corresponding Metric definition:

metrics:

• name: library.googleapis.com/read_calls display_name: Read requests metric_kind: DELTA value_type: INT64

• name: library.googleapis.com/write_calls display_name: Write requests metric_kind: DELTA value_type: INT64

Field number for the "limits" field.

Field number for the "metric_rules" field.

List of QuotaLimit definitions for the service.

List of MetricRule definitions, each one mapping a selected method to one or more metrics.