Quota

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