Because the Google Workspace Events API is a shared service, we apply quotas and
limitations to make sure that it's used fairly by all users and to protect the
overall performance of Google Workspace.

If you exceed a quota, you'll receive a `429: Too many requests` HTTP status
code response. Additional rate limit checks on the
Google Workspace Events API backend might also generate the same error
response. If this error happens, use an
[exponential backoff algorithm](https://en.wikipedia.org/wiki/Exponential_backoff#Binary_exponential_backoff_/_truncated_exponential_backoff)
and try again later. As long as you stay within the per-minute quotas listed in
the following tables, there's no limit to the number of requests you can make
per day.

## Per-project quotas

Per-project quotas limit the rate of queries for a Google Cloud project, and thus
apply to a single app calling the specified Google Workspace Events API
methods for each quota.

The following table details per-project query limits. You can also find
these limits on the [Quotas](https://console.cloud.google.com/iam-admin/quotas) page in the
Google Cloud console.

| Per-project Quota | Google Workspace Events API methods | Limit |
|---|---|---|
| Writes per minute | `Subscriptions.create` `Subscriptions.patch` `Subscriptions.delete` `Subscriptions.reactivate` | 600 |
| Writes per minute per user | `Subscriptions.create` `Subscriptions.patch` `Subscriptions.delete` `Subscriptions.reactivate` | 100 |
| Reads per minute | `Subscriptions.get` `Subscriptions.list` | 600 |
| Reads per minute per user | `Subscriptions.get` `Subscriptions.list` | 100 |

## Resolve time-based quota errors


For all time-based errors (maximum of N requests per X minutes), we recommend
your code catches the exception and uses a *truncated exponential backoff* to make sure your
devices don't generate excessive load.


Exponential backoff is a standard error handling strategy for network applications. An
exponential backoff algorithm retries requests using exponentially increasing wait times
between requests, up to a maximum backoff time. If requests are still unsuccessful, it's
important that the delays between requests increase over time until the request is successful.

### Example algorithm


An exponential backoff algorithm retries requests exponentially, increasing the wait time
between retries up to a maximum backoff time. For example:

1. Make a request to Google Workspace Events API.
2. If the request fails, wait 1 + `random_number_milliseconds` and retry the request.
3. If the request fails, wait 2 + `random_number_milliseconds` and retry the request.
4. If the request fails, wait 4 + `random_number_milliseconds` and retry the request.
5. And so on, up to a `maximum_backoff` time.
6. Continue waiting and retrying up to some maximum number of retries, but don't increase the wait period between retries.


where:

- The wait time is `min(((2^n)+random_number_milliseconds), maximum_backoff)`, with `n` incremented by 1 for each iteration (request).
- `random_number_milliseconds` is a random number of milliseconds less than or equal to 1,000. This helps to avoid cases in which many clients are synchronized by some situation and all retry at once, sending requests in synchronized waves. The value of `random_number_milliseconds` is recalculated after each retry request.
- `maximum_backoff` is typically 32 or 64 seconds. The appropriate value depends on the use case.


The client can continue retrying after it has reached the `maximum_backoff` time.
Retries after this point don't need to continue increasing backoff time. For
example, if a client uses a `maximum_backoff` time of 64 seconds, then after reaching
this value, the client can retry every 64 seconds. At some point,
clients should be prevented from retrying indefinitely.


The wait time between retries and the number of retries depend on your use case
and network conditions.

## Request a per-project quota increase


Depending on your project's resource usage, you might want to request a quota
adjustment. API calls by a service account are considered to be using a
single account. Applying for an adjusted quota doesn't guarantee approval. Quota adjustment
requests that would significantly increase the quota value can take longer to be approved.


Not all projects have the same quotas. As you increasingly use Google Cloud over
time, your quota values might need to increase. If you expect a notable upcoming
increase in usage, you can proactively
[request quota adjustments](https://docs.cloud.google.com/docs/quotas/view-manage#requesting_higher_quota)
from the [Quotas \& System Limits](https://console.cloud.google.com/iam-admin/quotas) page in the Google Cloud console.

To learn more, see the following resources:

- [About quota adjustments](https://docs.cloud.google.com/docs/quotas/overview#about_increase_requests)
- [View your quota usage and limits](https://docs.cloud.google.com/docs/quotas/view-manage#viewing_your_quota_console)
- [Request a higher quota limit](https://docs.cloud.google.com/docs/quotas/view-manage#requesting_higher_quota)