Eventarc uses quotas and system limits to maintain fair resource
allocation, prevent service overloads, and help you manage resource use.

Quotas and system limits are similar but differ in the following ways:

- *Quotas* have default values, but you can typically request adjustments.
- *System limits* are fixed values that can't be changed.

Google Cloud uses quotas to help maintain fairness and reduce
spikes in resource use and availability. A quota restricts how much of a
Google Cloud resource your Google Cloud project can use. Quotas
apply to a range of resource types, including hardware, software, and network
components. For example, quotas can restrict the number of API calls to a
service, the number of load balancers used concurrently by your project, or the
number of projects that you can create. Quotas protect the community of
Google Cloud users by preventing the overloading of services. Quotas also
help you to manage your own Google Cloud resources.

The Cloud Quotas system does the following:

- Monitors your consumption of Google Cloud products and services
- Restricts your consumption of those resources
- Provides a way to [request changes to the quota value](https://docs.cloud.google.com/docs/quotas/help/request_increase) and [automate quota adjustments](https://docs.cloud.google.com/docs/quotas/quota-adjuster.md.txt)

In most cases, when you attempt to consume more of a resource than its quota
allows, the system blocks access to the resource, and the task that
you're trying to perform fails.

Quotas generally apply at the Google Cloud project
level. Your use of a resource in one project doesn't affect
your available quota in another project. Within a Google Cloud project, quotas
are shared across all applications and IP addresses.


For more information, see the
[Cloud Quotas overview](https://docs.cloud.google.com/docs/quotas/overview.md.txt).


There are also *system limits* on Eventarc resources.
System limits can't be changed.

> [!NOTE]
> **Note:** Eventarc Standard uses Pub/Sub push subscriptions that are subject to [throughput limits](https://docs.cloud.google.com/pubsub/quotas.md.txt#resource_limits) per publish region.

## Quotas

If your project needs more of a particular resource than your quotas allow, you
can [request an adjustment](https://docs.cloud.google.com/docs/quotas/help/request_increase) to
most quotas in the Google Cloud console. For more information, see
[About quota adjustments](https://docs.cloud.google.com/docs/quotas/overview.md.txt#about_increase_requests).

### Eventarc Advanced

| Quota | Description | Value | Can be increased | Scope |
|---|---|---|---|---|
| Bus throughput | Publishing throughput ^1^ | 384 MB per minute ^2^ | No | Per project per region per minute |
| Enrollments | Number of enrollments | 100 | No | Per project per region |
| Enrollments | Number of enrollments that can be attached to a bus | 100 | No | Per bus |
| Pipelines | Number of pipelines | 100 | No | Per project per region |
| Write requests | Number of management plane ^3^ writes | 1000 | No | Per project per region per minute |

**^1^**
Throughput quota is measured in 64 kB increments. For example,
a 1 kB message would use 64 kB of quota.

**^2^** The
maximum pipeline throughput is also 384 MB per minute (or 6.4 MB per
second average).

**^3^**
Resource API operations.

### Eventarc Standard

| Quota | Description | Value | Can be increased | Scope |
|---|---|---|---|---|
| Trigger read requests | Number of trigger API reads | 6000 | Yes | Per project per minute |
| Trigger write requests | Number of trigger API writes | 600 | Yes. The [global location](https://docs.cloud.google.com/eventarc/docs/locations.md.txt#global-region) has a write limit of 10 QPS. | Per project per minute |

## Limits

The number of Eventarc resources is limited for a given project.
There is no direct limit on the size of the Eventarc API request.

### Eventarc Advanced

| Resource | Description | Limit | Can be increased | Scope |
|---|---|---|---|---|
| Bus | Number of `MessageBus` resources | 1 | No | Per project per region |
| Bus | Number of `MessageBus` resources | 5000 | No | Per organization |
| Event | Event size | 1 MB | No | N/A |
| Event message | Context attribute value size ^1^ | 1024 bytes | No | N/A |
| Event message | Number of context attributes (including required attributes) | 80 | No | N/A |
| Google API source | Number of `GoogleApiSource` resources | 1 | No | Per project per region |
| Pipeline | Queries per second | 100 (1 KB payload) | No | Per pipeline |
| Read requests | Number of management plane ^2^ reads | 6000 | No | Per project per region per minute |
| Schema | Size of input or output data format schemas when [converting the format](https://docs.cloud.google.com/eventarc/advanced/docs/receive-events/configure-format-events.md.txt) of an event | 8 KB | No | Per schema per pipeline |

**^1^**
Applicable to non-Google events that are
[directly published](https://docs.cloud.google.com/eventarc/advanced/docs/publish-events/publish-events-direct-format.md.txt): if the size limit of an event
[context attribute](https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/spec.md#context-attributes)
value is exceeded, an error occurs, and publishing is prevented.

**^2^**
Resource API operations.

### Eventarc Standard

| Resource | Description | Limit | Can be increased | Scope |
|---|---|---|---|---|
| Event | Event size | 512 KB | No | N/A |
| Event delivery | Maximum acknowledgment deadline (delivery timeout) on the underlying Pub/Sub subscription (configurable from 10 to 600 seconds; default is 10 seconds). For more information, see [Set the Pub/Sub acknowledgment deadline](https://docs.cloud.google.com/run/docs/triggering/trigger-with-events.md.txt#set-ack-deadline). | 600 seconds (10 minutes) | No | Per trigger subscription |
| Event message | Context attribute value size ^1^ | 1024 bytes | No | N/A |
| Published events (third-party and custom events) | Number of third-party and custom events that can be published per project across all channels | 300 | No. To request an exception, [contact support](https://docs.cloud.google.com/eventarc/docs/getting-support.md.txt). | Per project |
| Trigger | Number of `Trigger` resources | 500 | No | Per location per project |
| Trigger | Number of triggers for [internal HTTP endpoints](https://docs.cloud.google.com/eventarc/standard/docs/vpc-endpoints/route-vpc-internal-endpoint-events.md.txt) | 100 | No | Per project |

**^1^**
Applicable only to Cloud Audit Logs events: if the size limit of an event
[context attribute](https://github.com/cloudevents/spec/blob/v1.0.2/cloudevents/spec.md#context-attributes)
value is exceeded, the value is truncated. Attribute names for any truncated
values, delimited by semicolons, are listed in the extension attribute,
`ce_xgoogletruncatedattributes`.