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EventBridge:Limits

Last Updated:Jan 03, 2024

Limits are imposed on specific metrics of EventBridge. To prevent application exceptions, do not exceed the upper limits that are specified for the metrics when you use EventBridge.

The following table describes the limits on EventBridge metrics.

Category

Item

Limit

Event bus

Total number of system event buses

Up to one system event bus is allowed.

Total number of custom event buses

Up to 50 custom event buses are allowed.

Number of event rules

Up to 50 event rules are allowed.

Name of an event bus

  • The name of an event bus can be up to 127 characters in length. The name must start with a letter or a digit, and can contain letters, digits, and hyphens (-).

  • The reserved keyword default cannot be used as the name of an event bus.

  • The name of an event bus cannot be a string that is prefixed with eventbridge-reserved-.

Frequency to call the PutEvents API operation

Up to 3,000 queries per second (QPS) are allowed for each event bus.

Event rule

Event targets of an event rule

  • Up to five event targets are allowed.

  • Event targets must reside in the same region as the region where EventBridge is activated.

  • Event targets must be service instances in your Alibaba Cloud account.

  • The ID of an event target must be unique.

Pattern of an event rule

In the stringExpression pattern, each field can contain up to five expressions in the map data structure.

Name of an event rule

  • The name of an event rule can be up to 127 characters in length. The name must start with a letter or a digit, and can contain letters, digits, and hyphens (-).

  • The name of an event rule cannot be a string that is prefixed with eventbridge-reserved-.

Transformation of event content

  • template: The value can be up to 10,240 characters in length.

  • value: The value can be up to 1,0240 characters in length.

Event

Event message

  • An event message cannot exceed 256 KB in size.

  • Up to 16 event messages can be sent in a batch.

  • The total size of event messages that are sent in a batch cannot exceed 1 MB.

Event field

  • id: The value can be up to 128 characters in length. It must start with a letter or a digit, and can contain letters, digits, and hyphens (-).

  • source: The value can be up to 128 characters in length.

  • subject: The value can be up to 512 characters in length.

  • type: The value can be up to 64 characters in length.

Schema

Schema name

  • The name of a schema can contain only letters, digits, hyphens (-), underscores (_), and periods (.).

  • The name of a schema can be up to 128 characters in length. If the name that you specify is more than 128 characters in length, the system automatically truncates the value.

Number of schema versions

Up to 1,000 schema versions are allowed.

Event stream

Event stream name

  • The name of an event stream must start with a letter or a digit, and can contain letters, digits, and hyphens (-).

  • The name of an event stream can be up to 127 characters in length. If the name that you specify is more than 127 characters in length, the system automatically truncates the value.

Number of event streams

By default, up to 50 event streams are allowed. If you require more than 50 event streams, apply for a quota increase in Quota Center. The event stream quota that you can apply for ranges from 51 to 10,000. For more information, see Submit an application to increase a quota.

Pattern of an event rule

In the stringExpression pattern, each field can contain up to five expressions in the map data structure.

Transformation of event content

  • template: The value can be up to 10,240 characters in length.

  • value: The value can be up to 1,0240 characters in length.

Event source

Name of an event source

  • The name of an event source can contain letters, digits, hyphens (-), and periods (.).

  • The name of an event source can be up to 127 characters in length. If the name that you specify is more than 127 characters in length, the system automatically truncates the value.

Note

Limits on the number of event buses, event rules, and event streams in the preceding table are limits for a single region.