EventBridge is subject to the following quotas and constraints. To prevent program exceptions, do not exceed these limits when you use EventBridge.
Note: The limits on the number of event buses, event rules, and event streams apply per region.
Event buses
| Item | Limit |
|---|---|
| Default event buses per region | 1 |
| Custom event buses per region | 50 |
| Event rules per event bus | 50 |
| Throughput on the default event bus | 10,000 events per second |
| Throughput on a custom event bus | 3,000 events per second per bus |
Event bus naming rules
Maximum length: 127 characters.
Must start with a letter or digit. Can contain letters, digits, and hyphens (
-).The keyword
defaultis reserved and cannot be used as an event bus name.Names cannot start with
eventbridge-reserved-.
Event rules
| Item | Limit |
|---|---|
| Event targets per event rule | 5 |
Expressions per field in stringExpression mode | 5 (map structure) |
Event target constraints
Event targets must be in the same region as EventBridge.
Event targets must be service instances owned by your Alibaba Cloud account.
Each event target ID must be unique.
Event rule naming rules
Maximum length: 127 characters.
Must start with a letter or digit. Can contain letters, digits, and hyphens (
-).Names cannot start with
eventbridge-reserved-.
Event content transform
| Item | Limit |
|---|---|
| Template size | 10,240 characters |
| Value size | 10,240 characters |
Events
Event message size
| Item | Limit |
|---|---|
| Single event message | 256 KB |
| Messages per batch | 16 |
| Total batch size | 1 MB |
Event field constraints
| Field | Maximum length | Format |
|---|---|---|
id | 128 characters | Must start with a letter or digit. Can contain letters, digits, and hyphens (-). |
source | 128 characters | -- |
subject | 512 characters | -- |
type | 64 characters | -- |
Schemas
| Item | Limit |
|---|---|
| Schema versions | 1,000 |
Schema naming rules
Maximum length: 128 characters. Names that exceed this limit are automatically truncated.
Can contain letters, digits, hyphens (
-), underscores (_), and periods (.).
Event streams
| Item | Limit |
|---|---|
| Event streams per region | 50. You can request a quota increase in the range of [51, 10000] in Quota Center. For details, see Submit an application to increase a quota. |
Expressions per field in stringExpression mode | 5 (map structure) |
Event stream content transform
| Item | Limit |
|---|---|
| Template size | 10,240 characters |
| Value size | 10,240 characters |
Event stream naming rules
Maximum length: 127 characters. Names that exceed this limit are automatically truncated.
Must start with a letter or digit. Can contain letters, digits, and hyphens (
-).
Event sources
Event source naming rules
Maximum length: 127 characters. Names that exceed this limit are automatically truncated.
Can contain letters, digits, hyphens (
-), and periods (.).
Event store
Data catalogs
| Item | Limit |
|---|---|
| Data catalogs per region | 50 |
| Namespaces per data catalog | 50 |
| Query concurrency per data catalog (shared edition) | 5 concurrent queries |
Data catalog names must be unique within the same region.
Namespace names must be unique within the same data catalog.
Naming rules for event store resources
The following naming rules apply to data catalogs, namespaces, and event tables:
Maximum length: 127 characters.
Must start with a letter or digit. Can contain letters, digits, and hyphens (
-).
Luma
| Item | Limit |
|---|---|
| Agents per region | 50 |
| Query concurrency per region | 5 concurrent queries. You can request an increase in Quota Center. |
Agent names must be unique within the same region.