The following table lists quotas and limits specific to Azure Event Hubs. For information about Event Hubs pricing, see Event Hubs Pricing.
| Limit | Scope | Type | Behavior when exceeded | Value |
|---|---|---|---|---|
| Number of Event Hubs per namespace | Namespace | Static | Subsequent requests for creation of a new namespace will be rejected. | 10 |
| Number of partitions per Event Hub | Entity | Static | - | 32 |
| Number of consumer groups per Event Hub | Entity | Static | - | 20 |
| Number of AMQP connections per namespace | Namespace | Static | Subsequent requests for additional connections will be rejected and an exception will be received by the calling code. | 5,000 |
| Maximum size of Event Hubs event | System-wide | Static | - | 256KB |
| Maximum size of an Event Hub name | Entity | Static | - | 50 characters |
| Number of non-epoch receivers per consumer group | Entity | Static | - | 5 |
| Maximum retention period of event data | Entity | Static | - | 1-7 days |
| Maximum throughput units | Namespace | Static | Exceeding the throughput unit limit will cause your data to be throttled and generate a ServerBusyException. You can request a larger number of throughput units for a Standard tier by filing a support ticket. Additional throughput units are available in blocks of twenty on a committed purchase basis. | 20 |