Azure Event Hubs quotas and limits

The following tables provide quotas and limits specific to Azure Event Hubs. For information about Event Hubs pricing, see Event Hubs pricing.

Common limits for all tiers

The following limits are common across all tiers.

Limit Notes Value
Size of an event hub name - 256 characters
Size of a consumer group name Kafka protocol doesn't require the creation of a consumer group.

Kafka: 256 characters

AMQP: 50 characters

Number of non-epoch receivers per consumer group - 5
Number of authorization rules per namespace Subsequent requests for authorization rule creation are rejected. 12
Number of calls to the GetRuntimeInformation method - 50 per second
Number of virtual networks (VNet) - 128
Number of IP Config rules - 128
Maximum length of a schema group name 50
Maximum length of a schema name 100
Size in bytes per schema 1 MB
Number of properties per schema group 1024
Size in bytes per schema group property key 256
Size in bytes per schema group property value 1024

Basic vs. standard vs. premium vs. dedicated tiers

The following table shows limits that may be different for basic, standard, and dedicated tiers. In the table CU is capacity unit, PU is processing unit, TU is throughput unit.

Limit Basic Standard Premium Dedicated
Maximum size of Event Hubs publication 256 KB 1 MB 1 MB 1 MB
Number of consumer groups per event hub 1 20 100 1000
No limit per CU
Number of brokered connections per namespace 100 5,000 10000 per processing unit per PU 100, 000 per CU
Maximum retention period of event data 1 day 7 days 90 days
1 TB per PU
90 days
10 TB per CU
Maximum TUs or PUs or CUs 20 TUs 20 TUs 16 PUs 20 CUs
Number of partitions per event hub 32 32 100 per event hub
200 per PU
1024 per event hub
2000 per CU
Number of namespaces per subscription 1000 1000 1000 1000 (50 per CU)
Number of event hubs per namespace 10 10 100 1000
Capture N/A Pay per hour Included Included
Size of the schema registry (namespace) in mega bytes N/A 25 100 1024
Number of schema groups in a schema registry or namespace N/A 1 - excluding the default group 100
1 MB per schema
1000
1 MB per schema
Number of schema versions across all schema groups N/A 25 1000 10000
Throughput per unit Ingress - 1 MB/s or 1000 events per second
Egress – 2 Mb/s or 4096 events per second
Ingress - 1 MB/s or 1000 events per second
Egress – 2 Mb/s or 4096 events per second
No limits per PU * No limits per CU *

* Depends on various factors such as resource allocation, number of partitions, storage and so on.

Note

You can publish events individually or batched. The publication limit (according to SKU) applies regardless of whether it is a single event or a batch. Publishing events larger than the maximum threshold will be rejected.

The following table shows the list of features that are available (or not available) in a specific tier of Azure Event Hubs.

Feature Basic Standard Premium Dedicated
Tenancy Multi-tenant Multi-tenant Multi-tenant with resource isolation Exclusive single tenant
Private link N/A Yes Yes Yes
Customer-managed key
(Bring your own key)
N/A N/A Yes Yes
Capture N/A Priced separately Included Included
Dynamic Partition scale out N/A N/A Yes Yes
Ingress events Pay per million events Pay per million events Included Included

Note

Included in the table means the feature is available and there's no separate charge for using it.

Next steps

You can learn more about Event Hubs by visiting the following links: