Service Bus quotas

This section lists basic quotas and throttling thresholds in Azure Service Bus messaging.

Messaging quotas

The following table lists quota information specific to Service Bus messaging. For information about pricing and other quotas for Service Bus, see the Service Bus Pricing overview.

Quota Name Scope Type Behavior when exceeded Value
Maximum number of basic / standard namespaces per Azure subscription Namespace Static Subsequent requests for additional basic / standard namespaces will be rejected by the portal. 100
Maximum number of premium namespaces per Azure subscription Namespace Static Subsequent requests for additional premium namespaces will be rejected by the portal. 10
Queue/topic size Entity Defined upon creation of the queue/topic. Incoming messages will be rejected and an exception will be received by the calling code. 1, 2, 3, 4 or 5 GB.

If partitioning is enabled, the maximum queue/topic size is 80 GB.
Number of concurrent connections on a namespace Namespace Static Subsequent requests for additional connections will be rejected and an exception will be received by the calling code. REST operations do not count towards concurrent TCP connections. NetMessaging: 1,000

AMQP: 5,000
Number of concurrent receive requests on a queue/topic/subscription entity Entity Static Subsequent receive requests will be rejected and an exception will be received by the calling code. This quota applies to the combined number of concurrent receive operations across all subscriptions on a topic. 5,000
Number of topics/queues per service namespace System-wide Static Subsequent requests for creation of a new topic or queue on the service namespace will be rejected. As a result, if configured through the Azure portal, an error message will be generated. If called from the management API, an exception will be received by the calling code. 10,000

The total number of topics plus queues in a service namespace must be less than or equal to 10,000.
This is not applicable to Premium as all entities are partitioned.
Number of partitioned topics/queues per service namespace System-wide Static Subsequent requests for creation of a new partitioned topic or queue on the service namespace will be rejected. As a result, if configured through the Azure portal, an error message will be generated. If called from the management API, a QuotaExceededException exception will be received by the calling code. Basic and Standard Tiers - 100
Premium - 1,000 (per messaging unit)

Each partitioned queue or topic counts towards the quota of 10,000 entities per namespace.
Maximum size of any messaging entity path: queue or topic Entity Static - 260 characters
Maximum size of any messaging entity name: namespace, subscription, or subscription rule Entity Static - 50 characters
Message size for a queue/topic/subscription entity System-wide Static Incoming messages that exceed these quotas will be rejected and an exception will be received by the calling code. Maximum message size: 256KB (Standard tier) / 1MB (Premium tier).

Note Due to system overhead, this limit is usually slightly less.

Maximum header size: 64KB

Maximum number of header properties in property bag: byte/int.MaxValue

Maximum size of property in property bag: No explicit limit. Limited by maximum header size.
Message property size for a queue/topic/subscription entity System-wide Static A SerializationException exception is generated. Maximum message property size for each property is 32K. Cumulative size of all properties cannot exceed 64K. This applies to the entire header of the BrokeredMessage, which has both user properties as well as system properties (such as SequenceNumber, Label, MessageId, and so on).
Number of subscriptions per topic System-wide Static Subsequent requests for creating additional subscriptions for the topic will be rejected. As a result, if configured through the portal, an error message will be shown. If called from the management API an exception will be received by the calling code. 2,000
Number of SQL filters per topic System-wide Static Subsequent requests for creation of additional filters on the topic will be rejected and an exception will be received by the calling code. 2,000
Number of correlation filters per topic System-wide Static Subsequent requests for creation of additional filters on the topic will be rejected and an exception will be received by the calling code. 100,000
Size of SQL filters/actions System-wide Static Subsequent requests for creation of additional filters will be rejected and an exception will be received by the calling code. Maximum length of filter condition string: 1024 (1K).

Maximum length of rule action string: 1024 (1K).

Maximum number of expressions per rule action: 32.
Number of SharedAccessAuthorizationRule rules per namespace, queue, or topic Entity, namespace Static Subsequent requests for creation of additional rules will be rejected and an exception will be received by the calling code. Maximum number of rules: 12.

Rules that are configured on a Service Bus namespace apply to all queues and topics in that namespace.