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 Notes Value
Maximum number of basic / standard namespaces per Azure subscription Namespace Subsequent requests for additional basic / standard namespaces are rejected by the portal. 100
Maximum number of premium namespaces per Azure subscription Namespace Subsequent requests for additional premium namespaces are rejected by the portal. 10
Queue/topic size Entity Defined upon creation of the queue/topic.

Subsequent incoming messages are rejected and an exception is received by the calling code.
1, 2, 3, 4 GB or 5 GB.

In the Premium SKU, as well as Standard with partitioning enabled, the maximum queue/topic size is 80 GB.
Number of concurrent connections on a namespace Namespace Subsequent requests for additional connections are rejected and an exception is 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 Subsequent receive requests are rejected and an exception is 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 namespace Namespace Subsequent requests for creation of a new topic or queue on the namespace are rejected. As a result, if configured through the Azure portal, an error message is generated. If called from the management API, an exception is received by the calling code. 10,000 (Basic/Standard tier). The total number of topics and queues in a namespace must be less than or equal to 10,000.

For premium tier, 1000 per messaging unit(MU). Maximum limit is 4000.
Number of partitioned topics/queues per namespace Namespace Subsequent requests for creation of a new partitioned topic or queue on the namespace are rejected. As a result, if configured through the Azure portal, an error message is generated. If called from the management API, a QuotaExceededException exception is received by the calling code. Basic and Standard Tiers - 100

Partitioned entities are not supported in the Premium tier.

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 - 260 characters
Maximum size of any messaging entity name: namespace, subscription, or subscription rule Entity - 50 characters
Maximum size of a message SessionID Entity - 128
Message size for a queue/topic/subscription entity Entity Incoming messages that exceed these quotas are rejected and an exception is received by the calling code. Maximum message size: 256 KB (Standard tier) / 1 MB (Premium tier).

Due to system overhead, this limit is less than these values.

Maximum header size: 64 KB

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 Entity A SerializationException exception is generated. Maximum message property size for each property is 32 K. Cumulative size of all properties cannot exceed 64 K. This limit 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 Entity Subsequent requests for creating additional subscriptions for the topic are rejected. As a result, if configured through the portal, an error message is shown. If called from the management API an exception is received by the calling code. 2,000
Number of SQL filters per topic Entity Subsequent requests for creation of additional filters on the topic are rejected and an exception is received by the calling code. 2,000
Number of correlation filters per topic Entity Subsequent requests for creation of additional filters on the topic are rejected and an exception is received by the calling code. 100,000
Size of SQL filters/actions Namespace Subsequent requests for creation of additional filters are rejected and an exception is received by the calling code. Maximum length of filter condition string: 1024 (1 K).

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

Maximum number of expressions per rule action: 32.
Number of SharedAccessAuthorizationRule rules per namespace, queue, or topic Entity, namespace Subsequent requests for creation of additional rules are rejected and an exception is 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.
Number of messages per transaction Transaction Additional incoming messages are rejected and an exception stating "Cannot send more than 100 messages in a single transaction" is received by the calling code. 100

For both Send() and SendAsync() operations.