Message Queue for MQTT limits the frequency at which an API operation is called. The frequency is measured by the queries per second (QPS). Throttling is triggered when the number of calls to an API operation per second exceeds the QPS limit. Throttling may interrupt your services. Therefore, make API calls at a proper frequency.

Calls to the API operations on a Message Queue for MQTT broker are limited by QPS. Message Queue for MQTT has the following two types of QPS limits:
  • QPS limit for a single user to call an API operation: If this limit is exceeded, the traffic is throttled. Only traffic that meets the Service Level Agreement (SLA) is guaranteed. For more information about the QPS limit on each API operation, see the following table.Table 1
  • Outbound QPS limit on a single IP address. If this QPS limit is exceeded, the IP address is blocked.
    Note The outbound QPS limit on a single IP address is globally applied and is 300 for each API operation.
Table 1. QPS limit for a single user to call an API operation
API operation QPS limit
ApplyToken 500
QueryToken 100
RevokeToken 5
CreateGroupId 10
DeleteGroupId 10
ListGroupId 10
RegisterDeviceCredential 500
GetDeviceCredential 500
UnRegisterDeviceCredential 500
RefreshDeviceCredential 500
QueryMqttTraceDevice 500
QueryMqttTraceMessageOfClient 500
QueryMqttTraceMessagePublish 500
QueryMqttTraceMessageSubscribe 500
SendMessage 1000
QuerySessionByClientId 500
BatchQuerySessionByClientIds 100