This topic describes the limits on some parameters and metrics in Simple Message Queue (SMQ, formerly MNS). To prevent application exceptions, make sure that the limits of the parameters and metrics are not exceeded when you use SMQ.
Limits on SMQ queues
Item | Limit | Description |
Name length | 120 characters | If this limit is exceeded, the queue fails to be created. |
Number of queues | 1,000 Note If you require more queues, you can log on to Quota Center console and submit an application to increase the Maximum Queue Quantity in a Single Region. For more information, see Submit an application to increase a quota. | None. |
Message size | 64 KB | If this limit is exceeded, the message is discarded. |
Batch operations on messages | 16 | None. |
Long polling | 30 seconds | None. |
Message retention period | Seven days | We recommend that you specify a message retention period based on your business requirements. After the specified period expires, the message is deleted. |
Limits on SMQ topics
Item | Limit | Description |
Name length | 120 characters | If this limit is exceeded, the topic fails to be created. |
Number of topics | 1,000 Note If you require more topics, you can log on to Quota Center console and submit an application to increase the Maximum Topic Quantity in a Single Region. For more information, see Submit an application to increase a quota. | None. |
Message size | 64 KB | If this limit is exceeded, the message is discarded. |
Number of subscriptions to a single topic | 100 | None. |
Message retention period | One day | We recommend that you specify a message retention period based on your business requirements. After the specified period expires, the message is deleted. |
Message filtering tag | 1 | A message filtering tag can be up to 16 characters in length. |
Topic subscription on queues | The size of an SMQ queue is equal to or larger than the size of an SMQ topic. | If the limit is exceeded, the subscription fails to be created. |
Throttling description
Category | Throttling threshold for each Alibaba Cloud account in each region | Calculation method | Operation |
Data stream messaging | 20,000 QPS | If you call the BatchSendMessage operation to send requests to a queue, the queries per second (QPS) of BatchSendMessage can be calculated based on the following formula: QPS = Number of BatchSendMessage requests per second × Number of messages. For example, if you call the BatchSendMessage operation to initiate 100 requests in 1 second to send 10 messages, the QPS of a single queue is calculated based on the following formula: 100 × 10 = 1000. | |
Metadata | 200 QPS | Each time a request is sent, the number of QPS is increased by 1. |
If you require a higher throttling threshold for a specific operation, submit a ticket.