This topic describes the limits of Message Service (MNS). To prevent exceptions, you cannot exceed the limits when using MNS.
The following table lists the limits of MNS queues.
| Item | Limit | Description |
|---|---|---|
| Number of queues | The maximum number of queues and topics that a user can create is 1,000. | N/A |
| Message size | 64 KB | If the size of a message exceeds this limit, the message is discarded. |
| Batch operations on messages | The maximum messages that you can manage at a time is 16. batchsize is 16.
|
N/A |
| Long polling | The maximum time period for which a request waits is 30 seconds. | N/A |
| Message retention period | 7 days | We recommend that you specify the message retention period based on your needs. After the specified period, messages are automatically deleted. |
| Queries per second (QPS) for a single queue | 3000 (recommended) | N/A |
The following table lists the limits of MNS topics.
| Item | Limit | Description |
|---|---|---|
| Number of topics | The maximum number of queues and topics that a user can create is 1000. | N/A |
| Number of subscriptions to a single topic | 100 | N/A |
| Message retention period | 1 day | We recommend that you specify the message retention period based on your needs. After the specified period, messages are automatically deleted. |
| QPS for a single topic | 500 (recommended) | N/A |