This topic describes the limits when you use MNS.

The following table lists the limits of MNS queues.

Item Limit Description
Number of queues 1000 N/A.
Message size 64 KB If the size of a message exceeds this limit, the message is discarded.
Batch operations on messages 16 N/A.
Long polling 30 seconds N/A.
Message retention period Seven days We recommend that you specify the message retention period based on your needs. After the specified period expires, the message is deleted.
Queries per second (QPS) for a single queue 3000 N/A.

The following table lists the limits of MNS topics.

Item Limit Description
Number of topics 1000 N/A.
Number of subscriptions to a single topic 100 N/A.
Message retention period One day We recommend that you specify the message retention period based on your needs. After the specified period expires, the message is deleted.
QPS for a single topic 500 N/A.