This article describes the limits of MNS.

The following table describes the limits on MNS queues.

Item Limit Description
Name length 120 characters If this limit is exceeded, the queue fails to be created.
Number of queues 1,000 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 7 days We recommend that you specify a message retention period based on your needs. After the specified period expires, the message is deleted.
Queries per second (QPS) for a single queue 3,000 None.

The following table describes the limits on MNS topics.

Item Limit Description
Name length 120 characters If this limit is exceeded, the topic fails to be created.
Number of topics 1,000 None.
Number of subscriptions to a single topic 100 None.
Message retention period 1 day We recommend that you specify a message retention period based on your needs. After the specified period expires, the message is deleted.
QPS for a single topic 500 None.
Message filtering tag 1 A message filtering tag can be up to 16 characters in length.
Note The Queries per second (QPS) for a single queue and QPS for a single topic items in the preceding tables indicate the QPS of API operations. To extend the QPS limits, submit a ticket.