Message Queue for Apache RocketMQ regulates and sets constraints for some metrics. To avoid program exceptions when you use Message Queue for Apache RocketMQ, do not exceed the maximum limits.
The following table describes the limits of relevant items.
|Maximum number of Message Queue for Apache RocketMQ instances in a single region||
|Length of a topic name||64 characters||If the length of a topic name exceeds this limit, messages under this topic cannot be sent or subscribed to properly.|
||If the size of a message exceeds the corresponding limit, the message will be discarded.|
|Message retention period||3 days||Messages are retained for at most three days, and the system automatically deletes them after three days.|
|Reset consumption offset||3 days||Any message consumed within 3 days can be reset.|
|Transactions per second (TPS) for sending and receiving messages under a single Message Queue for Apache RocketMQ instance||
|Delay time of scheduled or delayed messages||40 days||The
Note A latency of 1 to 2 seconds may occur to scheduled messages.
|Sending messages in batches||Not supported||Message Queue for Apache RocketMQ does not support sending messages in batches.|