What limits are imposed on ApsaraMQ for RocketMQ? - ApsaraMQ for RocketMQ

This topic describes the limits that are imposed on the metrics of ApsaraMQ for RocketMQ. To prevent program exceptions, make sure that the setting of a specific configuration item is within the corresponding limit when you use ApsaraMQ for RocketMQ.

Metric	Limit	Description
Length of a topic name	64 characters	A topic name can be up to 64 characters in length. If a topic name is more than 64 characters in length, messages cannot be sent to the topic or messages in the topic cannot be subscribed to.
Groups on an instance	1,000	You can create up to 1,000 groups on an instance. We recommend that you reuse groups or delete groups that you no longer require at the earliest opportunity. If you want to increase the group quota on an instance, contact ApsaraMQ for RocketMQ technical support.
Message size	Normal or ordered message: 4 MB Transactional, scheduled, or delayed message: 64 KB Note The total attribute size of a message cannot exceed 16 KB.	The size of a message cannot exceed the corresponding upper limit. If the size of a message exceeds the corresponding upper limit, the message fails to be sent.
Message retention period	Standard Edition: 3 days. If the 3-day period elapses for a message, the message is automatically deleted. Enterprise Platinum Edition: 3 days. If the storage capacity that you purchased for your instance is insufficient, ApsaraMQ for RocketMQ automatically deletes the earliest stored messages. In this case, the messages may be retained for less than 3 days. Note The system starts to calculate the retention period of a scheduled or delayed message when the specified scheduled time or delay duration is reached. For example, if a producer sends a delayed message whose delay duration is specified as 10 days, the message can be retained in the broker for up to 13 days. This is calculated by using the following formula: 10 + 3 =13.	You can increase the upper limit of message retention period for Enterprise Platinum Edition instances. To increase the upper limit, contact ApsaraMQ for RocketMQ technical support.
Consumer offset resetting	3 days	When you reset the consumer offset for a topic, make sure that the specified point in time is within 3 days before the point in time when a message is sent to the topic.
Messaging TPS on an instance	Standard Edition: 5,000 messages per second. Enterprise Platinum Edition: The value varies based on the purchased specification.	If your ApsaraMQ for RocketMQ 4.x Standard Edition instance does not meet your business requirements, use one of the following methods to upgrade your instance: Upgrade the instance to an ApsaraMQ for RocketMQ 4.x Enterprise Platinum Edition instance. For more information, see Change the edition of an instance. After the upgrade, you can downgrade the instance to the Standard Edition. For more information, see Lifecycle management. Create an ApsaraMQ for RocketMQ 5.x instance. For more information, see Create an instance. For information about the differences between ApsaraMQ for RocketMQ 4.x and 5.x instances and their compatibility, see Differences between ApsaraMQ for RocketMQ 4.x and 5.x and compatibility description.
Delay period of a scheduled or delayed message	40 days	You can set the `msg.setStartDeliverTime` parameter of a message to a point in time within the following 40 days. The value is in milliseconds. If you specify a value that is greater than 40 days, the broker cannot deliver the message. Note A delay of 1 to 2 seconds exists between the scheduled time to send a scheduled message and the actual time to send the message.
Batch message sending	Not supported	ApsaraMQ for RocketMQ does not allow you to send messages in batches.