ApsaraMQ for RocketMQ 4.x series instances have the limits described in the following sections. Exceeding these limits causes message sending failures, connection errors, or degraded performance.
Message limits: Size, storage, and scheduling constraints.
Instance resource limits: Topics, groups, TPS, and subscriptions.
Connection limits: Maximum client connections by instance type.
Message limits
Resource | Limit | Adjustable | If exceeded |
Normal and ordered message size | 4 MB | No | The message fails to send. |
Transactional, scheduled, and delayed message size | 64 KB | No | The message fails to send. |
Custom properties per message | 16 KB | No | The message fails to send. |
Message storage duration | 3 days | No | Messages older than 3 days are automatically deleted. If the storage space of your purchased instance is insufficient, ApsaraMQ for RocketMQ performs a rolling deletion of the earliest messages, which may shorten the retention period to less than 3 days. |
Scheduled and delayed message delivery window | Up to 40 days in advance | No | The message fails to send. Set the |
Scheduled message latency | 1 to 2 seconds | N/A | Scheduled messages may be delivered up to 1-2 seconds after the specified time. This is expected behavior. |
Batch message sending | Not supported | N/A | Send messages individually. |
For scheduled and delayed messages, the 3-day storage duration starts after the scheduled time or delay period ends, not when the message is sent. For example, a delayed message with a 10-day delay can be stored for up to 10 + 3 = 13 days from the time it is sent.
Instance resource limits
Resource | Limit | Adjustable | If exceeded |
Topic name length | 64 characters | No | Messages cannot be sent to or received from the topic. |
Groups per instance | 1,000 | Yes | Group creation fails. Delete unused groups or contact ApsaraMQ for RocketMQ technical support to request an increase. |
Consumer offset reset window | 3 days | No | Offsets can only be reset to a point in time within the last 3 days. |
Filter expression length | 1,024 characters | No | The subscription fails. This limit applies to both tag filtering and SQL filtering expressions. |
Message TPS per instance
Throughput limits depend on the instance edition:
Edition | TPS limit | Adjustable |
Standard Edition | 5,000 transactions per second (TPS) | Yes (upgrade) |
Enterprise Platinum Edition | Varies based on purchased specifications | Yes (upgrade) |
If the Standard Edition TPS limit is insufficient, upgrade to a higher-capacity instance:
Upgrade to a 4.x series Enterprise Platinum Edition instance. After upgrading, you can downgrade back to the Standard Edition. See Lifecycle management of Enterprise Platinum Edition instances.
Create a 5.x series instance. For version differences, see Differences and compatibility between versions 4.x and 5.x.
Connection limits
Each client connection consumes instance resources. Too many connections can destabilize the service. Keep connections within the limits for your instance type.
Standard Edition
Standard Edition instances support a maximum of 4,000 connections.
Enterprise Platinum Edition
Connection limits scale with the peak messaging TPS of your purchased instance:
Peak messaging TPS | Maximum connections |
5,000 | 5,000 |
10,000 | 10,000 |
20,000 | 10,000 |
30,000 | 10,000 |
50,000 | 14,000 |
100,000 | 26,000 |
200,000 | 50,000 |
300,000 | 50,000 |
400,000 | 54,000 |
500,000 | 60,000 |
600,000 | 80,000 |
700,000 | 80,000 |
800,000 | 90,000 |
900,000 | 100,000 |
1,000,000 | 134,000 |