Item	Note
Instance	Once launched, the instances’ VPCs, subnets, AZs, and regions cannot be changed.
Scale-up/down	Currently, only nodes, specifications, and disks can be scaled up. No scale-down operation is supported.
Version	Current server version range is 2.13-2.8.2. After an instance is created, the server version cannot be upgraded or customized.
Elastic IP (EIP)	You can bind EIPs to nodes so that the topics can be accessed over the Internet. EIPs can only be accessed through SASL connections.
Creating a Topic	By default, topics cannot be created automatically. You must manually create the topics. The upper limit is 100.
Number of Topic Partitions	Partitions can only be added. The total number of partitions cannot exceed 2,000, because too many partitions can cause disk performance to be greatly reduced.
Private Topic	Support private topics.
Message Size	The default size is 1 MB. You can customize the value.
Batch Import/Export	Support batch import of topics, consumer groups, and connected users.
Private Consumer Group	Support private consumer groups. You must create and subscribe to the corresponding private topics on the page and authorize connected users.

Distributed Message Service (Kafka)

Limitations