This topic describes the limits of Message Queue for Apache Kafka. To prevent the program from exiting unexpectedly when you use Message Queue for Apache Kafka, do not exceed the limits.

The following table describes the limits of Message Queue for Apache Kafka.

Item Requirement Description
Maximum number of topics or partitions Supported Messages are stored and scheduled based on partitions in Message Queue for Apache Kafka. Each topic consists of multiple partitions. If an excessive number of topics or partitions exist, storage fragmentation occurs. This reduces the performance and stability of your cluster.
Decrease in the number of partitions of a topic Not supported This is due to the design constraints of Apache Kafka.
Exposed ZooKeeper Not supported You do not need to access ZooKeeper to use clients in Apache Kafka V0.9.0 and later. In Message Queue for Apache Kafka, ZooKeeper is partially shared. For security purposes, it is not exposed. You do not need to understand how ZooKeeper works.
Logons to the machines on which Message Queue for Apache Kafka is deployed Not supported None.
Supported versions V0.10.x to V2.2.x
  • Version 2.2.x is compatible with versions 0.10.x and 0.9.0.
  • Version 0.10.x is compatible with version 0.9.0.
  • For information about how to upgrade an instance from V0.10.x to V2.2.x, see Upgrade the instance version.
Group Quota for the number of consumer groups Twice the number of topics For example, if you can create a maximum of 50 topics in your Message Queue for Apache Kafka instance, you can create a maximum of 100 consumer groups in the instance.Group To create more consumer groups in your instance, you need to purchase more topics. Each time you purchase a topic, the quota for the number of consumer groups is increased by 2.Group For more information about how to upgrade instance specifications, see Upgrade instance specifications.
Relationship between the number of topics and the number of partitions 1:16 Each time you purchase an additional topic, the quota for the number of partitions is increased by 16. For example, you have purchased a Standard Edition (High Write) instance of the 2xlarge traffic specification that provides 50 topics and 400 default partitions. If you purchase 10 additional topics for the instance, 160 additional partitions are available for the instance. The quota for the total number of partitions is increased to 560.
Number of topics in a Professional Edition instance Twice the number of purchased topics For example, if you purchase a Professional Edition instance that provides 50 topics, you can create 100 topics in the instance.
Change of the region for an instance Not supported After an instance is purchased and deployed, its region is closely associated with the physical resources and cannot be changed. If you want to change the region of an instance, release the instance and purchase a new instance.
Change of the network properties for an instance Supported You can modify the network properties of an instance based on your business requirements. For more information, see Upgrade instance specifications.
Message size 10 MB The maximum message size is 10 MB. Messages that are larger than 10 MB in size cannot be sent. If you want to increase the maximum message size, to contact technical support.
Monitoring and alerting Supported The data latency is 1 minute.
Number of client connections to each broker 1,000 Message Queue for Apache Kafka clients must establish socket connections to brokers to send or consume messages. If the number of client connections to a broker exceeds 1,000, the broker occupies a large number of resources to maintain the connections. This can compromise the stability of the broker. We recommend that you establish no more than 1,000 client connections to each broker.
Endpoint Determined by the edition purchased
  • Standard Edition: supports the default and SSL endpoints.
  • Professional Edition: supports the default, SSL, and SASL endpoints.