The number of available topics on an ApsaraMQ for Kafka instance equals the total number of partitions on the instance.
For example, if you purchase an instance that has 50 partitions based on the alikafka.hw.2xlarge traffic specification that provides 1,000 free partitions, the total number of partitions on the instance is 1,050. The total number of partitions is calculated based on the following formula: Total number of partitions = Number of purchased partitions + Number of free partitions. The number of available topics on the instance is also 1,050. For information about how to purchase partitions, see Upgrade instance configurations.