How to specify partition number when create a topic

[majic31]

Librdkafka provides RdKafka::Topic::create method to create a topic. But I can't specify partition number. I try to find struct of rd_kakfa_properties in Rdkafka_defaultconf.c, but failed to find related config. Please help me~~~ Thanks~

[edenhill]

The partition is not instantiated as an object but is simply provided as an integer to the ::produce() function, where it may either be an absolute partition (0..N) or RdKafka::Topic::PARTITION_UA for using the configured partitioner.

From rdkafkacpp.h:

   * 'partition' is the target partition, either:
   *   - RdKafka::Topic::PARTITION_UA (unassigned) for
   *     automatic partitioning using the topic's partitioner function, or
   *   - a fixed partition (0..N)

[majic31]

Thanks for you answer. I means one topic including one or more partitions. I can create topic, which includes default partition number("num.partitions" in server.properties kafka configure file). But I can't assign number of partitions when create topic. Does librdkafka provide related interface? Thank you :) Best regards:)

[edenhill]

Specifying the number of partitions for a topic is a broker side thing, the clients, librdkafka included, reads the number of partitions created from the broker, so you dont need to do any configuration of available partitions on the client side (librdkafka). Does that answer your question?

[majic31]

Ps: I can create topic using RdKafka::Topic::create() method. The number of partitions in the topic is equal to "num.partitions" in server.properties configure file.

[edenhill]

Ah, yes, so if 'auto.create.topics.enable=true' is configured on the broker any unknown topic requested by the client will be automatically created using the default parameters in server.properties. There is no way for the client to specify the number of partitions in this case, it is a broker side thing.

[majic31]

Ok. I get it. Thank you ! :)