While sending the data to Eventhub we can define the partition key with message and internally a hashing function will map the key to a specific partition ID.
On the consumer side , the consumer group will need to read from a specific partition id value. Now if the Partition id is not known then how will I read the message? How will I map the consumer to a partition?
According to MSDN :
"When using partition keys, the event publisher is only aware of its partition key, not the partition to which the events are published. This decoupling of key and partition insulates the sender from needing to know too much about the downstream processing and storage of events. Partition keys are important for organizing data for downstream processing, but are fundamentally unrelated to partitions themselves."
And for Consumer:
" A consumer must connect to a specific partition."
This seems quite contradictory.