Symptom
After sending messages to a topic, some partitions contain many messages, while others contain few or none.
You can check the message distribution on the Topic Details page. On the Partition Status tab, the offset represents the message count for each partition. For example, if partition 2 contains significantly more messages than others, the message distribution is uneven.
Possible causes
- You specified a target partition when sending the message, so other partitions received no messages.
- You specified a message key when sending the message. Messages with the same key are always routed to the same partition, which can cause an uneven distribution.
- Your custom partitioner has flawed logic, which results in uneven message distribution.