Q5 Event Hubs Domain 3 · 20–25% of exam Priority · Real Exam

What is the effect of sending events without a partition key?

  1. A The send fails
  2. B Events are distributed round-robin across partitions, maximising throughput but losing per-key ordering (correct answer)
  3. C All events go to partition 0
  4. D Events are duplicated

Shortcut: Without a key the client balances events across partitions for maximum throughput. Ordering guarantees are then only per partition, not per logical entity.