Kafka NotControllerException: Why It Happens and How to Fix It
Kafka throws NotControllerException (code 41) when an admin request hits a broker that isn't the active controller. Here's the mechanism and the real fix.
kafka-admin
2 PostsKafka InvalidTopicException: Why It Happens and How to Fix It
Kafka InvalidTopicException — 'Topic name is illegal' from bad characters, 249-char limits, or '.'/'_' collisions. The exact rules, root cause, and the fix.