Question - What does red mean?

[spuder]

For some reason, one of the topics shows up as red.

I think this might be a bug in kafka-manager since this topic isn't currently marked for deletion or anything.

What causes a topic to be marked red?

[patelh]

A topic is marked red if it is marked for deletion in Zookeeper. I have seen cases where if you create a topic and then delete it and attempt to create a topic with the same name, it fails to create properly and just gets marked as deleted by Kafka controller in 0.8.2.1. I will try to validate this tomorrow in my dev environment.

[spuder]

That actually is what happened. I deleted the topic 'ndstreamer' and stopped everything from pushing to that topic for a day so it would have time to purge out.

I then made a new topic with the same name and started pushing to it again. Everything seemed fine for a day until it abruptly showed up red after the weekend.

Is there a way to 'unmark' a topic for deletion

[spuder]

Figured it out by looking at the source. When kafka marks a topic for deletion, it calls the ZkUtils.scala class and adds to zookeeper the following entry: /admin/delete_topics

https://github.com/apache/kafka/blob/5f3eb1cafaecee746641fa43945cc0762635a0bd/core/src/main/scala/kafka/utils/ZkUtils.scala#L46

I assume that if a topic appears in both kafka/admin/delete_topics and kafka/config/toipcs then it is marked for deletion. If the topic is in only one or the other then the topic is valid or deleted.

I worked around the issue by removing the topic from the delete_topics directory in zookeeper