Hi Kafka Fans, If you have one topic named "kafka_lab_2" and the other named "kafka.lab.2", the topic level metrics will be named kafka_lab_2 for both, effectively making it impossible to monitor them properly.
The reason this happens is that using "." in topic names is pretty common, especially as a way to group topics into data centers, relevant apps, etc - basically a work-around to our current lack of name spaces. However, most metric monitoring systems using "." to annotate hierarchy, so to avoid issues around metric names, Kafka replaces the "." in the name with an underscore. This generates good metric names, but creates the problem with name collisions. I'm wondering if it makes sense to simply limit the range of characters permitted in a topic name and disallow "_"? Obviously existing topics will need to remain as is, which is a bit awkward. If anyone has better backward-compatible solutions to this, I'm all ears :) Gwen
