Purge Kafka Topic

Question

Is there a way to purge the topic in kafka?

I pushed a message that was too big into a kafka message topic on my local machine, now I\'m getting an

Answer 1

The simplest approach is to set the date of the individual log files to be older than the retention period. Then the broker should clean them up and remove them for you within a few seconds. This offers several advantages:

1. No need to bring down brokers, it's a runtime operation.
2. Avoids the possibility of invalid offset exceptions (more on that below).

In my experience with Kafka 0.7.x, removing the log files and restarting the broker could lead to invalid offset exceptions for certain consumers. This would happen because the broker restarts the offsets at zero (in the absence of any existing log files), and a consumer that was previously consuming from the topic would reconnect to request a specific [once valid] offset. If this offset happens to fall outside the bounds of the new topic logs, then no harm and the consumer resumes at either the beginning or the end. But, if the offset falls within the bounds of the new topic logs, the broker attempts to fetch the message set but fails because the offset doesn't align to an actual message.

This could be mitigated by also clearing the consumer offsets in zookeeper for that topic. But if you don't need a virgin topic and just want to remove the existing contents, then simply 'touch'-ing a few topic logs is far easier and more reliable, than stopping brokers, deleting topic logs, and clearing certain zookeeper nodes.