How to
Several ways:
from the top bar: add a Consumer and select your topic inside
from the topic list: the inspect button next to the name of the topic
from the topic details view: from the CONSUME DATA button
Also see Consuming data for all the details.
The question is more: how to reset the offsets for a Consumer Group and a Topic it has subscribed to?
The offsets of a Topic cannot be "reset". The offsets are ever growing for all partitions of a Topic (data incoming into a Topic => offsets increases).
Go to the Consumer Group itself, and Reset Offsets from here.
In the Topic Details view, click on the "Advanced" drop-down, then choose "Reassign partitions..." to open the Reassignment dialog.
Choose the destination brokers, pick a strategy and Conduktor will generate the Reassignment Plan for you. You can also choose to import your own in the json format expected by kafka-reassign-partitions.sh.
You can decide to automatically elect partition leaders after the reassignment.
The throttle limit is an important option in production : without it, the reassignment may end up using all the available bandwidth, degrading your cluster performance. You can alter this configuration even when a reassignment is in progress, it will take effect immediately.
When a reassignment is in progress, you can monitor it from anywhere using the topbar button :
The opened dialog allows you to check the reassignment status and update the throttle limit.
Conduktor can empty a topic, or a specific partition:
a whole topic: "Empty Topic..."
a specific partition: the Delete icon on the right
You can only delete topic which have the "delete" policy.
If your topic only has the "compact" policy, this may not work:
Error emptying topicsorg.apache.kafka.common.errors.PolicyViolationException:Request parameters do not satisfy the configured policy.