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1. For each to-be-assigned source connector, if there is a set of task configurations present in the config topic after the most recent task count record for that connector:
1. If there is an existing task count record for the connector in the config topic, and either the task count in that record is above 1 or the new number of tasks for the connector is above 1*:
   1. Fence out all producers that may still be active for prior task instances of this connector by instantiating an admin client using the connector principal and invoking Admin::fenceProducers. The transactional IDs will be the IDs that each task of the connector would have used, assuming as many tasks were active as the most recent task count record for the connector.** 
2. Write the new task count record for all of the fenced-out connectors to the config topic
2. Read to the end of the config topic to verify that all task count records have been written successfully, and use the new latest offset of the config topic as the offset in the assignment given out to members of the cluster.

* - The check for task counts is done to avoid unnecessary fencing work for permanently single-task connectors, such as Debezium's CDC source connectors. If the most recent task count record for a connector shows one task, there is only one task that needs to be fenced out. And, if the new configuration for that connector contains one task, that new task will automatically fence out its single predecessor as they will use the same transactional ID. 

**  - This step will be done in parallel for all connectors

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