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By adding slf4j backends to dependencies, distributions will have their own slf4j backends, and its safe to define a slf4j provider in run-class. This allows to run kafka instance from source code with a specific provider too.

Avoid compatibility issue : The version of slf4j provider must be equal to slf4j API (https://www.slf4j.org/manual.html#compatibility). Including both in kafka distribution can avoid compatibility issue;

Public Interfaces

Update the below to upgrade slf4j, starting 4.0 version

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