Imagine, there is communication library to specialized communication protocol to end devices licensed by GPL v3 and implemented for JVM. Then I implement specialized Kafka Connector on top of this library in order to communicate to end devices utilizing Kafka messaging platform (sending messages with special schema definition based on API of library). Code of this "wrapper" will be published under GPL v3. Technically the wrapper could be run as separate process or on Kafka Connect platform (licensed by something similar to Apache v2 license).
Which of the following I am allowed to do from licensing point of view ?
Could I communicate with this standalone running wrapper from my proprietary application (via Kafka messaging) without the requirement to relicense my proprietary app also in GPL v3? My app is fully functional and usable without data sent from this wrapper, but end users my be interested to get them.
Could I do the same as in point 1, when wrapper with GPL licensed code is running from Apache Connect platform (I think wrapper will not be started as separate process, but as some threads inside) ?
Could I distribute this library with my proprietary app to end users without need to publish my proprietary code with GPL v3?