When we run the exclude command in fdbcli, it blocks until the exclusion is finished. This can be a problem for integrating into other higher-level tooling, where a blocking command that takes several hours could needless consume resources or introduces challenges with cancellations. Could we implement an option to have the exclusion command be non-blocking, so that it returns an error message when the exclusion is not yet finished? This would allow people to build polling workflows on top of the exclusion command more easily.

It would also be nice to have the output of the exclusion command in this case indicate which processes are not yet fully excluded, and to have an option for this output to be in JSON form to help ingest it into other tools.