The cloud providers would just build a competing service if they couldn't co-opt an existing popular open source solution. Or anoint an adjacent solution, like solr in the case of elasticsearch. But what can be done and we really haven't seen a "open-core" type infra component try this yet: is require open-sourcing changes. The opendistro approach sorta gets us there, in a hard-fork sense, but seems in adequate and is really only being done for connivence rather than licensing requirements. But we already have a licensing solution: the AGPL. But no enterprise or saas startup wants to touch AGPL software for the fear of it contaminating proprietary code. So it seems to me the solution is a hybrid APGL for cloud providers and apache/mit for others approach. Such a license seems feasible to write and would be superior to open-core for most users.