In HBASE-18095, the community provided a new way to get the registry information of a cluster, without touching ZooKeeper. The decision at that time was to use masters(including active and backup masters) as the connection registry endpoint.
Later, when discussing how to implement splittable meta, we planned to make use of this framework to hide the actual ROOT table implementation. But then we found out that the approach of using masters as connection registry, violates one of our tendencies that we do not want to inline masters, especially the active master in the normal read/write path. The several sub tasks of HBASE-26149 aims to solve this problem. We all agree that by default, we should not inline masters, but there are some conflicts on whether to still allow end users to configure that they want to use masters as registry endpoints, as it is a feature which has already been published in our releases. There are some discussions in the PR for HBASE-26172 https://github.com/apache/hbase/pull/3566#discussion_r684494130 Feel free to post your opinion here. Thanks.
