I recall that there was a concern about data freshness, that the masters were all tracking the necessary state and all of them would always be up-to-date. Region servers were not already in this business, and doing so would put undue burden on ZooKeeper.
Perhaps I miss-remember, or the discussion evolved since I last checked? On Sun, Aug 15, 2021 at 5:20 PM Bharath Vissapragada <bhara...@apache.org> wrote: > Thanks, Duo. I commented on the PR but want to respond here too to kick > start the discussion and in case anyone else has different viewpoints. > > I agree that the original decision of inlining active masters needs to be > corrected going forward. I vote for the proposal to deprecate the master > based registry in 2.5.0 in favor of a "RegionServer" based registry and > remove it completely in 4.0.0. IMO we should *not *expose any opt-in > configuration to allow masters as that violates the design principle that > we all agreed upon and instead only use region servers as the registry > hosting services. > > > On Fri, Aug 13, 2021 at 7:59 PM 张铎(Duo Zhang) <palomino...@gmail.com> > wrote: > > > 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. > > >
