+1 S On Tue, Nov 17, 2020 at 8:43 AM Stack <st...@duboce.net> wrote:
> Please VOTE on whether to merge HBASE-18070 feature branch to master (and > HBASE-18070.branch-2 to branch-2). The VOTE runs for 24 hours. The majority > prevails (+ or -). > > Quoting the design lead-in: > > Read Replicas on the hbase:meta Table currently only does primitive read > of the primary’s hfiles refreshing every (configurable) N seconds. This > issue is about making it so we can do the Async WAL Replication > <http://hbase.apache.org/book.html#_asnyc_wal_replication> ability, > currently only available for user-space Tables, against the hbase:meta > system Tables too; i.e. the primary replica pushes edits to its Replicas so > they run much closer to the primaries’ state. If clients could be satisfied > reading from Replicas, then we could have improved hbase:meta uptimes but > also, we can distribute load off of the primary and alleviate hbase:meta > Table (read) hotspotting. > > Each PR that comprises the feature branch has been reviewed before commit. > > * For the design, see [2]. > * For an amalgamated PR of the 5 or 6 reviewed PRs that comprise this > feature, see [3]. > * For a PE report that compared performance before and after, see > HBASE-25127 (no regression). > * A report on ITBLL runs is pending to be attached to HBASE-18070 but > runs so far show no regression with the feature enabled (ITBLL runs were > done against a backport of this feature to branch-2 as the ITBLL state of > master is currently an unknown). > > Testing continues mainly looking for further improvement and to better > understand this feature in operation. Documentation is included. There are > some follow-ons that have been identified but these can land later. > > Thanks and thanks to all who contributed to this feature; the reviewers > and the testers in particular. > > S > > 1. http://hbase.apache.org/book.html#_asnyc_wal_replication > 2. > https://docs.google.com/document/d/1jJWVc-idHhhgL4KDRpjMsQJKCl_NRaCLGiH3Wqwd3O8/edit# > This patch is currently missing HBASE-25280, a bug found in testing. > 3. https://github.com/apache/hbase/pull/2643 >
