[HBASE-18070] Enable memstore replication for meta replica

• Type: New Feature
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.4.0
• Labels: read-replicas
• Hadoop Flags: Reviewed

Release Note

"Async WAL Replication" [1] was added by HBASE-11183 "Timeline Consistent region replicas - Phase 2 design" but only for user-space tables. This feature adds "Async WAL Replication" for the hbase:meta table. It also adds a client 'LoadBalance' mode that has reads go to replicas first and to the primary only on fail so as to shed read load from the primary to alleviate *hotspotting* on the hbase:meta Region.

Configuration is as it was for the user-space 'Async WAL Replication'. See [2] and [3] for details on how to enable.

1. http://hbase.apache.org/book.html#async.wal.replication
2. http://hbase.apache.org/book.html#async.wal.replication.meta
3. http://hbase.apache.org/book.html#_async_wal_replication_for_meta_table_as_of_hbase_2_4_0

• Assignee: Huaxiang Sun
• Reporter: Hua Xiang
• Created: 18/May/17 17:36
• Updated: 17/Jun/22 04:49
• Resolved: 21/Nov/20 17:04

Description

Based on the current doc, memstore replication is not enabled for meta replica. Memstore replication will be a good improvement for meta replica. Create jira to track this effort (feasibility, design, implementation, etc).

Issue Links

• breaks: HBASE-15867 Move HBase replication tracking from ZooKeeper to HBase
• incorporates: HBASE-26649 Support meta replica LoadBalance mode for RegionLocator#getAllRegionLocations()
• is related to: HBASE-25272 Support scan on a specific replica
• is related to: HBASE-25099 Change meta replica count by altering meta table descriptor
• relates to: HBASE-11183 Timeline Consistent region replicas - Phase 2 design
• relates to: HBASE-10070 HBase read high-availability using timeline-consistent region replicas
• relates to: HBASE-25283 Undo meta replica specialization inside of the region replica framework
• relates to: HBASE-25315 Follow-on tasks that came of "HBASE-18070 Enable memstore replication for meta replica"
• relates to: HBASE-26233 The region replication framework should not be built upon the general replication framework
• links to: Design
• links to: GitHub Pull Request #2643

Sub-Tasks

• Allow configuring WALEntry filters on ReplicationSource: Closed
• Add ReplicationSource for meta WALs; add enable/disable when hbase:meta assigned to RS: Closed
• Edit of log messages around async WAL Replication; checkstyle fixes; and a bugfix: Closed
• Pass WALFactory to Replication so it knows of all WALProviders, not just default/user-space: Closed
• Add load balance logic in hbase-client to distribute read load over meta replica regions.: Closed
• WALReader quits if nothing to replicate (and won't restart): Closed
• warmupRegion frustrates registering WALs on the catalog replicationsource: Closed
• Check-in "Enable memstore replication..." design: Closed
• Document how to enable the meta replica load balance mode for the client and clean up around hbase:meta read replicas: Closed