[HBASE-25099] Change meta replica count by altering meta table descriptor

• Type: Umbrella
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.4.0
• Component/s: meta, read replicas

Release Note

Now you can change the region replication config for meta table by altering meta table.
The old "hbase.meta.replica.count" is deprecated and will be removed in 4.0.0. But if it is set, we will still honor it, which means, when master restart, if we find out that the value of 'hbase.meta.replica.count' is different with the region replication config of meta table, we will schedule an alter table operation to change the region replication config to the value you configured for 'hbase.meta.replica.count'.

• Assignee: Duo Zhang
• Reporter: Duo Zhang
• Created: 25/Sep/20 14:00
• Updated: 30/Oct/20 14:52
• Resolved: 13/Oct/20 03:59

Description

As now we support altering meta table, it will be better to also deal with changing meta replica number using altering meta, i.e, we could unify the logic in MasterMetaBootstrap to ModifyTableProcedure, and another benefit is that we do not need to restart master when changing the replica number for meta.

Issue Links

• is related to: HBASE-23055 Alter hbase:meta
• relates to: HBASE-25216 The client zk syncer should deal with meta replica count change
• relates to: HBASE-18070 Enable memstore replication for meta replica
• links to: Design Doc

Sub-Tasks

• Remove ZNodePaths.metaReplicaZNodes: Resolved
• Refactor MetaTableAccessor.addRegionsToMeta and its usage places: Resolved
• Support changing region replica count without disabling table: Resolved
• Make ModifyTableProcedure support changing meta replica count: Resolved
• Update documentation about meta region replica: Resolved