[HBASE-2357] Coprocessors: Add read-only region replicas (slaves) for availability and fast region recovery

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: master, regionserver
• Assignee: Unassigned
• Reporter: Todd Lipcon
• Created: 22/Mar/10 17:46
• Updated: 11/Jun/22 23:20
• Resolved: 12/Aug/14 19:08

Description

I dont plan on working on this in the short term, but the idea is to extend region ownership to have two modes. Each region has one primary region server and N slave region servers. The slaves would follow the master (probably by streaming the relevant HLog entries directly from it) and be able to serve stale reads. The benefit is twofold: (a) provides the ability to spread read load, (b) enables very fast region failover/rebalance since the memstore is already nearly up to date on the slave RS.

Issue Links

• is related to: HBASE-10070 HBase read high-availability using timeline-consistent region replicas
• relates to: HBASE-2001 Coprocessors: Colocate user code with regions
• relates to: HBASE-2002 Coprocessors: Client side support