[HBASE-9612] Ability to batch edits destined to different regions

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.95.0, 0.95.1, 0.95.2, 0.96.0
• Fix Version/s: 0.98.0, 0.96.0
• Hadoop Flags: Incompatible change, Reviewed

Release Note

Restores being able to send many regions's worth of edits to a regionserver when running the multi call (previous it was doing a single region's worth at a time). Required redo of the multi proto model. Removed multiGet since it had same problem in that it only did a region's worth at a time; use the multi call instead to do multiGets. All should be transparent to the user but those trying to do clients against hbase will see changes (flags moved from GetRequest to Get and the above mentioned refactor of the MultiRequest proto).

• Assignee: Michael Stack
• Reporter: Benoit Sigoure
• Created: 22/Sep/13 02:29
• Updated: 20/Nov/15 11:54
• Resolved: 05/Oct/13 00:11

Description

The old (pre-PB) "multi" and "multiPut" RPCs allowed one to batch edits destined to different regions. Seems like we've lost this ability after the switch to protobufs.

The MultiRequest only contains one RegionSpecifier, and a list of MultiAction. The MultiAction message is contains either a single MutationProto or a Get (but not both – so its name is misleading as there is nothing "multi" about it). Also it seems redundant with MultiGetRequest, I'm not sure what's the point of supporting Get in MultiAction.

I propose that we change MultiRequest to be a just a list of MultiAction, and MultiAction will contain the RegionSpecifier, the bool atomic and a list of MutationProto. This would be a non-backward compatible protobuf change.

If we want we can support mixing edits and reads, in which case we'd also add a list of Get in MultiAction, and we'd have support having both that list and the list of MutationProto set at the same time. But this is a bonus and can be done later (in a backward compatible manner, hence no need to rush on this one).