ClientSide batch RegionServer 2-phase commit calls Disabled by default, use the option in ms.env to enable: TM_BATCH_REGIONSERVER=1
Included in this change are the server-side stubs which are needed for building as new protocol buffers have been added to support the multiple regionserver sets of names. Server-side changes will be added later.
Basic design: On the client-side we have a list of all the regions we need to communicate with. On prepare/ commit/abort we send those calls out individually by region. This change will group the region names per regionserver into one protocol buffer and include that in the RPC call to the server.
Error handling is done by collecting the problematic regions into a separate list in the TransactionState. These 'retry' regions are then retried using the single-region calls.
Implemented coprocessor calls using single-region method.