TiKV Spanner transaction interface SDK

RO/RW Transaction lifetime

Begin()

do nothing, gen txn struct with RO/RW

Get()

get TS if not exist
start heartbeat with transaction nodes
call tikv get RO/RW with TS

Set()/Delete()

store key value in local storage(map)

Commit()

map & gather all keys with regions
choose coordinator leader
call commit on every perticipators and leader