wip: raft does not care about migrating
wip: optimize code
wip: raft election
wip
wip: fix raft leader missing log entries
wip
fix a dead lock
batch set slot route
wip: raft persist
wip
refactor cluster suite
remove relay
rename relay2
refactor: allow customizing client factory
test raft
refactor re-balance
avoid errors caused by inconsistent status on follower nodes during raft commits
test raft election
Add "copy" command,also fixes the out of range error of select when the number is negative.
Move execCopy to "keys.go" ,
Add test in "keys_test.go",
Add "copy.go" and "copy_test.go" file.