// committed instance will
// - reject all request messages (pre-accept, accept),
// - handle prepare to help it find committed,
// - ignore others
func (i *Instance) committedProcess(m message.Message) (action uint8, msg message.Message) {
defer i.checkStatus(committed)
if !i.isAtStatus(committed) {
panic("")
}
switch content := m.Content().(type) {
case *message.PreAccept:
return noAction, nil
case *message.Accept:
return noAction, nil
case *message.Timeout:
// here we ignore the timeout event instead of panic,
// because sometimes timeout event
// comes right after the instance becomes committed
return noAction, nil
case *message.Prepare:
return i.handlePrepare(content)
case *message.PreAcceptReply, *message.PreAcceptOk, *message.AcceptReply, *message.PrepareReply, *message.Commit:
return noAction, nil // ignore stale replies
default:
panic("")
}
}
// preparing instance could only acts as a sender.
// It handles most kinds of messages (in some conditions with larger ballot) and
// ignores all replies except prepare reply.
func (i *Instance) preparingProcess(m message.Message) (action uint8, msg message.Message) {
defer i.checkStatus(preparing, preAccepted, accepted, committed, nilStatus)
if !i.isAtStatus(preparing) || i.recoveryInfo == nil {
panic("")
}
switch content := m.Content().(type) {
case *message.PreAccept:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePreAccept(content)
case *message.Accept:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handleAccept(content)
case *message.Commit:
return i.handleCommit(content)
case *message.Timeout:
return i.handleTimeout(content)
case *message.Prepare:
// the instance itself is the first one to have ballot of this
// magnitude. It can't receive others having the same
if content.Ballot.Compare(i.ballot) == 0 {
panic("")
}
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.revertAndHandlePrepare(content)
case *message.PrepareReply:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePrepareReply(content)
case *message.PreAcceptReply:
if i.recoveryInfo.formerStatus < preAccepted {
panic("")
}
return noAction, nil
case *message.PreAcceptOk:
if i.recoveryInfo.formerStatus < preAccepted {
panic("")
}
return noAction, nil
case *message.AcceptReply:
if i.recoveryInfo.formerStatus < accepted {
panic("")
}
// ignore delayed replies
return noAction, nil
default:
panic("")
}
}
// preaccepted instance
// - handles preaccept-ok/-reply, preaccept, accept, commit, and prepare.
func (i *Instance) preAcceptedProcess(m message.Message) (action uint8, msg message.Message) {
defer i.checkStatus(preAccepted, accepted, committed, preparing)
if !i.isAtStatus(preAccepted) {
panic("")
}
switch content := m.Content().(type) {
case *message.PreAccept:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePreAccept(content)
case *message.Accept:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handleAccept(content)
case *message.Commit:
return i.handleCommit(content)
case *message.Timeout:
return i.handleTimeout(content)
case *message.Prepare:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePrepare(content)
case *message.PreAcceptReply:
if content.Ballot.Compare(i.ballot) < 0 {
// ignore stale PreAcceptReply
return noAction, nil
}
return i.handlePreAcceptReply(content)
case *message.PreAcceptOk:
if !i.ballot.IsInitialBallot() {
return noAction, nil // ignore stale reply
}
return i.handlePreAcceptOk(content)
case *message.AcceptReply:
panic("")
case *message.PrepareReply:
if i.ballot.IsInitialBallot() {
panic("")
}
return noAction, nil
default:
panic("")
}
}
// NilStatus exists for:
// - the instance is newly created when
// - - received a proposal first time and only once. (sender)
// - - received pre-accept, accept, commit, prepare the first time. (receiver)
// - - required by commit dependencies and transitioning to preparing. (sender)
// - the instance is not newly created when
// - - after reverted back from `preparing`(sender -> receiver)
// - - received prepare and waiting for further message. (receiver)
func (i *Instance) nilStatusProcess(m message.Message) (action uint8, msg message.Message) {
defer i.checkStatus(nilStatus, preAccepted, accepted, committed, preparing)
if !i.isAtStatus(nilStatus) {
panic("")
}
switch content := m.Content().(type) {
case *message.Propose:
return i.handlePropose(content)
case *message.PreAccept:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePreAccept(content)
case *message.Accept:
if content.Ballot.Compare(i.ballot) < 0 {
// [*] this could happens when the instance revert from preparing
return noAction, nil
}
return i.handleAccept(content)
case *message.Commit:
return i.handleCommit(content)
case *message.Timeout:
return i.handleTimeout(content)
case *message.Prepare:
if content.Ballot.Compare(i.ballot) < 0 {
return noAction, nil
}
return i.handlePrepare(content)
case *message.PrepareReply:
if i.isNewBorn() || i.ballot.GetNumber() == 0 {
panic("Never send prepare before but receive prepare reply")
}
return noAction, nil
case *message.PreAcceptReply, *message.AcceptReply, *message.PreAcceptOk:
panic("")
default:
panic("")
}
}
// This function is responsible for communicating with instance processing.
func (r *Replica) dispatch(msg message.Message) {
replicaId := msg.Replica()
instanceId := msg.Instance()
r.updateMaxInstanceNum(replicaId, instanceId)
v1Log.Infof("Replica[%v]: recv message[%s], from Replica[%v]\n",
r.Id, msg.String(), msg.Sender())
if glog.V(0) {
printDependencies(msg)
}
if instanceId <= conflictNotFound {
panic("")
}
if r.InstanceMatrix[replicaId][instanceId] == nil {
r.InstanceMatrix[replicaId][instanceId] = NewInstance(r, replicaId, instanceId)
if p, ok := msg.(*message.Propose); ok {
// send back a signal for this successfully creation
close(p.Created)
}
}
i := r.InstanceMatrix[replicaId][instanceId]
i.touch() // update last touched timestamp
v1Log.Infof("Replica[%v]: instance[%v][%v] status before = %v, ballot = [%v]\n",
r.Id, replicaId, instanceId, i.StatusString(), i.ballot.String())
v2Log.Infof("dependencies before: %v\n", i.Dependencies())
var action uint8
var rep message.Message
switch i.status {
case nilStatus:
action, rep = i.nilStatusProcess(msg)
case preAccepted:
action, rep = i.preAcceptedProcess(msg)
case accepted:
action, rep = i.acceptedProcess(msg)
case committed:
action, rep = i.committedProcess(msg)
case preparing:
action, rep = i.preparingProcess(msg)
default:
panic("")
}
v2Log.Infof("dependencies after: %v\n", i.Dependencies())
if action == noAction {
v1Log.Infof("Replica[%v]: instance[%v][%v] status after = %v, ballot = [%v]\n\n\n",
r.Id, replicaId, instanceId, i.StatusString(), i.ballot.String())
} else {
v1Log.Infof("Replica[%v]: instance[%v][%v] status after = %v, ballot = [%v]\n",
r.Id, replicaId, instanceId, i.StatusString(), i.ballot.String())
}
if r.enablePersistent {
r.StoreSingleInstance(i)
}
switch action {
case noAction:
return
case replyAction:
v1Log.Infof("Replica[%v]: send message[%s], to Replica[%v]\n\n\n",
r.Id, rep.String(), msg.Sender())
r.Transporter.Send(msg.Sender(), rep) // send back to the sender of the message
case fastQuorumAction:
v1Log.Infof("Replica[%v]: send message[%s], to FastQuorum\n\n\n",
r.Id, rep.String())
r.Transporter.MulticastFastquorum(rep)
case broadcastAction:
v1Log.Infof("Replica[%v]: send message[%s], to Everyone\n\n\n",
r.Id, rep.String())
r.Transporter.Broadcast(rep)
default:
panic("")
}
}