// returns true if successful
func RunCoordinator(view int, index int, reqs []msgs.ClientRequest, io *msgs.Io, config Config, prepare bool) bool {
entry := msgs.Entry{
View: view,
Committed: false,
Requests: reqs}
majority := Majority(config.N)
// phase 1: prepare
if prepare {
prepare := msgs.PrepareRequest{config.ID, view, index, entry}
glog.Info("Starting prepare phase", prepare)
(*io).OutgoingBroadcast.Requests.Prepare <- prepare
// collect responses
glog.Info("Waiting for ", majority, " prepare responses")
for i := 0; i < majority; {
msg := <-(*io).Incoming.Responses.Prepare
// check msg replies to the msg we just sent
if reflect.DeepEqual(msg.Request, prepare) {
glog.Info("Received ", msg)
if !msg.Response.Success {
glog.Warning("Master is stepping down")
return false
}
i++
glog.Info("Successful response received, waiting for ", majority-i, " more")
}
}
}
// phase 2: commit
entry.Committed = true
commit := msgs.CommitRequest{config.ID, view, index, entry}
glog.Info("Starting commit phase", commit)
(*io).OutgoingBroadcast.Requests.Commit <- commit
// TODO: handle replies properly
go func() {
for i := 0; i < majority; {
msg := <-(*io).Incoming.Responses.Commit
// check msg replies to the msg we just sent
if reflect.DeepEqual(msg.Request, commit) {
glog.Info("Received ", msg)
}
}
}()
return true
}
func TestInit(t *testing.T) {
flag.Parse()
defer glog.Flush()
// create a node in system of 3 nodes
io := msgs.MakeIo(10, 3)
conf := Config{0, 3}
go Init(io, conf)
// TEST 1 - SIMPLE COMMIT
// tell node to prepare update A 3
request1 := msgs.ClientRequest{
ClientID: 2,
RequestID: 0,
Request: "update A 3"}
entry1 := msgs.Entry{
View: 0,
Committed: false,
Request: request1}
prepare1 := msgs.PrepareRequest{
SenderID: 0,
View: 0,
Index: 0,
Entry: entry1}
prepare1_res := msgs.PrepareResponse{
SenderID: 0,
Success: true}
(*io).Incoming.Requests.Prepare <- prepare1
// check node replies correctly
select {
case reply := <-(*io).OutgoingUnicast[0].Responses.Prepare:
if reply != prepare1_res {
t.Error(reply)
}
case <-time.After(time.Second):
t.Error("Participant not responding")
}
// tell node to commit update A 3
entry1.Committed = true
commit1 := msgs.CommitRequest{
SenderID: 0,
View: 0,
Index: 0,
Entry: entry1}
commit1_res := msgs.CommitResponse{
SenderID: 0,
Success: true,
CommitIndex: 0}
(*io).Incoming.Requests.Commit <- commit1
// check node replies correctly
select {
case reply := <-(*io).OutgoingUnicast[0].Responses.Commit:
if reply != commit1_res {
t.Error(reply)
}
case <-time.After(time.Second):
t.Error("Participant not responding")
}
// check if update A 3 was committed to state machine
select {
case reply := <-(*io).OutgoingRequests:
if reply != request1 {
t.Error(reply)
}
case <-time.After(time.Second):
t.Error("Participant not responding")
}
}