func TestCandidateToLeader(t *testing.T) {
log.SetOutput(&bytes.Buffer{})
defer log.SetOutput(os.Stdout)
oldMin, oldMax := raft.ResetElectionTimeoutMs(25, 50)
defer raft.ResetElectionTimeoutMs(oldMin, oldMax)
noop := func([]byte) ([]byte, error) { return []byte{}, nil }
server := raft.NewServer(1, &bytes.Buffer{}, noop)
server.SetPeers(raft.MakePeers(nonresponsivePeer(1), approvingPeer(2), nonresponsivePeer(3)))
server.Start()
defer func() { server.Stop(); t.Logf("server stopped") }()
time.Sleep(raft.MaximumElectionTimeout())
cutoff := time.Now().Add(2 * raft.MaximumElectionTimeout())
backoff := raft.BroadcastInterval()
for {
if time.Now().After(cutoff) {
t.Fatal("failed to become Leader")
}
if state := server.State(); state != raft.Leader {
time.Sleep(backoff)
backoff *= 2
continue
}
t.Logf("became Leader")
break
}
}
func testServers(t *testing.T, n int) {
log.SetFlags(log.Lmicroseconds)
oldMin, oldMax := raft.ResetElectionTimeoutMs(50, 100)
defer raft.ResetElectionTimeoutMs(oldMin, oldMax)
// node = Raft protocol server + a HTTP server + a transport bridge
raftServers := make([]*raft.Server, n)
httpServers := make([]*http.Server, n)
raftHttpServers := make([]*rafthttp.Server, n)
// create them individually
for i := 0; i < n; i++ {
// create a Raft protocol server
raftServers[i] = raft.NewServer(uint64(i+1), &bytes.Buffer{}, noop)
// wrap that server in a HTTP transport
raftHttpServers[i] = rafthttp.NewServer(raftServers[i])
// connect that HTTP transport to a unique HTTP server
mux := http.NewServeMux()
httpServers[i] = &http.Server{
Addr: fmt.Sprintf("%s:%d", listenHost, basePort+i+1),
Handler: mux,
}
raftHttpServers[i].Install(mux)
// we have to start the HTTP server, so the NewHTTPPeer ID check works
// (it can work without starting the actual Raft protocol server)
go httpServers[i].ListenAndServe()
t.Logf("Server id=%d @ %s", raftServers[i].Id(), httpServers[i].Addr)
}
// build the common set of peers in the network
peers := raft.Peers{}
for i := 0; i < n; i++ {
u, err := url.Parse(fmt.Sprintf("http://%s:%d", listenHost, basePort+i+1))
if err != nil {
t.Fatal(err)
}
peer, err := rafthttp.NewPeer(*u)
if err != nil {
t.Fatal(err)
}
peers[peer.Id()] = peer
}
// inject each Raft protocol server with its peers
for _, raftServer := range raftServers {
raftServer.SetPeers(peers)
}
// start each Raft protocol server
for _, raftServer := range raftServers {
raftServer.Start()
defer raftServer.Stop()
}
time.Sleep(2 * raft.MaximumElectionTimeout())
}
func testOrderTimeout(t *testing.T, nServers int, timeout time.Duration) {
logBuffer := &bytes.Buffer{}
log.SetOutput(logBuffer)
defer log.SetOutput(os.Stdout)
defer printOnFailure(t, logBuffer)
oldMin, oldMax := raft.ResetElectionTimeoutMs(50, 100)
defer raft.ResetElectionTimeoutMs(oldMin, oldMax)
done := make(chan struct{})
go func() { testOrder(t, nServers); close(done) }()
select {
case <-done:
break
case <-time.After(timeout):
t.Fatalf("timeout (infinite loop?)")
}
}
func TestFailedElection(t *testing.T) {
log.SetOutput(&bytes.Buffer{})
defer log.SetOutput(os.Stdout)
oldMin, oldMax := raft.ResetElectionTimeoutMs(25, 50)
defer raft.ResetElectionTimeoutMs(oldMin, oldMax)
noop := func([]byte) ([]byte, error) { return []byte{}, nil }
server := raft.NewServer(1, &bytes.Buffer{}, noop)
server.SetPeers(raft.MakePeers(disapprovingPeer(2), nonresponsivePeer(3)))
server.Start()
defer func() { server.Stop(); t.Logf("server stopped") }()
time.Sleep(2 * raft.ElectionTimeout())
if server.State() == raft.Leader {
t.Fatalf("erroneously became Leader")
}
t.Logf("remained %s", server.State())
}
func TestSimpleConsensus(t *testing.T) {
logBuffer := &bytes.Buffer{}
log.SetOutput(logBuffer)
defer log.SetOutput(os.Stdout)
defer printOnFailure(t, logBuffer)
oldMin, oldMax := raft.ResetElectionTimeoutMs(25, 50)
defer raft.ResetElectionTimeoutMs(oldMin, oldMax)
type SetValue struct {
Value int32 `json:"value"`
}
var i1, i2, i3 int32
applyValue := func(id uint64, i *int32) func([]byte) ([]byte, error) {
return func(cmd []byte) ([]byte, error) {
var sv SetValue
if err := json.Unmarshal(cmd, &sv); err != nil {
return []byte{}, err
}
atomic.StoreInt32(i, sv.Value)
return json.Marshal(map[string]interface{}{"applied_to_server": id, "applied_value": sv.Value})
}
}
s1 := raft.NewServer(1, &bytes.Buffer{}, applyValue(1, &i1))
s2 := raft.NewServer(2, &bytes.Buffer{}, applyValue(2, &i2))
s3 := raft.NewServer(3, &bytes.Buffer{}, applyValue(3, &i3))
s1Responses := &synchronizedBuffer{}
s2Responses := &synchronizedBuffer{}
s3Responses := &synchronizedBuffer{}
defer func(sb *synchronizedBuffer) { t.Logf("s1 responses: %s", sb.String()) }(s1Responses)
defer func(sb *synchronizedBuffer) { t.Logf("s2 responses: %s", sb.String()) }(s2Responses)
defer func(sb *synchronizedBuffer) { t.Logf("s3 responses: %s", sb.String()) }(s3Responses)
peers := raft.MakePeers(
raft.NewLocalPeer(s1),
raft.NewLocalPeer(s2),
raft.NewLocalPeer(s3),
)
s1.SetPeers(peers)
s2.SetPeers(peers)
s3.SetPeers(peers)
s1.Start()
s2.Start()
s3.Start()
defer s1.Stop()
defer s2.Stop()
defer s3.Stop()
var v int32 = 42
cmd, _ := json.Marshal(SetValue{v})
response := make(chan []byte, 1)
func() {
for {
switch err := s1.Command(cmd, response); err {
case nil:
return
case raft.ErrUnknownLeader:
time.Sleep(raft.MinimumElectionTimeout())
default:
t.Fatal(err)
}
}
}()
r, ok := <-response
if ok {
s1Responses.Write(r)
} else {
t.Logf("didn't receive command response")
}
ticker := time.Tick(raft.BroadcastInterval())
timeout := time.After(1 * time.Second)
for {
select {
case <-ticker:
i1l := atomic.LoadInt32(&i1)
i2l := atomic.LoadInt32(&i2)
i3l := atomic.LoadInt32(&i3)
t.Logf("i1=%02d i2=%02d i3=%02d", i1l, i2l, i3l)
if i1l == v && i2l == v && i3l == v {
t.Logf("success!")
return
}
case <-timeout:
t.Fatal("timeout")
}
}
}