diff --git a/go-pool/stratum/handlers.go b/go-pool/stratum/handlers.go
index 7f80520..3b7d9a7 100644
--- a/go-pool/stratum/handlers.go
+++ b/go-pool/stratum/handlers.go
@@ -30,17 +30,16 @@ func (s *StratumServer) handleLoginRPC(cs *Session, e *Endpoint, params *LoginPa
 	id := extractWorkerId(params.Login)
 	miner, ok := s.miners.Get(id)
 	if !ok {
-		miner = NewMiner(id, e.config.Difficulty, cs.ip)
+		miner = NewMiner(id, cs.ip)
+		s.registerMiner(miner)
 	}
 
 	log.Printf("Miner connected %s@%s", id, cs.ip)
 
-	miner.Session = cs
-	miner.Endpoint = e
-	s.registerMiner(miner)
+	s.registerSession(cs)
 	miner.heartbeat()
 
-	return &JobReply{Id: id, Job: miner.getJob(t, true), Status: "OK"}, nil
+	return &JobReply{Id: id, Job: cs.getJob(t), Status: "OK"}, nil
 }
 
 func (s *StratumServer) handleGetJobRPC(cs *Session, e *Endpoint, params *GetJobParams) (reply *JobReplyData, errorReply *ErrorReply) {
@@ -55,7 +54,7 @@ func (s *StratumServer) handleGetJobRPC(cs *Session, e *Endpoint, params *GetJob
 		return
 	}
 	miner.heartbeat()
-	reply = miner.getJob(t, false)
+	reply = cs.getJob(t)
 	return
 }
 
@@ -67,7 +66,7 @@ func (s *StratumServer) handleSubmitRPC(cs *Session, e *Endpoint, params *Submit
 	}
 	miner.heartbeat()
 
-	job := miner.findJob(params.JobId)
+	job := cs.findJob(params.JobId)
 	if job == nil {
 		errorReply = &ErrorReply{Code: -1, Message: "Invalid job id", Close: true}
 		atomic.AddUint64(&miner.invalidShares, 1)
@@ -115,24 +114,27 @@ func (s *StratumServer) broadcastNewJobs() {
 	if t == nil {
 		return
 	}
-	log.Printf("Broadcasting new jobs to %v miners", s.miners.Count())
+	s.sessionsMu.RLock()
+	defer s.sessionsMu.RUnlock()
+	count := len(s.sessions)
+	log.Printf("Broadcasting new jobs to %d miners", count)
 	bcast := make(chan int, 1024*16)
 	n := 0
 
-	for m := range s.miners.IterBuffered() {
+	for m := range s.sessions {
 		n++
 		bcast <- n
-		go func(miner *Miner) {
-			reply := miner.getJob(t, true)
-			err := miner.Session.pushMessage("job", &reply)
+		go func(cs *Session) {
+			reply := cs.getJob(t)
+			err := cs.pushMessage("job", &reply)
 			<-bcast
 			if err != nil {
-				log.Printf("Job transmit error to %v@%v: %v", miner.Id, miner.IP, err)
-				s.removeMiner(miner.Id)
+				log.Printf("Job transmit error to %s: %v", cs.ip, err)
+				s.removeSession(cs)
 			} else {
-				s.setDeadline(miner.Session.conn)
+				s.setDeadline(cs.conn)
 			}
-		}(m.Val)
+		}(m)
 	}
 }
 
diff --git a/go-pool/stratum/miner.go b/go-pool/stratum/miner.go
index 5d884f2..2151247 100644
--- a/go-pool/stratum/miner.go
+++ b/go-pool/stratum/miner.go
@@ -25,16 +25,10 @@ type Job struct {
 
 type Miner struct {
 	sync.RWMutex
-	Id              string
-	IP              string
-	Difficulty      int64
-	ValidJobs       []*Job
-	LastBlockHeight int64
-	Target          uint32
-	TargetHex       string
-	LastBeat        int64
-	Session         *Session
-	Endpoint        *Endpoint
+	Id       string
+	IP       string
+	LastBeat int64
+	Endpoint *Endpoint
 
 	startedAt     int64
 	validShares   uint64
@@ -56,39 +50,46 @@ func (job *Job) submit(nonce string) bool {
 	return false
 }
 
-func NewMiner(id string, diff int64, ip string) *Miner {
+func NewMiner(id string, ip string) *Miner {
 	shares := make(map[int64]int64)
-	miner := &Miner{Id: id, Difficulty: diff, IP: ip, shares: shares}
-	target, targetHex := util.GetTargetHex(diff)
-	miner.Target = target
-	miner.TargetHex = targetHex
-	return miner
+	return &Miner{Id: id, IP: ip, shares: shares}
 }
 
-func (m *Miner) pushJob(job *Job) {
-	m.Lock()
-	defer m.Unlock()
-	m.ValidJobs = append(m.ValidJobs, job)
+func (cs *Session) getJob(t *BlockTemplate) *JobReplyData {
+	height := atomic.SwapInt64(&cs.lastBlockHeight, t.Height)
 
-	if len(m.ValidJobs) > 4 {
-		m.ValidJobs = m.ValidJobs[1:]
+	if height == t.Height {
+		return &JobReplyData{}
 	}
+
+	extraNonce := atomic.AddUint32(&cs.endpoint.extraNonce, 1)
+	blob := t.nextBlob(extraNonce, cs.endpoint.instanceId)
+	job := &Job{Id: util.Random(), ExtraNonce: extraNonce, Height: t.Height, Difficulty: cs.difficulty}
+	job.Submissions = make(map[string]bool)
+	cs.pushJob(job)
+	reply := &JobReplyData{JobId: job.Id, Blob: blob, Target: cs.targetHex}
+	return reply
 }
 
-func (m *Miner) getJob(t *BlockTemplate, force bool) *JobReplyData {
-	height := atomic.SwapInt64(&m.LastBlockHeight, t.Height)
+func (cs *Session) pushJob(job *Job) {
+	cs.Lock()
+	defer cs.Unlock()
+	cs.validJobs = append(cs.validJobs, job)
 
-	if !force && height == t.Height {
-		return &JobReplyData{}
+	if len(cs.validJobs) > 4 {
+		cs.validJobs = cs.validJobs[1:]
 	}
+}
 
-	extraNonce := atomic.AddUint32(&m.Endpoint.extraNonce, 1)
-	blob := t.nextBlob(extraNonce, m.Endpoint.instanceId)
-	job := &Job{Id: util.Random(), ExtraNonce: extraNonce, Height: t.Height, Difficulty: m.Difficulty}
-	job.Submissions = make(map[string]bool)
-	m.pushJob(job)
-	reply := &JobReplyData{JobId: job.Id, Blob: blob, Target: m.TargetHex}
-	return reply
+func (cs *Session) findJob(id string) *Job {
+	cs.Lock()
+	defer cs.Unlock()
+	for _, job := range cs.validJobs {
+		if job.Id == id {
+			return job
+		}
+	}
+	return nil
 }
 
 func (m *Miner) heartbeat() {
@@ -129,17 +130,6 @@ func (m *Miner) hashrate(estimationWindow time.Duration) float64 {
 	return float64(totalShares) / float64(boundary)
 }
 
-func (m *Miner) findJob(id string) *Job {
-	m.RLock()
-	defer m.RUnlock()
-	for _, job := range m.ValidJobs {
-		if job.Id == id {
-			return job
-		}
-	}
-	return nil
-}
-
 func (m *Miner) processShare(s *StratumServer, e *Endpoint, job *Job, t *BlockTemplate, nonce string, result string) bool {
 	r := s.rpc()
 
diff --git a/go-pool/stratum/stratum.go b/go-pool/stratum/stratum.go
index 91167fc..bc8a54c 100644
--- a/go-pool/stratum/stratum.go
+++ b/go-pool/stratum/stratum.go
@@ -15,6 +15,7 @@ import (
 
 	"../pool"
 	"../rpc"
+	"../util"
 )
 
 type StratumServer struct {
@@ -30,6 +31,8 @@ type StratumServer struct {
 	luckWindow       int64
 	luckLargeWindow  int64
 	roundShares      int64
+	sessionsMu       sync.RWMutex
+	sessions         map[*Session]struct{}
 }
 
 type Endpoint struct {
@@ -40,9 +43,15 @@ type Endpoint struct {
 
 type Session struct {
 	sync.Mutex
-	conn *net.TCPConn
-	enc  *json.Encoder
-	ip   string
+	conn            *net.TCPConn
+	enc             *json.Encoder
+	ip              string
+	endpoint        *Endpoint
+	difficulty      int64
+	validJobs       []*Job
+	lastBlockHeight int64
+	target          uint32
+	targetHex       string
 }
 
 const (
@@ -65,6 +74,7 @@ func NewStratum(cfg *pool.Config) *StratumServer {
 	log.Printf("Default upstream: %s => %s", stratum.rpc().Name, stratum.rpc().Url)
 
 	stratum.miners = NewMinersMap()
+	stratum.sessions = make(map[*Session]struct{})
 
 	timeout, _ := time.ParseDuration(cfg.Stratum.Timeout)
 	stratum.timeout = timeout
@@ -150,12 +160,14 @@ func (e *Endpoint) Listen(s *StratumServer) {
 		}
 		conn.SetKeepAlive(true)
 		ip, _, _ := net.SplitHostPort(conn.RemoteAddr().String())
+		cs := &Session{conn: conn, ip: ip, enc: json.NewEncoder(conn), endpoint: e}
 		n += 1
 
 		accept <- n
 		go func() {
-			err = s.handleClient(conn, e, ip)
+			err = s.handleClient(cs, e)
 			if err != nil {
+				s.removeSession(cs)
 				conn.Close()
 			}
 			<-accept
@@ -163,11 +175,12 @@ func (e *Endpoint) Listen(s *StratumServer) {
 	}
 }
 
-func (s *StratumServer) handleClient(conn *net.TCPConn, e *Endpoint, ip string) error {
-	cs := &Session{conn: conn, ip: ip}
-	cs.enc = json.NewEncoder(conn)
-	connbuff := bufio.NewReaderSize(conn, MaxReqSize)
-	s.setDeadline(conn)
+func (s *StratumServer) handleClient(cs *Session, e *Endpoint) error {
+	_, targetHex := util.GetTargetHex(e.config.Difficulty)
+	cs.targetHex = targetHex
+
+	connbuff := bufio.NewReaderSize(cs.conn, MaxReqSize)
+	s.setDeadline(cs.conn)
 
 	for {
 		data, isPrefix, err := connbuff.ReadLine()
@@ -192,7 +205,7 @@ func (s *StratumServer) handleClient(conn *net.TCPConn, e *Endpoint, ip string)
 				log.Printf("Malformed request: %v", err)
 				return err
 			}
-			s.setDeadline(conn)
+			s.setDeadline(cs.conn)
 			cs.handleMessage(s, e, &req)
 		}
 	}
@@ -292,6 +305,25 @@ func (s *StratumServer) setDeadline(conn *net.TCPConn) {
 	conn.SetDeadline(time.Now().Add(s.timeout))
 }
 
+func (s *StratumServer) registerSession(cs *Session) {
+	s.sessionsMu.Lock()
+	defer s.sessionsMu.Unlock()
+	s.sessions[cs] = struct{}{}
+}
+
+func (s *StratumServer) removeSession(cs *Session) {
+	s.sessionsMu.Lock()
+	defer s.sessionsMu.Unlock()
+	delete(s.sessions, cs)
+}
+
+func (s *StratumServer) isActive(cs *Session) bool {
+	s.sessionsMu.RLock()
+	defer s.sessionsMu.RUnlock()
+	_, exist := s.sessions[cs]
+	return exist
+}
+
 func (s *StratumServer) registerMiner(miner *Miner) {
 	s.miners.Set(miner.Id, miner)
 }