update

src/kvraft1/kvraft_test.go

@@ -1,7 +1,7 @@
 package kvraft
 
 import (
-	// "log"
+	//"log"
 	"strconv"
 	"testing"
 	"time"
@@ -288,7 +288,11 @@ func TestPersistPartitionUnreliableLinearizable4B(t *testing.T) {
 // also checks that majority discards committed log entries
 // even if minority doesn't respond.
 func TestSnapshotRPC4C(t *testing.T) {
-	ts := MakeTest(t, "4C SnapshotsRPC", 0, 3, false, false, false, 1000, false)
+	const (
+		NSRV         = 3
+		MAXRAFTSTATE = 1000
+	)
+	ts := MakeTest(t, "4C SnapshotsRPC", 0, NSRV, false, false, false, MAXRAFTSTATE, false)
 	defer ts.Cleanup()
 
 	ck := ts.MakeClerk()
@@ -304,10 +308,10 @@ func TestSnapshotRPC4C(t *testing.T) {
 	{
 		ck1 := ts.MakeClerkTo([]int{0, 1})
 		for i := 0; i < 50; i++ {
-			verb = ts.PutAtLeastOnce(ck1, strconv.Itoa(i), strconv.Itoa(i), rpc.Tversion(0), -1)
+			ts.PutAtLeastOnce(ck1, strconv.Itoa(i), strconv.Itoa(i), rpc.Tversion(0), -1)
 		}
 		time.Sleep(kvtest.ElectionTimeout)
-		verb = ts.PutAtLeastOnce(ck1, "b", "B", verb, -1)
+		verb = ts.PutAtLeastOnce(ck1, "b", "B", rpc.Tversion(0), -1)
 	}
 
 	// check that the majority partition has thrown away

src/kvraft1/rsm/rsm.go

@@ -6,10 +6,14 @@ import (
 	"6.5840/kvsrv1/rpc"
 	"6.5840/labrpc"
 	"6.5840/raft1"
+	"6.5840/raftapi"
 	"6.5840/tester1"
 
 )
 
+var useRaftStateMachine bool // to plug in another raft besided raft1
+
+
 type Op struct {
 	// Your definitions here.
 	// Field names must start with capital letters,
@@ -32,8 +36,8 @@ type StateMachine interface {
 type RSM struct {
 	mu           sync.Mutex
 	me           int
-	rf           *raft.Raft
-	applyCh      chan raft.ApplyMsg
+	rf           raftapi.Raft
+	applyCh      chan raftapi.ApplyMsg
 	maxraftstate int // snapshot if log grows this big
 	sm           StateMachine
 	// Your definitions here.
@@ -56,24 +60,23 @@ func MakeRSM(servers []*labrpc.ClientEnd, me int, persister *tester.Persister, m
 	rsm := &RSM{
 		me:           me,
 		maxraftstate: maxraftstate,
-		applyCh:      make(chan raft.ApplyMsg),
+		applyCh:      make(chan raftapi.ApplyMsg),
 		sm:           sm,
 	}
+	if !useRaftStateMachine {
 		rsm.rf = raft.Make(servers, me, persister, rsm.applyCh)
+	}
 	return rsm
 }
 
-func (rsm *RSM) Raft() *raft.Raft {
+func (rsm *RSM) Raft() raftapi.Raft {
 	return rsm.rf
 }
 
 
-// submit a command to Raft,
-// and wait for it to be committed.
-//
-// returns (executeError, executeResult)
-// if executeError==ErrWrongLeader, client should find new leader
-// and try again.
+// Submit a command to Raft, and wait for it to be committed.  It
+// should return ErrWrongLeader if client should find new leader and
+// try again.
 func (rsm *RSM) Submit(req any) (rpc.Err, any) {
 
 	// Submit creates an Op structure to run a command through Raft;

src/kvraft1/rsm/rsm_test.go

@@ -2,6 +2,7 @@ package rsm
 
 import (
 	//"log"
+	"sync"
 	"testing"
 	"time"
 
@@ -10,11 +11,12 @@ import (
 
 // test that each server executes increments and updates its counter.
 func TestBasic4A(t *testing.T) {
+	const NINC = 10
 	ts := makeTest(t, -1)
 	defer ts.cleanup()
 
 	ts.Begin("Test RSM basic")
-	for i := 0; i < 10; i++ {
+	for i := 0; i < NINC; i++ {
 		r := ts.oneInc()
 		if r.N != i+1 {
 			ts.t.Fatalf("expected %d instead of %d", i, r.N)
@@ -23,6 +25,26 @@ func TestBasic4A(t *testing.T) {
 	}
 }
 
+// test submitting concurrently
+func TestConcurrent4A(t *testing.T) {
+	const NINC = 50
+	ts := makeTest(t, -1)
+	defer ts.cleanup()
+
+	ts.Begin("Test concurrent submit")
+
+	var wg sync.WaitGroup
+	for i := 0; i < NINC; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			ts.oneInc()
+		}()
+	}
+	wg.Wait()
+	ts.checkCounter(NINC, NSRV)
+}
+
 // test that each server executes increments after disconnecting and
 // reconnecting leader
 func TestLeaderFailure4A(t *testing.T) {
@@ -43,7 +65,10 @@ func TestLeaderFailure4A(t *testing.T) {
 	ts.checkCounter(r.N, NSRV)
 }
 
+// test that partitioned leader doesn't commit an operation
 func TestLeaderPartition4A(t *testing.T) {
+	const NSUBMIT = 100
+
 	ts := makeTest(t, -1)
 	defer ts.cleanup()
 
@@ -58,18 +83,33 @@ func TestLeaderPartition4A(t *testing.T) {
 	p1, p2 := ts.Group(Gid).MakePartition(l)
 	ts.Group(Gid).Partition(p1, p2)
 
-	done := make(chan rpc.Err)
+	done := make(chan struct{})
 	go func() {
-		err, _ := ts.srvs[l].rsm.Submit(Inc{})
-		done <- err
+		// Submit many Dec's concurrently, which will results in many
+		// raft.Start()'s, but none should commit and be executed.
+		var wg sync.WaitGroup
+		for i := 0; i < NSUBMIT; i++ {
+			wg.Add(1)
+			go func(i int) {
+				defer wg.Done()
+				if err, rep := ts.srvs[l].rsm.Submit(Dec{}); err == rpc.OK {
+					t.Fatalf("Submit %d in minority completed %v", i, rep)
+				}
+			}(i)
+		}
+		wg.Wait()
+		done <- struct{}{}
 	}()
 
+	// give old leader some time to submit
+	time.Sleep(10 * time.Millisecond)
+
 	// submit an Inc in the majority
 	rep := ts.oneIncPartition(p1)
 
 	select {
-	case ver := <-done:
-		ts.Fatalf("Inc in minority completed %v", ver)
+	case err := <-done:
+		ts.Fatalf("Dec's in minority completed %v", err)
 	case <-time.After(time.Second):
 	}
 
@@ -77,10 +117,7 @@ func TestLeaderPartition4A(t *testing.T) {
 	ts.connect(l)
 
 	select {
-	case err := <-done:
-		if err == rpc.OK {
-			ts.Fatalf("Inc in minority didn't fail")
-		}
+	case <-done:
 	case <-time.After(time.Second):
 		ts.Fatalf("Submit after healing didn't return")
 	}

src/kvraft1/rsm/server.go

@@ -7,13 +7,16 @@ import (
 
 	"6.5840/labgob"
 	"6.5840/labrpc"
-	"6.5840/raft1"
+	"6.5840/raftapi"
 	"6.5840/tester1"
 )
 
 type Inc struct {
 }
 
+type Dec struct {
+}
+
 type Rep struct {
 	N int
 }
@@ -31,6 +34,7 @@ func makeRsmSrv(ts *Test, srv int, ends []*labrpc.ClientEnd, persister *tester.P
 	labgob.Register(Op{})
 	labgob.Register(Inc{})
 	labgob.Register(Rep{})
+	labgob.Register(Dec{})
 	s := &rsmSrv{
 		ts: ts,
 		me: srv,
@@ -43,7 +47,7 @@ func (rs *rsmSrv) DoOp(req any) any {
 	//log.Printf("%d: DoOp: %v", rs.me, req)
 	if _, ok := req.(Inc); ok == false {
 		// wrong type! expecting an Inc.
-		log.Fatalf("DoOp called with the wrong type")
+		log.Fatalf("DoOp should execute only Inc and not %T", req)
 	}
 	rs.mu.Lock()
 	rs.counter += 1
@@ -76,7 +80,7 @@ func (rs *rsmSrv) Kill() {
 	rs.rsm = nil
 }
 
-func (rs *rsmSrv) Raft() *raft.Raft {
+func (rs *rsmSrv) Raft() raftapi.Raft {
 	rs.mu.Lock()
 	defer rs.mu.Unlock()
 	return rs.rsm.Raft()

src/kvraft1/rsm/test.go

@@ -7,7 +7,7 @@ import (
 
 	"6.5840/kvsrv1/rpc"
 	"6.5840/labrpc"
-	"6.5840/raft1"
+	"6.5840/raftapi"
 	"6.5840/tester1"
 )
 
@@ -135,7 +135,7 @@ func Leader(cfg *tester.Config, gid tester.Tgid) (bool, int) {
 	for i, ss := range cfg.Group(gid).Services() {
 		for _, s := range ss {
 			switch r := s.(type) {
-			case *raft.Raft:
+			case raftapi.Raft:
 				_, isLeader := r.GetState()
 				if isLeader {
 					return true, i

src/kvtest1/kvtest.go

@@ -2,7 +2,7 @@ package kvtest
 
 import (
 	"encoding/json"
-	// "log"
+	//"log"
 	"math/rand"
 	"strconv"
 	"testing"
@@ -76,12 +76,21 @@ func (ts *Test) MakeClerk() IKVClerk {
 	return ts.mck.MakeClerk()
 }
 
+// Assumes different ck's put to different keys
 func (ts *Test) PutAtLeastOnce(ck IKVClerk, key, value string, ver rpc.Tversion, me int) rpc.Tversion {
 	for true {
-		if err := ts.Put(ck, key, value, ver, me); err == rpc.OK {
+		err := ts.Put(ck, key, value, ver, me)
+		if err == rpc.OK {
 			break
 		}
+		if err == rpc.ErrMaybe || err == rpc.ErrVersion {
 			ver += 1
+		} else {
+			// if failed with ver = 0, retry
+			if ver != 0 { // check that ver is indeed 0
+				ts.Fatalf("Put %v ver %d err %v", key, ver, err)
+			}
+		}
 	}
 	return ver
 }

src/raft1/raft.go

@@ -1,21 +1,10 @@
 package raft
 
+// The file raftapi/raft.go defines the interface that raft must
+// expose to servers (or the tester), but see comments below for each
+// of these functions for more details.
 //
-// this is an outline of the API that raft must expose to
-// the service (or tester). see comments below for
-// each of these functions for more details.
-//
-// rf = Make(...)
-//   create a new Raft server.
-// rf.Start(command interface{}) (index, term, isleader)
-//   start agreement on a new log entry
-// rf.GetState() (term, isLeader)
-//   ask a Raft for its current term, and whether it thinks it is leader
-// ApplyMsg
-//   each time a new entry is committed to the log, each Raft peer
-//   should send an ApplyMsg to the service (or tester)
-//   in the same server.
-//
+// Make() creates a new raft peer that implements the raft interface.
 
 import (
 	//	"bytes"
@@ -26,31 +15,11 @@ import (
 
 	//	"6.5840/labgob"
 	"6.5840/labrpc"
+	"6.5840/raftapi"
 	"6.5840/tester1"
 )
 
 
-// as each Raft peer becomes aware that successive log entries are
-// committed, the peer should send an ApplyMsg to the service (or
-// tester) on the same server, via the applyCh passed to Make(). set
-// CommandValid to true to indicate that the ApplyMsg contains a newly
-// committed log entry.
-//
-// in part 3D you'll want to send other kinds of messages (e.g.,
-// snapshots) on the applyCh, but set CommandValid to false for these
-// other uses.
-type ApplyMsg struct {
-	CommandValid bool
-	Command      interface{}
-	CommandIndex int
-
-	// For 3D:
-	SnapshotValid bool
-	Snapshot      []byte
-	SnapshotTerm  int
-	SnapshotIndex int
-}
-
 // A Go object implementing a single Raft peer.
 type Raft struct {
 	mu        sync.Mutex          // Lock to protect shared access to this peer's state
@@ -114,6 +83,13 @@ func (rf *Raft) readPersist(data []byte) {
 	// }
 }
 
+// how many bytes in Raft's persisted log?
+func (rf *Raft) PersistBytes() int {
+	rf.mu.Lock()
+	defer rf.mu.Unlock()
+	return rf.persister.RaftStateSize()
+}
+
 
 // the service says it has created a snapshot that has
 // all info up to and including index. this means the
@@ -241,7 +217,7 @@ func (rf *Raft) ticker() {
 // Make() must return quickly, so it should start goroutines
 // for any long-running work.
 func Make(peers []*labrpc.ClientEnd, me int,
-	persister *tester.Persister, applyCh chan ApplyMsg) *Raft {
+	persister *tester.Persister, applyCh chan raftapi.ApplyMsg) raftapi.Raft {
 	rf := &Raft{}
 	rf.peers = peers
 	rf.persister = persister

src/raft1/server.go

@@ -8,13 +8,18 @@ import (
 
 	"6.5840/labgob"
 	"6.5840/labrpc"
+	"6.5840/raftapi"
 	"6.5840/tester1"
+
 )
 
 const (
 	SnapShotInterval = 10
 )
 
+var useRaftStateMachine bool // to plug in another raft besided raft1
+
+
 type rfsrv struct {
 	ts          *Test
 	me          int
@@ -23,7 +28,7 @@ type rfsrv struct {
 	persister   *tester.Persister
 
 	mu   sync.Mutex
-	raft *Raft
+	raft raftapi.Raft
 	logs map[int]any // copy of each server's committed entries
 }
 
@@ -35,8 +40,10 @@ func newRfsrv(ts *Test, srv int, ends []*labrpc.ClientEnd, persister *tester.Per
 		logs:      map[int]any{},
 		persister: persister,
 	}
-	applyCh := make(chan ApplyMsg)
+	applyCh := make(chan raftapi.ApplyMsg)
+	if !useRaftStateMachine {
 		s.raft = Make(ends, srv, persister, applyCh)
+	}
 	if snapshot {
 		snapshot := persister.ReadSnapshot()
 		if snapshot != nil && len(snapshot) > 0 {
@@ -74,7 +81,7 @@ func (rs *rfsrv) GetState() (int, bool) {
 	return rs.raft.GetState()
 }
 
-func (rs *rfsrv) Raft() *Raft {
+func (rs *rfsrv) Raft() raftapi.Raft {
 	rs.mu.Lock()
 	defer rs.mu.Unlock()
 	return rs.raft
@@ -89,7 +96,7 @@ func (rs *rfsrv) Logs(i int) (any, bool) {
 
 // applier reads message from apply ch and checks that they match the log
 // contents
-func (rs *rfsrv) applier(applyCh chan ApplyMsg) {
+func (rs *rfsrv) applier(applyCh chan raftapi.ApplyMsg) {
 	for m := range applyCh {
 		if m.CommandValid == false {
 			// ignore other types of ApplyMsg
@@ -109,7 +116,7 @@ func (rs *rfsrv) applier(applyCh chan ApplyMsg) {
 }
 
 // periodically snapshot raft state
-func (rs *rfsrv) applierSnap(applyCh chan ApplyMsg) {
+func (rs *rfsrv) applierSnap(applyCh chan raftapi.ApplyMsg) {
 	if rs.raft == nil {
 		return // ???
 	}

src/raft1/test.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"6.5840/labrpc"
+	"6.5840/raftapi"
 	"6.5840/tester1"
 )
 
@@ -107,7 +108,7 @@ func (ts *Test) checkTerms() int {
 	return term
 }
 
-func (ts *Test) checkLogs(i int, m ApplyMsg) (string, bool) {
+func (ts *Test) checkLogs(i int, m raftapi.ApplyMsg) (string, bool) {
 	ts.mu.Lock()
 	defer ts.mu.Unlock()
 
@@ -189,7 +190,7 @@ func (ts *Test) one(cmd any, expectedServers int, retry bool) int {
 		index := -1
 		for range ts.srvs {
 			starts = (starts + 1) % len(ts.srvs)
-			var rf *Raft
+			var rf raftapi.Raft
 			if ts.g.IsConnected(starts) {
 				rf = ts.srvs[starts].raft
 			}

src/raftapi/raftapi.go

@@ -0,0 +1,40 @@
+package raftapi
+
+// The Raft interface
+type Raft interface {
+	// Start agreement on a new log entry, and return the log index
+	// for that entry, the term, and whether the peer is the leader.
+	Start(command interface{}) (int, int, bool)
+
+	// Ask a Raft for its current term, and whether it thinks it is
+	// leader
+	GetState() (int, bool)
+
+	// For Snaphots (3D)
+	Snapshot(index int, snapshot []byte)
+	PersistBytes() int
+
+	// For the tester to indicate to your code that is should cleanup
+	// any long-running go routines.
+	Kill()
+}
+
+// As each Raft peer becomes aware that successive log entries are
+// committed, the peer should send an ApplyMsg to the service (or
+// tester) on the same server, via the applyCh passed to Make(). set
+// CommandValid to true to indicate that the ApplyMsg contains a newly
+// committed log entry.
+//
+// In Lab 3 you'll want to send other kinds of messages (e.g.,
+// snapshots) on the applyCh; at that point you can add fields to
+// ApplyMsg, but set CommandValid to false for these other uses.
+type ApplyMsg struct {
+	CommandValid bool
+	Command      interface{}
+	CommandIndex int
+
+	SnapshotValid bool
+	Snapshot      []byte
+	SnapshotTerm  int
+	SnapshotIndex int
+}

src/shardkv1/shardctrler/client.go

@@ -0,0 +1,49 @@
+package shardctrler
+
+import (
+	// "log"
+	"sync/atomic"
+
+	"6.5840/kvsrv1/rpc"
+	"6.5840/tester1"
+)
+
+type Clerk struct {
+	clnt    *tester.Clnt
+	servers []string
+	deposed *int32
+	// You will have to modify this struct.
+}
+
+// The shard controller can use MakeClerk to make a clerk for the kvraft
+// group with the servers `servers`.
+func MakeClerk(clnt *tester.Clnt, servers []string, deposed *int32) *Clerk {
+	ck := &Clerk{clnt: clnt, servers: servers, deposed: deposed}
+	// You may add code here.
+	return ck
+}
+
+func (ck *Clerk) isDeposed() bool {
+	z := atomic.LoadInt32(ck.deposed)
+	return z == 1
+}
+
+// You can reuse your kvraft Get
+func (ck *Clerk) Get(key string) (string, rpc.Tversion, rpc.Err) {
+	args := rpc.GetArgs{}
+	args.Key = key
+
+	// You'll have to add code here.
+	return "", 0, ""
+}
+
+// You can reuse your kvraft Put
+func (ck *Clerk) Put(key string, value string, version rpc.Tversion) rpc.Err {
+	args := rpc.PutArgs{}
+	args.Key = key
+	args.Value = value
+	args.Version = version
+
+	// You'll have to add code here.
+	return ""
+}

src/tester1/clnts.go

@@ -2,7 +2,6 @@ package tester
 
 import (
 	//"log"
-	"os"
 	"sync"
 
 	"6.5840/labrpc"
@@ -98,7 +97,7 @@ func (clnt *Clnt) remove() {
 	defer clnt.mu.Unlock()
 
 	for _, e := range clnt.ends {
-		os.Remove(e.name)
+		clnt.net.DeleteEnd(e.name)
 	}
 }
 
@@ -142,12 +141,15 @@ func (clnts *Clnts) cleanup() {
 	for clnt, _ := range clnts.clerks {
 		clnt.remove()
 	}
+	clnts.clerks = nil
 }
 
 func (clnts *Clnts) DeleteClient(clnt *Clnt) {
 	clnts.mu.Lock()
 	defer clnts.mu.Unlock()
 
+	if _, ok := clnts.clerks[clnt]; ok {
 		clnt.remove()
 		delete(clnts.clerks, clnt)
+	}
 }

src/tester1/tester_test.go

@@ -0,0 +1,84 @@
+package tester_test
+
+import (
+	"testing"
+
+	"6.5840/kvsrv1/rpc"
+	"6.5840/labrpc"
+	"6.5840/tester1"
+)
+
+type Server struct {
+	n      rpc.Tversion
+	killed bool
+}
+
+func newSrv() *Server {
+	return &Server{}
+}
+
+func (s *Server) Kill() {
+	s.killed = true
+}
+
+func (s *Server) Get(args *rpc.GetArgs, reply *rpc.GetReply) {
+	s.n += 1
+	reply.Version = s.n
+}
+
+type Test struct {
+	t *testing.T
+	s *Server
+	*tester.Config
+	clnt *tester.Clnt
+	sn   string
+}
+
+func makeTest(t *testing.T, nsrv int) *Test {
+	ts := &Test{t: t, sn: tester.ServerName(tester.GRP0, 0)}
+	cfg := tester.MakeConfig(t, nsrv, true, ts.startServer)
+	ts.Config = cfg
+	ts.clnt = ts.Config.MakeClient()
+	return ts
+}
+
+func (ts *Test) startServer(servers []*labrpc.ClientEnd, gid tester.Tgid, me int, persister *tester.Persister) []tester.IService {
+	ts.s = newSrv()
+	return []tester.IService{ts.s}
+}
+
+func (ts *Test) cleanup() {
+	ts.Cleanup()
+}
+
+func (ts *Test) oneRPC() bool {
+	args := rpc.GetArgs{"xxx"}
+	var reply rpc.GetReply
+	if ok := ts.clnt.Call(ts.sn, "Server.Get", &args, &reply); !ok {
+		return false
+	}
+	if reply.Version != ts.s.n {
+		ts.Fatalf("Wrong version")
+	}
+	return true
+}
+
+func TestBasic(t *testing.T) {
+	ts := makeTest(t, 1)
+	defer ts.cleanup()
+	ts.oneRPC()
+}
+
+func TestShutdownServer(t *testing.T) {
+	ts := makeTest(t, 1)
+	defer ts.cleanup()
+
+	ts.oneRPC()
+	ts.Group(tester.GRP0).Shutdown()
+	if !ts.s.killed {
+		ts.Fatalf("Not killed")
+	}
+	if ok := ts.oneRPC(); ok {
+		ts.Fatalf("RPC succeeded")
+	}
+}