func StartServer(vshost string, me string) *PBServer {
pb := new(PBServer)
pb.me = me
pb.vs = viewservice.MakeClerk(me, vshost)
// Your pb.* initializations here.
pb.store = make(map[string]string)
rpcs := rpc.NewServer()
rpcs.Register(pb)
os.Remove(pb.me)
l, e := net.Listen("unix", pb.me)
if e != nil {
log.Fatal("listen error: ", e)
}
pb.l = l
// please do not change any of the following code,
// or do anything to subvert it.
go func() {
for pb.dead == false {
conn, err := pb.l.Accept()
if err == nil && pb.dead == false {
if pb.unreliable && (rand.Int63()%1000) < 100 {
// discard the request.
conn.Close()
} else if pb.unreliable && (rand.Int63()%1000) < 200 {
// process the request but force discard of reply.
c1 := conn.(*net.UnixConn)
f, _ := c1.File()
err := syscall.Shutdown(int(f.Fd()), syscall.SHUT_WR)
if err != nil {
fmt.Printf("shutdown: %v\n", err)
}
go rpcs.ServeConn(conn)
} else {
go rpcs.ServeConn(conn)
}
} else if err == nil {
conn.Close()
}
if err != nil && pb.dead == false {
fmt.Printf("PBServer(%v) accept: %v\n", me, err.Error())
pb.kill()
}
}
}()
go func() {
for pb.dead == false {
pb.tick()
time.Sleep(viewservice.PingInterval)
}
}()
return pb
}
func TestPartition2(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "part2"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
ck1 := MakeClerk(vshost, "")
vshosta := vshost + "a"
os.Link(vshost, vshosta)
s1 := StartServer(vshosta, port(tag, 1))
delay := 0
proxy(t, port(tag, 1), &delay)
fmt.Printf("Test: Partitioned old primary does not complete Gets ...\n")
deadtime := viewservice.PingInterval * viewservice.DeadPings
time.Sleep(deadtime * 2)
if vck.Primary() != s1.me {
t.Fatal("primary never formed initial view")
}
s2 := StartServer(vshost, port(tag, 2))
time.Sleep(deadtime * 2)
v1, _ := vck.Get()
if v1.Primary != s1.me || v1.Backup != s2.me {
t.Fatal("backup did not join view")
}
ck1.Put("a", "1")
check(ck1, "a", "1")
os.Remove(vshosta)
// start a client Get(), but use proxy to delay it long
// enough that it won't reach s1 until after s1 is no
// longer the primary.
delay = 5
stale_get := false
go func() {
x := ck1.Get("a")
if x == "1" {
stale_get = true
}
}()
// now s1 cannot talk to viewserver, so view will change.
for iter := 0; iter < viewservice.DeadPings*3; iter++ {
if vck.Primary() == s2.me {
break
}
time.Sleep(viewservice.PingInterval)
}
if vck.Primary() != s2.me {
t.Fatalf("primary never changed")
}
s3 := StartServer(vshost, port(tag, 3))
for iter := 0; iter < viewservice.DeadPings*3; iter++ {
v, _ := vck.Get()
if v.Backup == s3.me && v.Primary == s2.me {
break
}
time.Sleep(viewservice.PingInterval)
}
v2, _ := vck.Get()
if v2.Primary != s2.me || v2.Backup != s3.me {
t.Fatalf("new backup never joined")
}
time.Sleep(2 * time.Second)
ck2 := MakeClerk(vshost, "")
ck2.Put("a", "2")
check(ck2, "a", "2")
s2.kill()
// wait for delayed get to s1 to complete.
time.Sleep(6 * time.Second)
if stale_get == true {
t.Fatalf("partitioned primary replied to a Get with a stale value")
}
check(ck2, "a", "2")
fmt.Printf(" ... Passed\n")
s1.kill()
s2.kill()
s3.kill()
vs.Kill()
}
func MakeClerk(vshost string, me string) *Clerk {
ck := new(Clerk)
ck.vs = viewservice.MakeClerk(me, vshost)
return ck
}
func TestPartition1(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "part1"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
ck1 := MakeClerk(vshost, "")
fmt.Printf("Test: Old primary does not serve Gets ...\n")
vshosta := vshost + "a"
os.Link(vshost, vshosta)
s1 := StartServer(vshosta, port(tag, 1))
delay := 0
proxy(t, port(tag, 1), &delay)
deadtime := viewservice.PingInterval * viewservice.DeadPings
time.Sleep(deadtime * 2)
if vck.Primary() != s1.me {
t.Fatal("primary never formed initial view")
}
s2 := StartServer(vshost, port(tag, 2))
time.Sleep(deadtime * 2)
v1, _ := vck.Get()
if v1.Primary != s1.me || v1.Backup != s2.me {
t.Fatal("backup did not join view")
}
ck1.Put("a", "1")
check(ck1, "a", "1")
os.Remove(vshosta)
// start a client Get(), but use proxy to delay it long
// enough that it won't reach s1 until after s1 is no
// longer the primary.
delay = 4
stale_get := false
go func() {
x := ck1.Get("a")
if x == "1" {
stale_get = true
}
}()
// now s1 cannot talk to viewserver, so view will change,
// and s1 won't immediately realize.
for iter := 0; iter < viewservice.DeadPings*3; iter++ {
if vck.Primary() == s2.me {
break
}
time.Sleep(viewservice.PingInterval)
}
if vck.Primary() != s2.me {
t.Fatalf("primary never changed")
}
// wait long enough that s2 is guaranteed to have Pinged
// the viewservice, and thus that s2 must know about
// the new view.
time.Sleep(2 * viewservice.PingInterval)
// change the value (on s2) so it's no longer "1".
ck2 := MakeClerk(vshost, "")
ck2.Put("a", "111")
check(ck2, "a", "111")
// wait for the background Get to s1 to be delivered.
time.Sleep(5 * time.Second)
if stale_get {
t.Fatalf("Get to old primary succeeded and produced stale value")
}
check(ck2, "a", "111")
fmt.Printf(" ... Passed\n")
s1.kill()
s2.kill()
vs.Kill()
}
func TestRepeatedCrashUnreliable(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "rcu"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
fmt.Printf("Test: Repeated failures/restarts; unreliable ...\n")
const nservers = 3
var sa [nservers]*PBServer
for i := 0; i < nservers; i++ {
sa[i] = StartServer(vshost, port(tag, i+1))
sa[i].unreliable = true
}
for i := 0; i < viewservice.DeadPings; i++ {
v, _ := vck.Get()
if v.Primary != "" && v.Backup != "" {
break
}
time.Sleep(viewservice.PingInterval)
}
// wait a bit for primary to initialize backup
time.Sleep(viewservice.DeadPings * viewservice.PingInterval)
done := false
go func() {
// kill and restart servers
rr := rand.New(rand.NewSource(int64(os.Getpid())))
for done == false {
i := rr.Int() % nservers
// fmt.Printf("%v killing %v\n", ts(), 5001+i)
sa[i].kill()
// wait long enough for new view to form, backup to be initialized
time.Sleep(2 * viewservice.PingInterval * viewservice.DeadPings)
sa[i] = StartServer(vshost, port(tag, i+1))
// wait long enough for new view to form, backup to be initialized
time.Sleep(2 * viewservice.PingInterval * viewservice.DeadPings)
}
}()
const nth = 2
var cha [nth]chan bool
for xi := 0; xi < nth; xi++ {
cha[xi] = make(chan bool)
go func(i int) {
ok := false
defer func() { cha[i] <- ok }()
ck := MakeClerk(vshost, "")
data := map[string]string{}
rr := rand.New(rand.NewSource(int64(os.Getpid() + i)))
for done == false {
k := strconv.Itoa((i * 1000000) + (rr.Int() % 10))
wanted, ok := data[k]
if ok {
v := ck.Get(k)
if v != wanted {
t.Fatalf("key=%v wanted=%v got=%v", k, wanted, v)
}
}
nv := strconv.Itoa(rr.Int())
ck.Put(k, nv)
data[k] = nv
// if no sleep here, then server tick() threads do not get
// enough time to Ping the viewserver.
time.Sleep(10 * time.Millisecond)
}
ok = true
}(xi)
}
time.Sleep(20 * time.Second)
done = true
for i := 0; i < nth; i++ {
ok := <-cha[i]
if ok == false {
t.Fatal("child failed")
}
}
ck := MakeClerk(vshost, "")
ck.Put("aaa", "bbb")
if v := ck.Get("aaa"); v != "bbb" {
t.Fatalf("final Put/Get failed")
}
fmt.Printf(" ... Passed\n")
for i := 0; i < nservers; i++ {
sa[i].kill()
}
time.Sleep(time.Second)
vs.Kill()
time.Sleep(time.Second)
}
func TestConcurrentSameUnreliable(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "csu"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
fmt.Printf("Test: Concurrent Put()s to the same key; unreliable ...\n")
const nservers = 2
var sa [nservers]*PBServer
for i := 0; i < nservers; i++ {
sa[i] = StartServer(vshost, port(tag, i+1))
sa[i].unreliable = true
}
for iters := 0; iters < viewservice.DeadPings*2; iters++ {
view, _ := vck.Get()
if view.Primary != "" && view.Backup != "" {
break
}
time.Sleep(viewservice.PingInterval)
}
// give p+b time to ack, initialize
time.Sleep(viewservice.PingInterval * viewservice.DeadPings)
done := false
view1, _ := vck.Get()
const nclients = 3
const nkeys = 2
for xi := 0; xi < nclients; xi++ {
go func(i int) {
ck := MakeClerk(vshost, "")
rr := rand.New(rand.NewSource(int64(os.Getpid() + i)))
for done == false {
k := strconv.Itoa(rr.Int() % nkeys)
v := strconv.Itoa(rr.Int())
ck.Put(k, v)
}
}(xi)
}
time.Sleep(5 * time.Second)
done = true
time.Sleep(time.Second)
// read from primary
ck := MakeClerk(vshost, "")
var vals [nkeys]string
for i := 0; i < nkeys; i++ {
vals[i] = ck.Get(strconv.Itoa(i))
if vals[i] == "" {
t.Fatalf("Get(%v) failed from primary", i)
}
}
// kill the primary
for i := 0; i < nservers; i++ {
if view1.Primary == sa[i].me {
sa[i].kill()
break
}
}
for iters := 0; iters < viewservice.DeadPings*2; iters++ {
view, _ := vck.Get()
if view.Primary == view1.Backup {
break
}
time.Sleep(viewservice.PingInterval)
}
view2, _ := vck.Get()
if view2.Primary != view1.Backup {
t.Fatal("wrong Primary")
}
// read from old backup
for i := 0; i < nkeys; i++ {
z := ck.Get(strconv.Itoa(i))
if z != vals[i] {
t.Fatalf("Get(%v) from backup; wanted %v, got %v", i, vals[i], z)
}
}
fmt.Printf(" ... Passed\n")
for i := 0; i < nservers; i++ {
sa[i].kill()
}
time.Sleep(time.Second)
vs.Kill()
time.Sleep(time.Second)
}
func TestBasicFail(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "basic"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
ck := MakeClerk(vshost, "")
fmt.Printf("Test: Single primary, no backup ...\n")
s1 := StartServer(vshost, port(tag, 1))
deadtime := viewservice.PingInterval * viewservice.DeadPings
time.Sleep(deadtime * 2)
if vck.Primary() != s1.me {
t.Fatal("first primary never formed view")
}
ck.Put("111", "v1")
check(ck, "111", "v1")
ck.Put("2", "v2")
check(ck, "2", "v2")
ck.Put("1", "v1a")
check(ck, "1", "v1a")
fmt.Printf(" ... Passed\n")
// add a backup
fmt.Printf("Test: Add a backup ...\n")
s2 := StartServer(vshost, port(tag, 2))
for i := 0; i < viewservice.DeadPings*2; i++ {
v, _ := vck.Get()
if v.Backup == s2.me {
break
}
time.Sleep(viewservice.PingInterval)
}
v, _ := vck.Get()
if v.Backup != s2.me {
t.Fatal("backup never came up")
}
ck.Put("3", "33")
check(ck, "3", "33")
// give the backup time to initialize
time.Sleep(3 * viewservice.PingInterval)
ck.Put("4", "44")
check(ck, "4", "44")
fmt.Printf(" ... Passed\n")
// kill the primary
fmt.Printf("Test: Primary failure ...\n")
s1.kill()
for i := 0; i < viewservice.DeadPings*2; i++ {
v, _ := vck.Get()
if v.Primary == s2.me {
break
}
time.Sleep(viewservice.PingInterval)
}
v, _ = vck.Get()
if v.Primary != s2.me {
t.Fatal("backup never switched to primary")
}
check(ck, "1", "v1a")
check(ck, "3", "33")
check(ck, "4", "44")
fmt.Printf(" ... Passed\n")
// kill solo server, start new server, check that
// it does not start serving as primary
fmt.Printf("Test: Kill last server, new one should not be active ...\n")
s2.kill()
s3 := StartServer(vshost, port(tag, 3))
time.Sleep(1 * time.Second)
get_done := false
go func() {
ck.Get("1")
get_done = true
}()
time.Sleep(2 * time.Second)
if get_done {
t.Fatalf("ck.Get() returned even though no initialized primary")
}
fmt.Printf(" ... Passed\n")
s1.kill()
s2.kill()
s3.kill()
time.Sleep(time.Second)
vs.Kill()
time.Sleep(time.Second)
}
// Put right after a backup dies.
func TestFailPut(t *testing.T) {
runtime.GOMAXPROCS(4)
tag := "failput"
vshost := port(tag+"v", 1)
vs := viewservice.StartServer(vshost)
time.Sleep(time.Second)
vck := viewservice.MakeClerk("", vshost)
s1 := StartServer(vshost, port(tag, 1))
time.Sleep(time.Second)
s2 := StartServer(vshost, port(tag, 2))
time.Sleep(time.Second)
s3 := StartServer(vshost, port(tag, 3))
for i := 0; i < viewservice.DeadPings*3; i++ {
v, _ := vck.Get()
if v.Primary != "" && v.Backup != "" {
break
}
time.Sleep(viewservice.PingInterval)
}
time.Sleep(time.Second) // wait for backup initializion
v1, _ := vck.Get()
if v1.Primary != s1.me || v1.Backup != s2.me {
t.Fatalf("wrong primary or backup")
}
ck := MakeClerk(vshost, "")
ck.Put("a", "aa")
ck.Put("b", "bb")
ck.Put("c", "cc")
check(ck, "a", "aa")
check(ck, "b", "bb")
check(ck, "c", "cc")
// kill backup, then immediate Put
fmt.Printf("Test: Put() immediately after backup failure ...\n")
s2.kill()
ck.Put("a", "aaa")
check(ck, "a", "aaa")
for i := 0; i < viewservice.DeadPings*3; i++ {
v, _ := vck.Get()
if v.Viewnum > v1.Viewnum && v.Primary != "" && v.Backup != "" {
break
}
time.Sleep(viewservice.PingInterval)
}
time.Sleep(time.Second) // wait for backup initialization
v2, _ := vck.Get()
if v2.Primary != s1.me || v2.Backup != s3.me {
t.Fatal("wrong primary or backup")
}
check(ck, "a", "aaa")
fmt.Printf(" ... Passed\n")
// kill primary, then immediate Put
fmt.Printf("Test: Put() immediately after primary failure ...\n")
s1.kill()
ck.Put("b", "bbb")
check(ck, "b", "bbb")
for i := 0; i < viewservice.DeadPings*3; i++ {
v, _ := vck.Get()
if v.Viewnum > v2.Viewnum && v.Primary != "" {
break
}
time.Sleep(viewservice.PingInterval)
}
time.Sleep(time.Second)
check(ck, "a", "aaa")
check(ck, "b", "bbb")
check(ck, "c", "cc")
fmt.Printf(" ... Passed\n")
s1.kill()
s2.kill()
s3.kill()
time.Sleep(viewservice.PingInterval * 2)
vs.Kill()
}