Merge pull request #127 from xiangli-cmu/master

clean error handling
release-0.4
Xiang Li 2013-08-18 19:03:51 -07:00
commit 393ed439b1
12 changed files with 174 additions and 234 deletions

View File

@ -3,6 +3,7 @@ package main
import (
"encoding/json"
"fmt"
etcdErr "github.com/coreos/etcd/error"
"github.com/coreos/etcd/store"
"github.com/coreos/go-raft"
"path"
@ -147,7 +148,8 @@ func (c *JoinCommand) Apply(raftServer *raft.Server) (interface{}, error) {
// check machine number in the cluster
num := machineNum()
if num == maxClusterSize {
return []byte("join fail"), fmt.Errorf(errors[103])
debug("Reject join request from ", c.Name)
return []byte("join fail"), etcdErr.NewError(103, "")
}
addNameToURL(c.Name, c.RaftURL, c.EtcdURL)

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@ -1,11 +1,14 @@
package main
package error
import (
"encoding/json"
"net/http"
)
var errors map[int]string
const ()
func init() {
errors = make(map[int]string)
@ -33,17 +36,39 @@ func init() {
}
type jsonError struct {
type Error struct {
ErrorCode int `json:"errorCode"`
Message string `json:"message"`
Cause string `json:"cause,omitempty"`
}
func newJsonError(errorCode int, cause string) []byte {
b, _ := json.Marshal(jsonError{
func NewError(errorCode int, cause string) Error {
return Error{
ErrorCode: errorCode,
Message: errors[errorCode],
Cause: cause,
})
return b
}
}
func Message(code int) string {
return errors[code]
}
// Only for error interface
func (e Error) Error() string {
return e.Message
}
func (e Error) toJsonString() string {
b, _ := json.Marshal(e)
return string(b)
}
func (e Error) Write(w http.ResponseWriter) {
// 3xx is reft internal error
if e.ErrorCode/100 == 3 {
http.Error(w, e.toJsonString(), http.StatusInternalServerError)
} else {
http.Error(w, e.toJsonString(), http.StatusBadRequest)
}
}

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@ -2,6 +2,7 @@ package main
import (
"fmt"
etcdErr "github.com/coreos/etcd/error"
"github.com/coreos/etcd/store"
"github.com/coreos/go-raft"
"net/http"
@ -16,29 +17,42 @@ import (
func NewEtcdMuxer() *http.ServeMux {
// external commands
etcdMux := http.NewServeMux()
etcdMux.HandleFunc("/"+version+"/keys/", Multiplexer)
etcdMux.HandleFunc("/"+version+"/watch/", WatchHttpHandler)
etcdMux.HandleFunc("/leader", LeaderHttpHandler)
etcdMux.HandleFunc("/machines", MachinesHttpHandler)
etcdMux.HandleFunc("/version", VersionHttpHandler)
etcdMux.HandleFunc("/stats", StatsHttpHandler)
etcdMux.Handle("/"+version+"/keys/", errorHandler(Multiplexer))
etcdMux.Handle("/"+version+"/watch/", errorHandler(WatchHttpHandler))
etcdMux.Handle("/"+version+"/leader", errorHandler(LeaderHttpHandler))
etcdMux.Handle("/"+version+"/machines", errorHandler(MachinesHttpHandler))
etcdMux.Handle("/"+version+"/stats", errorHandler(StatsHttpHandler))
etcdMux.Handle("/version", errorHandler(VersionHttpHandler))
etcdMux.HandleFunc("/test/", TestHttpHandler)
return etcdMux
}
type errorHandler func(http.ResponseWriter, *http.Request) error
func (fn errorHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if e := fn(w, r); e != nil {
if etcdErr, ok := e.(etcdErr.Error); ok {
debug("Return error: ", etcdErr.Error())
etcdErr.Write(w)
} else {
http.Error(w, e.Error(), http.StatusInternalServerError)
}
}
}
// Multiplex GET/POST/DELETE request to corresponding handlers
func Multiplexer(w http.ResponseWriter, req *http.Request) {
func Multiplexer(w http.ResponseWriter, req *http.Request) error {
switch req.Method {
case "GET":
GetHttpHandler(&w, req)
return GetHttpHandler(w, req)
case "POST":
SetHttpHandler(&w, req)
return SetHttpHandler(w, req)
case "DELETE":
DeleteHttpHandler(&w, req)
return DeleteHttpHandler(w, req)
default:
w.WriteHeader(http.StatusMethodNotAllowed)
return
return nil
}
}
@ -48,15 +62,11 @@ func Multiplexer(w http.ResponseWriter, req *http.Request) {
//--------------------------------------
// Set Command Handler
func SetHttpHandler(w *http.ResponseWriter, req *http.Request) {
func SetHttpHandler(w http.ResponseWriter, req *http.Request) error {
key := req.URL.Path[len("/v1/keys/"):]
if store.CheckKeyword(key) {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(400, "Set"))
return
return etcdErr.NewError(400, "Set")
}
debugf("[recv] POST %v/v1/keys/%s [%s]", e.url, key, req.RemoteAddr)
@ -64,10 +74,7 @@ func SetHttpHandler(w *http.ResponseWriter, req *http.Request) {
value := req.FormValue("value")
if len(value) == 0 {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(200, "Set"))
return
return etcdErr.NewError(200, "Set")
}
prevValue := req.FormValue("prevValue")
@ -77,11 +84,7 @@ func SetHttpHandler(w *http.ResponseWriter, req *http.Request) {
expireTime, err := durationToExpireTime(strDuration)
if err != nil {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(202, "Set"))
return
return etcdErr.NewError(202, "Set")
}
if len(prevValue) != 0 {
@ -92,7 +95,7 @@ func SetHttpHandler(w *http.ResponseWriter, req *http.Request) {
ExpireTime: expireTime,
}
dispatch(command, w, req, true)
return dispatch(command, w, req, true)
} else {
command := &SetCommand{
@ -101,13 +104,12 @@ func SetHttpHandler(w *http.ResponseWriter, req *http.Request) {
ExpireTime: expireTime,
}
dispatch(command, w, req, true)
return dispatch(command, w, req, true)
}
}
// Delete Handler
func DeleteHttpHandler(w *http.ResponseWriter, req *http.Request) {
func DeleteHttpHandler(w http.ResponseWriter, req *http.Request) error {
key := req.URL.Path[len("/v1/keys/"):]
debugf("[recv] DELETE %v/v1/keys/%s [%s]", e.url, key, req.RemoteAddr)
@ -116,76 +118,40 @@ func DeleteHttpHandler(w *http.ResponseWriter, req *http.Request) {
Key: key,
}
dispatch(command, w, req, true)
return dispatch(command, w, req, true)
}
// Dispatch the command to leader
func dispatch(c Command, w *http.ResponseWriter, req *http.Request, etcd bool) {
func dispatch(c Command, w http.ResponseWriter, req *http.Request, etcd bool) error {
if r.State() == raft.Leader {
if body, err := r.Do(c); err != nil {
if _, ok := err.(store.NotFoundError); ok {
(*w).WriteHeader(http.StatusNotFound)
(*w).Write(newJsonError(100, err.Error()))
return
}
if _, ok := err.(store.TestFail); ok {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(101, err.Error()))
return
}
if _, ok := err.(store.NotFile); ok {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(102, err.Error()))
return
}
if err.Error() == errors[103] {
(*w).WriteHeader(http.StatusBadRequest)
(*w).Write(newJsonError(103, ""))
return
}
(*w).WriteHeader(http.StatusInternalServerError)
(*w).Write(newJsonError(300, err.Error()))
return
return err
} else {
if body == nil {
(*w).WriteHeader(http.StatusNotFound)
(*w).Write(newJsonError(300, "Empty result from raft"))
return etcdErr.NewError(300, "Empty result from raft")
} else {
body, ok := body.([]byte)
// this should not happen
if !ok {
panic("wrong type")
}
(*w).WriteHeader(http.StatusOK)
(*w).Write(body)
body, _ := body.([]byte)
w.WriteHeader(http.StatusOK)
w.Write(body)
return nil
}
return
}
} else {
leader := r.Leader()
// current no leader
if leader == "" {
(*w).WriteHeader(http.StatusInternalServerError)
(*w).Write(newJsonError(300, ""))
return
return etcdErr.NewError(300, "")
}
// tell the client where is the leader
path := req.URL.Path
var url string
if etcd {
etcdAddr, _ := nameToEtcdURL(leader)
if etcdAddr == "" {
panic(leader)
}
url = etcdAddr + path
} else {
raftAddr, _ := nameToRaftURL(leader)
@ -194,12 +160,10 @@ func dispatch(c Command, w *http.ResponseWriter, req *http.Request, etcd bool) {
debugf("Redirect to %s", url)
http.Redirect(*w, req, url, http.StatusTemporaryRedirect)
return
http.Redirect(w, req, url, http.StatusTemporaryRedirect)
return nil
}
(*w).WriteHeader(http.StatusInternalServerError)
(*w).Write(newJsonError(300, ""))
return
return etcdErr.NewError(300, "")
}
//--------------------------------------
@ -210,44 +174,44 @@ func dispatch(c Command, w *http.ResponseWriter, req *http.Request, etcd bool) {
//--------------------------------------
// Handler to return the current leader's raft address
func LeaderHttpHandler(w http.ResponseWriter, req *http.Request) {
func LeaderHttpHandler(w http.ResponseWriter, req *http.Request) error {
leader := r.Leader()
if leader != "" {
w.WriteHeader(http.StatusOK)
raftURL, _ := nameToRaftURL(leader)
w.Write([]byte(raftURL))
return nil
} else {
// not likely, but it may happen
w.WriteHeader(http.StatusInternalServerError)
w.Write(newJsonError(301, ""))
return etcdErr.NewError(301, "")
}
}
// Handler to return all the known machines in the current cluster
func MachinesHttpHandler(w http.ResponseWriter, req *http.Request) {
func MachinesHttpHandler(w http.ResponseWriter, req *http.Request) error {
machines := getMachines()
w.WriteHeader(http.StatusOK)
w.Write([]byte(strings.Join(machines, ", ")))
return nil
}
// Handler to return the current version of etcd
func VersionHttpHandler(w http.ResponseWriter, req *http.Request) {
func VersionHttpHandler(w http.ResponseWriter, req *http.Request) error {
w.WriteHeader(http.StatusOK)
w.Write([]byte(fmt.Sprintf("etcd %s", releaseVersion)))
w.Write([]byte(fmt.Sprintf("etcd API %s", version)))
fmt.Fprintf(w, "etcd %s", releaseVersion)
return nil
}
// Handler to return the basic stats of etcd
func StatsHttpHandler(w http.ResponseWriter, req *http.Request) {
func StatsHttpHandler(w http.ResponseWriter, req *http.Request) error {
w.WriteHeader(http.StatusOK)
w.Write(etcdStore.Stats())
return nil
}
// Get Handler
func GetHttpHandler(w *http.ResponseWriter, req *http.Request) {
func GetHttpHandler(w http.ResponseWriter, req *http.Request) error {
key := req.URL.Path[len("/v1/keys/"):]
debugf("[recv] GET %s/v1/keys/%s [%s]", e.url, key, req.RemoteAddr)
@ -257,31 +221,19 @@ func GetHttpHandler(w *http.ResponseWriter, req *http.Request) {
}
if body, err := command.Apply(r.Server); err != nil {
if _, ok := err.(store.NotFoundError); ok {
(*w).WriteHeader(http.StatusNotFound)
(*w).Write(newJsonError(100, err.Error()))
return
}
(*w).WriteHeader(http.StatusInternalServerError)
(*w).Write(newJsonError(300, ""))
return err
} else {
body, ok := body.([]byte)
if !ok {
panic("wrong type")
}
(*w).WriteHeader(http.StatusOK)
(*w).Write(body)
body, _ := body.([]byte)
w.WriteHeader(http.StatusOK)
w.Write(body)
return nil
}
}
// Watch handler
func WatchHttpHandler(w http.ResponseWriter, req *http.Request) {
func WatchHttpHandler(w http.ResponseWriter, req *http.Request) error {
key := req.URL.Path[len("/v1/watch/"):]
command := &WatchCommand{
@ -300,28 +252,23 @@ func WatchHttpHandler(w http.ResponseWriter, req *http.Request) {
sinceIndex, err := strconv.ParseUint(string(content), 10, 64)
if err != nil {
w.WriteHeader(http.StatusBadRequest)
w.Write(newJsonError(203, "Watch From Index"))
return etcdErr.NewError(203, "Watch From Index")
}
command.SinceIndex = sinceIndex
} else {
w.WriteHeader(http.StatusMethodNotAllowed)
return
return nil
}
if body, err := command.Apply(r.Server); err != nil {
w.WriteHeader(http.StatusInternalServerError)
w.Write(newJsonError(500, key))
return etcdErr.NewError(500, key)
} else {
w.WriteHeader(http.StatusOK)
body, ok := body.([]byte)
if !ok {
panic("wrong type")
}
body, _ := body.([]byte)
w.Write(body)
return nil
}
}

View File

@ -94,16 +94,16 @@ func EtcdURLHttpHandler(w http.ResponseWriter, req *http.Request) {
}
// Response to the join request
func JoinHttpHandler(w http.ResponseWriter, req *http.Request) {
func JoinHttpHandler(w http.ResponseWriter, req *http.Request) error {
command := &JoinCommand{}
if err := decodeJsonRequest(req, command); err == nil {
debugf("Receive Join Request from %s", command.Name)
dispatch(command, &w, req, false)
return dispatch(command, w, req, false)
} else {
w.WriteHeader(http.StatusInternalServerError)
return
return nil
}
}

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@ -5,11 +5,11 @@ import (
"crypto/tls"
"encoding/json"
"fmt"
etcdErr "github.com/coreos/etcd/error"
"github.com/coreos/go-raft"
"net/http"
"net/url"
"time"
"github.com/coreos/go-raft"
)
type raftServer struct {
@ -67,55 +67,10 @@ func (r *raftServer) ListenAndServe() {
// start as a leader in a new cluster
if len(cluster) == 0 {
startAsLeader()
time.Sleep(time.Millisecond * 20)
// leader need to join self as a peer
for {
_, err := r.Do(newJoinCommand())
if err == nil {
break
}
}
debugf("%s start as a leader", r.name)
// start as a follower in a existing cluster
} else {
time.Sleep(time.Millisecond * 20)
var err error
for i := 0; i < retryTimes; i++ {
success := false
for _, machine := range cluster {
if len(machine) == 0 {
continue
}
err = joinCluster(r.Server, machine, r.tlsConf.Scheme)
if err != nil {
if err.Error() == errors[103] {
fatal(err)
}
debugf("cannot join to cluster via machine %s %s", machine, err)
} else {
success = true
break
}
}
if success {
break
}
warnf("cannot join to cluster via given machines, retry in %d seconds", RetryInterval)
time.Sleep(time.Second * RetryInterval)
}
if err != nil {
fatalf("Cannot join the cluster via given machines after %x retries", retryTimes)
}
debugf("%s success join to the cluster", r.name)
startAsFollower()
}
} else {
@ -133,6 +88,47 @@ func (r *raftServer) ListenAndServe() {
}
func startAsLeader() {
// leader need to join self as a peer
for {
_, err := r.Do(newJoinCommand())
if err == nil {
break
}
}
debugf("%s start as a leader", r.name)
}
func startAsFollower() {
// start as a follower in a existing cluster
for i := 0; i < retryTimes; i++ {
for _, machine := range cluster {
if len(machine) == 0 {
continue
}
err := joinCluster(r.Server, machine, r.tlsConf.Scheme)
if err == nil {
debugf("%s success join to the cluster via machine %s", r.name, machine)
return
} else {
if _, ok := err.(etcdErr.Error); ok {
fatal(err)
}
debugf("cannot join to cluster via machine %s %s", machine, err)
}
}
warnf("cannot join to cluster via given machines, retry in %d seconds", RetryInterval)
time.Sleep(time.Second * RetryInterval)
}
fatalf("Cannot join the cluster via given machines after %x retries", retryTimes)
}
// Start to listen and response raft command
func (r *raftServer) startTransport(scheme string, tlsConf tls.Config) {
u, _ := url.Parse(r.url)
@ -148,7 +144,7 @@ func (r *raftServer) startTransport(scheme string, tlsConf tls.Config) {
// internal commands
raftMux.HandleFunc("/name", NameHttpHandler)
raftMux.HandleFunc("/join", JoinHttpHandler)
raftMux.Handle("/join", errorHandler(JoinHttpHandler))
raftMux.HandleFunc("/vote", VoteHttpHandler)
raftMux.HandleFunc("/log", GetLogHttpHandler)
raftMux.HandleFunc("/log/append", AppendEntriesHttpHandler)
@ -171,11 +167,7 @@ func joinCluster(s *raft.Server, raftURL string, scheme string) error {
json.NewEncoder(&b).Encode(newJoinCommand())
// t must be ok
t, ok := r.Transporter().(transporter)
if !ok {
panic("wrong type")
}
t, _ := r.Transporter().(transporter)
joinURL := url.URL{Host: raftURL, Scheme: scheme, Path: "/join"}
@ -203,7 +195,10 @@ func joinCluster(s *raft.Server, raftURL string, scheme string) error {
} else if resp.StatusCode == http.StatusBadRequest {
debug("Reach max number machines in the cluster")
return fmt.Errorf(errors[103])
decoder := json.NewDecoder(resp.Body)
err := &etcdErr.Error{}
decoder.Decode(err)
return *err
} else {
return fmt.Errorf("Unable to join")
}

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@ -1,25 +0,0 @@
package store
type NotFoundError string
func (e NotFoundError) Error() string {
return string(e)
}
type NotFile string
func (e NotFile) Error() string {
return string(e)
}
type TestFail string
func (e TestFail) Error() string {
return string(e)
}
type Keyword string
func (e Keyword) Error() string {
return string(e)
}

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@ -3,6 +3,7 @@ package store
import (
"encoding/json"
"fmt"
etcdErr "github.com/coreos/etcd/error"
"path"
"strconv"
"sync"
@ -239,8 +240,7 @@ func (s *Store) internalSet(key string, value string, expireTime time.Time, inde
ok := s.Tree.set(key, Node{value, expireTime, update})
if !ok {
err := NotFile(key)
return nil, err
return nil, etcdErr.NewError(102, "set: "+key)
}
if isExpire {
@ -393,8 +393,7 @@ func (s *Store) RawGet(key string) ([]*Response, error) {
return resps, nil
}
err := NotFoundError(key)
return nil, err
return nil, etcdErr.NewError(100, "get: "+key)
}
func (s *Store) Delete(key string, index uint64) ([]byte, error) {
@ -451,8 +450,7 @@ func (s *Store) internalDelete(key string, index uint64) ([]byte, error) {
return msg, err
} else {
err := NotFoundError(key)
return nil, err
return nil, etcdErr.NewError(100, "delete: "+key)
}
}
@ -467,8 +465,7 @@ func (s *Store) TestAndSet(key string, prevValue string, value string, expireTim
resp := s.internalGet(key)
if resp == nil {
err := NotFoundError(key)
return nil, err
return nil, etcdErr.NewError(100, "testandset: "+key)
}
if resp.Value == prevValue {
@ -478,8 +475,8 @@ func (s *Store) TestAndSet(key string, prevValue string, value string, expireTim
} else {
// If fails, return err
err := TestFail(fmt.Sprintf("TestAndSet: %s!=%s", resp.Value, prevValue))
return nil, err
return nil, etcdErr.NewError(101, fmt.Sprintf("TestAndSet: %s!=%s",
resp.Value, prevValue))
}
}

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@ -176,7 +176,7 @@ func Monitor(size int, allowDeadNum int, leaderChan chan string, all chan bool,
func getLeader(addr string) (string, error) {
resp, err := client.Get(addr + "/leader")
resp, err := client.Get(addr + "/v1/leader")
if err != nil {
return "", err

View File

@ -116,7 +116,7 @@ func (c *Client) SyncCluster() bool {
// sync cluster information by providing machine list
func (c *Client) internalSyncCluster(machines []string) bool {
for _, machine := range machines {
httpPath := c.createHttpPath(machine, "machines")
httpPath := c.createHttpPath(machine, "v1/machines")
resp, err := c.httpClient.Get(httpPath)
if err != nil {
// try another machine in the cluster

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@ -17,7 +17,6 @@ func main() {
c := etcd.NewClient()
c.Set("lock", "unlock", 0)
for i := 0; i < 10; i++ {
go t(i, ch, etcd.NewClient())
}

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@ -1,8 +1,8 @@
package main
package main
import (
"github.com/coreos/go-etcd/etcd"
"fmt"
"github.com/coreos/go-etcd/etcd"
"time"
)
@ -11,21 +11,21 @@ var count = 0
func main() {
ch := make(chan bool, 10)
// set up a lock
for i:=0; i < 100; i++ {
for i := 0; i < 100; i++ {
go t(i, ch, etcd.NewClient())
}
start := time.Now()
for i:=0; i< 100; i++ {
for i := 0; i < 100; i++ {
<-ch
}
fmt.Println(time.Now().Sub(start), ": ", 100 * 50, "commands")
fmt.Println(time.Now().Sub(start), ": ", 100*50, "commands")
}
func t(num int, ch chan bool, c *etcd.Client) {
c.SyncCluster()
for i := 0; i < 50; i++ {
str := fmt.Sprintf("foo_%d",num * i)
str := fmt.Sprintf("foo_%d", num*i)
c.Set(str, "10", 0)
}
ch<-true
ch <- true
}

View File

@ -29,12 +29,12 @@ func Start(raftServer *raft.Server, webURL string) {
webMux := http.NewServeMux()
server := &http.Server{
Handler: webMux,
Addr: u.Host,
Handler: webMux,
Addr: u.Host,
}
mainPage = &MainPage{
Leader: raftServer.Leader(),
Leader: raftServer.Leader(),
Address: u.Host,
}