seaweedfs/weed/server/raft_server.go
2019-01-17 23:38:33 -08:00

130 lines
3.1 KiB
Go

package weed_server
import (
"encoding/json"
"io/ioutil"
"math/rand"
"os"
"path"
"reflect"
"sort"
"strings"
"time"
"github.com/chrislusf/raft"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/topology"
"github.com/gorilla/mux"
)
type RaftServer struct {
peers []string // initial peers to join with
raftServer raft.Server
dataDir string
httpAddr string
router *mux.Router
topo *topology.Topology
}
func NewRaftServer(r *mux.Router, peers []string, httpAddr string, dataDir string, topo *topology.Topology, pulseSeconds int) *RaftServer {
s := &RaftServer{
peers: peers,
httpAddr: httpAddr,
dataDir: dataDir,
router: r,
topo: topo,
}
if glog.V(4) {
raft.SetLogLevel(2)
}
raft.RegisterCommand(&topology.MaxVolumeIdCommand{})
var err error
transporter := raft.NewHTTPTransporter("/cluster", time.Second)
transporter.Transport.MaxIdleConnsPerHost = 1024
glog.V(0).Infof("Starting RaftServer with %v", httpAddr)
// Clear old cluster configurations if peers are changed
if oldPeers, changed := isPeersChanged(s.dataDir, httpAddr, s.peers); changed {
glog.V(0).Infof("Peers Change: %v => %v", oldPeers, s.peers)
os.RemoveAll(path.Join(s.dataDir, "conf"))
os.RemoveAll(path.Join(s.dataDir, "log"))
os.RemoveAll(path.Join(s.dataDir, "snapshot"))
}
s.raftServer, err = raft.NewServer(s.httpAddr, s.dataDir, transporter, nil, topo, "")
if err != nil {
glog.V(0).Infoln(err)
return nil
}
transporter.Install(s.raftServer, s)
s.raftServer.SetHeartbeatInterval(500 * time.Millisecond)
s.raftServer.SetElectionTimeout(time.Duration(pulseSeconds) * 500 * time.Millisecond)
s.raftServer.Start()
s.router.HandleFunc("/cluster/status", s.statusHandler).Methods("GET")
for _, peer := range s.peers {
s.raftServer.AddPeer(peer, "http://"+peer)
}
time.Sleep(time.Duration(1000+rand.Int31n(3000)) * time.Millisecond)
if s.raftServer.IsLogEmpty() {
// Initialize the server by joining itself.
glog.V(0).Infoln("Initializing new cluster")
_, err := s.raftServer.Do(&raft.DefaultJoinCommand{
Name: s.raftServer.Name(),
ConnectionString: "http://" + s.httpAddr,
})
if err != nil {
glog.V(0).Infoln(err)
return nil
}
}
glog.V(0).Infof("current cluster leader: %v", s.raftServer.Leader())
return s
}
func (s *RaftServer) Peers() (members []string) {
peers := s.raftServer.Peers()
for _, p := range peers {
members = append(members, strings.TrimPrefix(p.ConnectionString, "http://"))
}
return
}
func isPeersChanged(dir string, self string, peers []string) (oldPeers []string, changed bool) {
confPath := path.Join(dir, "conf")
// open conf file
b, err := ioutil.ReadFile(confPath)
if err != nil {
return oldPeers, true
}
conf := &raft.Config{}
if err = json.Unmarshal(b, conf); err != nil {
return oldPeers, true
}
for _, p := range conf.Peers {
oldPeers = append(oldPeers, strings.TrimPrefix(p.ConnectionString, "http://"))
}
oldPeers = append(oldPeers, self)
if len(peers) == 0 && len(oldPeers) <= 1 {
return oldPeers, false
}
sort.Strings(peers)
sort.Strings(oldPeers)
return oldPeers, !reflect.DeepEqual(peers, oldPeers)
}