seaweedfs/weed/server/raft_server.go
Устюжанин Антон Александрович dc31b19469 fix: restore raft state
2020-10-03 14:03:41 +05:00

177 lines
4.1 KiB
Go

package weed_server
import (
"encoding/json"
"io/ioutil"
"os"
"path"
"reflect"
"sort"
"time"
"google.golang.org/grpc"
"github.com/chrislusf/seaweedfs/weed/pb"
"github.com/chrislusf/raft"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/topology"
)
type RaftServer struct {
peers []string // initial peers to join with
raftServer raft.Server
dataDir string
serverAddr string
topo *topology.Topology
*raft.GrpcServer
}
type StateMachine struct {
raft.StateMachine
topo *topology.Topology
}
func (s StateMachine) Save() ([]byte, error) {
state := topology.MaxVolumeIdCommand{
MaxVolumeId: s.topo.GetMaxVolumeId(),
}
glog.V(1).Infof("Save raft state %+v", state)
return json.Marshal(state)
}
func (s StateMachine) Recovery(data []byte) error {
state := topology.MaxVolumeIdCommand{}
err := json.Unmarshal(data, &state)
if err != nil {
return err
}
glog.V(1).Infof("Recovery raft state %+v", state)
s.topo.UpAdjustMaxVolumeId(state.MaxVolumeId)
return nil
}
func NewRaftServer(grpcDialOption grpc.DialOption, peers []string, serverAddr, dataDir string, topo *topology.Topology, pulseSeconds int, raftResumeState bool) (*RaftServer, error) {
s := &RaftServer{
peers: peers,
serverAddr: serverAddr,
dataDir: dataDir,
topo: topo,
}
if glog.V(4) {
raft.SetLogLevel(2)
}
raft.RegisterCommand(&topology.MaxVolumeIdCommand{})
var err error
transporter := raft.NewGrpcTransporter(grpcDialOption)
glog.V(0).Infof("Starting RaftServer with %v", serverAddr)
if !raftResumeState {
// always clear previous metadata
os.RemoveAll(path.Join(s.dataDir, "conf"))
os.RemoveAll(path.Join(s.dataDir, "log"))
os.RemoveAll(path.Join(s.dataDir, "snapshot"))
}
if err := os.MkdirAll(path.Join(s.dataDir, "snapshot"), 0600); err != nil {
return nil, err
}
// Clear old cluster configurations if peers are changed
if oldPeers, changed := isPeersChanged(s.dataDir, serverAddr, s.peers); changed {
glog.V(0).Infof("Peers Change: %v => %v", oldPeers, s.peers)
}
stateMachine := StateMachine{topo: topo}
s.raftServer, err = raft.NewServer(s.serverAddr, s.dataDir, transporter, stateMachine, topo, "")
if err != nil {
glog.V(0).Infoln(err)
return nil, err
}
s.raftServer.SetHeartbeatInterval(500 * time.Millisecond)
s.raftServer.SetElectionTimeout(time.Duration(pulseSeconds) * 500 * time.Millisecond)
if err := s.raftServer.LoadSnapshot(); err != nil {
return nil, err
}
if err := s.raftServer.Start(); err != nil {
return nil, err
}
for _, peer := range s.peers {
if err := s.raftServer.AddPeer(peer, pb.ServerToGrpcAddress(peer)); err != nil {
return nil, err
}
}
s.GrpcServer = raft.NewGrpcServer(s.raftServer)
if s.raftServer.IsLogEmpty() && isTheFirstOne(serverAddr, s.peers) {
// Initialize the server by joining itself.
glog.V(0).Infoln("Initializing new cluster")
_, err := s.raftServer.Do(&raft.DefaultJoinCommand{
Name: s.raftServer.Name(),
ConnectionString: pb.ServerToGrpcAddress(s.serverAddr),
})
if err != nil {
glog.V(0).Infoln(err)
return nil, err
}
}
glog.V(0).Infof("current cluster leader: %v", s.raftServer.Leader())
return s, nil
}
func (s *RaftServer) Peers() (members []string) {
peers := s.raftServer.Peers()
for _, p := range peers {
members = append(members, p.Name)
}
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, p.Name)
}
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)
}
func isTheFirstOne(self string, peers []string) bool {
sort.Strings(peers)
if len(peers) <= 0 {
return true
}
return self == peers[0]
}