package command import ( "context" "fmt" "github.com/aws/aws-sdk-go/aws" "github.com/chrislusf/seaweedfs/weed/glog" "github.com/chrislusf/seaweedfs/weed/pb" "github.com/chrislusf/seaweedfs/weed/pb/master_pb" "github.com/chrislusf/seaweedfs/weed/security" "github.com/chrislusf/seaweedfs/weed/server" "github.com/chrislusf/seaweedfs/weed/util" "github.com/gorilla/mux" "google.golang.org/grpc/reflection" "net/http" "time" ) var ( mf MasterOptions ) func init() { cmdMasterFollower.Run = runMasterFollower // break init cycle mf.port = cmdMasterFollower.Flag.Int("port", 9334, "http listen port") mf.portGrpc = cmdMasterFollower.Flag.Int("port.grpc", 19334, "grpc listen port") mf.ipBind = cmdMasterFollower.Flag.String("ip.bind", "", "ip address to bind to") mf.peers = cmdMasterFollower.Flag.String("masters", "localhost:9333", "all master nodes in comma separated ip:port list, example: 127.0.0.1:9093,127.0.0.1:9094,127.0.0.1:9095") mf.ip = aws.String(util.DetectedHostAddress()) mf.metaFolder = aws.String("") mf.volumeSizeLimitMB = nil mf.volumePreallocate = nil mf.defaultReplication = nil mf.garbageThreshold = aws.Float64(0.1) mf.whiteList = nil mf.disableHttp = aws.Bool(false) mf.metricsAddress = aws.String("") mf.metricsIntervalSec = aws.Int(0) mf.raftResumeState = aws.Bool(false) } var cmdMasterFollower = &Command{ UsageLine: "master.follower -port=9333 -masters=:", Short: "start a master follower", Long: `start a master follower to provide volume=>location mapping service The master follower does not participate in master election. It just follow the existing masters, and listen for any volume location changes. In most cases, the master follower is not needed. In big data centers with thousands of volume servers. In theory, the master may have trouble to keep up with the write requests and read requests. The master follower can relieve the master from from read requests, which only needs to lookup a fileId or volumeId. The master follower currently can handle fileId lookup requests: /dir/lookup?volumeId=4 /dir/lookup?fileId=4,49c50924569199 And gRPC API rpc LookupVolume (LookupVolumeRequest) returns (LookupVolumeResponse) {} This master follower is stateless and can run from any place. `, } func runMasterFollower(cmd *Command, args []string) bool { util.LoadConfiguration("security", false) util.LoadConfiguration("master", false) startMasterFollower(mf) return true } func startMasterFollower(masterOptions MasterOptions) { // collect settings from main masters masters := pb.ServerAddresses(*mf.peers).ToAddresses() var err error grpcDialOption := security.LoadClientTLS(util.GetViper(), "grpc.master") for i := 0; i < 10; i++ { err = pb.WithOneOfGrpcMasterClients(masters, grpcDialOption, func(client master_pb.SeaweedClient) error { resp, err := client.GetMasterConfiguration(context.Background(), &master_pb.GetMasterConfigurationRequest{}) if err != nil { return fmt.Errorf("get master grpc address %v configuration: %v", masters, err) } masterOptions.defaultReplication = &resp.DefaultReplication masterOptions.volumeSizeLimitMB = aws.Uint(uint(resp.VolumeSizeLimitMB)) masterOptions.volumePreallocate = &resp.VolumePreallocate return nil }) if err != nil { glog.V(0).Infof("failed to talk to filer %v: %v", masters, err) glog.V(0).Infof("wait for %d seconds ...", i+1) time.Sleep(time.Duration(i+1) * time.Second) } } if err != nil { glog.Errorf("failed to talk to filer %v: %v", masters, err) return } option := masterOptions.toMasterOption(nil) option.IsFollower = true r := mux.NewRouter() ms := weed_server.NewMasterServer(r, option, masters) listeningAddress := util.JoinHostPort(*masterOptions.ipBind, *masterOptions.port) glog.V(0).Infof("Start Seaweed Master %s at %s", util.Version(), listeningAddress) masterListener, e := util.NewListener(listeningAddress, 0) if e != nil { glog.Fatalf("Master startup error: %v", e) } // starting grpc server grpcPort := *masterOptions.portGrpc grpcL, err := util.NewListener(util.JoinHostPort(*masterOptions.ipBind, grpcPort), 0) if err != nil { glog.Fatalf("master failed to listen on grpc port %d: %v", grpcPort, err) } grpcS := pb.NewGrpcServer(security.LoadServerTLS(util.GetViper(), "grpc.master")) master_pb.RegisterSeaweedServer(grpcS, ms) reflection.Register(grpcS) glog.V(0).Infof("Start Seaweed Master %s grpc server at %s:%d", util.Version(), *masterOptions.ip, grpcPort) go grpcS.Serve(grpcL) go ms.MasterClient.KeepConnectedToMaster() // start http server httpS := &http.Server{Handler: r} go httpS.Serve(masterListener) select {} }