volume: get metrics configuration from master

fix https://github.com/chrislusf/seaweedfs/issues/1354

weed/server/master_grpc_server_volume.go

@@ -3,6 +3,7 @@ package weed_server
 import (
 	"context"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/storage/backend"
 
 	"github.com/chrislusf/raft"
@@ -182,6 +183,8 @@ func (ms *MasterServer) LookupEcVolume(ctx context.Context, req *master_pb.Looku
 
 func (ms *MasterServer) GetMasterConfiguration(ctx context.Context, req *master_pb.GetMasterConfigurationRequest) (*master_pb.GetMasterConfigurationResponse, error) {
 
+	glog.V(0).Infof("master sends metrics to %s every %d seconds", ms.option.MetricsAddress, ms.option.MetricsIntervalSec)
+
 	resp := &master_pb.GetMasterConfigurationResponse{
 		MetricsAddress:         ms.option.MetricsAddress,
 		MetricsIntervalSeconds: uint32(ms.option.MetricsIntervalSec),