package util import ( "fmt" "sync" "time" "google.golang.org/grpc" "google.golang.org/grpc/keepalive" ) var ( // cache grpc connections grpcClients = make(map[string]*grpc.ClientConn) grpcClientsLock sync.Mutex ) func NewGrpcServer() *grpc.Server { return grpc.NewServer(grpc.KeepaliveParams(keepalive.ServerParameters{ Time: 10 * time.Second, // wait time before ping if no activity Timeout: 20 * time.Second, // ping timeout }), grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{ MinTime: 60 * time.Second, // min time a client should wait before sending a ping })) } func GrpcDial(address string, opts ...grpc.DialOption) (*grpc.ClientConn, error) { opts = append(opts, grpc.WithInsecure()) opts = append(opts, grpc.WithKeepaliveParams(keepalive.ClientParameters{ Time: 30 * time.Second, // client ping server if no activity for this long Timeout: 20 * time.Second, })) return grpc.Dial(address, opts...) } func WithCachedGrpcClient(fn func(*grpc.ClientConn) error, address string, opts ...grpc.DialOption) error { grpcClientsLock.Lock() existingConnection, found := grpcClients[address] if found { grpcClientsLock.Unlock() return fn(existingConnection) } grpcConnection, err := GrpcDial(address, opts...) if err != nil { grpcClientsLock.Unlock() return fmt.Errorf("fail to dial %s: %v", address, err) } grpcClients[address] = grpcConnection grpcClientsLock.Unlock() err = fn(grpcConnection) if err != nil { grpcClientsLock.Lock() delete(grpcClients, address) grpcClientsLock.Unlock() } return err }