cli,pkg: use zap.Logger

cli/server/server.go

@@ -15,8 +15,9 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/network/metrics"
 	"github.com/CityOfZion/neo-go/pkg/rpc"
 	"github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 )
 
 // NewCommands returns 'node' command.
@@ -119,32 +120,40 @@ func getConfigFromContext(ctx *cli.Context) (config.Config, error) {
 // handleLoggingParams reads logging parameters.
 // If user selected debug level -- function enables it.
 // If logPath is configured -- function creates dir and file for logging.
-func handleLoggingParams(ctx *cli.Context, cfg config.ApplicationConfiguration) error {
+func handleLoggingParams(ctx *cli.Context, cfg config.ApplicationConfiguration) (*zap.Logger, error) {
+	level := zapcore.InfoLevel
 	if ctx.Bool("debug") {
-		log.SetLevel(log.DebugLevel)
+		level = zapcore.DebugLevel
 	}
 
+	cc := zap.NewProductionConfig()
+	cc.DisableCaller = true
+	cc.DisableStacktrace = true
+	cc.EncoderConfig.EncodeDuration = zapcore.StringDurationEncoder
+	cc.EncoderConfig.EncodeLevel = zapcore.CapitalLevelEncoder
+	cc.EncoderConfig.EncodeTime = zapcore.ISO8601TimeEncoder
+	cc.Encoding = "console"
+	cc.Level = zap.NewAtomicLevelAt(level)
+
 	if logPath := cfg.LogPath; logPath != "" {
 		if err := io.MakeDirForFile(logPath, "logger"); err != nil {
-			return err
+			return nil, err
 		}
-		f, err := os.Create(logPath)
+
-		if err != nil {
+		cc.OutputPaths = []string{logPath}
-			return err
-		}
-		log.SetOutput(f)
 	}
-	return nil
+
+	return cc.Build()
 }
 
-func initBCWithMetrics(cfg config.Config) (*core.Blockchain, *metrics.Service, *metrics.Service, error) {
+func initBCWithMetrics(cfg config.Config, log *zap.Logger) (*core.Blockchain, *metrics.Service, *metrics.Service, error) {
-	chain, err := initBlockChain(cfg)
+	chain, err := initBlockChain(cfg, log)
 	if err != nil {
 		return nil, nil, nil, cli.NewExitError(err, 1)
 	}
 	configureAddresses(cfg.ApplicationConfiguration)
-	prometheus := metrics.NewPrometheusService(cfg.ApplicationConfiguration.Prometheus)
+	prometheus := metrics.NewPrometheusService(cfg.ApplicationConfiguration.Prometheus, log)
-	pprof := metrics.NewPprofService(cfg.ApplicationConfiguration.Pprof)
+	pprof := metrics.NewPprofService(cfg.ApplicationConfiguration.Pprof, log)
 
 	go chain.Run()
 	go prometheus.Start()
@@ -158,7 +167,8 @@ func dumpDB(ctx *cli.Context) error {
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
-	if err := handleLoggingParams(ctx, cfg.ApplicationConfiguration); err != nil {
+	log, err := handleLoggingParams(ctx, cfg.ApplicationConfiguration)
+	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
 	count := uint32(ctx.Uint("count"))
@@ -174,7 +184,7 @@ func dumpDB(ctx *cli.Context) error {
 	defer outStream.Close()
 	writer := io.NewBinWriterFromIO(outStream)
 
-	chain, prometheus, pprof, err := initBCWithMetrics(cfg)
+	chain, prometheus, pprof, err := initBCWithMetrics(cfg, log)
 	if err != nil {
 		return err
 	}
@@ -213,7 +223,8 @@ func restoreDB(ctx *cli.Context) error {
 	if err != nil {
 		return err
 	}
-	if err := handleLoggingParams(ctx, cfg.ApplicationConfiguration); err != nil {
+	log, err := handleLoggingParams(ctx, cfg.ApplicationConfiguration)
+	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
 	count := uint32(ctx.Uint("count"))
@@ -229,7 +240,7 @@ func restoreDB(ctx *cli.Context) error {
 	defer inStream.Close()
 	reader := io.NewBinReaderFromIO(inStream)
 
-	chain, prometheus, pprof, err := initBCWithMetrics(cfg)
+	chain, prometheus, pprof, err := initBCWithMetrics(cfg, log)
 	if err != nil {
 		return err
 	}
@@ -265,7 +276,7 @@ func restoreDB(ctx *cli.Context) error {
 		if block.Index == 0 && i == 0 && skip == 0 {
 			genesis, err := chain.GetBlock(block.Hash())
 			if err == nil && genesis.Index == 0 {
-				log.Info("skipped genesis block ", block.Hash().StringLE())
+				log.Info("skipped genesis block", zap.String("hash", block.Hash().StringLE()))
 				continue
 			}
 		}
@@ -293,7 +304,8 @@ func startServer(ctx *cli.Context) error {
 	if err != nil {
 		return err
 	}
-	if err := handleLoggingParams(ctx, cfg.ApplicationConfiguration); err != nil {
+	log, err := handleLoggingParams(ctx, cfg.ApplicationConfiguration)
+	if err != nil {
 		return err
 	}
 
@@ -302,12 +314,12 @@ func startServer(ctx *cli.Context) error {
 
 	serverConfig := network.NewServerConfig(cfg)
 
-	chain, prometheus, pprof, err := initBCWithMetrics(cfg)
+	chain, prometheus, pprof, err := initBCWithMetrics(cfg, log)
 	if err != nil {
 		return err
 	}
 
-	server := network.NewServer(serverConfig, chain)
+	server := network.NewServer(serverConfig, chain, log)
 	rpcServer := rpc.NewServer(chain, cfg.ApplicationConfiguration.RPC, server)
 	errChan := make(chan error)
 
@@ -364,13 +376,13 @@ func configureAddresses(cfg config.ApplicationConfiguration) {
 }
 
 // initBlockChain initializes BlockChain with preselected DB.
-func initBlockChain(cfg config.Config) (*core.Blockchain, error) {
+func initBlockChain(cfg config.Config, log *zap.Logger) (*core.Blockchain, error) {
 	store, err := storage.NewStore(cfg.ApplicationConfiguration.DBConfiguration)
 	if err != nil {
 		return nil, cli.NewExitError(fmt.Errorf("could not initialize storage: %s", err), 1)
 	}
 
-	chain, err := core.NewBlockchain(store, cfg.ProtocolConfiguration)
+	chain, err := core.NewBlockchain(store, cfg.ProtocolConfiguration, log)
 	if err != nil {
 		return nil, cli.NewExitError(fmt.Errorf("could not initialize blockchain: %s", err), 1)
 	}

integration/performance_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/network"
 	"github.com/CityOfZion/neo-go/pkg/rpc"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 // Benchmark test to measure number of processed TX.
@@ -23,14 +24,15 @@ func BenchmarkTXPerformanceTest(t *testing.B) {
 	cfg, err := config.Load(configPath, net)
 	require.NoError(t, err, "could not load config")
 
+	logger := zaptest.NewLogger(t)
 	memoryStore := storage.NewMemoryStore()
-	chain, err := core.NewBlockchain(memoryStore, cfg.ProtocolConfiguration)
+	chain, err := core.NewBlockchain(memoryStore, cfg.ProtocolConfiguration, logger)
 	require.NoError(t, err, "could not create chain")
 
 	go chain.Run()
 
 	serverConfig := network.NewServerConfig(cfg)
-	server := network.NewServer(serverConfig, chain)
+	server := network.NewServer(serverConfig, chain, logger)
 	data := prepareData(t)
 	t.ResetTimer()
 

pkg/consensus/consensus.go

@@ -60,6 +60,8 @@ type service struct {
 
 // Config is a configuration for consensus services.
 type Config struct {
+	// Logger is a logger instance.
+	Logger *zap.Logger
 	// Broadcast is a callback which is called to notify server
 	// about new consensus payload to sent.
 	Broadcast func(p *Payload)
@@ -79,19 +81,18 @@ type Config struct {
 
 // NewService returns new consensus.Service instance.
 func NewService(cfg Config) (Service, error) {
-	log, err := getLogger()
-	if err != nil {
-		return nil, err
-	}
-
 	if cfg.TimePerBlock <= 0 {
 		cfg.TimePerBlock = defaultTimePerBlock
 	}
 
+	if cfg.Logger == nil {
+		return nil, errors.New("empty logger")
+	}
+
 	srv := &service{
 		Config: cfg,
 
-		log:      log.Sugar(),
+		log:      cfg.Logger.Sugar(),
 		cache:    newFIFOCache(cacheMaxCapacity),
 		txx:      newFIFOCache(cacheMaxCapacity),
 		messages: make(chan Payload, 100),

pkg/consensus/consensus_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/nspcc-dev/dbft/block"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 func TestNewService(t *testing.T) {
@@ -128,6 +129,7 @@ func shouldNotReceive(t *testing.T, ch chan Payload) {
 
 func newTestService(t *testing.T) *service {
 	srv, err := NewService(Config{
+		Logger:    zaptest.NewLogger(t),
 		Broadcast: func(*Payload) {},
 		Chain:     newTestChain(t),
 		RequestTx: func(...util.Uint256) {},
@@ -177,7 +179,7 @@ func newTestChain(t *testing.T) *core.Blockchain {
 	unitTestNetCfg, err := config.Load("../../config", config.ModeUnitTestNet)
 	require.NoError(t, err)
 
-	chain, err := core.NewBlockchain(storage.NewMemoryStore(), unitTestNetCfg.ProtocolConfiguration)
+	chain, err := core.NewBlockchain(storage.NewMemoryStore(), unitTestNetCfg.ProtocolConfiguration, zaptest.NewLogger(t))
 	require.NoError(t, err)
 
 	go chain.Run()

pkg/consensus/logger.go

@@ -1,19 +0,0 @@
-package consensus
-
-import (
-	"go.uber.org/zap"
-)
-
-func getLogger() (*zap.Logger, error) {
-	cc := zap.NewDevelopmentConfig()
-	cc.DisableCaller = true
-	cc.DisableStacktrace = true
-	cc.Encoding = "console"
-
-	log, err := cc.Build()
-	if err != nil {
-		return nil, err
-	}
-
-	return log.With(zap.String("module", "dbft")), nil
-}

pkg/core/blockchain.go

@@ -21,7 +21,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm"
 	"github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap"
 )
 
 // Tuning parameters.
@@ -80,13 +80,19 @@ type Blockchain struct {
 
 	// cache for block verification keys.
 	keyCache map[util.Uint160]map[string]*keys.PublicKey
+
+	log *zap.Logger
 }
 
 type headersOpFunc func(headerList *HeaderHashList)
 
 // NewBlockchain returns a new blockchain object the will use the
 // given Store as its underlying storage.
-func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration) (*Blockchain, error) {
+func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration, log *zap.Logger) (*Blockchain, error) {
+	if log == nil {
+		return nil, errors.New("empty logger")
+	}
+
 	bc := &Blockchain{
 		config:        cfg,
 		dao:           newDao(s),
@@ -96,6 +102,7 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration) (*Blockcha
 		runToExitCh:   make(chan struct{}),
 		memPool:       NewMemPool(50000),
 		keyCache:      make(map[util.Uint160]map[string]*keys.PublicKey),
+		log:           log,
 	}
 
 	if err := bc.init(); err != nil {
@@ -109,7 +116,7 @@ func (bc *Blockchain) init() error {
 	// If we could not find the version in the Store, we know that there is nothing stored.
 	ver, err := bc.dao.GetVersion()
 	if err != nil {
-		log.Infof("no storage version found! creating genesis block")
+		bc.log.Info("no storage version found! creating genesis block")
 		if err = bc.dao.PutVersion(version); err != nil {
 			return err
 		}
@@ -131,7 +138,7 @@ func (bc *Blockchain) init() error {
 	// At this point there was no version found in the storage which
 	// implies a creating fresh storage with the version specified
 	// and the genesis block as first block.
-	log.Infof("restoring blockchain with version: %s", version)
+	bc.log.Info("restoring blockchain", zap.String("version", version))
 
 	bHeight, err := bc.dao.GetCurrentBlockHeight()
 	if err != nil {
@@ -200,10 +207,10 @@ func (bc *Blockchain) Run() {
 	defer func() {
 		persistTimer.Stop()
 		if err := bc.persist(); err != nil {
-			log.Warnf("failed to persist: %s", err)
+			bc.log.Warn("failed to persist", zap.Error(err))
 		}
 		if err := bc.dao.store.Close(); err != nil {
-			log.Warnf("failed to close db: %s", err)
+			bc.log.Warn("failed to close db", zap.Error(err))
 		}
 		close(bc.runToExitCh)
 	}()
@@ -218,7 +225,7 @@ func (bc *Blockchain) Run() {
 			go func() {
 				err := bc.persist()
 				if err != nil {
-					log.Warnf("failed to persist blockchain: %s", err)
+					bc.log.Warn("failed to persist blockchain", zap.Error(err))
 				}
 			}()
 			persistTimer.Reset(persistInterval)
@@ -302,11 +309,10 @@ func (bc *Blockchain) AddHeaders(headers ...*Header) (err error) {
 			if err = bc.dao.store.PutBatch(batch); err != nil {
 				return
 			}
-			log.WithFields(log.Fields{
+			bc.log.Debug("done processing headers",
-				"headerIndex": headerList.Len() - 1,
+				zap.Int("headerIndex", headerList.Len()-1),
-				"blockHeight": bc.BlockHeight(),
+				zap.Uint32("blockHeight", bc.BlockHeight()),
-				"took":        time.Since(start),
+				zap.Duration("took", time.Since(start)))
-			}).Debug("done processing headers")
 		}
 	}
 	<-bc.headersOpDone
@@ -502,7 +508,7 @@ func (bc *Blockchain) storeBlock(block *Block) error {
 				return err
 			}
 		case *transaction.InvocationTX:
-			systemInterop := newInteropContext(trigger.Application, bc, cache.store, block, tx)
+			systemInterop := newInteropContext(trigger.Application, bc, cache.store, block, tx, bc.log)
 			v := bc.spawnVMWithInterops(systemInterop)
 			v.SetCheckedHash(tx.VerificationHash().BytesBE())
 			v.LoadScript(t.Script)
@@ -537,11 +543,10 @@ func (bc *Blockchain) storeBlock(block *Block) error {
 					_, _, _, _ = op, from, to, amount
 				}
 			} else {
-				log.WithFields(log.Fields{
+				bc.log.Warn("contract invocation failed",
-					"tx":    tx.Hash().StringLE(),
+					zap.String("tx", tx.Hash().StringLE()),
-					"block": block.Index,
+					zap.Uint32("block", block.Index),
-					"err":   err,
+					zap.Error(err))
-				}).Warn("contract invocation failed")
 			}
 			aer := &state.AppExecResult{
 				TxHash:      tx.Hash(),
@@ -710,13 +715,12 @@ func (bc *Blockchain) persist() error {
 		if err != nil {
 			return err
 		}
-		log.WithFields(log.Fields{
+		bc.log.Info("blockchain persist completed",
-			"persistedBlocks": diff,
+			zap.Uint32("persistedBlocks", diff),
-			"persistedKeys":   persisted,
+			zap.Int("persistedKeys", persisted),
-			"headerHeight":    storedHeaderHeight,
+			zap.Uint32("headerHeight", storedHeaderHeight),
-			"blockHeight":     bHeight,
+			zap.Uint32("blockHeight", bHeight),
-			"took":            time.Since(start),
+			zap.Duration("took", time.Since(start)))
-		}).Info("blockchain persist completed")
 
 		// update monitoring metrics.
 		updatePersistedHeightMetric(bHeight)
@@ -849,7 +853,9 @@ func (bc *Blockchain) HeaderHeight() uint32 {
 func (bc *Blockchain) GetAssetState(assetID util.Uint256) *state.Asset {
 	asset, err := bc.dao.GetAssetState(assetID)
 	if asset == nil && err != storage.ErrKeyNotFound {
-		log.Warnf("failed to get asset state %s : %s", assetID, err)
+		bc.log.Warn("failed to get asset state",
+			zap.Stringer("asset", assetID),
+			zap.Error(err))
 	}
 	return asset
 }
@@ -858,7 +864,7 @@ func (bc *Blockchain) GetAssetState(assetID util.Uint256) *state.Asset {
 func (bc *Blockchain) GetContractState(hash util.Uint160) *state.Contract {
 	contract, err := bc.dao.GetContractState(hash)
 	if contract == nil && err != storage.ErrKeyNotFound {
-		log.Warnf("failed to get contract state: %s", err)
+		bc.log.Warn("failed to get contract state", zap.Error(err))
 	}
 	return contract
 }
@@ -867,7 +873,7 @@ func (bc *Blockchain) GetContractState(hash util.Uint160) *state.Contract {
 func (bc *Blockchain) GetAccountState(scriptHash util.Uint160) *state.Account {
 	as, err := bc.dao.GetAccountState(scriptHash)
 	if as == nil && err != storage.ErrKeyNotFound {
-		log.Warnf("failed to get account state: %s", err)
+		bc.log.Warn("failed to get account state", zap.Error(err))
 	}
 	return as
 }
@@ -876,7 +882,7 @@ func (bc *Blockchain) GetAccountState(scriptHash util.Uint160) *state.Account {
 func (bc *Blockchain) GetUnspentCoinState(hash util.Uint256) *UnspentCoinState {
 	ucs, err := bc.dao.GetUnspentCoinState(hash)
 	if ucs == nil && err != storage.ErrKeyNotFound {
-		log.Warnf("failed to get unspent coin state: %s", err)
+		bc.log.Warn("failed to get unspent coin state", zap.Error(err))
 	}
 	return ucs
 }
@@ -1367,7 +1373,7 @@ func (bc *Blockchain) spawnVMWithInterops(interopCtx *interopContext) *vm.VM {
 // GetTestVM returns a VM and a Store setup for a test run of some sort of code.
 func (bc *Blockchain) GetTestVM() (*vm.VM, storage.Store) {
 	tmpStore := storage.NewMemCachedStore(bc.dao.store)
-	systemInterop := newInteropContext(trigger.Application, bc, tmpStore, nil, nil)
+	systemInterop := newInteropContext(trigger.Application, bc, tmpStore, nil, nil, bc.log)
 	vm := bc.spawnVMWithInterops(systemInterop)
 	return vm, tmpStore
 }
@@ -1446,7 +1452,7 @@ func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *Block
 	}
 	sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
 	sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
-	interopCtx := newInteropContext(trigger.Verification, bc, bc.dao.store, block, t)
+	interopCtx := newInteropContext(trigger.Verification, bc, bc.dao.store, block, t, bc.log)
 	for i := 0; i < len(hashes); i++ {
 		err := bc.verifyHashAgainstScript(hashes[i], &witnesses[i], t.VerificationHash(), interopCtx, false)
 		if err != nil {
@@ -1466,7 +1472,7 @@ func (bc *Blockchain) verifyBlockWitnesses(block *Block, prevHeader *Header) err
 	} else {
 		hash = prevHeader.NextConsensus
 	}
-	interopCtx := newInteropContext(trigger.Verification, bc, bc.dao.store, nil, nil)
+	interopCtx := newInteropContext(trigger.Verification, bc, bc.dao.store, nil, nil, bc.log)
 	return bc.verifyHashAgainstScript(hash, &block.Script, block.VerificationHash(), interopCtx, true)
 }
 

pkg/core/helper_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 var newBlockPrevHash util.Uint256
@@ -37,7 +38,7 @@ func newTestChain(t *testing.T) *Blockchain {
 	if err != nil {
 		t.Fatal(err)
 	}
-	chain, err := NewBlockchain(storage.NewMemoryStore(), unitTestNetCfg.ProtocolConfiguration)
+	chain, err := NewBlockchain(storage.NewMemoryStore(), unitTestNetCfg.ProtocolConfiguration, zaptest.NewLogger(t))
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/core/interop_neo_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/vm"
 	"github.com/CityOfZion/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 /*  Missing tests:
@@ -112,7 +113,7 @@ func TestHeaderGetVersion(t *testing.T) {
 func TestHeaderGetVersion_Negative(t *testing.T) {
 	v := vm.New()
 	block := newDumbBlock()
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), block, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), block, nil, zaptest.NewLogger(t))
 	v.Estack().PushVal(vm.NewBoolItem(false))
 
 	err := context.headerGetVersion(v)
@@ -197,7 +198,7 @@ func TestWitnessGetVerificationScript(t *testing.T) {
 	script := []byte{byte(opcode.PUSHM1), byte(opcode.RET)}
 	witness := transaction.Witness{InvocationScript: nil, VerificationScript: script}
 
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil, zaptest.NewLogger(t))
 	v.Estack().PushVal(vm.NewInteropItem(&witness))
 	err := context.witnessGetVerificationScript(v)
 	require.NoError(t, err)
@@ -418,7 +419,7 @@ func TestAssetGetPrecision(t *testing.T) {
 func createVMAndPushBlock(t *testing.T) (*vm.VM, *Block, *interopContext) {
 	v := vm.New()
 	block := newDumbBlock()
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), block, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), block, nil, zaptest.NewLogger(t))
 	v.Estack().PushVal(vm.NewInteropItem(block))
 	return v, block, context
 }
@@ -447,7 +448,7 @@ func createVMAndAssetState(t *testing.T) (*vm.VM, *state.Asset, *interopContext)
 		IsFrozen:   false,
 	}
 
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil, zaptest.NewLogger(t))
 	return v, assetState, context
 }
 
@@ -465,7 +466,7 @@ func createVMAndContractState(t *testing.T) (*vm.VM, *state.Contract, *interopCo
 		Description: random.String(10),
 	}
 
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil, zaptest.NewLogger(t))
 	return v, contractState, context
 }
 
@@ -479,7 +480,7 @@ func createVMAndAccState(t *testing.T) (*vm.VM, *state.Account, *interopContext)
 	accountState.Votes = []*keys.PublicKey{key}
 
 	require.NoError(t, err)
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil, zaptest.NewLogger(t))
 	return v, accountState, context
 }
 
@@ -509,6 +510,6 @@ func createVMAndTX(t *testing.T) (*vm.VM, *transaction.Transaction, *interopCont
 	tx.Attributes = attributes
 	tx.Inputs = inputs
 	tx.Outputs = outputs
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, tx)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, tx, zaptest.NewLogger(t))
 	return v, tx, context
 }

pkg/core/interop_system.go

@@ -13,7 +13,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm"
 	gherr "github.com/pkg/errors"
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap"
 )
 
 const (
@@ -350,7 +350,9 @@ func (ic *interopContext) runtimeNotify(v *vm.VM) error {
 // runtimeLog logs the message passed.
 func (ic *interopContext) runtimeLog(v *vm.VM) error {
 	msg := fmt.Sprintf("%q", v.Estack().Pop().Bytes())
-	log.Infof("script %s logs: %s", getContextScriptHash(v, 0), msg)
+	ic.log.Info("runtime log",
+		zap.Stringer("script", getContextScriptHash(v, 0)),
+		zap.String("logs", msg))
 	return nil
 }
 

pkg/core/interops.go

@@ -14,6 +14,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/core/storage"
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/vm"
+	"go.uber.org/zap"
 )
 
 type interopContext struct {
@@ -23,12 +24,13 @@ type interopContext struct {
 	tx            *transaction.Transaction
 	dao           *cachedDao
 	notifications []state.NotificationEvent
+	log           *zap.Logger
 }
 
-func newInteropContext(trigger byte, bc Blockchainer, s storage.Store, block *Block, tx *transaction.Transaction) *interopContext {
+func newInteropContext(trigger byte, bc Blockchainer, s storage.Store, block *Block, tx *transaction.Transaction, log *zap.Logger) *interopContext {
 	dao := newCachedDao(s)
 	nes := make([]state.NotificationEvent, 0)
-	return &interopContext{bc, trigger, block, tx, dao, nes}
+	return &interopContext{bc, trigger, block, tx, dao, nes, log}
 }
 
 // interopedFunction binds function name, id with the function itself and price,

pkg/core/interops_test.go

@@ -9,12 +9,13 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/smartcontract/trigger"
 	"github.com/CityOfZion/neo-go/pkg/vm"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 func testNonInterop(t *testing.T, value interface{}, f func(*interopContext, *vm.VM) error) {
 	v := vm.New()
 	v.Estack().PushVal(value)
-	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil)
+	context := newInteropContext(trigger.Application, newTestChain(t), storage.NewMemoryStore(), nil, nil, zaptest.NewLogger(t))
 	require.Error(t, f(context, v))
 }
 

pkg/network/blockqueue.go

@@ -3,17 +3,23 @@ package network
 import (
 	"github.com/CityOfZion/neo-go/pkg/core"
 	"github.com/Workiva/go-datastructures/queue"
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap"
 )
 
 type blockQueue struct {
+	log         *zap.Logger
 	queue       *queue.PriorityQueue
 	checkBlocks chan struct{}
 	chain       core.Blockchainer
 }
 
-func newBlockQueue(capacity int, bc core.Blockchainer) *blockQueue {
+func newBlockQueue(capacity int, bc core.Blockchainer, log *zap.Logger) *blockQueue {
+	if log == nil {
+		return nil
+	}
+
 	return &blockQueue{
+		log:         log,
 		queue:       queue.NewPriorityQueue(capacity, false),
 		checkBlocks: make(chan struct{}, 1),
 		chain:       bc,
@@ -38,11 +44,10 @@ func (bq *blockQueue) run() {
 				if minblock.Index == bq.chain.BlockHeight()+1 {
 					err := bq.chain.AddBlock(minblock)
 					if err != nil {
-						log.WithFields(log.Fields{
+						bq.log.Warn("blockQueue: failed adding block into the blockchain",
-							"error":       err.Error(),
+							zap.String("error", err.Error()),
-							"blockHeight": bq.chain.BlockHeight(),
+							zap.Uint32("blockHeight", bq.chain.BlockHeight()),
-							"nextIndex":   minblock.Index,
+							zap.Uint32("nextIndex", minblock.Index))
-						}).Warn("blockQueue: failed adding block into the blockchain")
 					}
 				}
 			} else {

pkg/network/blockqueue_test.go

@@ -6,12 +6,13 @@ import (
 
 	"github.com/CityOfZion/neo-go/pkg/core"
 	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap/zaptest"
 )
 
 func TestBlockQueue(t *testing.T) {
 	chain := &testChain{}
 	// notice, it's not yet running
-	bq := newBlockQueue(0, chain)
+	bq := newBlockQueue(0, chain, zaptest.NewLogger(t))
 	blocks := make([]*core.Block, 11)
 	for i := 1; i < 11; i++ {
 		blocks[i] = &core.Block{BlockBase: core.BlockBase{Index: uint32(i)}}

pkg/network/helper_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/network/payload"
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm"
+	"go.uber.org/zap/zaptest"
 )
 
 type testChain struct {
@@ -203,7 +204,7 @@ func (p *localPeer) Handshaked() bool {
 	return p.handshaked
 }
 
-func newTestServer() *Server {
+func newTestServer(t *testing.T) *Server {
 	return &Server{
 		ServerConfig: ServerConfig{},
 		chain:        &testChain{},
@@ -214,6 +215,7 @@ func newTestServer() *Server {
 		register:     make(chan Peer),
 		unregister:   make(chan peerDrop),
 		peers:        make(map[Peer]bool),
+		log:          zaptest.NewLogger(t),
 	}
 
 }

pkg/network/metrics/metrics.go

@@ -4,13 +4,14 @@ import (
 	"context"
 	"net/http"
 
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap"
 )
 
 // Service serves metrics.
 type Service struct {
 	*http.Server
 	config      Config
+	log         *zap.Logger
 	serviceType string
 }
 
@@ -24,27 +25,21 @@ type Config struct {
 // Start runs http service with exposed endpoint on configured port.
 func (ms *Service) Start() {
 	if ms.config.Enabled {
-		log.WithFields(log.Fields{
+		ms.log.Info("service is running", zap.String("endpoint", ms.Addr))
-			"endpoint": ms.Addr,
-			"service":  ms.serviceType,
-		}).Info("service running")
 		err := ms.ListenAndServe()
 		if err != nil && err != http.ErrServerClosed {
-			log.Warnf("%s service couldn't start on configured port", ms.serviceType)
+			ms.log.Warn("service couldn't start on configured port")
 		}
 	} else {
-		log.Infof("%s service hasn't started since it's disabled", ms.serviceType)
+		ms.log.Info("service hasn't started since it's disabled")
 	}
 }
 
 // ShutDown stops service.
 func (ms *Service) ShutDown() {
-	log.WithFields(log.Fields{
+	ms.log.Info("shutting down service", zap.String("endpoint", ms.Addr))
-		"endpoint": ms.Addr,
-		"service":  ms.serviceType,
-	}).Info("shutting down service")
 	err := ms.Shutdown(context.Background())
 	if err != nil {
-		log.Fatalf("can't shut down %s service", ms.serviceType)
+		ms.log.Panic("can't shut down service")
 	}
 }

pkg/network/metrics/pprof.go

@@ -3,13 +3,19 @@ package metrics
 import (
 	"net/http"
 	"net/http/pprof"
+
+	"go.uber.org/zap"
 )
 
 // PprofService https://golang.org/pkg/net/http/pprof/.
 type PprofService Service
 
 // NewPprofService created new service for gathering pprof metrics.
-func NewPprofService(cfg Config) *Service {
+func NewPprofService(cfg Config, log *zap.Logger) *Service {
+	if log == nil {
+		return nil
+	}
+
 	handler := http.NewServeMux()
 	handler.HandleFunc("/debug/pprof/", pprof.Index)
 	handler.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
@@ -18,9 +24,12 @@ func NewPprofService(cfg Config) *Service {
 	handler.HandleFunc("/debug/pprof/trace", pprof.Trace)
 
 	return &Service{
-		&http.Server{
+		Server: &http.Server{
 			Addr:    cfg.Address + ":" + cfg.Port,
 			Handler: handler,
-		}, cfg, "Pprof",
+		},
+		config:      cfg,
+		serviceType: "Pprof",
+		log:         log.With(zap.String("service", "Pprof")),
 	}
 }

pkg/network/metrics/prometheus.go

@@ -4,17 +4,25 @@ import (
 	"net/http"
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.uber.org/zap"
 )
 
 // PrometheusService https://prometheus.io/docs/guides/go-application.
 type PrometheusService Service
 
 // NewPrometheusService creates new service for gathering prometheus metrics.
-func NewPrometheusService(cfg Config) *Service {
+func NewPrometheusService(cfg Config, log *zap.Logger) *Service {
+	if log == nil {
+		return nil
+	}
+
 	return &Service{
-		&http.Server{
+		Server: &http.Server{
 			Addr:    cfg.Address + ":" + cfg.Port,
 			Handler: promhttp.Handler(),
-		}, cfg, "Prometheus",
+		},
+		config:      cfg,
+		serviceType: "Prometheus",
+		log:         log.With(zap.String("service", "Prometheus")),
 	}
 }

pkg/network/payload/headers.go

@@ -3,7 +3,6 @@ package payload
 import (
 	"github.com/CityOfZion/neo-go/pkg/core"
 	"github.com/CityOfZion/neo-go/pkg/io"
-	log "github.com/sirupsen/logrus"
 )
 
 // Headers payload.
@@ -22,7 +21,6 @@ func (p *Headers) DecodeBinary(br *io.BinReader) {
 
 	// C# node does it silently
 	if lenHeaders > MaxHeadersAllowed {
-		log.Warnf("received %d headers, capping to %d", lenHeaders, MaxHeadersAllowed)
 		lenHeaders = MaxHeadersAllowed
 	}
 

pkg/network/server.go

@@ -15,8 +15,8 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/network/payload"
 	"github.com/CityOfZion/neo-go/pkg/util"
-	log "github.com/sirupsen/logrus"
 	"go.uber.org/atomic"
+	"go.uber.org/zap"
 )
 
 const (
@@ -65,6 +65,8 @@ type (
 		quit       chan struct{}
 
 		connected *atomic.Bool
+
+		log *zap.Logger
 	}
 
 	peerDrop struct {
@@ -80,11 +82,15 @@ func randomID() uint32 {
 }
 
 // NewServer returns a new Server, initialized with the given configuration.
-func NewServer(config ServerConfig, chain core.Blockchainer) *Server {
+func NewServer(config ServerConfig, chain core.Blockchainer, log *zap.Logger) *Server {
+	if log == nil {
+		return nil
+	}
+
 	s := &Server{
 		ServerConfig: config,
 		chain:        chain,
-		bQueue:       newBlockQueue(maxBlockBatch, chain),
+		bQueue:       newBlockQueue(maxBlockBatch, chain, log),
 		id:           randomID(),
 		quit:         make(chan struct{}),
 		addrReq:      make(chan *Message, config.MinPeers),
@@ -92,9 +98,11 @@ func NewServer(config ServerConfig, chain core.Blockchainer) *Server {
 		unregister:   make(chan peerDrop),
 		peers:        make(map[Peer]bool),
 		connected:    atomic.NewBool(false),
+		log:          log,
 	}
 
 	srv, err := consensus.NewService(consensus.Config{
+		Logger:     log,
 		Broadcast:  s.handleNewPayload,
 		RelayBlock: s.relayBlock,
 		Chain:      chain,
@@ -108,30 +116,27 @@ func NewServer(config ServerConfig, chain core.Blockchainer) *Server {
 	s.consensus = srv
 
 	if s.MinPeers <= 0 {
-		log.WithFields(log.Fields{
+		s.log.Info("bad MinPeers configured, using the default value",
-			"MinPeers configured": s.MinPeers,
+			zap.Int("configured", s.MinPeers),
-			"MinPeers actual":     defaultMinPeers,
+			zap.Int("actual", defaultMinPeers))
-		}).Info("bad MinPeers configured, using the default value")
 		s.MinPeers = defaultMinPeers
 	}
 
 	if s.MaxPeers <= 0 {
-		log.WithFields(log.Fields{
+		s.log.Info("bad MaxPeers configured, using the default value",
-			"MaxPeers configured": s.MaxPeers,
+			zap.Int("configured", s.MaxPeers),
-			"MaxPeers actual":     defaultMaxPeers,
+			zap.Int("actual", defaultMaxPeers))
-		}).Info("bad MaxPeers configured, using the default value")
 		s.MaxPeers = defaultMaxPeers
 	}
 
 	if s.AttemptConnPeers <= 0 {
-		log.WithFields(log.Fields{
+		s.log.Info("bad AttemptConnPeers configured, using the default value",
-			"AttemptConnPeers configured": s.AttemptConnPeers,
+			zap.Int("configured", s.AttemptConnPeers),
-			"AttemptConnPeers actual":     defaultAttemptConnPeers,
+			zap.Int("actual", defaultAttemptConnPeers))
-		}).Info("bad AttemptConnPeers configured, using the default value")
 		s.AttemptConnPeers = defaultAttemptConnPeers
 	}
 
-	s.transport = NewTCPTransport(s, fmt.Sprintf("%s:%d", config.Address, config.Port))
+	s.transport = NewTCPTransport(s, fmt.Sprintf("%s:%d", config.Address, config.Port), s.log)
 	s.discovery = NewDefaultDiscovery(
 		s.DialTimeout,
 		s.transport,
@@ -147,10 +152,9 @@ func (s *Server) ID() uint32 {
 
 // Start will start the server and its underlying transport.
 func (s *Server) Start(errChan chan error) {
-	log.WithFields(log.Fields{
+	s.log.Info("node started",
-		"blockHeight":  s.chain.BlockHeight(),
+		zap.Uint32("blockHeight", s.chain.BlockHeight()),
-		"headerHeight": s.chain.HeaderHeight(),
+		zap.Uint32("headerHeight", s.chain.HeaderHeight()))
-	}).Info("node started")
 
 	s.discovery.BackFill(s.Seeds...)
 
@@ -162,9 +166,7 @@ func (s *Server) Start(errChan chan error) {
 
 // Shutdown disconnects all peers and stops listening.
 func (s *Server) Shutdown() {
-	log.WithFields(log.Fields{
+	s.log.Info("shutting down server", zap.Int("peers", s.PeerCount()))
-		"peers": s.PeerCount(),
-	}).Info("shutting down server")
 	s.bQueue.discard()
 	close(s.quit)
 }
@@ -205,9 +207,7 @@ func (s *Server) run() {
 			s.lock.Lock()
 			s.peers[p] = true
 			s.lock.Unlock()
-			log.WithFields(log.Fields{
+			s.log.Info("new peer connected", zap.Stringer("addr", p.RemoteAddr()))
-				"addr": p.RemoteAddr(),
-			}).Info("new peer connected")
 			peerCount := s.PeerCount()
 			if peerCount > s.MaxPeers {
 				s.lock.RLock()
@@ -225,11 +225,10 @@ func (s *Server) run() {
 			if s.peers[drop.peer] {
 				delete(s.peers, drop.peer)
 				s.lock.Unlock()
-				log.WithFields(log.Fields{
+				s.log.Warn("peer disconnected",
-					"addr":      drop.peer.RemoteAddr(),
+					zap.Stringer("addr", drop.peer.RemoteAddr()),
-					"reason":    drop.reason,
+					zap.String("reason", drop.reason.Error()),
-					"peerCount": s.PeerCount(),
+					zap.Int("peerCount", s.PeerCount()))
-				}).Warn("peer disconnected")
 				addr := drop.peer.PeerAddr().String()
 				if drop.reason == errIdenticalID {
 					s.discovery.RegisterBadAddr(addr)
@@ -254,7 +253,7 @@ func (s *Server) tryStartConsensus() {
 	}
 
 	if s.HandshakedPeersCount() >= s.MinPeers {
-		log.Info("minimum amount of peers were connected to")
+		s.log.Info("minimum amount of peers were connected to")
 		if s.connected.CAS(false, true) {
 			s.consensus.Start()
 		}
@@ -304,12 +303,11 @@ func (s *Server) HandshakedPeersCount() int {
 func (s *Server) startProtocol(p Peer) {
 	var err error
 
-	log.WithFields(log.Fields{
+	s.log.Info("started protocol",
-		"addr":        p.RemoteAddr(),
+		zap.Stringer("addr", p.RemoteAddr()),
-		"userAgent":   string(p.Version().UserAgent),
+		zap.ByteString("userAgent", p.Version().UserAgent),
-		"startHeight": p.Version().StartHeight,
+		zap.Uint32("startHeight", p.Version().StartHeight),
-		"id":          p.Version().Nonce,
+		zap.Uint32("id", p.Version().Nonce))
-	}).Info("started protocol")
 
 	s.discovery.RegisterGoodAddr(p.PeerAddr().String())
 	if s.chain.HeaderHeight() < p.Version().StartHeight {
@@ -386,7 +384,7 @@ func (s *Server) handleVersionCmd(p Peer, version *payload.Version) error {
 // This method could best be called in a separate routine.
 func (s *Server) handleHeadersCmd(p Peer, headers *payload.Headers) {
 	if err := s.chain.AddHeaders(headers.Hdrs...); err != nil {
-		log.Warnf("failed processing headers: %s", err)
+		s.log.Warn("failed processing headers", zap.Error(err))
 		return
 	}
 	// The peer will respond with a maximum of 2000 headers in one batch.

pkg/network/server_config.go

@@ -4,7 +4,7 @@ import (
 	"time"
 
 	"github.com/CityOfZion/neo-go/config"
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap/zapcore"
 )
 
 type (
@@ -53,7 +53,7 @@ type (
 		ProtoTickInterval time.Duration
 
 		// Level of the internal logger.
-		LogLevel log.Level
+		LogLevel zapcore.Level
 
 		// Wallet is a wallet configuration.
 		Wallet *config.WalletConfig

pkg/network/server_test.go

@@ -11,7 +11,7 @@ import (
 
 func TestSendVersion(t *testing.T) {
 	var (
-		s = newTestServer()
+		s = newTestServer(t)
 		p = newLocalPeer(t)
 	)
 	s.Port = 3000
@@ -37,7 +37,7 @@ func TestSendVersion(t *testing.T) {
 // Server should reply with a verack after receiving a valid version.
 func TestVerackAfterHandleVersionCmd(t *testing.T) {
 	var (
-		s = newTestServer()
+		s = newTestServer(t)
 		p = newLocalPeer(t)
 	)
 	na, _ := net.ResolveTCPAddr("tcp", "0.0.0.0:3000")
@@ -58,7 +58,7 @@ func TestVerackAfterHandleVersionCmd(t *testing.T) {
 // invalid version and disconnects the peer.
 func TestServerNotSendsVerack(t *testing.T) {
 	var (
-		s  = newTestServer()
+		s  = newTestServer(t)
 		p  = newLocalPeer(t)
 		p2 = newLocalPeer(t)
 	)
@@ -91,7 +91,7 @@ func TestServerNotSendsVerack(t *testing.T) {
 
 func TestRequestHeaders(t *testing.T) {
 	var (
-		s = newTestServer()
+		s = newTestServer(t)
 		p = newLocalPeer(t)
 	)
 	p.messageHandler = func(t *testing.T, msg *Message) {

pkg/network/tcp_transport.go

@@ -6,11 +6,12 @@ import (
 	"time"
 
 	"github.com/CityOfZion/neo-go/pkg/io"
-	log "github.com/sirupsen/logrus"
+	"go.uber.org/zap"
 )
 
 // TCPTransport allows network communication over TCP.
 type TCPTransport struct {
+	log      *zap.Logger
 	server   *Server
 	listener net.Listener
 	bindAddr string
@@ -20,8 +21,9 @@ var reClosedNetwork = regexp.MustCompile(".* use of closed network connection")
 
 // NewTCPTransport returns a new TCPTransport that will listen for
 // new incoming peer connections.
-func NewTCPTransport(s *Server, bindAddr string) *TCPTransport {
+func NewTCPTransport(s *Server, bindAddr string, log *zap.Logger) *TCPTransport {
 	return &TCPTransport{
+		log:      log,
 		server:   s,
 		bindAddr: bindAddr,
 	}
@@ -41,7 +43,7 @@ func (t *TCPTransport) Dial(addr string, timeout time.Duration) error {
 func (t *TCPTransport) Accept() {
 	l, err := net.Listen("tcp", t.bindAddr)
 	if err != nil {
-		log.Fatalf("TCP listen error %s", err)
+		t.log.Panic("TCP listen error", zap.Error(err))
 		return
 	}
 
@@ -50,7 +52,7 @@ func (t *TCPTransport) Accept() {
 	for {
 		conn, err := l.Accept()
 		if err != nil {
-			log.Warnf("TCP accept error: %s", err)
+			t.log.Warn("TCP accept error", zap.Error(err))
 			if t.isCloseError(err) {
 				break
 			}
@@ -80,9 +82,7 @@ func (t *TCPTransport) handleConn(conn net.Conn) {
 
 	// When a new peer is connected we send out our version immediately.
 	if err := t.server.sendVersion(p); err != nil {
-		log.WithFields(log.Fields{
+		t.log.Error("error on sendVersion", zap.Stringer("addr", p.RemoteAddr()), zap.Error(err))
-			"addr": p.RemoteAddr(),
-		}).Error(err)
 	}
 	r := io.NewBinReaderFromIO(p.conn)
 	for {

pkg/rpc/server_helper_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/rpc/result"
 	"github.com/CityOfZion/neo-go/pkg/rpc/wrappers"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap/zaptest"
 )
 
 // ErrorResponse struct represents JSON-RPC error.
@@ -180,7 +181,7 @@ func initServerWithInMemoryChain(t *testing.T) (*core.Blockchain, http.HandlerFu
 	require.NoError(t, err, "could not load config")
 
 	memoryStore := storage.NewMemoryStore()
-	chain, err := core.NewBlockchain(memoryStore, cfg.ProtocolConfiguration)
+	chain, err := core.NewBlockchain(memoryStore, cfg.ProtocolConfiguration, zaptest.NewLogger(t))
 	require.NoError(t, err, "could not create chain")
 
 	go chain.Run()
@@ -198,7 +199,7 @@ func initServerWithInMemoryChain(t *testing.T) (*core.Blockchain, http.HandlerFu
 	}
 
 	serverConfig := network.NewServerConfig(cfg)
-	server := network.NewServer(serverConfig, chain)
+	server := network.NewServer(serverConfig, chain, zaptest.NewLogger(t))
 	rpcServer := NewServer(chain, cfg.ApplicationConfiguration.RPC, server)
 	handler := http.HandlerFunc(rpcServer.requestHandler)