From 16c05af75cd077f2d211952cd9d4f41f3d21e95a Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Wed, 17 Jul 2024 17:03:44 +0900
Subject: [PATCH 01/11] use slog in handler

---
 cmd/ferretdb/main.go                          |  1 +
 ferretdb/ferretdb.go                          |  2 +
 integration/setup/listener.go                 |  2 +
 internal/handler/cmd_query.go                 |  9 ++--
 internal/handler/commands.go                  | 17 +++----
 internal/handler/common/count.go              |  4 +-
 internal/handler/common/delete_params.go      |  4 +-
 internal/handler/common/distinct.go           |  5 +-
 internal/handler/common/explain.go            |  4 +-
 internal/handler/common/find.go               |  4 +-
 internal/handler/common/findandmodify.go      |  5 +-
 internal/handler/common/insert.go             |  5 +-
 internal/handler/common/unimplemented.go      |  7 ++-
 internal/handler/common/update_params.go      |  4 +-
 internal/handler/handler.go                   | 46 ++++++++++++-------
 .../handler/handlerparams/extract_params.go   |  9 ++--
 .../handlerparams/extract_params_test.go      |  4 +-
 internal/handler/msg_aggregate.go             | 13 ++++--
 internal/handler/msg_find.go                  | 23 ++++++----
 internal/handler/msg_getlog.go                |  5 +-
 internal/handler/msg_getmore.go               | 10 ++--
 internal/handler/msg_listdatabases.go         |  7 ++-
 internal/handler/msg_saslcontinue.go          | 22 ++++-----
 internal/handler/msg_saslstart.go             | 21 +++++----
 internal/handler/registry/hana.go             |  3 +-
 internal/handler/registry/mysql.go            |  3 +-
 internal/handler/registry/postgresql.go       |  3 +-
 internal/handler/registry/registry.go         |  2 +
 internal/handler/registry/sqlite.go           |  3 +-
 29 files changed, 137 insertions(+), 110 deletions(-)

diff --git a/cmd/ferretdb/main.go b/cmd/ferretdb/main.go
index 58e23b7b153d..1128c76d734b 100644
--- a/cmd/ferretdb/main.go
+++ b/cmd/ferretdb/main.go
@@ -498,6 +498,7 @@ func run() {
 
 	h, closeBackend, err := registry.NewHandler(cli.Handler, &registry.NewHandlerOpts{
 		Logger:        logger,
+		SLogger:       slogger,
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: stateProvider,
 		TCPHost:       cli.Listen.Addr,
diff --git a/ferretdb/ferretdb.go b/ferretdb/ferretdb.go
index df2747f8c91c..91a4f50124cf 100644
--- a/ferretdb/ferretdb.go
+++ b/ferretdb/ferretdb.go
@@ -22,6 +22,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/url"
 	"sync"
 
@@ -126,6 +127,7 @@ func New(config *Config) (*FerretDB, error) {
 
 	h, closeBackend, err := registry.NewHandler(config.Handler, &registry.NewHandlerOpts{
 		Logger:        log,
+		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: sp,
 		TCPHost:       config.Listener.TCP,
diff --git a/integration/setup/listener.go b/integration/setup/listener.go
index 2d1e6e21b1a7..383e90a2071e 100644
--- a/integration/setup/listener.go
+++ b/integration/setup/listener.go
@@ -16,6 +16,7 @@ package setup
 
 import (
 	"context"
+	"log/slog"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -179,6 +180,7 @@ func setupListener(tb testtb.TB, ctx context.Context, logger *zap.Logger, opts *
 
 	handlerOpts := &registry.NewHandlerOpts{
 		Logger:        logger,
+		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   listenerMetrics.ConnMetrics,
 		StateProvider: sp,
 
diff --git a/internal/handler/cmd_query.go b/internal/handler/cmd_query.go
index b569ccb029a9..927dd02a20e7 100644
--- a/internal/handler/cmd_query.go
+++ b/internal/handler/cmd_query.go
@@ -19,12 +19,11 @@ import (
 	"fmt"
 	"strings"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -75,7 +74,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 
 		dbName, err := common.GetRequiredParam[string](authDoc, "db")
 		if err != nil {
-			h.L.Debug("No `db` in `speculativeAuthenticate`", zap.Error(err))
+			h.L.DebugContext(connCtx, "No `db` in `speculativeAuthenticate`", logging.Error(err))
 
 			opReply.SetDocument(reply)
 
@@ -84,7 +83,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 
 		speculativeAuthenticate, err := h.saslStart(connCtx, dbName, authDoc)
 		if err != nil {
-			h.L.Debug("Speculative authentication failed", zap.Error(err))
+			h.L.DebugContext(connCtx, "Speculative authentication failed", logging.Error(err))
 
 			// unsuccessful speculative authentication leave `speculativeAuthenticate` field unset
 			// and let `saslStart` return an error
@@ -93,7 +92,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 			return &opReply, nil
 		}
 
-		h.L.Debug("Speculative authentication passed")
+		h.L.DebugContext(connCtx, "Speculative authentication passed")
 
 		reply.Set("speculativeAuthenticate", speculativeAuthenticate)
 
diff --git a/internal/handler/commands.go b/internal/handler/commands.go
index c523c54b6bd2..98a39046b535 100644
--- a/internal/handler/commands.go
+++ b/internal/handler/commands.go
@@ -16,8 +16,7 @@ package handler
 
 import (
 	"context"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -295,23 +294,25 @@ func (h *Handler) initCommands() {
 }
 
 // checkSCRAMConversation returns error if SCRAM conversation is not valid.
-func checkSCRAMConversation(ctx context.Context, l *zap.Logger) error {
+func checkSCRAMConversation(ctx context.Context, l *slog.Logger) error {
 	_, _, conv, _ := conninfo.Get(ctx).Auth()
 
 	switch {
 	case conv == nil:
-		l.Warn("checkSCRAMConversation: no conversation")
+		l.WarnContext(ctx, "checkSCRAMConversation: no conversation")
 
 	case !conv.Valid():
-		l.Warn(
+		l.WarnContext(
+			ctx,
 			"checkSCRAMConversation: invalid conversation",
-			zap.String("username", conv.Username()), zap.Bool("valid", conv.Valid()), zap.Bool("done", conv.Done()),
+			slog.String("username", conv.Username()), slog.Bool("valid", conv.Valid()), slog.Bool("done", conv.Done()),
 		)
 
 	default:
-		l.Debug(
+		l.DebugContext(
+			ctx,
 			"checkSCRAMConversation: passed",
-			zap.String("username", conv.Username()), zap.Bool("valid", conv.Valid()), zap.Bool("done", conv.Done()),
+			slog.String("username", conv.Username()), slog.Bool("valid", conv.Valid()), slog.Bool("done", conv.Done()),
 		)
 
 		return nil
diff --git a/internal/handler/common/count.go b/internal/handler/common/count.go
index 642faeb14c0c..7cbdeeef6a05 100644
--- a/internal/handler/common/count.go
+++ b/internal/handler/common/count.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -44,7 +44,7 @@ type CountParams struct {
 }
 
 // GetCountParams returns the parameters for the count command.
-func GetCountParams(document *types.Document, l *zap.Logger) (*CountParams, error) {
+func GetCountParams(document *types.Document, l *slog.Logger) (*CountParams, error) {
 	var count CountParams
 
 	err := handlerparams.ExtractParams(document, "count", &count, l)
diff --git a/internal/handler/common/delete_params.go b/internal/handler/common/delete_params.go
index 30e5dfa77eab..36e3d806176f 100644
--- a/internal/handler/common/delete_params.go
+++ b/internal/handler/common/delete_params.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -55,7 +55,7 @@ type Delete struct {
 }
 
 // GetDeleteParams returns parameters for delete operation.
-func GetDeleteParams(document *types.Document, l *zap.Logger) (*DeleteParams, error) {
+func GetDeleteParams(document *types.Document, l *slog.Logger) (*DeleteParams, error) {
 	params := DeleteParams{
 		Ordered: true,
 	}
diff --git a/internal/handler/common/distinct.go b/internal/handler/common/distinct.go
index 66622c73c38c..e3e1f5435277 100644
--- a/internal/handler/common/distinct.go
+++ b/internal/handler/common/distinct.go
@@ -17,8 +17,7 @@ package common
 import (
 	"errors"
 	"fmt"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/commonpath"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -49,7 +48,7 @@ type DistinctParams struct {
 }
 
 // GetDistinctParams returns `distinct` command parameters.
-func GetDistinctParams(document *types.Document, l *zap.Logger) (*DistinctParams, error) {
+func GetDistinctParams(document *types.Document, l *slog.Logger) (*DistinctParams, error) {
 	var dp DistinctParams
 
 	err := handlerparams.ExtractParams(document, "distinct", &dp, l)
diff --git a/internal/handler/common/explain.go b/internal/handler/common/explain.go
index 857c2b1cbf3f..14b28487741f 100644
--- a/internal/handler/common/explain.go
+++ b/internal/handler/common/explain.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -45,7 +45,7 @@ type ExplainParams struct {
 }
 
 // GetExplainParams returns the parameters for the explain command.
-func GetExplainParams(document *types.Document, l *zap.Logger) (*ExplainParams, error) {
+func GetExplainParams(document *types.Document, l *slog.Logger) (*ExplainParams, error) {
 	var err error
 
 	var db, collection string
diff --git a/internal/handler/common/find.go b/internal/handler/common/find.go
index ace9752043bf..4ee10a0d5947 100644
--- a/internal/handler/common/find.go
+++ b/internal/handler/common/find.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -65,7 +65,7 @@ type FindParams struct {
 }
 
 // GetFindParams returns `find` command parameters.
-func GetFindParams(doc *types.Document, l *zap.Logger) (*FindParams, error) {
+func GetFindParams(doc *types.Document, l *slog.Logger) (*FindParams, error) {
 	params := FindParams{
 		BatchSize: 101,
 	}
diff --git a/internal/handler/common/findandmodify.go b/internal/handler/common/findandmodify.go
index b11be8ed0765..0de40a780977 100644
--- a/internal/handler/common/findandmodify.go
+++ b/internal/handler/common/findandmodify.go
@@ -16,8 +16,7 @@ package common
 
 import (
 	"fmt"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -59,7 +58,7 @@ type FindAndModifyParams struct {
 }
 
 // GetFindAndModifyParams returns `findAndModifyParams` command parameters.
-func GetFindAndModifyParams(doc *types.Document, l *zap.Logger) (*FindAndModifyParams, error) {
+func GetFindAndModifyParams(doc *types.Document, l *slog.Logger) (*FindAndModifyParams, error) {
 	var params FindAndModifyParams
 
 	err := handlerparams.ExtractParams(doc, "findAndModify", &params, l)
diff --git a/internal/handler/common/insert.go b/internal/handler/common/insert.go
index dcf6c087bab0..e63bdf770e1c 100644
--- a/internal/handler/common/insert.go
+++ b/internal/handler/common/insert.go
@@ -16,8 +16,7 @@ package common
 
 import (
 	"fmt"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -45,7 +44,7 @@ type InsertParams struct {
 }
 
 // GetInsertParams returns the parameters for an insert command.
-func GetInsertParams(document *types.Document, l *zap.Logger) (*InsertParams, error) {
+func GetInsertParams(document *types.Document, l *slog.Logger) (*InsertParams, error) {
 	params := InsertParams{
 		Ordered: true,
 	}
diff --git a/internal/handler/common/unimplemented.go b/internal/handler/common/unimplemented.go
index 153a23ae5ea5..c80f45a7c3cf 100644
--- a/internal/handler/common/unimplemented.go
+++ b/internal/handler/common/unimplemented.go
@@ -16,8 +16,7 @@ package common
 
 import (
 	"fmt"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -60,12 +59,12 @@ func UnimplementedNonDefault(doc *types.Document, field string, isDefault func(v
 }
 
 // Ignored logs a message if doc has any of the given fields.
-func Ignored(doc *types.Document, l *zap.Logger, fields ...string) {
+func Ignored(doc *types.Document, l *slog.Logger, fields ...string) {
 	for _, field := range fields {
 		if v, err := doc.Get(field); err == nil {
 			l.Debug(
 				"ignoring field",
-				zap.String("command", doc.Command()), zap.String("field", field), zap.Any("value", v),
+				slog.String("command", doc.Command()), slog.String("field", field), slog.Any("value", v),
 			)
 		}
 	}
diff --git a/internal/handler/common/update_params.go b/internal/handler/common/update_params.go
index fc943a50481c..dd2c5fde7aec 100644
--- a/internal/handler/common/update_params.go
+++ b/internal/handler/common/update_params.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -84,7 +84,7 @@ type UpdateResult struct {
 }
 
 // GetUpdateParams returns parameters for update command.
-func GetUpdateParams(document *types.Document, l *zap.Logger) (*UpdateParams, error) {
+func GetUpdateParams(document *types.Document, l *slog.Logger) (*UpdateParams, error) {
 	var params UpdateParams
 
 	err := handlerparams.ExtractParams(document, "update", &params, l)
diff --git a/internal/handler/handler.go b/internal/handler/handler.go
index 74b46eb3332e..8faeeda17a23 100644
--- a/internal/handler/handler.go
+++ b/internal/handler/handler.go
@@ -19,6 +19,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"sync"
 	"time"
 
@@ -35,6 +36,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/util/ctxutil"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/util/password"
 	"github.com/FerretDB/FerretDB/internal/util/state"
@@ -88,7 +90,7 @@ type NewOpts struct {
 	SetupPassword password.Password
 	SetupTimeout  time.Duration
 
-	L             *zap.Logger
+	L             *slog.Logger
 	ConnMetrics   *connmetrics.ConnMetrics
 	StateProvider *state.Provider
 
@@ -119,12 +121,12 @@ func New(opts *NewOpts) (*Handler, error) {
 		opts.MaxBsonObjectSizeBytes = types.MaxDocumentLen
 	}
 
-	b := oplog.NewBackend(opts.Backend, opts.L.Named("oplog"))
+	b := oplog.NewBackend(opts.Backend, zap.L().Named("oplog"))
 
 	h := &Handler{
 		b:       b,
 		NewOpts: opts,
-		cursors: cursor.NewRegistry(opts.L.Named("cursors")),
+		cursors: cursor.NewRegistry(zap.L().Named("cursors")),
 
 		cappedCleanupStop: make(chan struct{}),
 		cleanupCappedCollectionsDocs: prometheus.NewCounterVec(
@@ -184,7 +186,7 @@ func (h *Handler) setup() error {
 
 	ctx = conninfo.Ctx(ctx, info)
 
-	l := h.L.Named("setup")
+	l := logging.WithName(h.L, "setup")
 
 	var retry int64
 
@@ -194,7 +196,7 @@ func (h *Handler) setup() error {
 			break
 		}
 
-		l.Debug("Status failed", zap.Error(err))
+		l.DebugContext(ctx, "Status failed", logging.Error(err))
 
 		retry++
 		ctxutil.SleepWithJitter(ctx, time.Second, retry)
@@ -206,11 +208,16 @@ func (h *Handler) setup() error {
 	}
 
 	if len(res.Databases) > 0 {
-		l.Debug("Database already exists")
+		l.DebugContext(ctx, "Database already exists")
 		return nil
 	}
 
-	l.Info("Setting up database and user", zap.String("database", h.SetupDatabase), zap.String("username", h.SetupUsername))
+	l.InfoContext(
+		ctx,
+		"Setting up database and user",
+		slog.String("database", h.SetupDatabase),
+		slog.String("username", h.SetupUsername),
+	)
 
 	db, err := h.b.Database(h.SetupDatabase)
 	if err != nil {
@@ -245,7 +252,7 @@ func (h *Handler) runCappedCleanup() {
 		return
 	}
 
-	h.L.Info("Capped collections cleanup enabled.", zap.Duration("interval", h.CappedCleanupInterval))
+	h.L.Info("Capped collections cleanup enabled.", slog.Duration("interval", h.CappedCleanupInterval))
 
 	ticker := time.NewTicker(h.CappedCleanupInterval)
 	defer ticker.Stop()
@@ -254,7 +261,7 @@ func (h *Handler) runCappedCleanup() {
 		select {
 		case <-ticker.C:
 			if err := h.cleanupAllCappedCollections(context.Background()); err != nil {
-				h.L.Error("Failed to cleanup capped collections.", zap.Error(err))
+				h.L.Error("Failed to cleanup capped collections.", logging.Error(err))
 			}
 
 		case <-h.cappedCleanupStop:
@@ -290,11 +297,11 @@ func (h *Handler) Collect(ch chan<- prometheus.Metric) {
 
 // cleanupAllCappedCollections drops the given percent of documents from all capped collections.
 func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
-	h.L.Debug("cleanupAllCappedCollections: started", zap.Uint8("percentage", h.CappedCleanupPercentage))
+	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Any("percentage", h.CappedCleanupPercentage))
 
 	start := time.Now()
 	defer func() {
-		h.L.Debug("cleanupAllCappedCollections: finished", zap.Duration("duration", time.Since(start)))
+		h.L.DebugContext(ctx, "cleanupAllCappedCollections: finished", slog.Duration("duration", time.Since(start)))
 	}()
 
 	connInfo := conninfo.New()
@@ -333,9 +340,13 @@ func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
 			}
 
 			if deleted > 0 || bytesFreed > 0 {
-				h.L.Info("Capped collection cleaned up.",
-					zap.String("db", dbInfo.Name), zap.String("collection", cInfo.Name),
-					zap.Int32("deleted", deleted), zap.Int64("bytesFreed", bytesFreed),
+				h.L.InfoContext(
+					ctx,
+					"Capped collection cleaned up.",
+					slog.String("db", dbInfo.Name),
+					slog.String("collection", cInfo.Name),
+					slog.Any("deleted", deleted),
+					slog.Int64("bytes_freed", bytesFreed),
 				)
 			}
 
@@ -364,7 +375,8 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 	if err != nil {
 		return 0, 0, lazyerrors.Error(err)
 	}
-	h.L.Debug("cleanupCappedCollection: stats before", zap.Any("stats", statsBefore))
+
+	h.L.DebugContext(ctx, "cleanupCappedCollection: stats before", slog.Any("stats", statsBefore))
 
 	// In order to be more precise w.r.t number of documents getting dropped and to avoid
 	// deleting too many documents unnecessarily,
@@ -385,7 +397,7 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 			return 0, 0, lazyerrors.Error(err)
 		}
 
-		h.L.Debug("cleanupCappedCollection: stats after document count reduction", zap.Any("stats", statsAfter))
+		h.L.DebugContext(ctx, "cleanupCappedCollection: stats after document count reduction", slog.Any("stats", statsAfter))
 
 		docsDeleted += int32(count)
 		bytesFreed += (statsBefore.SizeTotal - statsAfter.SizeTotal)
@@ -411,7 +423,7 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 		return 0, 0, lazyerrors.Error(err)
 	}
 
-	h.L.Debug("cleanupCappedCollection: stats after compact", zap.Any("stats", statsAfter))
+	h.L.DebugContext(ctx, "cleanupCappedCollection: stats after compact", slog.Any("stats", statsAfter))
 
 	bytesFreed += (statsBefore.SizeTotal - statsAfter.SizeTotal)
 
diff --git a/internal/handler/handlerparams/extract_params.go b/internal/handler/handlerparams/extract_params.go
index cac6aa9456b3..f247a04d9ae4 100644
--- a/internal/handler/handlerparams/extract_params.go
+++ b/internal/handler/handlerparams/extract_params.go
@@ -17,12 +17,11 @@ package handlerparams
 import (
 	"errors"
 	"fmt"
+	"log/slog"
 	"reflect"
 	"slices"
 	"strings"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
@@ -58,7 +57,7 @@ import (
 //   - `ErrBadValue` when field is out of integer range;
 //   - `ErrBadValue` when field has negative value;
 //   - `ErrInvalidNamespace` - collection name has invalid type.
-func ExtractParams(doc *types.Document, command string, value any, l *zap.Logger) error {
+func ExtractParams(doc *types.Document, command string, value any, l *slog.Logger) error {
 	rv := reflect.ValueOf(value)
 	if rv.Kind() != reflect.Ptr || rv.IsNil() {
 		panic("value must be a non-nil pointer")
@@ -107,7 +106,7 @@ func ExtractParams(doc *types.Document, command string, value any, l *zap.Logger
 		if options.ignored {
 			l.Debug(
 				"ignoring field",
-				zap.String("command", doc.Command()), zap.String("field", key), zap.Any("value", val),
+				slog.String("command", doc.Command()), slog.String("field", key), slog.Any("value", val),
 			)
 
 			continue
@@ -229,7 +228,7 @@ func tagOptionsFromList(optionsList []string) *tagOptions {
 }
 
 // setStructField sets the value of the document field to the structure field.
-func setStructField(elem *reflect.Value, o *tagOptions, i int, command, key string, val any, l *zap.Logger) error {
+func setStructField(elem *reflect.Value, o *tagOptions, i int, command, key string, val any, l *slog.Logger) error {
 	var err error
 
 	field := elem.Type().Field(i)
diff --git a/internal/handler/handlerparams/extract_params_test.go b/internal/handler/handlerparams/extract_params_test.go
index 12c7f6660ee9..20036a9764b2 100644
--- a/internal/handler/handlerparams/extract_params_test.go
+++ b/internal/handler/handlerparams/extract_params_test.go
@@ -19,10 +19,10 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
-	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/must"
+	"github.com/FerretDB/FerretDB/internal/util/testutil"
 )
 
 func TestParse(t *testing.T) {
@@ -369,7 +369,7 @@ func TestParse(t *testing.T) {
 	}
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {
-			err := ExtractParams(tt.doc, tt.command, tt.params, zap.NewNop())
+			err := ExtractParams(tt.doc, tt.command, tt.params, testutil.SLogger(t))
 			if tt.wantErr != "" {
 				require.Regexp(t, regexp.MustCompile(".*"+tt.wantErr), err.Error())
 				return
diff --git a/internal/handler/msg_aggregate.go b/internal/handler/msg_aggregate.go
index 4855dfd68839..bf13813c35a1 100644
--- a/internal/handler/msg_aggregate.go
+++ b/internal/handler/msg_aggregate.go
@@ -18,13 +18,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"math"
 	"os"
 	"strings"
 	"time"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -381,9 +380,13 @@ func (h *Handler) MsgAggregate(connCtx context.Context, msg *wire.OpMsg) (*wire.
 		return nil, handleMaxTimeMSError(err, maxTimeMS, "aggregate")
 	}
 
-	h.L.Debug(
-		"Got first batch", zap.Int64("cursor_id", cursorID), zap.Stringer("type", cursor.Type),
-		zap.Int("count", len(docs)), zap.Int64("batch_size", batchSize),
+	h.L.DebugContext(
+		ctx,
+		"Got first batch",
+		slog.Int64("cursor_id", cursorID),
+		slog.Any("type", cursor.Type),
+		slog.Int("count", len(docs)),
+		slog.Int64("batch_size", batchSize),
 	)
 
 	firstBatch := types.MakeArray(len(docs))
diff --git a/internal/handler/msg_find.go b/internal/handler/msg_find.go
index 790f947ab8fe..13ace3920743 100644
--- a/internal/handler/msg_find.go
+++ b/internal/handler/msg_find.go
@@ -18,11 +18,10 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"strings"
 	"time"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -95,7 +94,7 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		}
 	}
 
-	qp, err := h.makeFindQueryParams(params, &cInfo)
+	qp, err := h.makeFindQueryParams(connCtx, params, &cInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -165,10 +164,14 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		return nil, handleMaxTimeMSError(err, params.MaxTimeMS, "find")
 	}
 
-	h.L.Debug(
-		"Got first batch", zap.Int64("cursor_id", cursorID), zap.Stringer("type", c.Type),
-		zap.Int("count", len(docs)), zap.Int64("batch_size", params.BatchSize),
-		zap.Bool("single_batch", params.SingleBatch),
+	h.L.DebugContext(
+		ctx,
+		"Got first batch",
+		slog.Int64("cursor_id", cursorID),
+		slog.Any("type", c.Type),
+		slog.Int("count", len(docs)),
+		slog.Int64("batch_size", params.BatchSize),
+		slog.Bool("single_batch", params.SingleBatch),
 	)
 
 	if params.SingleBatch || len(docs) < int(params.BatchSize) {
@@ -210,7 +213,7 @@ type findCursorData struct {
 }
 
 // makeFindQueryParams creates the backend's query parameters for the find command.
-func (h *Handler) makeFindQueryParams(params *common.FindParams, cInfo *backends.CollectionInfo) (*backends.QueryParams, error) {
+func (h *Handler) makeFindQueryParams(ctx context.Context, params *common.FindParams, cInfo *backends.CollectionInfo) (*backends.QueryParams, error) { //nolint:lll // for readability
 	qp := &backends.QueryParams{
 		Comment: params.Comment,
 	}
@@ -282,7 +285,9 @@ func (h *Handler) makeFindQueryParams(params *common.FindParams, cInfo *backends
 		qp.Limit = params.Limit
 	}
 
-	h.L.Sugar().Debugf("Converted %+v for %+v to %+v.", params, cInfo, qp)
+	if h.L.Enabled(ctx, slog.LevelDebug) {
+		h.L.DebugContext(ctx, fmt.Sprintf("Converted %+v for %+v to %+v.", params, cInfo, qp))
+	}
 
 	return qp, nil
 }
diff --git a/internal/handler/msg_getlog.go b/internal/handler/msg_getlog.go
index 51ff07d498e3..18bfab499d16 100644
--- a/internal/handler/msg_getlog.go
+++ b/internal/handler/msg_getlog.go
@@ -18,11 +18,10 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"strings"
 	"time"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/build/version"
 	"github.com/FerretDB/FerretDB/internal/bson"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -111,7 +110,7 @@ func (h *Handler) MsgGetLog(connCtx context.Context, msg *wire.OpMsg) (*wire.OpM
 			startupWarnings = append(startupWarnings, "This is debug build. The performance will be affected.")
 		}
 
-		if h.L.Level().Enabled(zap.DebugLevel) {
+		if h.L.Enabled(connCtx, slog.LevelDebug) {
 			startupWarnings = append(startupWarnings, "Debug logging enabled. The security and performance will be affected.")
 		}
 
diff --git a/internal/handler/msg_getmore.go b/internal/handler/msg_getmore.go
index bd4cd855dd2b..9f237964b75e 100644
--- a/internal/handler/msg_getmore.go
+++ b/internal/handler/msg_getmore.go
@@ -18,11 +18,10 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"math"
 	"time"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -284,8 +283,11 @@ func (h *Handler) makeNextBatch(c *cursor.Cursor, batchSize int64) (*types.Array
 	}
 
 	h.L.Debug(
-		"Got next batch", zap.Int64("cursor_id", c.ID), zap.Stringer("type", c.Type),
-		zap.Int("count", len(docs)), zap.Int64("batch_size", batchSize),
+		"Got next batch",
+		slog.Int64("cursor_id", c.ID),
+		slog.Any("type", c.Type),
+		slog.Int("count", len(docs)),
+		slog.Int64("batch_size", batchSize),
 	)
 
 	nextBatch := types.MakeArray(len(docs))
diff --git a/internal/handler/msg_listdatabases.go b/internal/handler/msg_listdatabases.go
index 3a3928f7533b..ff89e5cca8e4 100644
--- a/internal/handler/msg_listdatabases.go
+++ b/internal/handler/msg_listdatabases.go
@@ -17,12 +17,11 @@ package handler
 import (
 	"context"
 
-	"go.uber.org/zap"
-
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -66,13 +65,13 @@ func (h *Handler) MsgListDatabases(connCtx context.Context, msg *wire.OpMsg) (*w
 	for _, dbInfo := range res.Databases {
 		db, err := h.b.Database(dbInfo.Name)
 		if err != nil {
-			h.L.Warn("Failed to get database", zap.Error(err))
+			h.L.WarnContext(connCtx, "Failed to get database", logging.Error(err))
 			continue
 		}
 
 		stats, err := db.Stats(connCtx, nil)
 		if err != nil {
-			h.L.Warn("Failed to get database stats", zap.Error(err))
+			h.L.WarnContext(connCtx, "Failed to get database stats", logging.Error(err))
 			continue
 		}
 
diff --git a/internal/handler/msg_saslcontinue.go b/internal/handler/msg_saslcontinue.go
index 8757d473f40b..836c201c6045 100644
--- a/internal/handler/msg_saslcontinue.go
+++ b/internal/handler/msg_saslcontinue.go
@@ -16,14 +16,14 @@ package handler
 
 import (
 	"context"
-
-	"go.uber.org/zap"
+	"log/slog"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -49,7 +49,7 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 	_, _, conv, _ := conninfo.Get(connCtx).Auth()
 
 	if conv == nil {
-		h.L.Warn("saslContinue: no conversation to continue")
+		h.L.WarnContext(connCtx, "saslContinue: no conversation to continue")
 
 		return nil, handlererrors.NewCommandErrorMsgWithArgument(
 			handlererrors.ErrAuthenticationFailed,
@@ -60,18 +60,18 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 
 	response, err := conv.Step(string(payload))
 
-	fields := []zap.Field{
-		zap.String("username", conv.Username()),
-		zap.Bool("valid", conv.Valid()),
-		zap.Bool("done", conv.Done()),
+	attrs := []any{
+		slog.String("username", conv.Username()),
+		slog.Bool("valid", conv.Valid()),
+		slog.Bool("done", conv.Done()),
 	}
 
 	if err != nil {
-		if h.L.Level().Enabled(zap.DebugLevel) {
-			fields = append(fields, zap.Error(err))
+		if h.L.Enabled(connCtx, slog.LevelDebug) {
+			attrs = append(attrs, logging.Error(err))
 		}
 
-		h.L.Warn("saslContinue: step failed", fields...)
+		h.L.WarnContext(connCtx, "saslContinue: step failed", attrs...) //nolint:sloglint // attrs is not key-value pairs
 
 		return nil, handlererrors.NewCommandErrorMsgWithArgument(
 			handlererrors.ErrAuthenticationFailed,
@@ -80,7 +80,7 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 		)
 	}
 
-	h.L.Debug("saslContinue: step succeed", fields...)
+	h.L.DebugContext(connCtx, "saslContinue: step succeed", attrs...) //nolint:sloglint // attrs is not key-value pairs
 
 	if conv.Valid() {
 		conninfo.Get(connCtx).SetBypassBackendAuth()
diff --git a/internal/handler/msg_saslstart.go b/internal/handler/msg_saslstart.go
index 2719e2379d85..aafd452a302f 100644
--- a/internal/handler/msg_saslstart.go
+++ b/internal/handler/msg_saslstart.go
@@ -20,9 +20,9 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"log/slog"
 
 	"github.com/xdg-go/scram"
-	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/common"
@@ -30,6 +30,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -232,7 +233,7 @@ func (h *Handler) scramCredentialLookup(ctx context.Context, dbName, username, m
 		}
 	}
 
-	h.L.Warn("scramCredentialLookup: failed", zap.String("user", username))
+	h.L.WarnContext(ctx, "scramCredentialLookup: failed", slog.String("user", username))
 
 	return nil, handlererrors.NewCommandErrorMsgWithArgument(
 		handlererrors.ErrAuthenticationFailed,
@@ -281,23 +282,23 @@ func (h *Handler) saslStartSCRAM(ctx context.Context, dbName, mechanism string,
 
 	response, err := conv.Step(string(payload))
 
-	fields := []zap.Field{
-		zap.String("username", conv.Username()),
-		zap.Bool("valid", conv.Valid()),
-		zap.Bool("done", conv.Done()),
+	attrs := []any{
+		slog.String("username", conv.Username()),
+		slog.Bool("valid", conv.Valid()),
+		slog.Bool("done", conv.Done()),
 	}
 
 	if err != nil {
-		if h.L.Level().Enabled(zap.DebugLevel) {
-			fields = append(fields, zap.Error(err))
+		if h.L.Enabled(ctx, slog.LevelDebug) {
+			attrs = append(attrs, logging.Error(err))
 		}
 
-		h.L.Warn("saslStartSCRAM: step failed", fields...)
+		h.L.WarnContext(ctx, "saslStartSCRAM: step failed", attrs...) //nolint:sloglint // attrs is not key-value pairs
 
 		return "", err
 	}
 
-	h.L.Debug("saslStartSCRAM: step succeed", fields...)
+	h.L.DebugContext(ctx, "saslStartSCRAM: step succeed", attrs...) //nolint:sloglint // attrs is not key-value pairs
 
 	conninfo.Get(ctx).SetAuth(conv.Username(), "", conv, dbName)
 
diff --git a/internal/handler/registry/hana.go b/internal/handler/registry/hana.go
index e7f7c0343cc8..f9dfb7535ff8 100644
--- a/internal/handler/registry/hana.go
+++ b/internal/handler/registry/hana.go
@@ -20,6 +20,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/hana"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "hana" handler for Hana when "ferretdb_hana" build tag is provided.
@@ -47,7 +48,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             opts.Logger.Named("hana"),
+			L:             logging.WithName(opts.SLogger, "hana"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/mysql.go b/internal/handler/registry/mysql.go
index 6d2636c31ad9..ad198681c131 100644
--- a/internal/handler/registry/mysql.go
+++ b/internal/handler/registry/mysql.go
@@ -18,6 +18,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/mysql"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "mysql" handler.
@@ -42,7 +43,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             opts.Logger.Named("mysql"),
+			L:             logging.WithName(opts.SLogger, "mysql"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/postgresql.go b/internal/handler/registry/postgresql.go
index 2ee11d2abf2f..6fec2dc82263 100644
--- a/internal/handler/registry/postgresql.go
+++ b/internal/handler/registry/postgresql.go
@@ -20,6 +20,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/postgresql"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "postgresql" handler.
@@ -45,7 +46,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             opts.Logger.Named("postgresql"),
+			L:             logging.WithName(opts.SLogger, "postgresql"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/registry.go b/internal/handler/registry/registry.go
index 4cf1ec6a8416..d835cfc60a75 100644
--- a/internal/handler/registry/registry.go
+++ b/internal/handler/registry/registry.go
@@ -17,6 +17,7 @@ package registry
 
 import (
 	"fmt"
+	"log/slog"
 	"time"
 
 	"go.uber.org/zap"
@@ -43,6 +44,7 @@ var registry = map[string]newHandlerFunc{}
 type NewHandlerOpts struct {
 	// for all backends
 	Logger        *zap.Logger
+	SLogger       *slog.Logger
 	ConnMetrics   *connmetrics.ConnMetrics
 	StateProvider *state.Provider
 	TCPHost       string
diff --git a/internal/handler/registry/sqlite.go b/internal/handler/registry/sqlite.go
index eb9ce38433af..aab062e84400 100644
--- a/internal/handler/registry/sqlite.go
+++ b/internal/handler/registry/sqlite.go
@@ -20,6 +20,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/sqlite"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "sqlite" handler.
@@ -45,7 +46,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             opts.Logger.Named("sqlite"),
+			L:             logging.WithName(opts.SLogger, "sqlite"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 

From 4607329179ac7c0fc032271c509106622e6b2f0f Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 11:48:35 +0900
Subject: [PATCH 02/11] avoid using Any

---
 internal/handler/handler.go       | 4 ++--
 internal/handler/msg_aggregate.go | 2 +-
 internal/handler/msg_find.go      | 2 +-
 internal/handler/msg_getmore.go   | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/internal/handler/handler.go b/internal/handler/handler.go
index 8faeeda17a23..906fa413c5e3 100644
--- a/internal/handler/handler.go
+++ b/internal/handler/handler.go
@@ -297,7 +297,7 @@ func (h *Handler) Collect(ch chan<- prometheus.Metric) {
 
 // cleanupAllCappedCollections drops the given percent of documents from all capped collections.
 func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
-	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Any("percentage", h.CappedCleanupPercentage))
+	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Int("percentage", int(h.CappedCleanupPercentage)))
 
 	start := time.Now()
 	defer func() {
@@ -345,7 +345,7 @@ func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
 					"Capped collection cleaned up.",
 					slog.String("db", dbInfo.Name),
 					slog.String("collection", cInfo.Name),
-					slog.Any("deleted", deleted),
+					slog.Int("deleted", int(deleted)),
 					slog.Int64("bytes_freed", bytesFreed),
 				)
 			}
diff --git a/internal/handler/msg_aggregate.go b/internal/handler/msg_aggregate.go
index bf13813c35a1..ab9aec38edd3 100644
--- a/internal/handler/msg_aggregate.go
+++ b/internal/handler/msg_aggregate.go
@@ -384,7 +384,7 @@ func (h *Handler) MsgAggregate(connCtx context.Context, msg *wire.OpMsg) (*wire.
 		ctx,
 		"Got first batch",
 		slog.Int64("cursor_id", cursorID),
-		slog.Any("type", cursor.Type),
+		slog.String("type", cursor.Type.String()),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", batchSize),
 	)
diff --git a/internal/handler/msg_find.go b/internal/handler/msg_find.go
index 13ace3920743..8e9cbdf056f0 100644
--- a/internal/handler/msg_find.go
+++ b/internal/handler/msg_find.go
@@ -168,7 +168,7 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		ctx,
 		"Got first batch",
 		slog.Int64("cursor_id", cursorID),
-		slog.Any("type", c.Type),
+		slog.String("type", c.Type.String()),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", params.BatchSize),
 		slog.Bool("single_batch", params.SingleBatch),
diff --git a/internal/handler/msg_getmore.go b/internal/handler/msg_getmore.go
index 9f237964b75e..00e9be3d004d 100644
--- a/internal/handler/msg_getmore.go
+++ b/internal/handler/msg_getmore.go
@@ -285,7 +285,7 @@ func (h *Handler) makeNextBatch(c *cursor.Cursor, batchSize int64) (*types.Array
 	h.L.Debug(
 		"Got next batch",
 		slog.Int64("cursor_id", c.ID),
-		slog.Any("type", c.Type),
+		slog.String("type", c.Type.String()),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", batchSize),
 	)

From 4b53f0c4c9a00cf1079afd8daf83be2062ff0d7e Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:31:56 +0900
Subject: [PATCH 03/11] use slog in debug package

---
 cmd/envtool/envtool.go            |  2 +-
 cmd/ferretdb/main.go              |  6 +++---
 cmd/ferretdb/ping.go              | 34 +++++++++++++++++--------------
 internal/util/debug/debug.go      | 33 +++++++++++++++++-------------
 internal/util/debug/debug_test.go |  2 +-
 5 files changed, 43 insertions(+), 34 deletions(-)

diff --git a/cmd/envtool/envtool.go b/cmd/envtool/envtool.go
index a6ba19b55788..f00eba5fe5f7 100644
--- a/cmd/envtool/envtool.go
+++ b/cmd/envtool/envtool.go
@@ -255,7 +255,7 @@ func setupMongodbSecured(ctx context.Context, logger *zap.SugaredLogger) error {
 func setup(ctx context.Context, logger *zap.SugaredLogger) error {
 	h, err := debug.Listen(&debug.ListenOpts{
 		TCPAddr: "127.0.0.1:8089",
-		L:       logger.Named("debug").Desugar(),
+		L:       logging.WithName(slog.Default(), "debug"), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		R:       prometheus.DefaultRegisterer,
 	})
 	if err != nil {
diff --git a/cmd/ferretdb/main.go b/cmd/ferretdb/main.go
index 915a99fe47c2..ca8d987748c2 100644
--- a/cmd/ferretdb/main.go
+++ b/cmd/ferretdb/main.go
@@ -225,7 +225,7 @@ func main() {
 		checkFlags(logger)
 
 		ready := ReadyZ{
-			l: logger,
+			l: slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		}
 
 		ctx, stop := ctxutil.SigTerm(context.Background())
@@ -419,7 +419,7 @@ func run() {
 		go func() {
 			defer wg.Done()
 
-			l := logger.Named("debug")
+			l := logging.WithName(slogger, "debug")
 			ready := ReadyZ{
 				l: l,
 			}
@@ -438,7 +438,7 @@ func run() {
 				Readyz: ready.Probe,
 			})
 			if err != nil {
-				l.Sugar().Fatalf("Failed to create debug handler: %s.", err)
+				l.LogAttrs(ctx, logging.LevelFatal, "Failed to create debug handler", logging.Error(err))
 			}
 
 			h.Serve(ctx)
diff --git a/cmd/ferretdb/ping.go b/cmd/ferretdb/ping.go
index e827daaee7e3..8b833546ba4a 100644
--- a/cmd/ferretdb/ping.go
+++ b/cmd/ferretdb/ping.go
@@ -16,18 +16,21 @@ package main
 
 import (
 	"context"
+	"fmt"
+	"log/slog"
 	"net"
 	"net/url"
 
 	"go.mongodb.org/mongo-driver/mongo"
 	"go.mongodb.org/mongo-driver/mongo/options"
-	"go.uber.org/zap"
+
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // ReadyZ represents the Readiness probe, which is used to run `ping`
 // command against the FerretDB instance specified by cli flags.
 type ReadyZ struct {
-	l *zap.Logger
+	l *slog.Logger
 }
 
 // Probe executes ping queries to open listeners, and returns true if they succeed.
@@ -38,7 +41,7 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 	l := ready.l
 
 	if cli.Setup.Database == "" {
-		l.Info("Setup database not specified - skipping ping.")
+		l.InfoContext(ctx, "Setup database not specified - skipping ping")
 		return true
 	}
 
@@ -47,16 +50,16 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 	if cli.Listen.Addr != "" {
 		host, port, err := net.SplitHostPort(cli.Listen.Addr)
 		if err != nil {
-			l.Error("Getting host and port failed.", zap.Error(err))
+			l.ErrorContext(ctx, "Getting host and port failed", logging.Error(err))
 			return false
 		}
 
-		l.Sugar().Debugf("--listen-addr flag is set. Ping to %s will be performed.", cli.Listen.Addr)
+		l.DebugContext(ctx, fmt.Sprintf("--listen-addr flag is set. Ping to %s will be performed", cli.Listen.Addr))
 
 		if host == "" {
 			host = "127.0.0.1"
 
-			l.Sugar().Debugf("Host not specified, defaulting to %s.", host)
+			l.DebugContext(ctx, fmt.Sprintf("Host not specified, defaulting to %s", host))
 		}
 
 		u := &url.URL{
@@ -71,29 +74,30 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 
 	if cli.Listen.TLS != "" {
 		// TODO https://github.com/FerretDB/FerretDB/issues/4427
-		l.Warn("TLS ping is not implemented yet.")
+		l.WarnContext(ctx, "TLS ping is not implemented yet")
 	}
 
 	if cli.Listen.Unix != "" {
-		l.Sugar().Debugf("--listen-unix flag is set. Ping to %s will be performed.", cli.Listen.Unix)
+		l.DebugContext(ctx, fmt.Sprintf("--listen-addr flag is set. Ping to %s will be performed", cli.Listen.Addr))
 
 		urls = append(urls, "mongodb://"+url.PathEscape(cli.Listen.Unix))
 	}
 
 	if len(urls) == 0 {
-		l.Info("Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping.")
+		l.WarnContext(ctx, "Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping.")
 		return true
 	}
 
 	for _, u := range urls {
-		l.Sugar().Debugf("Pinging %s...", u)
+		l.DebugContext(ctx, fmt.Sprintf("Pinging %s...", u))
 
-		ctx, cancel := context.WithTimeout(ctx, cli.Setup.Timeout)
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, cli.Setup.Timeout)
 		defer cancel()
 
 		client, err := mongo.Connect(ctx, options.Client().ApplyURI(u))
 		if err != nil {
-			l.Error("Connection failed.", zap.Error(err))
+			l.ErrorContext(ctx, "Connection failed", logging.Error(err))
 			return false
 		}
 
@@ -101,12 +105,12 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 
 		// do not leave connection open when ping error causes os.Exit with Fatal
 		if err = client.Disconnect(ctx); err != nil {
-			l.Error("Disconnect failed.", zap.Error(err))
+			l.ErrorContext(ctx, "Disconnect failed", logging.Error(err))
 			return false
 		}
 
 		if pingErr != nil {
-			l.Error("Ping failed.", zap.Error(pingErr))
+			l.ErrorContext(ctx, "Ping failed", logging.Error(pingErr))
 			return false
 		}
 
@@ -115,7 +119,7 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 			u = uri.Redacted()
 		}
 
-		l.Sugar().Infof("Ping to %s successful.", u)
+		l.InfoContext(ctx, fmt.Sprintf("Ping to %s successful", u))
 	}
 
 	return true
diff --git a/internal/util/debug/debug.go b/internal/util/debug/debug.go
index 54d7f8e29910..ff960b65d28e 100644
--- a/internal/util/debug/debug.go
+++ b/internal/util/debug/debug.go
@@ -22,6 +22,7 @@ import (
 	_ "expvar" // for metrics
 	"fmt"
 	"log"
+	"log/slog"
 	"net"
 	"net/http"
 	_ "net/http/pprof" // for profiling
@@ -32,11 +33,11 @@ import (
 	"github.com/arl/statsviz"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"go.uber.org/zap"
 	"golang.org/x/exp/maps"
 
 	"github.com/FerretDB/FerretDB/internal/util/ctxutil"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 )
 
@@ -70,7 +71,7 @@ type Handler struct {
 //nolint:vet // for readability
 type ListenOpts struct {
 	TCPAddr string
-	L       *zap.Logger
+	L       *slog.Logger
 	R       prometheus.Registerer
 	Livez   Probe
 	Readyz  Probe
@@ -86,7 +87,9 @@ func Listen(opts *ListenOpts) (*Handler, error) {
 
 	must.NotBeZero(opts)
 
-	stdL := must.NotFail(zap.NewStdLogAt(opts.L, zap.WarnLevel))
+	l := opts.L
+
+	stdL := slog.NewLogLogger(l.Handler(), slog.LevelError)
 
 	http.Handle("/debug/metrics", promhttp.InstrumentMetricHandler(
 		opts.R, promhttp.HandlerFor(prometheus.DefaultGatherer, promhttp.HandlerOpts{
@@ -122,13 +125,13 @@ func Listen(opts *ListenOpts) (*Handler, error) {
 			ctx := req.Context()
 
 			if !opts.Livez(ctx) {
-				opts.L.Warn("Livez probe failed")
+				l.Warn("Livez probe failed")
 				rw.WriteHeader(http.StatusInternalServerError)
 
 				return
 			}
 
-			opts.L.Debug("Livez probe succeeded")
+			l.Debug("Livez probe succeeded")
 			rw.WriteHeader(http.StatusOK)
 		}),
 	))
@@ -139,20 +142,20 @@ func Listen(opts *ListenOpts) (*Handler, error) {
 			ctx := req.Context()
 
 			if !opts.Livez(ctx) {
-				opts.L.Warn("Readyz probe failed - livez probe failed")
+				l.Warn("Readyz probe failed - livez probe failed")
 				rw.WriteHeader(http.StatusInternalServerError)
 
 				return
 			}
 
 			if !opts.Readyz(ctx) {
-				opts.L.Warn("Readyz probe failed")
+				l.Warn("Readyz probe failed")
 				rw.WriteHeader(http.StatusInternalServerError)
 
 				return
 			}
 
-			opts.L.Debug("Readyz probe succeeded")
+			l.Debug("Readyz probe succeeded")
 			rw.WriteHeader(http.StatusOK)
 		}),
 	))
@@ -216,20 +219,22 @@ func (h *Handler) Serve(ctx context.Context) {
 		},
 	}
 
+	l := h.opts.L
+
 	root := fmt.Sprintf("http://%s", h.lis.Addr())
 
-	h.opts.L.Sugar().Infof("Starting debug server on %s...", root)
+	l.InfoContext(ctx, fmt.Sprintf("Starting debug server on %s...", root))
 
 	paths := maps.Keys(h.handlers)
 	slices.Sort(paths)
 
 	for _, path := range paths {
-		h.opts.L.Sugar().Infof("%s%s - %s", root, path, h.handlers[path])
+		l.InfoContext(ctx, fmt.Sprintf("%s%s - %s", root, path, h.handlers[path]))
 	}
 
 	go func() {
 		if err := s.Serve(h.lis); !errors.Is(err, http.ErrServerClosed) {
-			h.opts.L.DPanic("Serve exited with unexpected error", zap.Error(err))
+			l.LogAttrs(ctx, logging.LevelDPanic, "Serve exited with unexpected error", logging.Error(err))
 		}
 	}()
 
@@ -240,12 +245,12 @@ func (h *Handler) Serve(ctx context.Context) {
 	defer stopCancel(nil)
 
 	if err := s.Shutdown(stopCtx); err != nil {
-		h.opts.L.DPanic("Shutdown exited with unexpected error", zap.Error(err))
+		l.LogAttrs(ctx, logging.LevelDPanic, "Shutdown exited with unexpected error", logging.Error(err))
 	}
 
 	if err := s.Close(); err != nil {
-		h.opts.L.DPanic("Close exited with unexpected error", zap.Error(err))
+		l.LogAttrs(ctx, logging.LevelDPanic, "Close exited with unexpected error", logging.Error(err))
 	}
 
-	h.opts.L.Sugar().Info("Debug server stopped.")
+	l.InfoContext(ctx, "Debug server stopped")
 }
diff --git a/internal/util/debug/debug_test.go b/internal/util/debug/debug_test.go
index 034500a62c7c..978aeee3c68c 100644
--- a/internal/util/debug/debug_test.go
+++ b/internal/util/debug/debug_test.go
@@ -43,7 +43,7 @@ func TestProbes(t *testing.T) {
 
 	h, err := Listen(&ListenOpts{
 		TCPAddr: "127.0.0.1:0",
-		L:       testutil.Logger(t),
+		L:       testutil.SLogger(t),
 		R:       prometheus.NewRegistry(),
 		Livez:   func(context.Context) bool { return livez.Load() },
 		Readyz:  func(context.Context) bool { return readyz.Load() },

From 973060e651c14ae81071fb9e5dc54306fbcaad70 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:34:25 +0900
Subject: [PATCH 04/11] use slog in debug integration test startup

---
 integration/setup/startup.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/integration/setup/startup.go b/integration/setup/startup.go
index 5541cbc9d409..411f6418e0ca 100644
--- a/integration/setup/startup.go
+++ b/integration/setup/startup.go
@@ -16,6 +16,7 @@ package setup
 
 import (
 	"context"
+	"log/slog"
 	"os"
 	"runtime"
 	"slices"
@@ -58,7 +59,7 @@ func Startup() {
 	// use any available port to allow running different configurations in parallel
 	h, err := debug.Listen(&debug.ListenOpts{
 		TCPAddr: "127.0.0.1:0",
-		L:       zap.L().Named("debug"),
+		L:       logging.WithName(slog.Default(), "debug"), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		R:       prometheus.DefaultRegisterer,
 	})
 	if err != nil {

From 044a566c14463de173e1e2fb75bd3363bed55fd0 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:36:45 +0900
Subject: [PATCH 05/11] Revert "avoid using Any"

This reverts commit 4607329179ac7c0fc032271c509106622e6b2f0f.
---
 internal/handler/handler.go       | 4 ++--
 internal/handler/msg_aggregate.go | 2 +-
 internal/handler/msg_find.go      | 2 +-
 internal/handler/msg_getmore.go   | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/internal/handler/handler.go b/internal/handler/handler.go
index 906fa413c5e3..8faeeda17a23 100644
--- a/internal/handler/handler.go
+++ b/internal/handler/handler.go
@@ -297,7 +297,7 @@ func (h *Handler) Collect(ch chan<- prometheus.Metric) {
 
 // cleanupAllCappedCollections drops the given percent of documents from all capped collections.
 func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
-	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Int("percentage", int(h.CappedCleanupPercentage)))
+	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Any("percentage", h.CappedCleanupPercentage))
 
 	start := time.Now()
 	defer func() {
@@ -345,7 +345,7 @@ func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
 					"Capped collection cleaned up.",
 					slog.String("db", dbInfo.Name),
 					slog.String("collection", cInfo.Name),
-					slog.Int("deleted", int(deleted)),
+					slog.Any("deleted", deleted),
 					slog.Int64("bytes_freed", bytesFreed),
 				)
 			}
diff --git a/internal/handler/msg_aggregate.go b/internal/handler/msg_aggregate.go
index ab9aec38edd3..bf13813c35a1 100644
--- a/internal/handler/msg_aggregate.go
+++ b/internal/handler/msg_aggregate.go
@@ -384,7 +384,7 @@ func (h *Handler) MsgAggregate(connCtx context.Context, msg *wire.OpMsg) (*wire.
 		ctx,
 		"Got first batch",
 		slog.Int64("cursor_id", cursorID),
-		slog.String("type", cursor.Type.String()),
+		slog.Any("type", cursor.Type),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", batchSize),
 	)
diff --git a/internal/handler/msg_find.go b/internal/handler/msg_find.go
index 8e9cbdf056f0..13ace3920743 100644
--- a/internal/handler/msg_find.go
+++ b/internal/handler/msg_find.go
@@ -168,7 +168,7 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		ctx,
 		"Got first batch",
 		slog.Int64("cursor_id", cursorID),
-		slog.String("type", c.Type.String()),
+		slog.Any("type", c.Type),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", params.BatchSize),
 		slog.Bool("single_batch", params.SingleBatch),
diff --git a/internal/handler/msg_getmore.go b/internal/handler/msg_getmore.go
index 00e9be3d004d..9f237964b75e 100644
--- a/internal/handler/msg_getmore.go
+++ b/internal/handler/msg_getmore.go
@@ -285,7 +285,7 @@ func (h *Handler) makeNextBatch(c *cursor.Cursor, batchSize int64) (*types.Array
 	h.L.Debug(
 		"Got next batch",
 		slog.Int64("cursor_id", c.ID),
-		slog.String("type", c.Type.String()),
+		slog.Any("type", c.Type),
 		slog.Int("count", len(docs)),
 		slog.Int64("batch_size", batchSize),
 	)

From a48bae6981f96f44c974268368e11b6f92c5aeb7 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:36:53 +0900
Subject: [PATCH 06/11] Revert "use slog in handler"

This reverts commit 16c05af75cd077f2d211952cd9d4f41f3d21e95a.
---
 cmd/ferretdb/main.go                          |  1 -
 ferretdb/ferretdb.go                          |  2 -
 integration/setup/listener.go                 |  2 -
 internal/handler/cmd_query.go                 |  9 ++--
 internal/handler/commands.go                  | 17 ++++---
 internal/handler/common/count.go              |  4 +-
 internal/handler/common/delete_params.go      |  4 +-
 internal/handler/common/distinct.go           |  5 +-
 internal/handler/common/explain.go            |  4 +-
 internal/handler/common/find.go               |  4 +-
 internal/handler/common/findandmodify.go      |  5 +-
 internal/handler/common/insert.go             |  5 +-
 internal/handler/common/unimplemented.go      |  7 +--
 internal/handler/common/update_params.go      |  4 +-
 internal/handler/handler.go                   | 46 +++++++------------
 .../handler/handlerparams/extract_params.go   |  9 ++--
 .../handlerparams/extract_params_test.go      |  4 +-
 internal/handler/msg_aggregate.go             | 13 ++----
 internal/handler/msg_find.go                  | 23 ++++------
 internal/handler/msg_getlog.go                |  5 +-
 internal/handler/msg_getmore.go               | 10 ++--
 internal/handler/msg_listdatabases.go         |  7 +--
 internal/handler/msg_saslcontinue.go          | 22 ++++-----
 internal/handler/msg_saslstart.go             | 21 ++++-----
 internal/handler/registry/hana.go             |  3 +-
 internal/handler/registry/mysql.go            |  3 +-
 internal/handler/registry/postgresql.go       |  3 +-
 internal/handler/registry/registry.go         |  2 -
 internal/handler/registry/sqlite.go           |  3 +-
 29 files changed, 110 insertions(+), 137 deletions(-)

diff --git a/cmd/ferretdb/main.go b/cmd/ferretdb/main.go
index ca8d987748c2..b05b3cacae92 100644
--- a/cmd/ferretdb/main.go
+++ b/cmd/ferretdb/main.go
@@ -498,7 +498,6 @@ func run() {
 
 	h, closeBackend, err := registry.NewHandler(cli.Handler, &registry.NewHandlerOpts{
 		Logger:        logger,
-		SLogger:       slogger,
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: stateProvider,
 		TCPHost:       cli.Listen.Addr,
diff --git a/ferretdb/ferretdb.go b/ferretdb/ferretdb.go
index 5032010e4460..32e042df3c59 100644
--- a/ferretdb/ferretdb.go
+++ b/ferretdb/ferretdb.go
@@ -22,7 +22,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"net/url"
 	"sync"
 
@@ -129,7 +128,6 @@ func New(config *Config) (*FerretDB, error) {
 
 	h, closeBackend, err := registry.NewHandler(config.Handler, &registry.NewHandlerOpts{
 		Logger:        log,
-		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: sp,
 		TCPHost:       config.Listener.TCP,
diff --git a/integration/setup/listener.go b/integration/setup/listener.go
index 3699eb188f2e..b30fe022f149 100644
--- a/integration/setup/listener.go
+++ b/integration/setup/listener.go
@@ -16,7 +16,6 @@ package setup
 
 import (
 	"context"
-	"log/slog"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -180,7 +179,6 @@ func setupListener(tb testtb.TB, ctx context.Context, logger *zap.Logger, opts *
 
 	handlerOpts := &registry.NewHandlerOpts{
 		Logger:        logger,
-		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   listenerMetrics.ConnMetrics,
 		StateProvider: sp,
 
diff --git a/internal/handler/cmd_query.go b/internal/handler/cmd_query.go
index 927dd02a20e7..b569ccb029a9 100644
--- a/internal/handler/cmd_query.go
+++ b/internal/handler/cmd_query.go
@@ -19,11 +19,12 @@ import (
 	"fmt"
 	"strings"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -74,7 +75,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 
 		dbName, err := common.GetRequiredParam[string](authDoc, "db")
 		if err != nil {
-			h.L.DebugContext(connCtx, "No `db` in `speculativeAuthenticate`", logging.Error(err))
+			h.L.Debug("No `db` in `speculativeAuthenticate`", zap.Error(err))
 
 			opReply.SetDocument(reply)
 
@@ -83,7 +84,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 
 		speculativeAuthenticate, err := h.saslStart(connCtx, dbName, authDoc)
 		if err != nil {
-			h.L.DebugContext(connCtx, "Speculative authentication failed", logging.Error(err))
+			h.L.Debug("Speculative authentication failed", zap.Error(err))
 
 			// unsuccessful speculative authentication leave `speculativeAuthenticate` field unset
 			// and let `saslStart` return an error
@@ -92,7 +93,7 @@ func (h *Handler) CmdQuery(connCtx context.Context, query *wire.OpQuery) (*wire.
 			return &opReply, nil
 		}
 
-		h.L.DebugContext(connCtx, "Speculative authentication passed")
+		h.L.Debug("Speculative authentication passed")
 
 		reply.Set("speculativeAuthenticate", speculativeAuthenticate)
 
diff --git a/internal/handler/commands.go b/internal/handler/commands.go
index 98a39046b535..c523c54b6bd2 100644
--- a/internal/handler/commands.go
+++ b/internal/handler/commands.go
@@ -16,7 +16,8 @@ package handler
 
 import (
 	"context"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -294,25 +295,23 @@ func (h *Handler) initCommands() {
 }
 
 // checkSCRAMConversation returns error if SCRAM conversation is not valid.
-func checkSCRAMConversation(ctx context.Context, l *slog.Logger) error {
+func checkSCRAMConversation(ctx context.Context, l *zap.Logger) error {
 	_, _, conv, _ := conninfo.Get(ctx).Auth()
 
 	switch {
 	case conv == nil:
-		l.WarnContext(ctx, "checkSCRAMConversation: no conversation")
+		l.Warn("checkSCRAMConversation: no conversation")
 
 	case !conv.Valid():
-		l.WarnContext(
-			ctx,
+		l.Warn(
 			"checkSCRAMConversation: invalid conversation",
-			slog.String("username", conv.Username()), slog.Bool("valid", conv.Valid()), slog.Bool("done", conv.Done()),
+			zap.String("username", conv.Username()), zap.Bool("valid", conv.Valid()), zap.Bool("done", conv.Done()),
 		)
 
 	default:
-		l.DebugContext(
-			ctx,
+		l.Debug(
 			"checkSCRAMConversation: passed",
-			slog.String("username", conv.Username()), slog.Bool("valid", conv.Valid()), slog.Bool("done", conv.Done()),
+			zap.String("username", conv.Username()), zap.Bool("valid", conv.Valid()), zap.Bool("done", conv.Done()),
 		)
 
 		return nil
diff --git a/internal/handler/common/count.go b/internal/handler/common/count.go
index 7cbdeeef6a05..642faeb14c0c 100644
--- a/internal/handler/common/count.go
+++ b/internal/handler/common/count.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"log/slog"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -44,7 +44,7 @@ type CountParams struct {
 }
 
 // GetCountParams returns the parameters for the count command.
-func GetCountParams(document *types.Document, l *slog.Logger) (*CountParams, error) {
+func GetCountParams(document *types.Document, l *zap.Logger) (*CountParams, error) {
 	var count CountParams
 
 	err := handlerparams.ExtractParams(document, "count", &count, l)
diff --git a/internal/handler/common/delete_params.go b/internal/handler/common/delete_params.go
index 36e3d806176f..30e5dfa77eab 100644
--- a/internal/handler/common/delete_params.go
+++ b/internal/handler/common/delete_params.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"log/slog"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -55,7 +55,7 @@ type Delete struct {
 }
 
 // GetDeleteParams returns parameters for delete operation.
-func GetDeleteParams(document *types.Document, l *slog.Logger) (*DeleteParams, error) {
+func GetDeleteParams(document *types.Document, l *zap.Logger) (*DeleteParams, error) {
 	params := DeleteParams{
 		Ordered: true,
 	}
diff --git a/internal/handler/common/distinct.go b/internal/handler/common/distinct.go
index e3e1f5435277..66622c73c38c 100644
--- a/internal/handler/common/distinct.go
+++ b/internal/handler/common/distinct.go
@@ -17,7 +17,8 @@ package common
 import (
 	"errors"
 	"fmt"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/commonpath"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -48,7 +49,7 @@ type DistinctParams struct {
 }
 
 // GetDistinctParams returns `distinct` command parameters.
-func GetDistinctParams(document *types.Document, l *slog.Logger) (*DistinctParams, error) {
+func GetDistinctParams(document *types.Document, l *zap.Logger) (*DistinctParams, error) {
 	var dp DistinctParams
 
 	err := handlerparams.ExtractParams(document, "distinct", &dp, l)
diff --git a/internal/handler/common/explain.go b/internal/handler/common/explain.go
index 14b28487741f..857c2b1cbf3f 100644
--- a/internal/handler/common/explain.go
+++ b/internal/handler/common/explain.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"log/slog"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -45,7 +45,7 @@ type ExplainParams struct {
 }
 
 // GetExplainParams returns the parameters for the explain command.
-func GetExplainParams(document *types.Document, l *slog.Logger) (*ExplainParams, error) {
+func GetExplainParams(document *types.Document, l *zap.Logger) (*ExplainParams, error) {
 	var err error
 
 	var db, collection string
diff --git a/internal/handler/common/find.go b/internal/handler/common/find.go
index 4ee10a0d5947..ace9752043bf 100644
--- a/internal/handler/common/find.go
+++ b/internal/handler/common/find.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"log/slog"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -65,7 +65,7 @@ type FindParams struct {
 }
 
 // GetFindParams returns `find` command parameters.
-func GetFindParams(doc *types.Document, l *slog.Logger) (*FindParams, error) {
+func GetFindParams(doc *types.Document, l *zap.Logger) (*FindParams, error) {
 	params := FindParams{
 		BatchSize: 101,
 	}
diff --git a/internal/handler/common/findandmodify.go b/internal/handler/common/findandmodify.go
index 0de40a780977..b11be8ed0765 100644
--- a/internal/handler/common/findandmodify.go
+++ b/internal/handler/common/findandmodify.go
@@ -16,7 +16,8 @@ package common
 
 import (
 	"fmt"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -58,7 +59,7 @@ type FindAndModifyParams struct {
 }
 
 // GetFindAndModifyParams returns `findAndModifyParams` command parameters.
-func GetFindAndModifyParams(doc *types.Document, l *slog.Logger) (*FindAndModifyParams, error) {
+func GetFindAndModifyParams(doc *types.Document, l *zap.Logger) (*FindAndModifyParams, error) {
 	var params FindAndModifyParams
 
 	err := handlerparams.ExtractParams(doc, "findAndModify", &params, l)
diff --git a/internal/handler/common/insert.go b/internal/handler/common/insert.go
index e63bdf770e1c..dcf6c087bab0 100644
--- a/internal/handler/common/insert.go
+++ b/internal/handler/common/insert.go
@@ -16,7 +16,8 @@ package common
 
 import (
 	"fmt"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -44,7 +45,7 @@ type InsertParams struct {
 }
 
 // GetInsertParams returns the parameters for an insert command.
-func GetInsertParams(document *types.Document, l *slog.Logger) (*InsertParams, error) {
+func GetInsertParams(document *types.Document, l *zap.Logger) (*InsertParams, error) {
 	params := InsertParams{
 		Ordered: true,
 	}
diff --git a/internal/handler/common/unimplemented.go b/internal/handler/common/unimplemented.go
index c80f45a7c3cf..153a23ae5ea5 100644
--- a/internal/handler/common/unimplemented.go
+++ b/internal/handler/common/unimplemented.go
@@ -16,7 +16,8 @@ package common
 
 import (
 	"fmt"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
@@ -59,12 +60,12 @@ func UnimplementedNonDefault(doc *types.Document, field string, isDefault func(v
 }
 
 // Ignored logs a message if doc has any of the given fields.
-func Ignored(doc *types.Document, l *slog.Logger, fields ...string) {
+func Ignored(doc *types.Document, l *zap.Logger, fields ...string) {
 	for _, field := range fields {
 		if v, err := doc.Get(field); err == nil {
 			l.Debug(
 				"ignoring field",
-				slog.String("command", doc.Command()), slog.String("field", field), slog.Any("value", v),
+				zap.String("command", doc.Command()), zap.String("field", field), zap.Any("value", v),
 			)
 		}
 	}
diff --git a/internal/handler/common/update_params.go b/internal/handler/common/update_params.go
index dd2c5fde7aec..fc943a50481c 100644
--- a/internal/handler/common/update_params.go
+++ b/internal/handler/common/update_params.go
@@ -15,7 +15,7 @@
 package common
 
 import (
-	"log/slog"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
@@ -84,7 +84,7 @@ type UpdateResult struct {
 }
 
 // GetUpdateParams returns parameters for update command.
-func GetUpdateParams(document *types.Document, l *slog.Logger) (*UpdateParams, error) {
+func GetUpdateParams(document *types.Document, l *zap.Logger) (*UpdateParams, error) {
 	var params UpdateParams
 
 	err := handlerparams.ExtractParams(document, "update", &params, l)
diff --git a/internal/handler/handler.go b/internal/handler/handler.go
index 8faeeda17a23..74b46eb3332e 100644
--- a/internal/handler/handler.go
+++ b/internal/handler/handler.go
@@ -19,7 +19,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"sync"
 	"time"
 
@@ -36,7 +35,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/util/ctxutil"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/util/password"
 	"github.com/FerretDB/FerretDB/internal/util/state"
@@ -90,7 +88,7 @@ type NewOpts struct {
 	SetupPassword password.Password
 	SetupTimeout  time.Duration
 
-	L             *slog.Logger
+	L             *zap.Logger
 	ConnMetrics   *connmetrics.ConnMetrics
 	StateProvider *state.Provider
 
@@ -121,12 +119,12 @@ func New(opts *NewOpts) (*Handler, error) {
 		opts.MaxBsonObjectSizeBytes = types.MaxDocumentLen
 	}
 
-	b := oplog.NewBackend(opts.Backend, zap.L().Named("oplog"))
+	b := oplog.NewBackend(opts.Backend, opts.L.Named("oplog"))
 
 	h := &Handler{
 		b:       b,
 		NewOpts: opts,
-		cursors: cursor.NewRegistry(zap.L().Named("cursors")),
+		cursors: cursor.NewRegistry(opts.L.Named("cursors")),
 
 		cappedCleanupStop: make(chan struct{}),
 		cleanupCappedCollectionsDocs: prometheus.NewCounterVec(
@@ -186,7 +184,7 @@ func (h *Handler) setup() error {
 
 	ctx = conninfo.Ctx(ctx, info)
 
-	l := logging.WithName(h.L, "setup")
+	l := h.L.Named("setup")
 
 	var retry int64
 
@@ -196,7 +194,7 @@ func (h *Handler) setup() error {
 			break
 		}
 
-		l.DebugContext(ctx, "Status failed", logging.Error(err))
+		l.Debug("Status failed", zap.Error(err))
 
 		retry++
 		ctxutil.SleepWithJitter(ctx, time.Second, retry)
@@ -208,16 +206,11 @@ func (h *Handler) setup() error {
 	}
 
 	if len(res.Databases) > 0 {
-		l.DebugContext(ctx, "Database already exists")
+		l.Debug("Database already exists")
 		return nil
 	}
 
-	l.InfoContext(
-		ctx,
-		"Setting up database and user",
-		slog.String("database", h.SetupDatabase),
-		slog.String("username", h.SetupUsername),
-	)
+	l.Info("Setting up database and user", zap.String("database", h.SetupDatabase), zap.String("username", h.SetupUsername))
 
 	db, err := h.b.Database(h.SetupDatabase)
 	if err != nil {
@@ -252,7 +245,7 @@ func (h *Handler) runCappedCleanup() {
 		return
 	}
 
-	h.L.Info("Capped collections cleanup enabled.", slog.Duration("interval", h.CappedCleanupInterval))
+	h.L.Info("Capped collections cleanup enabled.", zap.Duration("interval", h.CappedCleanupInterval))
 
 	ticker := time.NewTicker(h.CappedCleanupInterval)
 	defer ticker.Stop()
@@ -261,7 +254,7 @@ func (h *Handler) runCappedCleanup() {
 		select {
 		case <-ticker.C:
 			if err := h.cleanupAllCappedCollections(context.Background()); err != nil {
-				h.L.Error("Failed to cleanup capped collections.", logging.Error(err))
+				h.L.Error("Failed to cleanup capped collections.", zap.Error(err))
 			}
 
 		case <-h.cappedCleanupStop:
@@ -297,11 +290,11 @@ func (h *Handler) Collect(ch chan<- prometheus.Metric) {
 
 // cleanupAllCappedCollections drops the given percent of documents from all capped collections.
 func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
-	h.L.DebugContext(ctx, "cleanupAllCappedCollections: started", slog.Any("percentage", h.CappedCleanupPercentage))
+	h.L.Debug("cleanupAllCappedCollections: started", zap.Uint8("percentage", h.CappedCleanupPercentage))
 
 	start := time.Now()
 	defer func() {
-		h.L.DebugContext(ctx, "cleanupAllCappedCollections: finished", slog.Duration("duration", time.Since(start)))
+		h.L.Debug("cleanupAllCappedCollections: finished", zap.Duration("duration", time.Since(start)))
 	}()
 
 	connInfo := conninfo.New()
@@ -340,13 +333,9 @@ func (h *Handler) cleanupAllCappedCollections(ctx context.Context) error {
 			}
 
 			if deleted > 0 || bytesFreed > 0 {
-				h.L.InfoContext(
-					ctx,
-					"Capped collection cleaned up.",
-					slog.String("db", dbInfo.Name),
-					slog.String("collection", cInfo.Name),
-					slog.Any("deleted", deleted),
-					slog.Int64("bytes_freed", bytesFreed),
+				h.L.Info("Capped collection cleaned up.",
+					zap.String("db", dbInfo.Name), zap.String("collection", cInfo.Name),
+					zap.Int32("deleted", deleted), zap.Int64("bytesFreed", bytesFreed),
 				)
 			}
 
@@ -375,8 +364,7 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 	if err != nil {
 		return 0, 0, lazyerrors.Error(err)
 	}
-
-	h.L.DebugContext(ctx, "cleanupCappedCollection: stats before", slog.Any("stats", statsBefore))
+	h.L.Debug("cleanupCappedCollection: stats before", zap.Any("stats", statsBefore))
 
 	// In order to be more precise w.r.t number of documents getting dropped and to avoid
 	// deleting too many documents unnecessarily,
@@ -397,7 +385,7 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 			return 0, 0, lazyerrors.Error(err)
 		}
 
-		h.L.DebugContext(ctx, "cleanupCappedCollection: stats after document count reduction", slog.Any("stats", statsAfter))
+		h.L.Debug("cleanupCappedCollection: stats after document count reduction", zap.Any("stats", statsAfter))
 
 		docsDeleted += int32(count)
 		bytesFreed += (statsBefore.SizeTotal - statsAfter.SizeTotal)
@@ -423,7 +411,7 @@ func (h *Handler) cleanupCappedCollection(ctx context.Context, db backends.Datab
 		return 0, 0, lazyerrors.Error(err)
 	}
 
-	h.L.DebugContext(ctx, "cleanupCappedCollection: stats after compact", slog.Any("stats", statsAfter))
+	h.L.Debug("cleanupCappedCollection: stats after compact", zap.Any("stats", statsAfter))
 
 	bytesFreed += (statsBefore.SizeTotal - statsAfter.SizeTotal)
 
diff --git a/internal/handler/handlerparams/extract_params.go b/internal/handler/handlerparams/extract_params.go
index f247a04d9ae4..cac6aa9456b3 100644
--- a/internal/handler/handlerparams/extract_params.go
+++ b/internal/handler/handlerparams/extract_params.go
@@ -17,11 +17,12 @@ package handlerparams
 import (
 	"errors"
 	"fmt"
-	"log/slog"
 	"reflect"
 	"slices"
 	"strings"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
@@ -57,7 +58,7 @@ import (
 //   - `ErrBadValue` when field is out of integer range;
 //   - `ErrBadValue` when field has negative value;
 //   - `ErrInvalidNamespace` - collection name has invalid type.
-func ExtractParams(doc *types.Document, command string, value any, l *slog.Logger) error {
+func ExtractParams(doc *types.Document, command string, value any, l *zap.Logger) error {
 	rv := reflect.ValueOf(value)
 	if rv.Kind() != reflect.Ptr || rv.IsNil() {
 		panic("value must be a non-nil pointer")
@@ -106,7 +107,7 @@ func ExtractParams(doc *types.Document, command string, value any, l *slog.Logge
 		if options.ignored {
 			l.Debug(
 				"ignoring field",
-				slog.String("command", doc.Command()), slog.String("field", key), slog.Any("value", val),
+				zap.String("command", doc.Command()), zap.String("field", key), zap.Any("value", val),
 			)
 
 			continue
@@ -228,7 +229,7 @@ func tagOptionsFromList(optionsList []string) *tagOptions {
 }
 
 // setStructField sets the value of the document field to the structure field.
-func setStructField(elem *reflect.Value, o *tagOptions, i int, command, key string, val any, l *slog.Logger) error {
+func setStructField(elem *reflect.Value, o *tagOptions, i int, command, key string, val any, l *zap.Logger) error {
 	var err error
 
 	field := elem.Type().Field(i)
diff --git a/internal/handler/handlerparams/extract_params_test.go b/internal/handler/handlerparams/extract_params_test.go
index 20036a9764b2..12c7f6660ee9 100644
--- a/internal/handler/handlerparams/extract_params_test.go
+++ b/internal/handler/handlerparams/extract_params_test.go
@@ -19,10 +19,10 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/must"
-	"github.com/FerretDB/FerretDB/internal/util/testutil"
 )
 
 func TestParse(t *testing.T) {
@@ -369,7 +369,7 @@ func TestParse(t *testing.T) {
 	}
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {
-			err := ExtractParams(tt.doc, tt.command, tt.params, testutil.SLogger(t))
+			err := ExtractParams(tt.doc, tt.command, tt.params, zap.NewNop())
 			if tt.wantErr != "" {
 				require.Regexp(t, regexp.MustCompile(".*"+tt.wantErr), err.Error())
 				return
diff --git a/internal/handler/msg_aggregate.go b/internal/handler/msg_aggregate.go
index bf13813c35a1..4855dfd68839 100644
--- a/internal/handler/msg_aggregate.go
+++ b/internal/handler/msg_aggregate.go
@@ -18,12 +18,13 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"math"
 	"os"
 	"strings"
 	"time"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -380,13 +381,9 @@ func (h *Handler) MsgAggregate(connCtx context.Context, msg *wire.OpMsg) (*wire.
 		return nil, handleMaxTimeMSError(err, maxTimeMS, "aggregate")
 	}
 
-	h.L.DebugContext(
-		ctx,
-		"Got first batch",
-		slog.Int64("cursor_id", cursorID),
-		slog.Any("type", cursor.Type),
-		slog.Int("count", len(docs)),
-		slog.Int64("batch_size", batchSize),
+	h.L.Debug(
+		"Got first batch", zap.Int64("cursor_id", cursorID), zap.Stringer("type", cursor.Type),
+		zap.Int("count", len(docs)), zap.Int64("batch_size", batchSize),
 	)
 
 	firstBatch := types.MakeArray(len(docs))
diff --git a/internal/handler/msg_find.go b/internal/handler/msg_find.go
index 13ace3920743..790f947ab8fe 100644
--- a/internal/handler/msg_find.go
+++ b/internal/handler/msg_find.go
@@ -18,10 +18,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"strings"
 	"time"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -94,7 +95,7 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		}
 	}
 
-	qp, err := h.makeFindQueryParams(connCtx, params, &cInfo)
+	qp, err := h.makeFindQueryParams(params, &cInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -164,14 +165,10 @@ func (h *Handler) MsgFind(connCtx context.Context, msg *wire.OpMsg) (*wire.OpMsg
 		return nil, handleMaxTimeMSError(err, params.MaxTimeMS, "find")
 	}
 
-	h.L.DebugContext(
-		ctx,
-		"Got first batch",
-		slog.Int64("cursor_id", cursorID),
-		slog.Any("type", c.Type),
-		slog.Int("count", len(docs)),
-		slog.Int64("batch_size", params.BatchSize),
-		slog.Bool("single_batch", params.SingleBatch),
+	h.L.Debug(
+		"Got first batch", zap.Int64("cursor_id", cursorID), zap.Stringer("type", c.Type),
+		zap.Int("count", len(docs)), zap.Int64("batch_size", params.BatchSize),
+		zap.Bool("single_batch", params.SingleBatch),
 	)
 
 	if params.SingleBatch || len(docs) < int(params.BatchSize) {
@@ -213,7 +210,7 @@ type findCursorData struct {
 }
 
 // makeFindQueryParams creates the backend's query parameters for the find command.
-func (h *Handler) makeFindQueryParams(ctx context.Context, params *common.FindParams, cInfo *backends.CollectionInfo) (*backends.QueryParams, error) { //nolint:lll // for readability
+func (h *Handler) makeFindQueryParams(params *common.FindParams, cInfo *backends.CollectionInfo) (*backends.QueryParams, error) {
 	qp := &backends.QueryParams{
 		Comment: params.Comment,
 	}
@@ -285,9 +282,7 @@ func (h *Handler) makeFindQueryParams(ctx context.Context, params *common.FindPa
 		qp.Limit = params.Limit
 	}
 
-	if h.L.Enabled(ctx, slog.LevelDebug) {
-		h.L.DebugContext(ctx, fmt.Sprintf("Converted %+v for %+v to %+v.", params, cInfo, qp))
-	}
+	h.L.Sugar().Debugf("Converted %+v for %+v to %+v.", params, cInfo, qp)
 
 	return qp, nil
 }
diff --git a/internal/handler/msg_getlog.go b/internal/handler/msg_getlog.go
index 18bfab499d16..51ff07d498e3 100644
--- a/internal/handler/msg_getlog.go
+++ b/internal/handler/msg_getlog.go
@@ -18,10 +18,11 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"log/slog"
 	"strings"
 	"time"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/build/version"
 	"github.com/FerretDB/FerretDB/internal/bson"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
@@ -110,7 +111,7 @@ func (h *Handler) MsgGetLog(connCtx context.Context, msg *wire.OpMsg) (*wire.OpM
 			startupWarnings = append(startupWarnings, "This is debug build. The performance will be affected.")
 		}
 
-		if h.L.Enabled(connCtx, slog.LevelDebug) {
+		if h.L.Level().Enabled(zap.DebugLevel) {
 			startupWarnings = append(startupWarnings, "Debug logging enabled. The security and performance will be affected.")
 		}
 
diff --git a/internal/handler/msg_getmore.go b/internal/handler/msg_getmore.go
index 9f237964b75e..bd4cd855dd2b 100644
--- a/internal/handler/msg_getmore.go
+++ b/internal/handler/msg_getmore.go
@@ -18,10 +18,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log/slog"
 	"math"
 	"time"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/backends"
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/clientconn/cursor"
@@ -283,11 +284,8 @@ func (h *Handler) makeNextBatch(c *cursor.Cursor, batchSize int64) (*types.Array
 	}
 
 	h.L.Debug(
-		"Got next batch",
-		slog.Int64("cursor_id", c.ID),
-		slog.Any("type", c.Type),
-		slog.Int("count", len(docs)),
-		slog.Int64("batch_size", batchSize),
+		"Got next batch", zap.Int64("cursor_id", c.ID), zap.Stringer("type", c.Type),
+		zap.Int("count", len(docs)), zap.Int64("batch_size", batchSize),
 	)
 
 	nextBatch := types.MakeArray(len(docs))
diff --git a/internal/handler/msg_listdatabases.go b/internal/handler/msg_listdatabases.go
index ff89e5cca8e4..3a3928f7533b 100644
--- a/internal/handler/msg_listdatabases.go
+++ b/internal/handler/msg_listdatabases.go
@@ -17,11 +17,12 @@ package handler
 import (
 	"context"
 
+	"go.uber.org/zap"
+
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlerparams"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -65,13 +66,13 @@ func (h *Handler) MsgListDatabases(connCtx context.Context, msg *wire.OpMsg) (*w
 	for _, dbInfo := range res.Databases {
 		db, err := h.b.Database(dbInfo.Name)
 		if err != nil {
-			h.L.WarnContext(connCtx, "Failed to get database", logging.Error(err))
+			h.L.Warn("Failed to get database", zap.Error(err))
 			continue
 		}
 
 		stats, err := db.Stats(connCtx, nil)
 		if err != nil {
-			h.L.WarnContext(connCtx, "Failed to get database stats", logging.Error(err))
+			h.L.Warn("Failed to get database stats", zap.Error(err))
 			continue
 		}
 
diff --git a/internal/handler/msg_saslcontinue.go b/internal/handler/msg_saslcontinue.go
index 836c201c6045..8757d473f40b 100644
--- a/internal/handler/msg_saslcontinue.go
+++ b/internal/handler/msg_saslcontinue.go
@@ -16,14 +16,14 @@ package handler
 
 import (
 	"context"
-	"log/slog"
+
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/common"
 	"github.com/FerretDB/FerretDB/internal/handler/handlererrors"
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -49,7 +49,7 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 	_, _, conv, _ := conninfo.Get(connCtx).Auth()
 
 	if conv == nil {
-		h.L.WarnContext(connCtx, "saslContinue: no conversation to continue")
+		h.L.Warn("saslContinue: no conversation to continue")
 
 		return nil, handlererrors.NewCommandErrorMsgWithArgument(
 			handlererrors.ErrAuthenticationFailed,
@@ -60,18 +60,18 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 
 	response, err := conv.Step(string(payload))
 
-	attrs := []any{
-		slog.String("username", conv.Username()),
-		slog.Bool("valid", conv.Valid()),
-		slog.Bool("done", conv.Done()),
+	fields := []zap.Field{
+		zap.String("username", conv.Username()),
+		zap.Bool("valid", conv.Valid()),
+		zap.Bool("done", conv.Done()),
 	}
 
 	if err != nil {
-		if h.L.Enabled(connCtx, slog.LevelDebug) {
-			attrs = append(attrs, logging.Error(err))
+		if h.L.Level().Enabled(zap.DebugLevel) {
+			fields = append(fields, zap.Error(err))
 		}
 
-		h.L.WarnContext(connCtx, "saslContinue: step failed", attrs...) //nolint:sloglint // attrs is not key-value pairs
+		h.L.Warn("saslContinue: step failed", fields...)
 
 		return nil, handlererrors.NewCommandErrorMsgWithArgument(
 			handlererrors.ErrAuthenticationFailed,
@@ -80,7 +80,7 @@ func (h *Handler) MsgSASLContinue(connCtx context.Context, msg *wire.OpMsg) (*wi
 		)
 	}
 
-	h.L.DebugContext(connCtx, "saslContinue: step succeed", attrs...) //nolint:sloglint // attrs is not key-value pairs
+	h.L.Debug("saslContinue: step succeed", fields...)
 
 	if conv.Valid() {
 		conninfo.Get(connCtx).SetBypassBackendAuth()
diff --git a/internal/handler/msg_saslstart.go b/internal/handler/msg_saslstart.go
index aafd452a302f..2719e2379d85 100644
--- a/internal/handler/msg_saslstart.go
+++ b/internal/handler/msg_saslstart.go
@@ -20,9 +20,9 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
-	"log/slog"
 
 	"github.com/xdg-go/scram"
+	"go.uber.org/zap"
 
 	"github.com/FerretDB/FerretDB/internal/clientconn/conninfo"
 	"github.com/FerretDB/FerretDB/internal/handler/common"
@@ -30,7 +30,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/types"
 	"github.com/FerretDB/FerretDB/internal/util/iterator"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 	"github.com/FerretDB/FerretDB/internal/util/must"
 	"github.com/FerretDB/FerretDB/internal/wire"
 )
@@ -233,7 +232,7 @@ func (h *Handler) scramCredentialLookup(ctx context.Context, dbName, username, m
 		}
 	}
 
-	h.L.WarnContext(ctx, "scramCredentialLookup: failed", slog.String("user", username))
+	h.L.Warn("scramCredentialLookup: failed", zap.String("user", username))
 
 	return nil, handlererrors.NewCommandErrorMsgWithArgument(
 		handlererrors.ErrAuthenticationFailed,
@@ -282,23 +281,23 @@ func (h *Handler) saslStartSCRAM(ctx context.Context, dbName, mechanism string,
 
 	response, err := conv.Step(string(payload))
 
-	attrs := []any{
-		slog.String("username", conv.Username()),
-		slog.Bool("valid", conv.Valid()),
-		slog.Bool("done", conv.Done()),
+	fields := []zap.Field{
+		zap.String("username", conv.Username()),
+		zap.Bool("valid", conv.Valid()),
+		zap.Bool("done", conv.Done()),
 	}
 
 	if err != nil {
-		if h.L.Enabled(ctx, slog.LevelDebug) {
-			attrs = append(attrs, logging.Error(err))
+		if h.L.Level().Enabled(zap.DebugLevel) {
+			fields = append(fields, zap.Error(err))
 		}
 
-		h.L.WarnContext(ctx, "saslStartSCRAM: step failed", attrs...) //nolint:sloglint // attrs is not key-value pairs
+		h.L.Warn("saslStartSCRAM: step failed", fields...)
 
 		return "", err
 	}
 
-	h.L.DebugContext(ctx, "saslStartSCRAM: step succeed", attrs...) //nolint:sloglint // attrs is not key-value pairs
+	h.L.Debug("saslStartSCRAM: step succeed", fields...)
 
 	conninfo.Get(ctx).SetAuth(conv.Username(), "", conv, dbName)
 
diff --git a/internal/handler/registry/hana.go b/internal/handler/registry/hana.go
index f9dfb7535ff8..e7f7c0343cc8 100644
--- a/internal/handler/registry/hana.go
+++ b/internal/handler/registry/hana.go
@@ -20,7 +20,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/hana"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "hana" handler for Hana when "ferretdb_hana" build tag is provided.
@@ -48,7 +47,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             logging.WithName(opts.SLogger, "hana"),
+			L:             opts.Logger.Named("hana"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/mysql.go b/internal/handler/registry/mysql.go
index ad198681c131..6d2636c31ad9 100644
--- a/internal/handler/registry/mysql.go
+++ b/internal/handler/registry/mysql.go
@@ -18,7 +18,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/mysql"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "mysql" handler.
@@ -43,7 +42,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             logging.WithName(opts.SLogger, "mysql"),
+			L:             opts.Logger.Named("mysql"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/postgresql.go b/internal/handler/registry/postgresql.go
index bcbf7f59d5b3..994f922c598e 100644
--- a/internal/handler/registry/postgresql.go
+++ b/internal/handler/registry/postgresql.go
@@ -20,7 +20,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/postgresql"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "postgresql" handler.
@@ -46,7 +45,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             logging.WithName(opts.SLogger, "postgresql"),
+			L:             opts.Logger.Named("postgresql"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 
diff --git a/internal/handler/registry/registry.go b/internal/handler/registry/registry.go
index d835cfc60a75..4cf1ec6a8416 100644
--- a/internal/handler/registry/registry.go
+++ b/internal/handler/registry/registry.go
@@ -17,7 +17,6 @@ package registry
 
 import (
 	"fmt"
-	"log/slog"
 	"time"
 
 	"go.uber.org/zap"
@@ -44,7 +43,6 @@ var registry = map[string]newHandlerFunc{}
 type NewHandlerOpts struct {
 	// for all backends
 	Logger        *zap.Logger
-	SLogger       *slog.Logger
 	ConnMetrics   *connmetrics.ConnMetrics
 	StateProvider *state.Provider
 	TCPHost       string
diff --git a/internal/handler/registry/sqlite.go b/internal/handler/registry/sqlite.go
index 04912d25c997..ed21c791d1d8 100644
--- a/internal/handler/registry/sqlite.go
+++ b/internal/handler/registry/sqlite.go
@@ -20,7 +20,6 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/sqlite"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
-	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "sqlite" handler.
@@ -46,7 +45,7 @@ func init() {
 			SetupPassword: opts.SetupPassword,
 			SetupTimeout:  opts.SetupTimeout,
 
-			L:             logging.WithName(opts.SLogger, "sqlite"),
+			L:             opts.Logger.Named("sqlite"),
 			ConnMetrics:   opts.ConnMetrics,
 			StateProvider: opts.StateProvider,
 

From 6c03fefe85040772de8233d6344f784eba2bd789 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:40:52 +0900
Subject: [PATCH 07/11] fix mistaken commit

---
 ferretdb/ferretdb.go                    | 2 ++
 integration/setup/listener.go           | 2 ++
 internal/handler/registry/postgresql.go | 1 +
 internal/handler/registry/registry.go   | 2 ++
 internal/handler/registry/sqlite.go     | 1 +
 5 files changed, 8 insertions(+)

diff --git a/ferretdb/ferretdb.go b/ferretdb/ferretdb.go
index 32e042df3c59..5032010e4460 100644
--- a/ferretdb/ferretdb.go
+++ b/ferretdb/ferretdb.go
@@ -22,6 +22,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/url"
 	"sync"
 
@@ -128,6 +129,7 @@ func New(config *Config) (*FerretDB, error) {
 
 	h, closeBackend, err := registry.NewHandler(config.Handler, &registry.NewHandlerOpts{
 		Logger:        log,
+		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: sp,
 		TCPHost:       config.Listener.TCP,
diff --git a/integration/setup/listener.go b/integration/setup/listener.go
index b30fe022f149..3699eb188f2e 100644
--- a/integration/setup/listener.go
+++ b/integration/setup/listener.go
@@ -16,6 +16,7 @@ package setup
 
 import (
 	"context"
+	"log/slog"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -179,6 +180,7 @@ func setupListener(tb testtb.TB, ctx context.Context, logger *zap.Logger, opts *
 
 	handlerOpts := &registry.NewHandlerOpts{
 		Logger:        logger,
+		SLogger:       slog.Default(), // TODO https://github.com/FerretDB/FerretDB/issues/4013
 		ConnMetrics:   listenerMetrics.ConnMetrics,
 		StateProvider: sp,
 
diff --git a/internal/handler/registry/postgresql.go b/internal/handler/registry/postgresql.go
index 994f922c598e..487d312f0785 100644
--- a/internal/handler/registry/postgresql.go
+++ b/internal/handler/registry/postgresql.go
@@ -20,6 +20,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/postgresql"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "postgresql" handler.
diff --git a/internal/handler/registry/registry.go b/internal/handler/registry/registry.go
index 4cf1ec6a8416..d835cfc60a75 100644
--- a/internal/handler/registry/registry.go
+++ b/internal/handler/registry/registry.go
@@ -17,6 +17,7 @@ package registry
 
 import (
 	"fmt"
+	"log/slog"
 	"time"
 
 	"go.uber.org/zap"
@@ -43,6 +44,7 @@ var registry = map[string]newHandlerFunc{}
 type NewHandlerOpts struct {
 	// for all backends
 	Logger        *zap.Logger
+	SLogger       *slog.Logger
 	ConnMetrics   *connmetrics.ConnMetrics
 	StateProvider *state.Provider
 	TCPHost       string
diff --git a/internal/handler/registry/sqlite.go b/internal/handler/registry/sqlite.go
index ed21c791d1d8..5c2119c7d9b6 100644
--- a/internal/handler/registry/sqlite.go
+++ b/internal/handler/registry/sqlite.go
@@ -20,6 +20,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/backends/sqlite"
 	"github.com/FerretDB/FerretDB/internal/handler"
 	"github.com/FerretDB/FerretDB/internal/util/lazyerrors"
+	"github.com/FerretDB/FerretDB/internal/util/logging"
 )
 
 // init registers "sqlite" handler.

From c8782ee7cc2cfdca383055c52453ec9bd0444beb Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:48:30 +0900
Subject: [PATCH 08/11] fix log format

---
 cmd/ferretdb/ping.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/cmd/ferretdb/ping.go b/cmd/ferretdb/ping.go
index 8b833546ba4a..b5a36733548c 100644
--- a/cmd/ferretdb/ping.go
+++ b/cmd/ferretdb/ping.go
@@ -78,18 +78,18 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 	}
 
 	if cli.Listen.Unix != "" {
-		l.DebugContext(ctx, fmt.Sprintf("--listen-addr flag is set. Ping to %s will be performed", cli.Listen.Addr))
+		l.DebugContext(ctx, fmt.Sprintf("--listen-unix flag is set. Ping to %s will be performed", cli.Listen.Addr))
 
 		urls = append(urls, "mongodb://"+url.PathEscape(cli.Listen.Unix))
 	}
 
 	if len(urls) == 0 {
-		l.WarnContext(ctx, "Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping.")
+		l.WarnContext(ctx, "Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping")
 		return true
 	}
 
 	for _, u := range urls {
-		l.DebugContext(ctx, fmt.Sprintf("Pinging %s...", u))
+		l.DebugContext(ctx, fmt.Sprintf("Pinging %s", u))
 
 		var cancel func()
 		ctx, cancel = context.WithTimeout(ctx, cli.Setup.Timeout)

From 47c863fffda852e691a21296d93bd555913d9639 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:52:54 +0900
Subject: [PATCH 09/11] fix

---
 cmd/ferretdb/ping.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cmd/ferretdb/ping.go b/cmd/ferretdb/ping.go
index b5a36733548c..c0a3b2d6a9a8 100644
--- a/cmd/ferretdb/ping.go
+++ b/cmd/ferretdb/ping.go
@@ -78,7 +78,7 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 	}
 
 	if cli.Listen.Unix != "" {
-		l.DebugContext(ctx, fmt.Sprintf("--listen-unix flag is set. Ping to %s will be performed", cli.Listen.Addr))
+		l.DebugContext(ctx, fmt.Sprintf("--listen-unix flag is set. Ping to %s will be performed", cli.Listen.Unix))
 
 		urls = append(urls, "mongodb://"+url.PathEscape(cli.Listen.Unix))
 	}
@@ -93,6 +93,7 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 
 		var cancel func()
 		ctx, cancel = context.WithTimeout(ctx, cli.Setup.Timeout)
+
 		defer cancel()
 
 		client, err := mongo.Connect(ctx, options.Client().ApplyURI(u))

From bd1ab3119edafa54d54dd95fbda3582592eb1696 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 12:54:41 +0900
Subject: [PATCH 10/11] use correct log level

---
 cmd/ferretdb/ping.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/ferretdb/ping.go b/cmd/ferretdb/ping.go
index c0a3b2d6a9a8..89438e69cafe 100644
--- a/cmd/ferretdb/ping.go
+++ b/cmd/ferretdb/ping.go
@@ -84,7 +84,7 @@ func (ready *ReadyZ) Probe(ctx context.Context) bool {
 	}
 
 	if len(urls) == 0 {
-		l.WarnContext(ctx, "Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping")
+		l.InfoContext(ctx, "Neither --listen-addr nor --listen-unix nor --listen-tls flags were specified - skipping ping")
 		return true
 	}
 

From 2ad9fef3bc6998c4b8b1fafea53ad9ef70bd2777 Mon Sep 17 00:00:00 2001
From: Chi Fujii <chi.fujii@ferretdb.io>
Date: Thu, 18 Jul 2024 14:29:10 +0900
Subject: [PATCH 11/11] undo

---
 cmd/ferretdb/main.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/cmd/ferretdb/main.go b/cmd/ferretdb/main.go
index b05b3cacae92..ca8d987748c2 100644
--- a/cmd/ferretdb/main.go
+++ b/cmd/ferretdb/main.go
@@ -498,6 +498,7 @@ func run() {
 
 	h, closeBackend, err := registry.NewHandler(cli.Handler, &registry.NewHandlerOpts{
 		Logger:        logger,
+		SLogger:       slogger,
 		ConnMetrics:   metrics.ConnMetrics,
 		StateProvider: stateProvider,
 		TCPHost:       cli.Listen.Addr,