diff --git a/cluster/join.go b/cluster/join.go
index 1cff1202..0bd39f15 100644
--- a/cluster/join.go
+++ b/cluster/join.go
@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net"
 	"net/http"
@@ -148,7 +148,7 @@ func (j *Joiner) join(joinAddr, id, addr string, voter bool) (string, error) {
 		}
 		defer resp.Body.Close()
 
-		b, err = ioutil.ReadAll(resp.Body)
+		b, err = io.ReadAll(resp.Body)
 		if err != nil {
 			return "", err
 		}
diff --git a/cluster/join_test.go b/cluster/join_test.go
index 87b7570e..3fe4f92a 100644
--- a/cluster/join_test.go
+++ b/cluster/join_test.go
@@ -4,7 +4,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -28,7 +28,7 @@ func Test_SingleJoinOK(t *testing.T) {
 			t.Fatalf("incorrect Content-Type set")
 		}
 
-		b, err := ioutil.ReadAll(r.Body)
+		b, err := io.ReadAll(r.Body)
 		if err != nil {
 			w.WriteHeader(http.StatusBadRequest)
 			return
@@ -74,7 +74,7 @@ func Test_SingleJoinHTTPSOK(t *testing.T) {
 			t.Fatalf("incorrect Content-Type set")
 		}
 
-		b, err := ioutil.ReadAll(r.Body)
+		b, err := io.ReadAll(r.Body)
 		if err != nil {
 			w.WriteHeader(http.StatusBadRequest)
 			return
@@ -130,7 +130,7 @@ func Test_SingleJoinOKBasicAuth(t *testing.T) {
 			t.Fatalf("bad Basic Auth credentials received (%s, %s", username, password)
 		}
 
-		b, err := ioutil.ReadAll(r.Body)
+		b, err := io.ReadAll(r.Body)
 		if err != nil {
 			w.WriteHeader(http.StatusBadRequest)
 			return
diff --git a/cluster/service.go b/cluster/service.go
index f4c3a8f1..a8d29ed4 100644
--- a/cluster/service.go
+++ b/cluster/service.go
@@ -263,9 +263,7 @@ func (s *Service) handleConn(conn net.Conn) {
 					resp.Error = err.Error()
 				} else {
 					resp.Results = make([]*command.ExecuteResult, len(res))
-					for i := range res {
-						resp.Results[i] = res[i]
-					}
+					copy(resp.Results, res)
 				}
 			}
 
@@ -291,9 +289,7 @@ func (s *Service) handleConn(conn net.Conn) {
 					resp.Error = err.Error()
 				} else {
 					resp.Rows = make([]*command.QueryRows, len(res))
-					for i := range res {
-						resp.Rows[i] = res[i]
-					}
+					copy(resp.Rows, res)
 				}
 			}
 
diff --git a/cluster/service_db_clstr_test.go b/cluster/service_db_clstr_test.go
index 0094ff8c..d349dcac 100644
--- a/cluster/service_db_clstr_test.go
+++ b/cluster/service_db_clstr_test.go
@@ -296,7 +296,7 @@ func Test_ServiceBackup(t *testing.T) {
 		t.Fatalf("failed to backup database: %s", err.Error())
 	}
 
-	if bytes.Compare(buf.Bytes(), testData) != 0 {
+	if !bytes.Equal(buf.Bytes(), testData) {
 		t.Fatalf("backup data is not as expected, exp: %s, got: %s", testData, buf.Bytes())
 	}
 
@@ -332,7 +332,7 @@ func Test_ServiceLoad(t *testing.T) {
 	testData := []byte("this is SQLite data")
 	db.loadFn = func(lr *command.LoadRequest) error {
 		called = true
-		if bytes.Compare(lr.Data, testData) != 0 {
+		if !bytes.Equal(lr.Data, testData) {
 			t.Fatalf("load data is not as expected, exp: %s, got: %s", testData, lr.Data)
 		}
 		return nil
@@ -458,13 +458,6 @@ func queryRequestFromStrings(s []string) *command.QueryRequest {
 	}
 }
 
-func backupRequestSQL(leader bool) *command.BackupRequest {
-	return &command.BackupRequest{
-		Format: command.BackupRequest_BACKUP_REQUEST_FORMAT_SQL,
-		Leader: leader,
-	}
-}
-
 func backupRequestBinary(leader bool) *command.BackupRequest {
 	return &command.BackupRequest{
 		Format: command.BackupRequest_BACKUP_REQUEST_FORMAT_BINARY,
diff --git a/rtls/config.go b/rtls/config.go
index e81859e4..6b380e02 100644
--- a/rtls/config.go
+++ b/rtls/config.go
@@ -29,7 +29,7 @@ func CreateConfig(certFile, keyFile, caCertFile string, noverify, tls1011 bool)
 
 	// load the CA certificate file, if provided, as the root CA and client CA
 	if caCertFile != "" {
-		asn1Data, err := ioutil.ReadFile(caCertFile)
+		asn1Data, err := os.ReadFile(caCertFile)
 		if err != nil {
 			return nil, err
 		}
@@ -69,7 +69,7 @@ func CreateClientConfig(certFile, keyFile, caCertFile string, noverify, tls1011
 		}
 	}
 	if caCertFile != "" {
-		asn1Data, err := ioutil.ReadFile(caCertFile)
+		asn1Data, err := os.ReadFile(caCertFile)
 		if err != nil {
 			return nil, err
 		}
@@ -99,7 +99,7 @@ func CreateServerConfig(certFile, keyFile, caCertFile string, noverify, tls1011
 		return nil, err
 	}
 	if caCertFile != "" {
-		asn1Data, err := ioutil.ReadFile(caCertFile)
+		asn1Data, err := os.ReadFile(caCertFile)
 		if err != nil {
 			return nil, err
 		}
diff --git a/tcp/dialer_test.go b/tcp/dialer_test.go
index a53ba7d8..bea9325a 100644
--- a/tcp/dialer_test.go
+++ b/tcp/dialer_test.go
@@ -121,7 +121,7 @@ func (e *echoServer) Start(t *testing.T) {
 				// Successful testing can cause this.
 				return
 			}
-			t.Fatalf("failed to accept a connection: %s", err.Error())
+			t.Logf("failed to accept a connection: %s", err.Error())
 		}
 		go func(c net.Conn) {
 			buf := make([]byte, 1)
diff --git a/tcp/mux_test.go b/tcp/mux_test.go
index 7b9d5e05..7c12086e 100644
--- a/tcp/mux_test.go
+++ b/tcp/mux_test.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"crypto/tls"
 	"io"
-	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -41,7 +40,7 @@ func TestMux(t *testing.T) {
 		}
 		mux.Timeout = 200 * time.Millisecond
 		if !testing.Verbose() {
-			mux.Logger = log.New(ioutil.Discard, "", 0)
+			mux.Logger = log.New(io.Discard, "", 0)
 		}
 		for i := uint8(0); i < n; i++ {
 			ln := mux.Listen(i)
@@ -140,7 +139,7 @@ func TestMux_Advertise(t *testing.T) {
 	}
 	mux.Timeout = 200 * time.Millisecond
 	if !testing.Verbose() {
-		mux.Logger = log.New(ioutil.Discard, "", 0)
+		mux.Logger = log.New(io.Discard, "", 0)
 	}
 
 	layer := mux.Listen(1)