Revert "ConnPool check fd for bad conns (#1824)" (#1849)

This reverts commit 346bfafddd.

internal/pool/conncheck.go

@@ -1,45 +0,0 @@
-// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
-
-package pool
-
-import (
-	"errors"
-	"io"
-	"net"
-	"syscall"
-)
-
-var errUnexpectedRead = errors.New("unexpected read from socket")
-
-func connCheck(conn net.Conn) error {
-	sysConn, ok := conn.(syscall.Conn)
-	if !ok {
-		return nil
-	}
-	rawConn, err := sysConn.SyscallConn()
-	if err != nil {
-		return err
-	}
-
-	var sysErr error
-	err = rawConn.Read(func(fd uintptr) bool {
-		var buf [1]byte
-		n, err := syscall.Read(int(fd), buf[:])
-		switch {
-		case n == 0 && err == nil:
-			sysErr = io.EOF
-		case n > 0:
-			sysErr = errUnexpectedRead
-		case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
-			sysErr = nil
-		default:
-			sysErr = err
-		}
-		return true
-	})
-	if err != nil {
-		return err
-	}
-
-	return sysErr
-}

internal/pool/conncheck_dummy.go

@@ -1,9 +0,0 @@
-// +build !linux,!darwin,!dragonfly,!freebsd,!netbsd,!openbsd,!solaris,!illumos
-
-package pool
-
-import "net"
-
-func connCheck(conn net.Conn) error {
-	return nil
-}

internal/pool/conncheck_test.go

@@ -1,46 +0,0 @@
-// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
-
-package pool
-
-import (
-	"net"
-	"net/http/httptest"
-	"testing"
-	"time"
-)
-
-func Test_connCheck(t *testing.T) {
-	// tests with real conns
-	ts := httptest.NewServer(nil)
-	defer ts.Close()
-
-	t.Run("good conn", func(t *testing.T) {
-		conn, err := net.DialTimeout(ts.Listener.Addr().Network(), ts.Listener.Addr().String(), time.Second)
-		if err != nil {
-			t.Fatalf(err.Error())
-		}
-		defer conn.Close()
-		if err = connCheck(conn); err != nil {
-			t.Fatalf(err.Error())
-		}
-		conn.Close()
-
-		if err = connCheck(conn); err == nil {
-			t.Fatalf("expect has error")
-		}
-	})
-
-	t.Run("bad conn 2", func(t *testing.T) {
-		conn, err := net.DialTimeout(ts.Listener.Addr().Network(), ts.Listener.Addr().String(), time.Second)
-		if err != nil {
-			t.Fatalf(err.Error())
-		}
-		defer conn.Close()
-
-		ts.Close()
-
-		if err = connCheck(conn); err == nil {
-			t.Fatalf("expect has err")
-		}
-	})
-}

internal/pool/main_test.go

@@ -2,12 +2,9 @@ package pool_test
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"sync"
-	"syscall"
 	"testing"
-	"time"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -35,87 +32,5 @@ func perform(n int, cbs ...func(int)) {
 }
 
 func dummyDialer(context.Context) (net.Conn, error) {
-	// return &net.TCPConn{}, nil
-	return newDummyConn(), nil
-}
-
-func newDummyConn() net.Conn {
-	return &dummyConn{
-		rawConn: &dummyRawConn{},
-	}
-}
-
-var _ net.Conn = (*dummyConn)(nil)
-var _ syscall.Conn = (*dummyConn)(nil)
-
-type dummyConn struct {
-	rawConn *dummyRawConn
-}
-
-func (d *dummyConn) SyscallConn() (syscall.RawConn, error) {
-	return d.rawConn, nil
-}
-
-var errDummy = fmt.Errorf("dummyConn err")
-
-func (d *dummyConn) Read(b []byte) (n int, err error) {
-	return 0, errDummy
-}
-
-func (d *dummyConn) Write(b []byte) (n int, err error) {
-	return 0, errDummy
-}
-
-func (d *dummyConn) Close() error {
-	d.rawConn.Close()
-	return nil
-}
-
-func (d *dummyConn) LocalAddr() net.Addr {
-	return &net.TCPAddr{}
-}
-
-func (d *dummyConn) RemoteAddr() net.Addr {
-	return &net.TCPAddr{}
-}
-
-func (d *dummyConn) SetDeadline(t time.Time) error {
-	return nil
-}
-
-func (d *dummyConn) SetReadDeadline(t time.Time) error {
-	return nil
-}
-
-func (d *dummyConn) SetWriteDeadline(t time.Time) error {
-	return nil
-}
-
-var _ syscall.RawConn = (*dummyRawConn)(nil)
-
-type dummyRawConn struct {
-	closed bool
-	mux    sync.Mutex
-}
-
-func (d *dummyRawConn) Control(f func(fd uintptr)) error {
-	return nil
-}
-
-func (d *dummyRawConn) Read(f func(fd uintptr) (done bool)) error {
-	d.mux.Lock()
-	defer d.mux.Unlock()
-	if d.closed {
-		return fmt.Errorf("dummyRawConn closed")
-	}
-	return nil
-}
-
-func (d *dummyRawConn) Write(f func(fd uintptr) (done bool)) error {
-	return nil
-}
-func (d *dummyRawConn) Close() {
-	d.mux.Lock()
-	d.closed = true
-	d.mux.Unlock()
+	return &net.TCPConn{}, nil
 }

internal/pool/pool.go

@@ -520,7 +520,7 @@ func (p *ConnPool) reapStaleConn() *Conn {
 
 func (p *ConnPool) isStaleConn(cn *Conn) bool {
 	if p.opt.IdleTimeout == 0 && p.opt.MaxConnAge == 0 {
-		return connCheck(cn.netConn) != nil
+		return false
 	}
 
 	now := time.Now()
@@ -531,5 +531,5 @@ func (p *ConnPool) isStaleConn(cn *Conn) bool {
 		return true
 	}
 
-	return connCheck(cn.netConn) != nil
+	return false
 }

internal/pool/pool_test.go

@@ -6,10 +6,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-redis/redis/v8/internal/pool"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-
-	"github.com/go-redis/redis/v8/internal/pool"
 )
 
 var _ = Describe("ConnPool", func() {
@@ -285,8 +285,6 @@ var _ = Describe("conns reaper", func() {
 					cn.SetUsedAt(time.Now().Add(-2 * idleTimeout))
 				case "aged":
 					cn.SetCreatedAt(time.Now().Add(-2 * maxAge))
-				case "conncheck":
-					cn.Close()
 				}
 				conns = append(conns, cn)
 				staleConns = append(staleConns, cn)
@@ -373,7 +371,6 @@ var _ = Describe("conns reaper", func() {
 
 	assert("idle")
 	assert("aged")
-	assert("conncheck")
 })
 
 var _ = Describe("race", func() {

main_test.go

@@ -12,10 +12,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/go-redis/redis/v8"
+
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-
-	"github.com/go-redis/redis/v8"
 )
 
 const (

pool_test.go

@@ -87,9 +87,8 @@ var _ = Describe("pool", func() {
 		cn.SetNetConn(&badConn{})
 		client.Pool().Put(ctx, cn)
 
-		// connCheck will automatically remove damaged connections.
 		err = client.Ping(ctx).Err()
-		Expect(err).NotTo(HaveOccurred())
+		Expect(err).To(MatchError("bad connection"))
 
 		val, err := client.Ping(ctx).Result()
 		Expect(err).NotTo(HaveOccurred())

sentinel_test.go

@@ -191,7 +191,7 @@ var _ = Describe("NewFailoverClusterClient", func() {
 		err = master.Shutdown(ctx).Err()
 		Expect(err).NotTo(HaveOccurred())
 		Eventually(func() error {
-			return master.Ping(ctx).Err()
+			return sentinelMaster.Ping(ctx).Err()
 		}, "15s", "100ms").Should(HaveOccurred())
 
 		// Check that client picked up new master.

tx_test.go

@@ -123,7 +123,7 @@ var _ = Describe("Tx", func() {
 		Expect(num).To(Equal(int64(N)))
 	})
 
-	It("should remove from bad connection", func() {
+	It("should recover from bad connection", func() {
 		// Put bad connection in the pool.
 		cn, err := client.Pool().Get(context.Background())
 		Expect(err).NotTo(HaveOccurred())
@@ -134,14 +134,17 @@ var _ = Describe("Tx", func() {
 		do := func() error {
 			err := client.Watch(ctx, func(tx *redis.Tx) error {
 				_, err := tx.TxPipelined(ctx, func(pipe redis.Pipeliner) error {
-					return pipe.Ping(ctx).Err()
+					pipe.Ping(ctx)
+					return nil
 				})
 				return err
 			})
 			return err
 		}
 
-		// connCheck will automatically remove damaged connections.
+		err = do()
+		Expect(err).To(MatchError("bad connection"))
+
 		err = do()
 		Expect(err).NotTo(HaveOccurred())
 	})