From 6bfe168a3eb7d1e3d5246bb62f9738666b59ad61 Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Mon, 8 Jul 2019 13:31:44 +0800
Subject: [PATCH 1/6] plugin: add disable flag to plugin

---
 executor/show.go |  2 +-
 plugin/plugin.go | 63 +++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/executor/show.go b/executor/show.go
index 33720f277426e..acc93e7fa3e80 100644
--- a/executor/show.go
+++ b/executor/show.go
@@ -1030,7 +1030,7 @@ func (e *ShowExec) fetchShowPlugins() error {
 	tiPlugins := plugin.GetAll()
 	for _, ps := range tiPlugins {
 		for _, p := range ps {
-			e.appendRow([]interface{}{p.Name, p.State.String(), p.Kind.String(), p.Path, p.License, strconv.Itoa(int(p.Version))})
+			e.appendRow([]interface{}{p.Name, p.StateValue(), p.Kind.String(), p.Path, p.License, strconv.Itoa(int(p.Version))})
 		}
 	}
 	return nil
diff --git a/plugin/plugin.go b/plugin/plugin.go
index f0093dfef60bb..0a6952d43d823 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -95,9 +95,32 @@ type Config struct {
 // Plugin presents a TiDB plugin.
 type Plugin struct {
 	*Manifest
-	library *gplugin.Plugin
-	State   State
-	Path    string
+	library  *gplugin.Plugin
+	State    State
+	Path     string
+	Disabled uint32
+}
+
+// StateValue returns readable state string.
+func (p *Plugin) StateValue() string {
+	disabled, err := p.flushWatcher.getPluginDisabledFlag()
+	flag := "enable"
+	if err != nil {
+		logutil.BgLogger().Error("get plugin disable fail", zap.Error(err))
+		flag = "unknown"
+	} else if disabled {
+		flag = "disable"
+	}
+	return p.State.String() + "(" + flag + ")"
+}
+
+// DisableFlag changes the disable flag of plugin.
+func (p *Plugin) DisableFlag(disable bool) {
+	if disable {
+		atomic.StoreUint32(&p.Disabled, 1)
+	} else {
+		atomic.StoreUint32(&p.Disabled, 0)
+	}
 }
 
 func (p *Plugin) validate(ctx context.Context, tiPlugins *plugins) error {
@@ -225,6 +248,7 @@ func Init(ctx context.Context, cfg Config) (err error) {
 					path:     pluginWatchPrefix + tiPlugins.plugins[kind][i].Name,
 					etcd:     cfg.EtcdClient,
 					manifest: tiPlugins.plugins[kind][i].Manifest,
+					plugin:   &tiPlugins.plugins[kind][i],
 				}
 				tiPlugins.plugins[kind][i].flushWatcher = watcher
 				go util.WithRecovery(watcher.watchLoop, nil)
@@ -241,6 +265,7 @@ type flushWatcher struct {
 	path     string
 	etcd     *clientv3.Client
 	manifest *Manifest
+	plugin   *Plugin
 }
 
 func (w *flushWatcher) watchLoop() {
@@ -250,7 +275,16 @@ func (w *flushWatcher) watchLoop() {
 		case <-w.ctx.Done():
 			return
 		case <-watchChan:
-			err := w.manifest.OnFlush(w.ctx, w.manifest)
+			disabled, err := w.getPluginDisabledFlag()
+			if err != nil {
+				logutil.BgLogger().Error("get plugin disabled flag failure", zap.String("plugin", w.manifest.Name), zap.Error(err))
+			}
+			if disabled {
+				atomic.StoreUint32(&w.manifest.flushWatcher.plugin.Disabled, 1)
+			} else {
+				atomic.StoreUint32(&w.manifest.flushWatcher.plugin.Disabled, 0)
+			}
+			err = w.manifest.OnFlush(w.ctx, w.manifest)
 			if err != nil {
 				logutil.BgLogger().Error("notify plugin flush event failed", zap.String("plugin", w.manifest.Name), zap.Error(err))
 			}
@@ -258,6 +292,20 @@ func (w *flushWatcher) watchLoop() {
 	}
 }
 
+func (w *flushWatcher) getPluginDisabledFlag() (bool, error) {
+	if w == nil || w.etcd == nil {
+		return true, errors.New("etcd is need to get plugin enable status")
+	}
+	resp, err := w.etcd.Get(context.Background(), w.manifest.flushWatcher.path)
+	if err != nil {
+		return true, errors.Trace(err)
+	}
+	if len(resp.Kvs) == 0 {
+		return false, nil
+	}
+	return string(resp.Kvs[0].Value) == "1", nil
+}
+
 type loadFn func(plugin *Plugin, dir string, pluginID ID) (manifest func() *Manifest, err error)
 
 var testHook *struct {
@@ -366,6 +414,9 @@ func ForeachPlugin(kind Kind, fn func(plugin *Plugin) error) error {
 		if p.State != Ready {
 			continue
 		}
+		if atomic.LoadUint32(&p.Disabled) == 1 {
+			continue
+		}
 		err := fn(p)
 		if err != nil {
 			return err
@@ -382,7 +433,7 @@ func IsEnable(kind Kind) bool {
 	}
 	for i := range plugins.plugins[kind] {
 		p := &plugins.plugins[kind][i]
-		if p.State == Ready {
+		if p.State == Ready && atomic.LoadUint32(&p.Disabled) != 1 {
 			return true
 		}
 	}
@@ -404,7 +455,7 @@ func NotifyFlush(dom *domain.Domain, pluginName string) error {
 	if p == nil || p.Manifest.flushWatcher == nil || p.State != Ready {
 		return errors.Errorf("plugin %s doesn't exists or unsupported flush or doesn't start with PD", pluginName)
 	}
-	_, err := dom.GetEtcdClient().KV.Put(context.Background(), p.Manifest.flushWatcher.path, "")
+	_, err := dom.GetEtcdClient().KV.Put(context.Background(), p.Manifest.flushWatcher.path, strconv.Itoa(int(p.Disabled)))
 	if err != nil {
 		return err
 	}

From 2776f5464de8d0ced45f120c2d8906b6bed6fdca Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Mon, 8 Jul 2019 15:37:29 +0800
Subject: [PATCH 2/6] plugin: support dynamic enable/disable plugins

---
 executor/admin_plugins.go    | 52 ++++++++++++++++++++++++++++++++++++
 executor/builder.go          |  6 +++++
 go.mod                       |  2 ++
 go.sum                       |  4 +--
 planner/core/common_plans.go | 17 ++++++++++++
 planner/core/planbuilder.go  |  4 +++
 plugin/plugin.go             | 26 +++++++++++++-----
 7 files changed, 103 insertions(+), 8 deletions(-)
 create mode 100644 executor/admin_plugins.go

diff --git a/executor/admin_plugins.go b/executor/admin_plugins.go
new file mode 100644
index 0000000000000..440c1c0852306
--- /dev/null
+++ b/executor/admin_plugins.go
@@ -0,0 +1,52 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package executor
+
+import (
+	"context"
+
+	"github.com/pingcap/tidb/domain"
+	"github.com/pingcap/tidb/planner/core"
+	"github.com/pingcap/tidb/plugin"
+	"github.com/pingcap/tidb/util/chunk"
+)
+
+// AdminPluginsExec indicates AdminPlugins executor.
+type AdminPluginsExec struct {
+	baseExecutor
+	Action  core.AdminPluginsAction
+	Plugins []string
+}
+
+// Next implements the Executor Next interface.
+func (e *AdminPluginsExec) Next(ctx context.Context, _ *chunk.Chunk) error {
+	switch e.Action {
+	case core.Enable:
+		return e.changeDisableFlagAndFlush(false)
+	case core.Disable:
+		return e.changeDisableFlagAndFlush(true)
+	}
+	return nil
+}
+
+func (e *AdminPluginsExec) changeDisableFlagAndFlush(disabled bool) error {
+	dom := domain.GetDomain(e.ctx)
+	for _, pluginName := range e.Plugins {
+		err := plugin.ChangeDisableFlagAndFlush(dom, pluginName, disabled)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/executor/builder.go b/executor/builder.go
index 2bec6ffa8b769..94aa7fd37fdf4 100644
--- a/executor/builder.go
+++ b/executor/builder.go
@@ -108,6 +108,8 @@ func (b *executorBuilder) build(p plannercore.Plan) Executor {
 		return b.buildChecksumTable(v)
 	case *plannercore.ReloadExprPushdownBlacklist:
 		return b.buildReloadExprPushdownBlacklist(v)
+	case *plannercore.AdminPlugins:
+		return b.buildAdminPlugins(v)
 	case *plannercore.DDL:
 		return b.buildDDL(v)
 	case *plannercore.Deallocate:
@@ -467,6 +469,10 @@ func (b *executorBuilder) buildReloadExprPushdownBlacklist(v *plannercore.Reload
 	return &ReloadExprPushdownBlacklistExec{baseExecutor{ctx: b.ctx}}
 }
 
+func (b *executorBuilder) buildAdminPlugins(v *plannercore.AdminPlugins) Executor {
+	return &AdminPluginsExec{baseExecutor: baseExecutor{ctx: b.ctx}, Action: v.Action, Plugins: v.Plugins}
+}
+
 func (b *executorBuilder) buildDeallocate(v *plannercore.Deallocate) Executor {
 	base := newBaseExecutor(b.ctx, nil, v.ExplainID())
 	base.initCap = chunk.ZeroCapacity
diff --git a/go.mod b/go.mod
index 64917a182d71d..ab4496dab2a6b 100644
--- a/go.mod
+++ b/go.mod
@@ -76,3 +76,5 @@ require (
 	sourcegraph.com/sourcegraph/appdash v0.0.0-20180531100431-4c381bd170b4
 	sourcegraph.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67
 )
+
+replace github.com/pingcap/parser => github.com/lysu/parser v0.0.0-20190708064737-237a492d418c
diff --git a/go.sum b/go.sum
index 675d987a4cd1b..861fd1d0e6f5d 100644
--- a/go.sum
+++ b/go.sum
@@ -115,6 +115,8 @@ github.com/kr/pty v1.0.0/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/lysu/parser v0.0.0-20190708064737-237a492d418c h1:JluV8M16PnT+9L2f6gZ3gZuOeLlBjywzeXqyfd5TDRw=
+github.com/lysu/parser v0.0.0-20190708064737-237a492d418c/go.mod h1:CJk6LPzPxAcwHIcTugQaKxzvTR10NDJ5ln8XR7uYTJk=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
@@ -164,8 +166,6 @@ github.com/pingcap/kvproto v0.0.0-20190703131923-d9830856b531/go.mod h1:QMdbTAXC
 github.com/pingcap/log v0.0.0-20190214045112-b37da76f67a7/go.mod h1:xsfkWVaFVV5B8e1K9seWfyJWFrIhbtUTAD8NV1Pq3+w=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596 h1:t2OQTpPJnrPDGlvA+3FwJptMTt6MEPdzK1Wt99oaefQ=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596/go.mod h1:WpHUKhNZ18v116SvGrmjkA9CBhYmuUTKL+p8JC9ANEw=
-github.com/pingcap/parser v0.0.0-20190701123046-5768e68c1e65 h1:yVYWPPQIq3csxtHvzx2fVO4HrQQOhxYDdYDQ4euSCIc=
-github.com/pingcap/parser v0.0.0-20190701123046-5768e68c1e65/go.mod h1:1FNvfp9+J0wvc4kl8eGNh7Rqrxveg15jJoWo/a0uHwA=
 github.com/pingcap/pd v0.0.0-20190617100349-293d4b5189bf h1:vmlN6DpZI5LtHd8r9YRAsyCeTU2pxRq+WlWn5CZ+ax4=
 github.com/pingcap/pd v0.0.0-20190617100349-293d4b5189bf/go.mod h1:3DlDlFT7EF64A1bmb/tulZb6wbPSagm5G4p1AlhaEDs=
 github.com/pingcap/tidb-tools v2.1.3-0.20190321065848-1e8b48f5c168+incompatible h1:MkWCxgZpJBgY2f4HtwWMMFzSBb3+JPzeJgF3VrXE/bU=
diff --git a/planner/core/common_plans.go b/planner/core/common_plans.go
index a98ed76d66d30..55a63915f9e3b 100644
--- a/planner/core/common_plans.go
+++ b/planner/core/common_plans.go
@@ -133,6 +133,23 @@ type ReloadExprPushdownBlacklist struct {
 	baseSchemaProducer
 }
 
+// AdminPluginsAction indicate action will be taken on plugins.
+type AdminPluginsAction int
+
+const (
+	// Enable indicates enable plugins.
+	Enable AdminPluginsAction = iota + 1
+	// Disable indicates disable plugins.
+	Disable
+)
+
+// AdminPlugins administrates tidb plugins.
+type AdminPlugins struct {
+	baseSchemaProducer
+	Action  AdminPluginsAction
+	Plugins []string
+}
+
 // Change represents a change plan.
 type Change struct {
 	baseSchemaProducer
diff --git a/planner/core/planbuilder.go b/planner/core/planbuilder.go
index 1f2b2afff5942..5a4688b8fe0e6 100644
--- a/planner/core/planbuilder.go
+++ b/planner/core/planbuilder.go
@@ -673,6 +673,10 @@ func (b *PlanBuilder) buildAdmin(as *ast.AdminStmt) (Plan, error) {
 		ret = p
 	case ast.AdminReloadExprPushdownBlacklist:
 		return &ReloadExprPushdownBlacklist{}, nil
+	case ast.AdminPluginEnable:
+		return &AdminPlugins{Action: Enable, Plugins: as.Plugins}, nil
+	case ast.AdminPluginDisable:
+		return &AdminPlugins{Action: Disable, Plugins: as.Plugins}, nil
 	default:
 		return nil, ErrUnsupportedType.GenWithStack("Unsupported ast.AdminStmt(%T) for buildAdmin", as)
 	}
diff --git a/plugin/plugin.go b/plugin/plugin.go
index 0a6952d43d823..622cbf61bd263 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -103,15 +103,11 @@ type Plugin struct {
 
 // StateValue returns readable state string.
 func (p *Plugin) StateValue() string {
-	disabled, err := p.flushWatcher.getPluginDisabledFlag()
 	flag := "enable"
-	if err != nil {
-		logutil.BgLogger().Error("get plugin disable fail", zap.Error(err))
-		flag = "unknown"
-	} else if disabled {
+	if atomic.LoadUint32(&p.Disabled) == 1 {
 		flag = "disable"
 	}
-	return p.State.String() + "(" + flag + ")"
+	return p.State.String() + "-" + flag
 }
 
 // DisableFlag changes the disable flag of plugin.
@@ -462,6 +458,24 @@ func NotifyFlush(dom *domain.Domain, pluginName string) error {
 	return nil
 }
 
+// ChangeDisableFlagAndFlush changes plugin disable flag and notify other nodes to do same change..
+func ChangeDisableFlagAndFlush(dom *domain.Domain, pluginName string, disable bool) error {
+	p := getByName(pluginName)
+	disableInt := uint32(0)
+	if disable {
+		disableInt = 1
+	}
+	atomic.StoreUint32(&p.Disabled, disableInt)
+	if p == nil || p.Manifest.flushWatcher == nil || p.State != Ready {
+		return errors.Errorf("plugin %s doesn't exists or unsupported flush or doesn't start with PD", pluginName)
+	}
+	_, err := dom.GetEtcdClient().KV.Put(context.Background(), p.Manifest.flushWatcher.path, strconv.Itoa(int(disableInt)))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func getByName(pluginName string) *Plugin {
 	for _, plugins := range GetAll() {
 		for _, p := range plugins {

From 796b8351130cbd8e6a02340c2ef5a476be2532b4 Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Mon, 8 Jul 2019 20:53:02 +0800
Subject: [PATCH 3/6] make plugin un-dep parser

---
 plugin/audit.go  | 3 +--
 server/conn.go   | 2 +-
 server/server.go | 7 +++----
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/plugin/audit.go b/plugin/audit.go
index 8ad556495ac62..603b7e0f8982f 100644
--- a/plugin/audit.go
+++ b/plugin/audit.go
@@ -16,7 +16,6 @@ package plugin
 import (
 	"context"
 
-	"github.com/pingcap/parser/auth"
 	"github.com/pingcap/tidb/sessionctx/variable"
 )
 
@@ -77,7 +76,7 @@ type AuditManifest struct {
 	Manifest
 	// OnConnectionEvent will be called when TiDB receive or disconnect from client.
 	// return error will ignore and close current connection.
-	OnConnectionEvent func(ctx context.Context, identity *auth.UserIdentity, event ConnectionEvent, info *variable.ConnectionInfo) error
+	OnConnectionEvent func(ctx context.Context, event ConnectionEvent, info *variable.ConnectionInfo) error
 	// OnGeneralEvent will be called during TiDB execution.
 	OnGeneralEvent func(ctx context.Context, sctx *variable.SessionVars, event GeneralEvent, cmd string)
 	// OnGlobalVariableEvent will be called when Change GlobalVariable.
diff --git a/server/conn.go b/server/conn.go
index d22f6f5c91e10..8fb03b7cd1811 100644
--- a/server/conn.go
+++ b/server/conn.go
@@ -1457,7 +1457,7 @@ func (cc *clientConn) handleChangeUser(ctx context.Context, data []byte) error {
 		authPlugin := plugin.DeclareAuditManifest(p.Manifest)
 		if authPlugin.OnConnectionEvent != nil {
 			connInfo := cc.ctx.GetSessionVars().ConnectionInfo
-			err = authPlugin.OnConnectionEvent(context.Background(), &auth.UserIdentity{Hostname: connInfo.Host}, plugin.ChangeUser, connInfo)
+			err = authPlugin.OnConnectionEvent(context.Background(), plugin.ChangeUser, connInfo)
 			if err != nil {
 				return err
 			}
diff --git a/server/server.go b/server/server.go
index 12a3e303cc841..6d1945fb6b22a 100644
--- a/server/server.go
+++ b/server/server.go
@@ -49,7 +49,6 @@ import (
 
 	"github.com/blacktear23/go-proxyprotocol"
 	"github.com/pingcap/errors"
-	"github.com/pingcap/parser/auth"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
 	"github.com/pingcap/tidb/config"
@@ -342,7 +341,7 @@ func (s *Server) Run() error {
 					terror.Log(clientConn.Close())
 					return errors.Trace(err)
 				}
-				err = authPlugin.OnConnectionEvent(context.Background(), &auth.UserIdentity{Hostname: host}, plugin.PreAuth, nil)
+				err = authPlugin.OnConnectionEvent(context.Background(), plugin.PreAuth, &variable.ConnectionInfo{Host: host})
 				if err != nil {
 					logutil.BgLogger().Info("do connection event failed", zap.Error(err))
 					terror.Log(clientConn.Close())
@@ -429,7 +428,7 @@ func (s *Server) onConn(conn *clientConn) {
 		authPlugin := plugin.DeclareAuditManifest(p.Manifest)
 		if authPlugin.OnConnectionEvent != nil {
 			sessionVars := conn.ctx.GetSessionVars()
-			return authPlugin.OnConnectionEvent(context.Background(), sessionVars.User, plugin.Connected, sessionVars.ConnectionInfo)
+			return authPlugin.OnConnectionEvent(context.Background(), plugin.Connected, sessionVars.ConnectionInfo)
 		}
 		return nil
 	})
@@ -445,7 +444,7 @@ func (s *Server) onConn(conn *clientConn) {
 		if authPlugin.OnConnectionEvent != nil {
 			sessionVars := conn.ctx.GetSessionVars()
 			sessionVars.ConnectionInfo.Duration = float64(time.Since(connectedTime)) / float64(time.Millisecond)
-			err := authPlugin.OnConnectionEvent(context.Background(), sessionVars.User, plugin.Disconnect, sessionVars.ConnectionInfo)
+			err := authPlugin.OnConnectionEvent(context.Background(), plugin.Disconnect, sessionVars.ConnectionInfo)
 			if err != nil {
 				logutil.BgLogger().Warn("do connection event failed", zap.String("plugin", authPlugin.Name), zap.Error(err))
 			}

From 8745f93aa0b23ea59ad2826bd8cc3e034590d4b1 Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Mon, 8 Jul 2019 20:53:20 +0800
Subject: [PATCH 4/6] update go.mod version

---
 go.mod | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/go.mod b/go.mod
index ab4496dab2a6b..39205b92d67a3 100644
--- a/go.mod
+++ b/go.mod
@@ -41,7 +41,7 @@ require (
 	github.com/pingcap/goleveldb v0.0.0-20171020122428-b9ff6c35079e
 	github.com/pingcap/kvproto v0.0.0-20190703131923-d9830856b531
 	github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596
-	github.com/pingcap/parser v0.0.0-20190701123046-5768e68c1e65
+	github.com/pingcap/parser v0.0.0-20190708123555-29973f7a22eb
 	github.com/pingcap/pd v0.0.0-20190617100349-293d4b5189bf
 	github.com/pingcap/tidb-tools v2.1.3-0.20190321065848-1e8b48f5c168+incompatible
 	github.com/pingcap/tipb v0.0.0-20190428032612-535e1abaa330

From 2af5cf17d79130159db3df798528c05c85f48892 Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Mon, 8 Jul 2019 21:11:33 +0800
Subject: [PATCH 5/6] go mod tidy

---
 go.mod | 2 --
 go.sum | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/go.mod b/go.mod
index 39205b92d67a3..91aa99b647cee 100644
--- a/go.mod
+++ b/go.mod
@@ -76,5 +76,3 @@ require (
 	sourcegraph.com/sourcegraph/appdash v0.0.0-20180531100431-4c381bd170b4
 	sourcegraph.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67
 )
-
-replace github.com/pingcap/parser => github.com/lysu/parser v0.0.0-20190708064737-237a492d418c
diff --git a/go.sum b/go.sum
index 861fd1d0e6f5d..7757f3e24a50f 100644
--- a/go.sum
+++ b/go.sum
@@ -115,8 +115,6 @@ github.com/kr/pty v1.0.0/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/lysu/parser v0.0.0-20190708064737-237a492d418c h1:JluV8M16PnT+9L2f6gZ3gZuOeLlBjywzeXqyfd5TDRw=
-github.com/lysu/parser v0.0.0-20190708064737-237a492d418c/go.mod h1:CJk6LPzPxAcwHIcTugQaKxzvTR10NDJ5ln8XR7uYTJk=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
@@ -166,6 +164,8 @@ github.com/pingcap/kvproto v0.0.0-20190703131923-d9830856b531/go.mod h1:QMdbTAXC
 github.com/pingcap/log v0.0.0-20190214045112-b37da76f67a7/go.mod h1:xsfkWVaFVV5B8e1K9seWfyJWFrIhbtUTAD8NV1Pq3+w=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596 h1:t2OQTpPJnrPDGlvA+3FwJptMTt6MEPdzK1Wt99oaefQ=
 github.com/pingcap/log v0.0.0-20190307075452-bd41d9273596/go.mod h1:WpHUKhNZ18v116SvGrmjkA9CBhYmuUTKL+p8JC9ANEw=
+github.com/pingcap/parser v0.0.0-20190708123555-29973f7a22eb h1:jfhJo/D1bWMF+zVaVdmixWG5EnxbnFt99GS2pdxuToo=
+github.com/pingcap/parser v0.0.0-20190708123555-29973f7a22eb/go.mod h1:1FNvfp9+J0wvc4kl8eGNh7Rqrxveg15jJoWo/a0uHwA=
 github.com/pingcap/pd v0.0.0-20190617100349-293d4b5189bf h1:vmlN6DpZI5LtHd8r9YRAsyCeTU2pxRq+WlWn5CZ+ax4=
 github.com/pingcap/pd v0.0.0-20190617100349-293d4b5189bf/go.mod h1:3DlDlFT7EF64A1bmb/tulZb6wbPSagm5G4p1AlhaEDs=
 github.com/pingcap/tidb-tools v2.1.3-0.20190321065848-1e8b48f5c168+incompatible h1:MkWCxgZpJBgY2f4HtwWMMFzSBb3+JPzeJgF3VrXE/bU=

From 304f0d6421aa687c0e551c746628ce4bd7ae259d Mon Sep 17 00:00:00 2001
From: lysu <sulifx@gmail.com>
Date: Tue, 9 Jul 2019 10:58:57 +0800
Subject: [PATCH 6/6] address comment

---
 plugin/plugin.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/plugin/plugin.go b/plugin/plugin.go
index 622cbf61bd263..06c9fe520159e 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -458,17 +458,17 @@ func NotifyFlush(dom *domain.Domain, pluginName string) error {
 	return nil
 }
 
-// ChangeDisableFlagAndFlush changes plugin disable flag and notify other nodes to do same change..
+// ChangeDisableFlagAndFlush changes plugin disable flag and notify other nodes to do same change.
 func ChangeDisableFlagAndFlush(dom *domain.Domain, pluginName string, disable bool) error {
 	p := getByName(pluginName)
+	if p == nil || p.Manifest.flushWatcher == nil || p.State != Ready {
+		return errors.Errorf("plugin %s doesn't exists or unsupported flush or doesn't start with PD", pluginName)
+	}
 	disableInt := uint32(0)
 	if disable {
 		disableInt = 1
 	}
 	atomic.StoreUint32(&p.Disabled, disableInt)
-	if p == nil || p.Manifest.flushWatcher == nil || p.State != Ready {
-		return errors.Errorf("plugin %s doesn't exists or unsupported flush or doesn't start with PD", pluginName)
-	}
 	_, err := dom.GetEtcdClient().KV.Put(context.Background(), p.Manifest.flushWatcher.path, strconv.Itoa(int(disableInt)))
 	if err != nil {
 		return err