*: integrate plugin framework with TiDB (#9006)

Makefile

@@ -12,7 +12,7 @@ path_to_add := $(addsuffix /bin,$(subst :,/bin:,$(GOPATH)))
 export PATH := $(path_to_add):$(PATH)
 
 GO        := GO111MODULE=on go
-GOBUILD   := CGO_ENABLED=0 $(GO) build $(BUILD_FLAG)
+GOBUILD   := CGO_ENABLED=1 $(GO) build $(BUILD_FLAG)
 GOTEST    := CGO_ENABLED=1 $(GO) test -p 3
 OVERALLS  := CGO_ENABLED=1 overalls
 GOVERALLS := goveralls

config/config.go

@@ -74,6 +74,7 @@ type Config struct {
 	Binlog              Binlog            `toml:"binlog" json:"binlog"`
 	CompatibleKillQuery bool              `toml:"compatible-kill-query" json:"compatible-kill-query"`
 	CheckMb4ValueInUtf8 bool              `toml:"check-mb4-value-in-utf8" json:"check-mb4-value-in-utf8"`
+	Plugin              Plugin            `toml:"plugin" json:"plugin"`
 }
 
 // Log is the log section of config.
@@ -240,6 +241,12 @@ type TiKVClient struct {
 	CommitTimeout string `toml:"commit-timeout" json:"commit-timeout"`
 }
 
+// Plugin is the config for plugin
+type Plugin struct {
+	Dir  string `toml:"dir" json:"dir"`
+	Load string `toml:"load" json:"load"`
+}
+
 // Binlog is the config for binlog.
 type Binlog struct {
 	Enable       bool   `toml:"enable" json:"enable"`

executor/show.go

@@ -16,6 +16,7 @@ package executor
 import (
 	"bytes"
 	"fmt"
+	"github.com/pingcap/tidb/plugin"
 	"sort"
 	"strconv"
 	"strings"
@@ -807,6 +808,12 @@ func (e *ShowExec) fetchShowProcedureStatus() error {
 }
 
 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))})
+		}
+	}
 	return nil
 }
 

planner/core/planbuilder.go

@@ -1631,9 +1631,9 @@ func buildShowSchema(s *ast.ShowStmt) (schema *expression.Schema) {
 			mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeLonglong, mysql.TypeLonglong,
 			mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar}
 	case ast.ShowPlugins:
-		names = []string{"Name", "Status", "Type", "Library", "License"}
+		names = []string{"Name", "Status", "Type", "Library", "License", "Version"}
 		ftypes = []byte{
-			mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar,
+			mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar, mysql.TypeVarchar,
 		}
 	case ast.ShowProcessList:
 		names = []string{"Id", "User", "Host", "db", "Command", "Time", "State", "Info", "Mem"}

session/session.go

@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
+	"github.com/pingcap/tidb/plugin"
 	"net"
 	"strings"
 	"sync"
@@ -1168,6 +1169,21 @@ func loadSystemTZ(se *session) (string, error) {
 
 // BootstrapSession runs the first time when the TiDB server start.
 func BootstrapSession(store kv.Storage) (*domain.Domain, error) {
+	cfg := config.GetGlobalConfig()
+	if len(cfg.Plugin.Load) > 0 {
+		err := plugin.Init(context.Background(), plugin.Config{
+			Plugins:        strings.Split(cfg.Plugin.Load, ","),
+			PluginDir:      cfg.Plugin.Dir,
+			GlobalSysVar:   &variable.SysVars,
+			PluginVarNames: &variable.PluginVarNames,
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	initLoadCommonGlobalVarsSQL()
+
 	ver := getStoreBootstrapVersion(store)
 	if ver == notBootstrapped {
 		runInBootstrapSession(store, bootstrap)
@@ -1338,33 +1354,51 @@ func finishBootstrap(store kv.Storage) {
 }
 
 const quoteCommaQuote = "', '"
-const loadCommonGlobalVarsSQL = "select HIGH_PRIORITY * from mysql.global_variables where variable_name in ('" +
-	variable.AutocommitVar + quoteCommaQuote +
-	variable.SQLModeVar + quoteCommaQuote +
-	variable.MaxAllowedPacket + quoteCommaQuote +
-	variable.TimeZone + quoteCommaQuote +
-	variable.BlockEncryptionMode + quoteCommaQuote +
+
+var builtinGlobalVariable = []string{
+	variable.AutocommitVar,
+	variable.SQLModeVar,
+	variable.MaxAllowedPacket,
+	variable.TimeZone,
+	variable.BlockEncryptionMode,
 	/* TiDB specific global variables: */
-	variable.TiDBSkipUTF8Check + quoteCommaQuote +
-	variable.TiDBIndexJoinBatchSize + quoteCommaQuote +
-	variable.TiDBIndexLookupSize + quoteCommaQuote +
-	variable.TiDBIndexLookupConcurrency + quoteCommaQuote +
-	variable.TiDBIndexLookupJoinConcurrency + quoteCommaQuote +
-	variable.TiDBIndexSerialScanConcurrency + quoteCommaQuote +
-	variable.TiDBHashJoinConcurrency + quoteCommaQuote +
-	variable.TiDBProjectionConcurrency + quoteCommaQuote +
-	variable.TiDBHashAggPartialConcurrency + quoteCommaQuote +
-	variable.TiDBHashAggFinalConcurrency + quoteCommaQuote +
-	variable.TiDBBackoffLockFast + quoteCommaQuote +
-	variable.TiDBConstraintCheckInPlace + quoteCommaQuote +
-	variable.TiDBOptInSubqUnFolding + quoteCommaQuote +
-	variable.TiDBDistSQLScanConcurrency + quoteCommaQuote +
-	variable.TiDBMaxChunkSize + quoteCommaQuote +
-	variable.TiDBRetryLimit + quoteCommaQuote +
-	variable.TiDBDisableTxnAutoRetry + "')"
+	variable.TiDBSkipUTF8Check,
+	variable.TiDBIndexJoinBatchSize,
+	variable.TiDBIndexLookupSize,
+	variable.TiDBIndexLookupConcurrency,
+	variable.TiDBIndexLookupJoinConcurrency,
+	variable.TiDBIndexSerialScanConcurrency,
+	variable.TiDBHashJoinConcurrency,
+	variable.TiDBProjectionConcurrency,
+	variable.TiDBHashAggPartialConcurrency,
+	variable.TiDBHashAggFinalConcurrency,
+	variable.TiDBBackoffLockFast,
+	variable.TiDBConstraintCheckInPlace,
+	variable.TiDBOptInSubqUnFolding,
+	variable.TiDBDistSQLScanConcurrency,
+	variable.TiDBMaxChunkSize,
+	variable.TiDBRetryLimit,
+	variable.TiDBDisableTxnAutoRetry,
+}
+
+var (
+	loadCommonGlobalVarsSQLOnce sync.Once
+	loadCommonGlobalVarsSQL     string
+)
+
+func initLoadCommonGlobalVarsSQL() {
+	loadCommonGlobalVarsSQLOnce.Do(func() {
+		vars := append(make([]string, 0, len(builtinGlobalVariable)+len(variable.PluginVarNames)), builtinGlobalVariable...)
+		if len(variable.PluginVarNames) > 0 {
+			vars = append(vars, variable.PluginVarNames...)
+		}
+		loadCommonGlobalVarsSQL = "select HIGH_PRIORITY * from mysql.global_variables where variable_name in ('" + strings.Join(vars, quoteCommaQuote) + "')"
+	})
+}
 
 // loadCommonGlobalVariablesIfNeeded loads and applies commonly used global variables for the session.
 func (s *session) loadCommonGlobalVariablesIfNeeded() error {
+	initLoadCommonGlobalVarsSQL()
 	vars := s.sessionVars
 	if vars.CommonGlobalLoaded {
 		return nil

sessionctx/variable/sysvar.go

@@ -57,6 +57,9 @@ func GetSysVar(name string) *SysVar {
 	return SysVars[name]
 }
 
+// PluginVarNames is global plugin var names set.
+var PluginVarNames []string
+
 // Variable error codes.
 const (
 	CodeUnknownStatusVar    terror.ErrCode = 1
@@ -312,7 +315,8 @@ var defaultSysVars = []*SysVar{
 	{ScopeGlobal | ScopeSession, "sort_buffer_size", "262144"},
 	{ScopeGlobal, "innodb_flush_neighbors", "1"},
 	{ScopeNone, "innodb_use_sys_malloc", "ON"},
-	{ScopeNone, "plugin_dir", "/usr/local/mysql/lib/plugin/"},
+	{ScopeSession, PluginLoad, ""},
+	{ScopeNone, PluginDir, "/data/deploy/plugin"},
 	{ScopeNone, "performance_schema_max_socket_classes", "10"},
 	{ScopeNone, "performance_schema_max_stage_classes", "150"},
 	{ScopeGlobal, "innodb_purge_batch_size", "300"},
@@ -777,6 +781,10 @@ const (
 	SyncBinlog = "sync_binlog"
 	// BlockEncryptionMode is the name for 'block_encryption_mode' system variable.
 	BlockEncryptionMode = "block_encryption_mode"
+	// PluginDir is the name of 'plugin_dir' system variable.
+	PluginDir = "plugin_dir"
+	// PluginLoad is the name of 'plugin_load' system variable.
+	PluginLoad = "plugin_load"
 )
 
 // GlobalVarAccessor is the interface for accessing global scope system and status variables.

sessionctx/variable/varsutil.go

@@ -106,6 +106,10 @@ func GetSessionOnlySysVars(s *SessionVars, key string) (string, bool, error) {
 		return strconv.FormatUint(atomic.LoadUint64(&config.GetGlobalConfig().Log.SlowThreshold), 10), true, nil
 	case TiDBQueryLogMaxLen:
 		return strconv.FormatUint(atomic.LoadUint64(&config.GetGlobalConfig().Log.QueryLogMaxLen), 10), true, nil
+	case PluginDir:
+		return config.GetGlobalConfig().Plugin.Dir, true, nil
+	case PluginLoad:
+		return config.GetGlobalConfig().Plugin.Load, true, nil
 	case TiDBCheckMb4ValueInUtf8:
 		return BoolToIntStr(config.GetGlobalConfig().CheckMb4ValueInUtf8), true, nil
 	}

tidb-server/main.go

@@ -74,6 +74,8 @@ const (
 	nmMetricsInterval  = "metrics-interval"
 	nmDdlLease         = "lease"
 	nmTokenLimit       = "token-limit"
+	nmPluginDir        = "plugin-dir"
+	nmPluginLoad       = "plugin-load"
 
 	nmProxyProtocolNetworks      = "proxy-protocol-networks"
 	nmProxyProtocolHeaderTimeout = "proxy-protocol-header-timeout"
@@ -94,6 +96,8 @@ var (
 	runDDL           = flagBoolean(nmRunDDL, true, "run ddl worker on this tidb-server")
 	ddlLease         = flag.String(nmDdlLease, "45s", "schema lease duration, very dangerous to change only if you know what you do")
 	tokenLimit       = flag.Int(nmTokenLimit, 1000, "the limit of concurrent executed sessions")
+	pluginDir        = flag.String(nmPluginDir, "/data/deploy/plugin", "the folder that hold plugin")
+	pluginLoad       = flag.String(nmPluginLoad, "", "wait load plugin name(seperated by comma)")
 
 	// Log
 	logLevel     = flag.String(nmLogLevel, "info", "log level: info, debug, warn, error, fatal")
@@ -315,6 +319,12 @@ func overrideConfig() {
 	if actualFlags[nmTokenLimit] {
 		cfg.TokenLimit = uint(*tokenLimit)
 	}
+	if actualFlags[nmPluginLoad] {
+		cfg.Plugin.Load = *pluginLoad
+	}
+	if actualFlags[nmPluginDir] {
+		cfg.Plugin.Dir = *pluginDir
+	}
 
 	// Log
 	if actualFlags[nmLogLevel] {