session: support system variable interactive_timeout (#8487)

server/server.go

@@ -72,7 +72,7 @@ const defaultCapability = mysql.ClientLongPassword | mysql.ClientLongFlag |
 	mysql.ClientConnectWithDB | mysql.ClientProtocol41 |
 	mysql.ClientTransactions | mysql.ClientSecureConnection | mysql.ClientFoundRows |
 	mysql.ClientMultiStatements | mysql.ClientMultiResults | mysql.ClientLocalFiles |
-	mysql.ClientConnectAtts | mysql.ClientPluginAuth
+	mysql.ClientConnectAtts | mysql.ClientPluginAuth | mysql.ClientInteractive
 
 // Server is the MySQL protocol server
 type Server struct {

session/session.go

@@ -1389,6 +1389,7 @@ const loadCommonGlobalVarsSQL = "select HIGH_PRIORITY * from mysql.global_variab
 	variable.TimeZone + quoteCommaQuote +
 	variable.BlockEncryptionMode + quoteCommaQuote +
 	variable.WaitTimeout + quoteCommaQuote +
+	variable.InteractiveTimeout + quoteCommaQuote +
 	variable.MaxPreparedStmtCount + quoteCommaQuote +
 	/* TiDB specific global variables: */
 	variable.TiDBSkipUTF8Check + quoteCommaQuote +
@@ -1451,6 +1452,14 @@ func (s *session) loadCommonGlobalVariablesIfNeeded() error {
 			}
 		}
 	}
+
+	// when client set Capability Flags CLIENT_INTERACTIVE, init wait_timeout with interactive_timeout
+	if vars.ClientCapability&mysql.ClientInteractive > 0 {
+		if varVal, ok := vars.GetSystemVar(variable.InteractiveTimeout); ok {
+			vars.SetSystemVar(variable.WaitTimeout, varVal)
+		}
+	}
+
 	vars.CommonGlobalLoaded = true
 	return nil
 }

sessionctx/variable/sysvar.go

@@ -254,7 +254,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeGlobal | ScopeSession, BlockEncryptionMode, "aes-128-ecb"},
 	{ScopeGlobal | ScopeSession, "max_length_for_sort_data", "1024"},
 	{ScopeNone, "character_set_system", "utf8"},
-	{ScopeGlobal | ScopeSession, "interactive_timeout", "28800"},
+	{ScopeGlobal | ScopeSession, InteractiveTimeout, "28800"},
 	{ScopeGlobal, "innodb_optimize_fulltext_only", "OFF"},
 	{ScopeNone, "character_sets_dir", "/usr/local/mysql-5.6.25-osx10.8-x86_64/share/charsets/"},
 	{ScopeGlobal | ScopeSession, "query_cache_type", "OFF"},