server: add grpc server config for a suitable behavior

config/config.go

@@ -445,6 +445,18 @@ type Status struct {
 	MetricsInterval uint   `toml:"metrics-interval" json:"metrics-interval"`
 	ReportStatus    bool   `toml:"report-status" json:"report-status"`
 	RecordQPSbyDB   bool   `toml:"record-db-qps" json:"record-db-qps"`
+	// After a duration of this time in seconds if the server doesn't see any activity it pings
+	// the client to see if the transport is still alive.
+	GRPCKeepAliveTime uint `toml:"grpc-keepalive-time" json:"grpc-keepalive-time"`
+	// After having pinged for keepalive check, the server waits for a duration of timeout in seconds
+	// and if no activity is seen even after that the connection is closed.
+	GRPCKeepAliveTimeout uint `toml:"grpc-keepalive-timeout" json:"grpc-keepalive-timeout"`
+	// The number of max concurrent streams/requests on a client connection.
+	GRPCConcurrentStreams uint `toml:"grpc-concurrent-streams" json:"grpc-concurrent-streams"`
+	// Sets window size for stream. The default value is 2MB.
+	GRPCInitialWindowSize int `toml:"grpc-initial-window-size" json:"grpc-initial-window-size"`
+	// Set maximum message length in bytes that gRPC can send. `-1` means unlimited. The default value is 10MB.
+	GRPCMaxSendMsgSize int `toml:"grpc-max-send-msg-size" json:"grpc-max-send-msg-size"`
 }
 
 // Performance is the performance section of the config.
@@ -658,11 +670,16 @@ var defaultConf = Config{
 		EnableSlowLog:       *NewAtomicBool(logutil.DefaultTiDBEnableSlowLog),
 	},
 	Status: Status{
-		ReportStatus:    true,
-		StatusHost:      DefStatusHost,
-		StatusPort:      DefStatusPort,
-		MetricsInterval: 15,
-		RecordQPSbyDB:   false,
+		ReportStatus:          true,
+		StatusHost:            DefStatusHost,
+		StatusPort:            DefStatusPort,
+		MetricsInterval:       15,
+		RecordQPSbyDB:         false,
+		GRPCKeepAliveTime:     10,
+		GRPCKeepAliveTimeout:  3,
+		GRPCConcurrentStreams: 1024,
+		GRPCInitialWindowSize: 2 * 1024 * 1024,
+		GRPCMaxSendMsgSize:    10 * 1024 * 1024,
 	},
 	Performance: Performance{
 		MaxMemory:             0,

config/config_test.go

@@ -261,6 +261,12 @@ deadlock-history-capacity = 123
 deadlock-history-collect-retryable = true
 [top-sql]
 receiver-address = "127.0.0.1:10100"
+[status]
+grpc-keepalive-time = 20
+grpc-keepalive-timeout = 10
+grpc-concurrent-streams = 2048
+grpc-initial-window-size = 10240
+grpc-max-send-msg-size = 40960
 `)
 
 	require.NoError(t, err)
@@ -318,6 +324,11 @@ receiver-address = "127.0.0.1:10100"
 	require.False(t, conf.Experimental.EnableNewCharset)
 	require.Equal(t, "127.0.0.1:10100", conf.TopSQL.ReceiverAddress)
 	require.True(t, conf.Experimental.AllowsExpressionIndex)
+	require.Equal(t, uint(20), conf.Status.GRPCKeepAliveTime)
+	require.Equal(t, uint(10), conf.Status.GRPCKeepAliveTimeout)
+	require.Equal(t, uint(2048), conf.Status.GRPCConcurrentStreams)
+	require.Equal(t, 10240, conf.Status.GRPCInitialWindowSize)
+	require.Equal(t, 40960, conf.Status.GRPCMaxSendMsgSize)
 
 	err = f.Truncate(0)
 	require.NoError(t, err)

server/rpc_server.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"time"
 
 	"github.com/pingcap/kvproto/pkg/coprocessor"
 	"github.com/pingcap/kvproto/pkg/diagnosticspb"
@@ -34,6 +35,7 @@ import (
 	"github.com/pingcap/tidb/util/memory"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/peer"
 )
 
@@ -46,7 +48,15 @@ func NewRPCServer(config *config.Config, dom *domain.Domain, sm util.SessionMana
 		}
 	}()
 
-	s := grpc.NewServer()
+	s := grpc.NewServer(
+		grpc.KeepaliveParams(keepalive.ServerParameters{
+			Time:    time.Duration(config.Status.GRPCKeepAliveTime) * time.Second,
+			Timeout: time.Duration(config.Status.GRPCKeepAliveTimeout) * time.Second,
+		}),
+		grpc.MaxConcurrentStreams(uint32(config.Status.GRPCConcurrentStreams)),
+		grpc.InitialWindowSize(int32(config.Status.GRPCInitialWindowSize)),
+		grpc.MaxSendMsgSize(config.Status.GRPCMaxSendMsgSize),
+	)
 	rpcSrv := &rpcServer{
 		DiagnosticsServer: sysutil.NewDiagnosticsServer(config.Log.File.Filename),
 		dom:               dom,