Merge pull request #574 from giantwu/fix-grpc-client-banlance

Fix grpc client banlance

client/dtmgrpc/dtmgimp/grpc_clients.go

@@ -8,6 +8,7 @@ package dtmgimp
 
 import (
 	"fmt"
+	"os"
 	"sync"
 
 	"github.com/dtm-labs/dtm/client/dtmcli/dtmimp"
@@ -39,6 +40,9 @@ var normalClients, rawClients sync.Map
 // ClientInterceptors declares grpc.UnaryClientInterceptors slice
 var ClientInterceptors = []grpc.UnaryClientInterceptor{}
 
+// GrpcServiceConfigGetter is a function to get gRPC service config, can be set by server config
+var GrpcServiceConfigGetter func() string
+
 // MustGetDtmClient 1
 func MustGetDtmClient(grpcServer string) dtmgpb.DtmClient {
 	return dtmgpb.NewDtmClient(MustGetGrpcConn(grpcServer, false))
@@ -61,7 +65,12 @@ func GetGrpcConn(grpcServer string, isRaw bool) (conn *grpc.ClientConn, rerr err
 		interceptors := append(ClientInterceptors, GrpcClientLog)
 		interceptors = append(interceptors, dtmdriver.Middlewares.Grpc...)
 		inOpt := grpc.WithChainUnaryInterceptor(interceptors...)
-		conn, rerr := grpc.Dial(grpcServer, inOpt, grpc.WithTransportCredentials(insecure.NewCredentials()), opts)
+		grpcServiceConfig, hasConfig := getGrpcServiceConfig()
+		dialOpts := []grpc.DialOption{inOpt, grpc.WithTransportCredentials(insecure.NewCredentials()), opts}
+		if hasConfig {
+			dialOpts = append(dialOpts, grpc.WithDefaultServiceConfig(grpcServiceConfig))
+		}
+		conn, rerr := grpc.Dial(grpcServer, dialOpts...)
 		if rerr == nil {
 			clients.Store(grpcServer, conn)
 			v = conn
@@ -77,3 +86,20 @@ func MustGetGrpcConn(grpcServer string, isRaw bool) *grpc.ClientConn {
 	dtmimp.E2P(err)
 	return conn
 }
+
+// getGrpcServiceConfig returns the gRPC service config from config getter or environment variable, and a bool indicating if config is set
+func getGrpcServiceConfig() (string, bool) {
+	// First try to get from config getter (set by server)
+	if GrpcServiceConfigGetter != nil {
+		if config := GrpcServiceConfigGetter(); config != "" {
+			return config, true
+		}
+	}
+	// Fallback to environment variable
+	config := os.Getenv("GRPC_SERVICE_CONFIG")
+	if config != "" {
+		return config, true
+	}
+	// No config set
+	return "", false
+}

conf.sample.yml

@@ -70,3 +70,6 @@
 # AlertRetryLimit: 3 # default 3; if a transaction branch has been retried 3 times, the AlertHook will be called
 # AlertWebHook: '' # default ''; sample: 'http://localhost:8080/dtm-hook'. this hook will be called like this:
 ## curl -H "Content-Type: application/json" -d '{"gid":"xxxx","status":"submitted","retry_count":3}' http://localhost:8080/dtm-hook
+
+# GrpcBalancer: 'round_robin' # default round_robin,For more information about service configs, see:https://github.com/grpc/grpc/blob/master/doc/service_config.md
+# GrpcServiceConfig: '{"loadBalancingConfig": [{"round_robin":{}}]}' # default gRPC service config for client connections

dtmsvr/config/config.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 
 	"github.com/dtm-labs/dtm/client/dtmcli"
+	"github.com/dtm-labs/dtm/client/dtmgrpc/dtmgimp"
 	"github.com/dtm-labs/logger"
 	"gopkg.in/yaml.v3"
 )
@@ -104,6 +105,7 @@ type Type struct {
 	AlertRetryLimit               int64            `yaml:"AlertRetryLimit" default:"3"`
 	AlertWebHook                  string           `yaml:"AlertWebHook"`
 	AdminBasePath                 string           `yaml:"AdminBasePath"`
+	GrpcServiceConfig             string           `yaml:"GrpcServiceConfig" default:"{\"loadBalancingConfig\": [{\"round_robin\":{}}]}"`
 }
 
 // Config config
@@ -124,4 +126,12 @@ func MustLoadConfig(confFile string) {
 	err = checkConfig(&Config)
 	logger.FatalfIf(err != nil, `config error: '%v'.
 	please visit http://d.dtm.pub to see the config document.`, err)
+	// Set gRPC service config for client library
+	if Config.GrpcServiceConfig == "" {
+		Config.GrpcServiceConfig = `{"loadBalancingConfig": [{"round_robin":{}}]}`
+	}
+	// Set config getter function for client library to read config directly
+	dtmgimp.GrpcServiceConfigGetter = func() string {
+		return Config.GrpcServiceConfig
+	}
 }