The GoFrame
framework includes multiple microservice components and provides an easy-to-use GRPC
scaffold module and tools. The scaffold is implemented by the grpcx
community package: https://github.com/gogf/gf/tree/master/contrib/rpc/grpcx which contains multiple modules.
Server - Server
The server is maintained by the grpcx.Server
module, used for creating and maintaining server objects. Example usage: https://github.com/gogf/gf/blob/master/example/rpc/grpcx/basic/server/main.go
The creation of the server often involves using configuration files. For an introduction to server configuration files, please refer to the chapter: GRPC Server Configuration
package main
import (
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/basic/controller"
)
func main() {
s := grpcx.Server.New()
controller.Register(s)
s.Run()
}
Client - Client
The client is maintained by the grpcx.Client
module, used for creating and maintaining client objects. Example usage: https://github.com/gogf/gf/blob/master/example/rpc/grpcx/basic/client/main.go
In most scenarios, service access is based on service names.
package main
import (
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/basic/protobuf"
"github.com/gogf/gf/v2/frame/g"
"github.com/gogf/gf/v2/os/gctx"
)
func main() {
var (
ctx = gctx.New()
conn = grpcx.Client.MustNewGrpcClientConn("demo")
client = protobuf.NewGreeterClient(conn)
)
res, err := client.SayHello(ctx, &protobuf.HelloRequest{Name: "World"})
if err != nil {
g.Log().Error(ctx, err)
return
}
g.Log().Debug(ctx, "Response:", res.Message)
}
Common Issue
Should the Client
object that is created and reused be saved?
Each grpc Client
object actually corresponds to access to a target service. This object should be saved and reused, rather than creating a new Client
object each time, as this can improve efficiency, reduce resource usage, and be GC-friendly.
Context - Ctx
The context is maintained by the grpcx.Ctx
module, used for custom data transfer between clients and servers, as well as between services. It includes the following commonly used methods:
func (c Ctx) NewIncoming(ctx context.Context, data ...g.Map) context.Context
func (c Ctx) NewOutgoing(ctx context.Context, data ...g.Map) context.Context
func (c Ctx) IncomingToOutgoing(ctx context.Context, keys ...string) context.Context
func (c Ctx) IncomingMap(ctx context.Context) *gmap.Map
func (c Ctx) OutgoingMap(ctx context.Context) *gmap.Map
func (c Ctx) SetIncoming(ctx context.Context, data g.Map) context.Context
func (c Ctx) SetOutgoing(ctx context.Context, data g.Map) context.Context
The Outgoing
is used on the client side to indicate custom data to be transmitted to the server, usually composed of Key-Value
pairs in Map
data format. The Incoming
is used on the server side to indicate data received from the client. Some framework-related embedded information, such as trace information and client version information, is also written into the Incoming
key-value pairs. Example usage:
server.go
package main
import (
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/ctx/controller"
)
func main() {
s := grpcx.Server.New()
controller.Register(s)
s.Run()
}
controller.go
package controller
import (
"context"
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/ctx/protobuf"
"github.com/gogf/gf/v2/frame/g"
)
type Controller struct {
protobuf.UnimplementedGreeterServer
}
func Register(s *grpcx.GrpcServer) {
protobuf.RegisterGreeterServer(s.Server, &Controller{})
}
// SayHello implements helloworld.GreeterServer
func (s *Controller) SayHello(ctx context.Context, in *protobuf.HelloRequest) (*protobuf.HelloReply, error) {
m := grpcx.Ctx.IncomingMap(ctx)
g.Log().Infof(ctx, `incoming data: %v`, m.Map())
return &protobuf.HelloReply{Message: "Hello " + in.GetName()}, nil
}
client.go
package main
import (
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/ctx/protobuf"
"github.com/gogf/gf/v2/frame/g"
"github.com/gogf/gf/v2/os/gctx"
)
func main() {
var (
conn = grpcx.Client.MustNewGrpcClientConn("demo")
client = protobuf.NewGreeterClient(conn)
ctx = grpcx.Ctx.NewOutgoing(gctx.New(), g.Map{
"UserId": "1000",
"UserName": "john",
})
)
g.Log().Infof(ctx, `outgoing data: %v`, grpcx.Ctx.OutgoingMap(ctx).Map())
res, err := client.SayHello(ctx, &protobuf.HelloRequest{Name: "World"})
if err != nil {
g.Log().Error(ctx, err)
return
}
g.Log().Debug(ctx, "Response:", res.Message)
}
After execution, the server outputs:
$ go run server.go
2023-03-15 19:28:45.331 [DEBU] set default registry using file registry as no custom registry set
2023-03-15 19:28:45.331 [DEBU] service register: &{Head: Deployment: Namespace: Name:demo Version: Endpoints:10.35.12.81:51707 Metadata:map[protocol:grpc]}
2023-03-15 19:28:45.332 [INFO] pid[83753]: grpc server started listening on [:51707]
2023-03-15 19:28:54.093 [INFO] {d049db1a39944c1711bd9f37d58a88f9} incoming data: map[:authority:service/default/default/demo/latest/ content-type:application/grpc traceparent:00-d049db1a39944c1711bd9f37d58a88f9-adbd2ba657ffea45-01 user-agent:grpc-go/1.49.0 userid:1000 username:john]
2023-03-15 19:28:54.093 {d049db1a39944c1711bd9f37d58a88f9} /protobuf.Greeter/SayHello, 0.049ms, name:"World", message:"Hello World"
Client output:
$ go run client.go
2023-03-15 19:28:54.087 [INFO] {d049db1a39944c1711bd9f37d58a88f9} outgoing data: map[userid:1000 username:john]
2023-03-15 19:28:54.089 [DEBU] client conn updated with addresses [{"Addr":"10.35.12.81:51707","ServerName":"demo","Attributes":{},"BalancerAttributes":null,"Type":0,"Metadata":null}]
2023-03-15 19:28:54.093 [DEBU] {d049db1a39944c1711bd9f37d58a88f9} Response: Hello World
Load Balancer - Balancer
Load balancing is maintained by the grpcx.Balancer
module, used to implement how requests are made when the server has multiple access addresses. If the client does not set a load balancing strategy, the default round-robin strategy is used. For detailed information about load balancing, please refer to the chapter: Service Load Balancing
Here, we use the random strategy as an example, where the random strategy will make the number of requests received by different servers relatively random.
server.go
package main
import (
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/balancer/controller"
)
func main() {
s := grpcx.Server.New()
controller.Register(s)
s.Run()
}
client.go
package main
import (
"context"
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/balancer/protobuf"
"github.com/gogf/gf/v2/frame/g"
"github.com/gogf/gf/v2/os/gctx"
)
func main() {
var (
ctx context.Context
conn = grpcx.Client.MustNewGrpcClientConn("demo", grpcx.Balancer.WithRandom())
client = protobuf.NewGreeterClient(conn)
)
for i := 0; i < 10; i++ {
ctx = gctx.New()
res, err := client.SayHello(ctx, &protobuf.HelloRequest{Name: "World"})
if err != nil {
g.Log().Error(ctx, err)
return
}
g.Log().Debug(ctx, "Response:", res.Message)
}
}
Here, grpcx.Balancer.WithRandom()
indicates the use of a random request strategy.
Start two server.go
instances, then run the client.go
client, and observe the servers' request logs:
server1
terminal output:
$ go run server.go
2023-03-15 19:50:44.801 [DEBU] set default registry using file registry as no custom registry set
2023-03-15 19:50:44.802 [DEBU] service register: &{Head: Deployment: Namespace: Name:demo Version: Endpoints:10.35.12.81:53962 Metadata:map[protocol:grpc]}
2023-03-15 19:50:44.802 [INFO] pid[89290]: grpc server started listening on [:53962]
2023-03-15 19:50:57.282 {7025612f6d954c17c5f335051bf10899} /protobuf.Greeter/SayHello, 0.003ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.283 {60567c2f6d954c17c7f335052ce05185} /protobuf.Greeter/SayHello, 0.002ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.285 {f8d09b2f6d954c17ccf33505dff1a4ea} /protobuf.Greeter/SayHello, 0.002ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.287 {f0fab02f6d954c17cdf33505438b2c80} /protobuf.Greeter/SayHello, 0.001ms, name:"World", message:"Hello World"
server2
terminal output:
$ go run server.go
2023-03-15 19:50:51.720 [DEBU] set default registry using file registry as no custom registry set
2023-03-15 19:50:51.721 [DEBU] service register: &{Head: Deployment: Namespace: Name:demo Version: Endpoints:10.35.12.81:53973 Metadata:map[protocol:grpc]}
2023-03-15 19:50:51.722 [INFO] pid[89351]: grpc server started listening on [:53973]
2023-03-15 19:50:57.280 {b89a0d2f6d954c17c4f33505a046817c} /protobuf.Greeter/SayHello, 0.002ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.282 {28bf732f6d954c17c6f33505adedff5f} /protobuf.Greeter/SayHello, 0.002ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.283 {9876832f6d954c17c8f3350580ed535b} /protobuf.Greeter/SayHello, 0.002ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.284 {684e8b2f6d954c17c9f33505d56e4b05} /protobuf.Greeter/SayHello, 0.001ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.284 {c045912f6d954c17caf3350599006197} /protobuf.Greeter/SayHello, 0.001ms, name:"World", message:"Hello World"
2023-03-15 19:50:57.284 {500a972f6d954c17cbf33505252b0e01} /protobuf.Greeter/SayHello, 0.001ms, name:"World", message:"Hello World"
Client terminal output:
$ go run client.go
2023-03-15 19:50:57.278 [DEBU] client conn updated with addresses [{"Addr":"10.35.12.81:53962","ServerName":"demo","Attributes":{},"BalancerAttributes":null,"Type":0,"Metadata":null},{"Addr":"10.35.12.81:53973","ServerName":"demo","Attributes":{},"BalancerAttributes":null,"Type":0,"Metadata":null}]
2023-03-15 19:50:57.281 [DEBU] {b89a0d2f6d954c17c4f33505a046817c} Response: Hello World
2023-03-15 19:50:57.282 [DEBU] {7025612f6d954c17c5f335051bf10899} Response: Hello World
2023-03-15 19:50:57.282 [DEBU] {28bf732f6d954c17c6f33505adedff5f} Response: Hello World
2023-03-15 19:50:57.283 [DEBU] {60567c2f6d954c17c7f335052ce05185} Response: Hello World
2023-03-15 19:50:57.283 [DEBU] {9876832f6d954c17c8f3350580ed535b} Response: Hello World
2023-03-15 19:50:57.284 [DEBU] {684e8b2f6d954c17c9f33505d56e4b05} Response: Hello World
2023-03-15 19:50:57.284 [DEBU] {c045912f6d954c17caf3350599006197} Response: Hello World
2023-03-15 19:50:57.285 [DEBU] {500a972f6d954c17cbf33505252b0e01} Response: Hello World
2023-03-15 19:50:57.286 [DEBU] {f8d09b2f6d954c17ccf33505dff1a4ea} Response: Hello World
2023-03-15 19:50:57.287 [DEBU] {f0fab02f6d954c17cdf33505438b2c80} Response: Hello World
You can see that the client sent 10
requests, and the two servers each received 4
and 6
requests, respectively, with the load of requests being relatively random.
Service Discovery - Resolver
Service discovery is maintained by the grpcx.Resolver
module, used for GRPC
service name resolution. The grpcx
component uses the local file system for service discovery by default, only for testing purposes. For production environments, other service discovery components are required. A simple example:
server.go
package main
import (
"github.com/gogf/gf/contrib/registry/etcd/v2"
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/resolver/controller"
)
func main() {
grpcx.Resolver.Register(etcd.New("127.0.0.1:2379"))
s := grpcx.Server.New()
controller.Register(s)
s.Run()
}
The grpcx.Resolver.Register(etcd.New("127.0.0.1:2379"))
is used to set the service discovery component to etcd
, which only supports GRPC
protocol.
client.go
package main
import (
"github.com/gogf/gf/contrib/registry/etcd/v2"
"github.com/gogf/gf/contrib/rpc/grpcx/v2"
"github.com/gogf/gf/example/rpc/grpcx/resolver/protobuf"
"github.com/gogf/gf/v2/frame/g"
"github.com/gogf/gf/v2/os/gctx"
)
func main() {
grpcx.Resolver.Register(etcd.New("127.0.0.1:2379"))
var (
ctx = gctx.New()
conn = grpcx.Client.MustNewGrpcClientConn("demo")
client = protobuf.NewGreeterClient(conn)
)
res, err := client.SayHello(ctx, &protobuf.HelloRequest{Name: "World"})
if err != nil {
g.Log().Error(ctx, err)
return
}
g.Log().Debug(ctx, "Response:", res.Message)
}
Start etcd
:
$ etcd
{"level":"info","ts":"2023-03-15T20:02:50.966+0800","caller":"etcdmain/etcd.go:73","msg":"Running: ","args":["etcd"]}
{"level":"info","ts":"2023-03-15T20:02:50.967+0800","caller":"etcdmain/etcd.go:100","msg":"failed to detect default host","error":"default host not supported on darwin_amd64"}
{"level":"warn","ts":"2023-03-15T20:02:50.967+0800","caller":"etcdmain/etcd.go:105","msg":"'data-dir' was empty; using default","data-dir":"default.etcd"}
{"level":"info","ts":"2023-03-15T20:02:50.967+0800","caller":"etcdmain/etcd.go:116","msg":"server has been already initialized","data-dir":"default.etcd","dir-type":"member"}
{"level":"info","ts":"2023-03-15T20:02:50.967+0800","caller":"embed/etcd.go:124","msg":"configuring peer listeners","listen-peer-urls":["http://localhost:2380"]}
{"level":"info","ts":"2023-03-15T20:02:50.968+0800","caller":"embed/etcd.go:132","msg":"configuring client listeners","listen-client-urls":["http://localhost:2379"]}
...
Run server.go
:
$ go run server.go
2023-03-15 20:02:19.472 [DEBU] service register: &{Head: Deployment: Namespace: Name:demo Version: Endpoints:10.35.12.81:55066 Metadata:map[protocol:grpc]}
2023-03-15 20:02:19.516 [DEBU] etcd put success with key "/service/default/default/demo/latest/10.35.12.81:55066", value "{"protocol":"grpc"}", lease "7587869265929863945"
2023-03-15 20:02:19.516 [INFO] pid[92040]: grpc server started listening on [:55066]
2023-03-15 20:02:29.310 {88c4c04e0e964c17dddec53b1adb54f7} /protobuf.Greeter/SayHello, 0.001ms, name:"World", message:"Hello World"
Run client.go
:
$ go run client.go
2023-03-15 20:02:29.297 [DEBU] Watch key "/service/default/default/demo/latest/"
2023-03-15 20:02:29.307 [DEBU] client conn updated with addresses [{"Addr":"10.35.12.81:55066","ServerName":"demo","Attributes":{},"BalancerAttributes":null,"Type":0,"Metadata":null}]
2023-03-15 20:02:29.308 [DEBU] client conn updated with addresses [{"Addr":"10.35.12.81:55066","ServerName":"demo","Attributes":{},"BalancerAttributes":null,"Type":0,"Metadata":null}]
2023-03-15 20:02:29.310 [DEBU] {88c4c04e0e964c17dddec53b1adb54f7} Response: Hello World