Tracing

Kitex supports OpenTelemetry tracer, OpenTracing tracer and also customized tracer.

OpenTelemetry

Kitex’s OpenTelemetry extension provides support for tracing, metrics and logging.

Example

client side:

import (
    ...
    "github.com/kitex-contrib/obs-opentelemetry/provider"
    "github.com/kitex-contrib/obs-opentelemetry/tracing"
)

func main(){
    serviceName := "echo-client"

    p := provider.NewOpenTelemetryProvider(
        provider.WithServiceName(serviceName),
        provider.WithExportEndpoint("localhost:4317"),
        provider.WithInsecure(),
    )
    defer p.Shutdown(context.Background())

    c, err := echo.NewClient(
        "echo",
        client.WithSuite(tracing.NewClientSuite()),
        // Please keep the same as provider.WithServiceName
        client.WithClientBasicInfo(&rpcinfo.EndpointBasicInfo{ServiceName: serviceName}),
    )
    if err != nil {
        klog.Fatal(err)
    }

}

server side:

import (
    ...
    "github.com/kitex-contrib/obs-opentelemetry/provider"
    "github.com/kitex-contrib/obs-opentelemetry/tracing"
)


func main()  {
    serviceName := "echo"

    p := provider.NewOpenTelemetryProvider(
        provider.WithServiceName(serviceName),
        provider.WithExportEndpoint("localhost:4317"),
        provider.WithInsecure(),
    )
    defer p.Shutdown(context.Background())

    svr := echo.NewServer(
        new(EchoImpl),
        server.WithSuite(tracing.NewServerSuite()),
        // Please keep the same as provider.WithServiceName
        server.WithServerBasicInfo(&rpcinfo.EndpointBasicInfo{ServiceName: serviceName}),
    )
    if err := svr.Run(); err != nil {
        klog.Fatalf("server stopped with error:", err)
    }
}

For more information see obs-opentelemetry

OpenTracing

client side, use OpenTracing GlobalTracer by default

import (
    "github.com/cloudwego/kitex/client"
    "github.com/cloudwego/kitex-examples/kitex_gen/api/echo"
    internal_opentracing "github.com/kitex-contrib/tracer-opentracing"
)
...
tracer := internal_opentracing.NewDefaultClientSuite()
client, err := echo.NewClient("echo", client.WithSuite(tracer))
if err != nil {
	log.Fatal(err)
}

server side, use OpenTracing GlobalTracer by default

import (
    "github.com/cloudwego/kitex/server"
    "github.com/cloudwego/kitex-examples/kitex_gen/api/echo"
    internal_opentracing "github.com/kitex-contrib/tracer-opentracing"
)
...
tracer := internal_opentracing.NewDefaultServerSuite()
svr, err := echo.NewServer(new(EchoImpl), server.WithSuite(tracer))
if err := svr.Run(); err != nil {
	log.Println("server stopped with error:", err)
} else {
	log.Println("server stopped")
}

For more information see tracer-opentracing

Customize opentracing tracer and operation name

client side:

import (
	...
	ko "github.com/kitex-contrib/opentracing"
	"github.com/opentracing/opentracing-go"
	"github.com/cloudwego/kitex/pkg/endpoint"
	"github.com/cloudwego/kitex/pkg/rpcinfo"
  ...
)
...
myTracer := opentracing.GlobalTracer()
operationNameFunc := func(ctx context.Context) string {
	endpoint := rpcinfo.GetRPCInfo(ctx).To()
	return endpoint.ServiceName() + "::" + endpoint.Method()
}
...
client, err := echo.NewClient("echo", ko.ClientOption(myTracer, operationNameFunc))
if err != nil {
	log.Fatal(err)
}

server side:

import (
	...
	ko "github.com/kitex-contrib/opentracing"
	"github.com/opentracing/opentracing-go"
	"github.com/cloudwego/kitex/pkg/endpoint"
	"github.com/cloudwego/kitex/pkg/rpcinfo"
	...
)
...
myTracer := opentracing.GlobalTracer()
operationNameFunc := func(ctx context.Context) string {
	endpoint := rpcinfo.GetRPCInfo(ctx).To()
	return endpoint.ServiceName() + "::" + endpoint.Method()
}
...
svr, err := echo.NewServer(ko.ClientOption(myTracer, operationNameFunc))
if err := svr.Run(); err != nil {
	log.Println("server stopped with error:", err)
} else {
	log.Println("server stopped")
}

Customize tracer

tracer interface:

type Tracer interface {
	Start(ctx context.Context) context.Context
	Finish(ctx context.Context)
}

Example

client side:

import "github.com/cloudwego/kitex/client"
...
type myTracer struct {}

func (m *myTracer) Start(ctx context.Context) context.Context {
	_, ctx = opentracing.StartSpanFromContextWithTracer(ctx, o.tracer, "RPC call")
	return ctx
}

func (m *myTracer) Finish(ctx context.Context) {
	span := opentracing.SpanFromContext(ctx)
	span.Finish()
}
...
client, err := echo.NewClient("echo", client.WithTracer(&myTracer{}))
if err != nil {
	log.Fatal(err)
}

server side:

import "github.com/cloudwego/kitex/server"
...
type myTracer struct {}

func (m *myTracer) Start(ctx context.Context) context.Context {
	_, ctx = opentracing.StartSpanFromContextWithTracer(ctx, o.tracer, "RPC handle")
	return ctx
}

func (m *myTracer) Finish(ctx context.Context) {
	span := opentracing.SpanFromContext(ctx)
	span.Finish()
}
...
svr, err := echo.NewServer(server.WithTracer(&myTracer{}))
if err := svr.Run(); err != nil {
	log.Println("server stopped with error:", err)
} else {
	log.Println("server stopped")
}

Last modified July 3, 2023 : Update response.md (0a36fb2)