Microservices have everything from code to k8s deployment (12. Link tracking)

We use a series to explain the complete practice of microservices from requirements to online, from code to k8s deployment, from logging to monitoring, etc.

The whole project uses microservices developed by go-zero, which basically includes go-zero and some middleware developed by related go-zero authors. The technology stack used is basically the self-developed components of the go-zero project team, basically go -zero the whole family bucket.

Actual project address: https://github.com/Mikaelemmmm/go-zero-looklook

1 Overview

If you follow the error handling and log collection configuration in the previous two sections, we can also see the overall link log when an error is reported through the traceId in the log, but when no error is reported or you want to easily view the call of the entire link of a single business The execution time is not very convenient to view, so it is better to add link tracking.

The bottom layer of go-zero has already written the code to help us connect the code with the link tracking

 func startAgent(c Config) error {
  opts := []sdktrace.TracerProviderOption{
    // Set the sampling rate based on the parent span to 100%
    sdktrace.WithSampler(sdktrace.ParentBased(sdktrace.TraceIDRatioBased(c.Sampler))),
    // Record information about this application in an Resource.
    sdktrace.WithResource(resource.NewSchemaless(semconv.ServiceNameKey.String(c.Name))),
  }

  if len(c.Endpoint) > 0 {
    exp, err := createExporter(c)
    if err != nil {
      logx.Error(err)
      return err
    }

    // Always be sure to batch in production.
    opts = append(opts, sdktrace.WithBatcher(exp))
  }

  tp := sdktrace.NewTracerProvider(opts...)
  otel.SetTracerProvider(tp)
  otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(
    propagation.TraceContext{}, propagation.Baggage{}))
  otel.SetErrorHandler(otel.ErrorHandlerFunc(func(err error) {
    logx.Errorf("[otel] error: %v", err)
  }))

  return nil
}

Default support for jaeger, zinpink

 package trace

// TraceName represents the tracing name.
const TraceName = "go-zero"

// A Config is a opentelemetry config.
type Config struct {
  Name     string  `json:",optional"`
  Endpoint string  `json:",optional"`
  Sampler  float64 `json:",default=1.0"`
  Batcher  string  `json:",default=jaeger,options=jaeger|zipkin"`
}

We only need to configure the parameters in our business code configuration, that is, the yaml of your business configuration.

2. Realize

go-zero-looklook is implemented by jaeger

2.1 Jaeger

jaeger is configured in the project's docker-compose-env.yaml

 services:
  #jaeger链路追踪
  jaeger:
    image: jaegertracing/all-in-one:latest
    container_name: jaeger
    ports:
      - "5775:5775/udp"
      - "6831:6831/udp"
      - "6832:6832/udp"
      - "5778:5778"
      - "16686:16686"
      - "14268:14268"
      - "9411:9411"
    environment:
      - SPAN_STORAGE_TYPE=elasticsearch
      - ES_SERVER_URLS=http://elasticsearch:9200
      - LOG_LEVEL=debug
    networks:
      - looklook_net
      
   ........

Among them, jager_collector relies on elasticsearch for storage, so elasticsearch should be installed, as we have demonstrated in the previous section when collecting logs.

2.2 Business Configuration

Let's take user service as an example

1) api configuration

app/usercenter/cmd/api/etc/usercenter.yaml

 Name: usercenter-api
Host: 0.0.0.0
Port: 8002
Mode: dev
......

#链路追踪
Telemetry:
  Name: usercenter-api
  Endpoint: http://jaeger:14268/api/traces
  Sampler: 1.0
  Batcher: jaeger

2) rpc configuration

 Name: usercenter-rpc
ListenOn: 0.0.0.0:9002
Mode: dev

.....

#链路追踪
Telemetry:
  Name: usercenter-rpc
  Endpoint: http://jaeger:14268/api/traces
  Sampler: 1.0
  Batcher: jaeger

2.3 View link

Request user service registration, login, and obtain login user information

Browser input http://127.0.0.1:16686/search to view

3. Summary

We have finished sorting out logs and link tracking. A good system must be able to monitor abnormalities in time. Next, we will look at service monitoring.

project address

https://github.com/zeromicro/go-zero

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