Master OpenTracing & SkyWalking with .NET6: From Basics to Advanced Integration

OpenTracing Specification

OpenTracing is a design principle, specification, and standard for distributed system tracing. Similar to JDBC, it provides a vendor‑agnostic API that lets developers easily add or replace tracing implementations.

Why OpenTracing is Needed

It offers a platform‑independent, vendor‑neutral API, simplifying the integration or replacement of tracing systems and providing auxiliary libraries for operational support.

What Is a Trace

A trace represents the execution of a transaction or workflow across a distributed system. In OpenTracing, a trace is a directed acyclic graph (DAG) of spans, where each span records a timed, named segment of the execution.

In a typical RPC call, OpenTracing recommends at least one span on the client side and one on the server side to capture the call details.

A parent span can launch multiple child spans in parallel or serially, and a child span may have multiple parents.

A Typical Trace Example

This diagram shows component relationships but lacks timing details. A more effective view adds execution time context, hierarchy, and serial/parallel relationships, helping teams identify critical paths for performance optimization.

SkyWalking

SkyWalking is an Application Performance Management (APM) system designed for microservices, cloud‑native, and container‑based architectures (Docker, Kubernetes, Mesos). It provides distributed tracing, service‑mesh telemetry, metric aggregation, and unified visualization.

Key Features

Multiple monitoring methods via language agents and service mesh.

Automatic agents for Java, .NET Core, and Node.js.

Lightweight without requiring a big‑data platform.

Modular UI, storage, and cluster management.

Built‑in alerting.

Rich visualization capabilities.

Overall Architecture

Probe – Collects data from various sources and formats it for SkyWalking.

Backend – Cluster‑capable service that aggregates, analyzes, and drives data flow from probes to the UI; supports pluggable data sources, storage, and custom analysis scripts.

Storage – Open‑ended; can use Elasticsearch, H2, MySQL (Sharding‑Sphere), or custom implementations.

User Interface – Powerful, customizable UI for end users.

Tracing, Logging, and Metrics

In microservices, tracing captures the end‑to‑end request flow, logging records discrete events, and metrics aggregate quantitative data such as QPS or latency.

.NET6 Integration with SkyWalking

Deploy SkyWalking Environment

version: '3.3'
services:
  elasticsearch:
    image: docker.elastic.co/elasticsearch/elasticsearch:7.5.0
    container_name: elasticsearch
    restart: always
    ports:
      - 9200:9200
    environment:
      - discovery.type=single-node
      - bootstrap.memory_lock=true
      - "ES_JAVA_OPTS=-Xms256m -Xmx256m"
    ulimits:
      memlock:
        soft: -1
        hard: -1
  oap:
    image: apache/skywalking-oap-server:6.6.0-es7
    container_name: oap
    depends_on:
      - elasticsearch
    restart: always
    ports:
      - 11800:11800
      - 12800:12800
    environment:
      SW_STORAGE: elasticsearch
      SW_STORAGE_ES_CLUSTER_NODES: elasticsearch:9200
  ui:
    image: apache/skywalking-ui:6.6.0
    container_name: ui
    depends_on:
      - oap
    restart: always
    ports:
      - 8080:8080
    environment:
      SW_OAP_ADDRESS: http://oap:12800

After installation, the UI is accessible at http:// :8080

Add Dependencies

<ItemGroup>
    <PackageReference Include="SkyAPM.Agent.AspNetCore" Version="1.3.0" />
</ItemGroup>

Edit SkyWalking Configuration (skyapm.json)

{
  "SkyWalking": {
    "ServiceName": "MySkyWalkingDemoTest",
    "Namespace": "",
    "HeaderVersions": ["sw8"],
    "Sampling": {
      "SamplePer3Secs": -1,
      "Percentage": -1.0
    },
    "Logging": {
      "Level": "Information",
      "FilePath": "logs\\skyapm-{Date}.log"
    },
    "Transport": {
      "Interval": 3000,
      "ProtocolVersion": "v8",
      "QueueSize": 30000,
      "BatchSize": 3000,
      "gRPC": {
        "Servers": "192.168.3.245:11800",
        "Timeout": 10000,
        "ConnectTimeout": 10000,
        "ReportTimeout": 600000,
        "Authentication": ""
      }
    }
  }
}

Generate skyapm.json via CLI

dotnet tool install -g SkyAPM.DotNet.CLI

dotnet skyapm config MySkyWalkingDemoTest 192.168.3.245:11800

Configure launchSettings.json

{
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "weatherforecast",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_HOSTINGSTARTUPASSEMBLIES": "SkyAPM.Agent.AspNetCore",
        "SKYWALKING__SERVICENAME": "MySkyWalkingDemoTest"
      }
    },
    "SkyWalkingDemo": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "weatherforecast",
      "applicationUrl": "http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_HOSTINGSTARTUPASSEMBLIES": "SkyAPM.Agent.AspNetCore",
        "SKYWALKING__SERVICENAME": "MySkyWalkingDemoTest"
      }
    }
  }
}

Modify startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddSkyApmExtensions(); // Add SkyWalking extensions
    services.AddControllers();
    services.AddHttpClient();
}

Get TraceId

private readonly IEntrySegmentContextAccessor segContext;

public SkywalkingController(IEntrySegmentContextAccessor segContext)
{
    this.segContext = segContext;
}

[HttpGet("traceId")]
public string GetSkywalkingTraceId()
{
    return segContext.Context.TraceId;
}

Custom Span Logging

[HttpGet]
public async Task<IActionResult> SkywalkingTest()
{
    var TraceId = _segContext.Context.TraceId;
    Console.WriteLine($"TraceId={TraceId}");
    _segContext.Context.Span.AddLog(LogEvent.Message($"SkywalkingTest---Worker running at: {DateTime.Now}"));
    System.Threading.Thread.Sleep(1000);
    _segContext.Context.Span.AddLog(LogEvent.Message($"SkywalkingTest---Worker running at--end: {DateTime.Now}"));
    return Ok($"Ok,SkywalkingTest-TraceId={TraceId} ");
}

Microservice Gateway Integration

Add Dependencies

<ItemGroup>
    <PackageReference Include="SkyAPM.Agent.AspNetCore" Version="1.3.0" />
</ItemGroup>

Copy and Modify Configuration (skyapm.json)

{
  "SkyWalking": {
    "ServiceName": "MySkyWalking_Gateway",
    "Namespace": "",
    "HeaderVersions": ["sw8"],
    "Sampling": {"SamplePer3Secs": -1, "Percentage": -1.0},
    "Logging": {"Level": "Debug", "FilePath": "logs\\skyapm-{Date}.log"},
    "Transport": {"Interval": 3000, "ProtocolVersion": "v8", "QueueSize": 30000, "BatchSize": 3000, "gRPC": {"Servers": "192.168.3.245:11800", "Timeout": 10000, "ConnectTimeout": 10000, "ReportTimeout": 600000, "Authentication": ""}}
  }
}

Update launchSettings.json for Gateway

{
  "profiles": {
    "Zhaoxi.MicroService.GatewayCenter": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_HOSTINGSTARTUPASSEMBLIES": "SkyAPM.Agent.AspNetCore",
        "SKYWALKING__SERVICENAME": "MySkyWalking_Gateway"
      }
    }
  }
}

Configure Route for Order Service

{
    "DownstreamPathTemplate": "/api/{url}",
    "DownstreamScheme": "http",
    "UpstreamPathTemplate": "/microservice/{url}",
    "UpstreamHttpMethod": ["Get", "Post"],
    "UseServiceDiscovery": true,
    "ServiceName": "OrderService",
    "LoadBalancerOptions": {"Type": "RoundRobin"}
}

Start Gateway

dotnet run --urls=http://*:6299

Order Service Integration

Add Dependencies

<ItemGroup>
    <PackageReference Include="SkyAPM.Agent.AspNetCore" Version="1.3.0" />
</ItemGroup>

Copy skyapm.json (Order Service)

{
  "SkyWalking": {
    "ServiceName": "MySkyWalking_OrderService",
    "Namespace": "",
    "HeaderVersions": ["sw8"],
    "Sampling": {"SamplePer3Secs": -1, "Percentage": -1.0},
    "Logging": {"Level": "Debug", "FilePath": "logs\\skyapm-{Date}.log"},
    "Transport": {"Interval": 3000, "ProtocolVersion": "v8", "QueueSize": 30000, "BatchSize": 3000, "gRPC": {"Servers": "192.168.3.245:11800", "Timeout": 10000, "ConnectTimeout": 10000, "ReportTimeout": 600000, "Authentication": ""}}
  }
}

Configure launchSettings.json for Order Service

{
  "profiles": {
    "Zhaoxi.MicroService.OrderServiceInstance": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "launchBrowser": true,
      "launchUrl": "swagger",
      "applicationUrl": "http://192.168.3.105:7900",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development",
        "ASPNETCORE_HOSTINGSTARTUPASSEMBLIES": "SkyAPM.Agent.AspNetCore",
        "SKYWALKING__SERVICENAME": "MySkyWalking_OrderService"
      }
    }
  }
}

Start Order Service

dotnet run

SkyWalking Alert Configuration

Enter Container to Edit Rules

docker exec -it 12f053748e85 /bin/sh

ls -l

View Alarm Settings

cat alarm-settings.yml

rules:
  service_resp_time_rule:
    metrics-name: service_resp_time
    op: ">"
    threshold: 1000
    period: 10
    count: 3
    silence-period: 5
    message: Response time of service {name} is more than 1000ms in 3 minutes of last 10 minutes.
  service_sla_rule:
    metrics-name: service_sla
    op: "<"
    threshold: 8000
    period: 10
    count: 2
    silence-period: 3
    message: Successful rate of service {name} is lower than 80% in 2 minutes of last 10 minutes.
  ... (other rules omitted for brevity) ...
webhooks:
  - http://192.168.3.105:7900/api/Skywalking/AlarmMsg

Modify an Alarm Rule Example

rules:
  service_test_sal_rule:
    metrics-name: service_test_sal
    op: "<"
    threshold: 8000
    period: 2
    count: 1
    silence-period: 3
    message: Successful rate of service {name} is lower than 80% in 2 minutes of last 10 minutes.

Alarm API Implementation

public class AlarmMsg
{
    public int scopeId { get; set; }
    public string? scope { get; set; }
    public string? name { get; set; }
    public string? id0 { get; set; }
    public string? id1 { get; set; }
    public string? ruleName { get; set; }
    public string? alarmMessage { get; set; }
}

[HttpPost("AlarmMsg")]
public void AlarmMsg(List<AlarmMsg> msgs)
{
    string msg = "触发告警：" + msgs.FirstOrDefault()?.alarmMessage;
    Console.WriteLine(msg);
    SendMail(msg);
}

Configure WebHook Endpoint

http://192.168.3.105:7900/api/Skywalking/AlarmMsg