Tracing - In-Process Service (gRPC Exporter)

Code Source: https://github.com/gogf/examples/tree/main/observability/trace/inprocess-grpc

Description

This example demonstrates how to implement distributed tracing in in-process services using GoFrame with gRPC-based OpenTelemetry exporter. It shows how to:

• Configure tracing in a single process using gRPC exporter
• Trace function calls and operations
• Propagate trace context through gRPC
• Visualize distributed traces

Requirements

• Go 1.22 or higher
• Git
• GoFrame
• GoFrame OpenTelemetry gRPC Tracing

Structure

.
├── main.go         # Main application with gRPC-based tracing
├── go.mod          # Go module file
└── go.sum          # Go module checksums

Features

The example showcases the following features:

1. Distributed Tracing with gRPC Exporter

   • gRPC-based trace data transmission
   • Span management with gRPC context
   • Trace visualization

2. Function Call Tracing

   • Function entry/exit tracing
   • gRPC context propagation
   • Error handling

3. Data Operations

   • User data retrieval
   • Data aggregation
   • Error handling

Prerequisites

1. Running Jaeger instance:

   docker run --rm --name jaeger \
   -e COLLECTOR_ZIPKIN_HOST_PORT=:9411 \
   -p 6831:6831/udp \
   -p 6832:6832/udp \
   -p 5778:5778 \
   -p 16686:16686 \
   -p 4317:4317 \
   -p 4318:4318 \
   -p 14250:14250 \
   -p 14268:14268 \
   -p 14269:14269 \
   -p 9411:9411 \
   jaegertracing/all-in-one:1.55

Usage

1. Run the application:

   go run main.go

2. View traces: Open http://localhost:16686 in your browser to view traces in Jaeger UI.

Implementation Details

The example demonstrates:

1. User Data Operations

   GetUser(ctx, id)       // Retrieves complete user data
   ├── GetInfo(ctx, id)   // Gets basic user information
   ├── GetDetail(ctx, id) // Gets detailed user information
   └── GetScores(ctx, id) // Gets user scores

2. Trace Context Flow

   • Main function creates root span with gRPC context
   • Each function creates child span with gRPC metadata
   • Context propagates through gRPC calls
   • All spans are properly ended with gRPC cleanup

3. Error Handling

   • Non-existent user IDs return nil
   • Each function handles errors independently
   • Errors are traced and logged with gRPC status codes

4. gRPC-based Trace Export

   • Uses gRPC protocol for trace data transmission
   • Configures gRPC trace collector endpoint
   • Handles gRPC connection management
   • Supports gRPC authentication and TLS

Troubleshooting

1. Application Issues:

   • Check if application is running correctly
   • Verify function call outputs
   • Review error logs

2. Tracing Issues:

   • Verify Jaeger is running: docker ps | grep jaeger
   • Check Jaeger UI accessibility: http://localhost:16686
   • Ensure gRPC endpoint is correct in configuration

3. gRPC Issues:

   • Check gRPC connection status
   • Verify gRPC endpoint accessibility
   • Review gRPC error messages and status codes
   • Verify gRPC authentication token

Example Output

For user ID 100:

{
    "id":      100,
    "name":    "john",
    "gender":  1,
    "site":    "https://goframe.org",
    "email":   "john@goframe.org",
    "math":    100,
    "english": 60,
    "chinese": 50
}

For non-existent user IDs:

{}