How to Master Microservice Performance Monitoring with SkyWalking APM

SkyWalking Overview

SkyWalking is an APM tool for tracing request chains in microservices. It helps identify latency or errors across multiple services by visualizing the call graph.

Download and Installation

Download the SkyWalking APM distribution, which contains skywalking-oap (collector) and skywalking-ui (UI) from the official site. Install JDK 17 and set JAVA_HOME. Unzip the package and run startup.bat in the bin directory to start both OAP and UI, then access the UI at http://localhost:8080/.

Viewing Monitoring Information

Start the Nacos registry, then launch the two services with the following JVM arguments:

-javaagent:D:\developer\env\skywalking-agent\skywalking-agent.jar
-Dskywalking.agent.service_name=sky-user-service
-Dskywalking.collector.backend_service=127.0.0.1:11800

Repeat the same for sky-feign-service (changing the service name). After both services start, you can see them in the SkyWalking UI, view trace data at http://localhost:8701/userFeign/1, and view the topology graph.

Performance Profiling

To simulate a slow request, add a 5‑second sleep in sky-user-service ’s getByUsername method. After invoking the endpoint, create a profiling task in SkyWalking, run the test several times, and click “Analyze”. The Thread Stack view reveals the slow operation and points to the exact line in UserFeignController.

Custom Trace

Use the @Trace annotation for method‑level tracing. Add the apm-toolkit-trace dependency to sky-feign-service and create a CustomTraceController with a test endpoint. Implement a service method annotated with @Trace and additional @Tag annotations to capture parameters and results.

<dependency>
  <groupId>org.apache.skywalking</groupId>
  <artifactId>apm-toolkit-trace</artifactId>
  <version>9.1.0</version>
</dependency>

Invoke the custom endpoint (e.g., http://localhost:8701/trace/annotation?userId=1) to see method‑level trace data and tagged results.

ActiveSpan Logging

Log messages directly to SkyWalking using ActiveSpan methods ( debug, info, error) inside a service method. Errors appear in red in the UI, and detailed logs are viewable in the trace details.

@Service
public class CustomTraceServiceImpl implements CustomTraceService {
    @Override
    public CommonResult<User> activeSpan(Long userId) {
        ActiveSpan.debug("activeSpan debug message...");
        ActiveSpan.info("activeSpan info message...");
        ActiveSpan.error("activeSpan error message...");
        return userService.getUser(userId);
    }
}

OpenTracing Usage

Add the apm-toolkit-opentracing dependency to sky-feign-service. In a service method, create a manual span to monitor a specific code segment:

Tracer tracer = new SkywalkingTracer();
Tracer.SpanBuilder spanBuilder = tracer.buildSpan("/trace-span/openTracing");
Span span = spanBuilder.withTag("tag", "openTracing").startManual();
// business logic
span.finish();

Calling the endpoint (e.g., http://localhost:8701/trace/openTracing?userId=1) shows the total request time (~1000 ms) and the traced segment time (~6 ms).

Conclusion

The guide demonstrates how to use SkyWalking for request‑level, method‑level, and code‑segment tracing in microservices, highlighting its low intrusion for basic tracing and richer capabilities for deeper analysis.

References

Official documentation: https://skywalking.apache.org/docs/