Why Do ab and wrk Produce Disparate Results When Testing a Go HTTP Server?

Go HTTP Server Testing: Understanding the Disparity Between ab and wrk Results

Introduction

Load testing plays a crucial role in determining the performance capabilities of a server. However, discrepancies can arise among different benchmarking tools, as exemplified by the ab and wrk tools when testing a Go HTTP server. This article aims to elucidate these differences and shed light on the underlying factors that contribute to the disparity in results.

ab vs. wrk

ab and wrk are two commonly used HTTP load testing tools. While both serve similar purposes, they exhibit distinct characteristics and preferences.

• ab is a more traditional tool designed for HTTP/1.0 testing and does not support keep-alive connections. It is also generally considered less reliable than wrk.
• wrk, on the other hand, is a more modern tool tailored for HTTP/1.1 and HTTP/2 testing. It supports keep-alive connections and provides more detailed performance metrics.

Factors Influencing Disparity

The substantial difference in results between ab and wrk can be attributed to the following factors:

• Version Differences: ab follows the HTTP/1.0 protocol, while wrk supports HTTP/1.1 and HTTP/2. This leads to differences in request handling and performance.
• Keep-Alive Connections: ab does not support keep-alive connections, whereas wrk does. Keep-alive connections reduce overhead by maintaining established connections, resulting in higher request throughput.
• Latency Measurement: wrk provides more detailed latency metrics compared to ab. By reporting both average latency and distribution, wrk offers a clearer understanding of performance characteristics.
• Execution Duration: The test durations for ab and wrk differ, with ab running for 12 seconds and wrk for 5 seconds. This difference can affect the overall results.

Additional Considerations

Apart from the tool-specific factors, the following aspects can also influence benchmark outcomes:

• Machine Configuration: The performance of a server depends on the hardware and operating system it runs on. Factors such as CPU cores, memory, and network configuration can impact test results.
• Concurrent Requests: The number of concurrent requests during testing can significantly affect the server's performance.
• Server Code: The server code being tested can introduce performance bottlenecks or optimization opportunities.

Conclusion

Understanding the underlying factors responsible for discrepancies in HTTP load testing tools is crucial for interpreting results accurately. With its advanced capabilities and support for modern HTTP protocols, wrk is generally preferred over ab for Go HTTP server testing. Keep in mind the limitations and potential sources of performance variability when drawing conclusions or comparing results from different benchmarking tools.

The above is the detailed content of Why Do ab and wrk Produce Disparate Results When Testing a Go HTTP Server?. For more information, please follow other related articles on the PHP Chinese website!