A system detection method and apparatus. Throughput and response time of a system are acquired. Throughput reflects the number of requests processed by the system that are received from outside the system. The response time reflects time required to process requests from outside the system. A system performance characteristic parameter based on the throughput and response time is obtained and used to describe congestion of the system to determine bottlenecks in the system by at least obtaining system performance characteristic parameter based on the throughput and the response time and conducting noise filtering on the system performance characteristic parameter. A bottleneck is determined based on the noise filtered system performance characteristic parameter. The system detection method and apparatus allow detecting a bottleneck and flow control are provided in a simple and effective way to ensure that requests are processed in time.