What are the Apdex threshold calculation rules?

The Apdex (Application Performance Index) threshold calculation rules are used to measure user satisfaction with application performance by categorizing response times into three levels: Satisfied, Tolerating, and Frustrated.

1. Threshold Definition:

   • A single threshold value (T) is defined, representing the maximum response time considered "Satisfactory."
   • The "Tolerating" range is from T to 4T.
   • The "Frustrated" range is any response time above 4T.

2. Calculation Formula:
   The Apdex score is calculated as:

   $\text{Apdex} = \frac{\text{Satisfied} + \frac{\text{Tolerating}}{2}}{\text{Total Requests}}$

   Where:

   • Satisfied = Requests with response time ≤ T.
   • Tolerating = Requests with response time > T but ≤ 4T.
   • Total Requests = Sum of all requests in the three categories.

3. Example:
   If T = 2 seconds:

   • Responses ≤ 2s → Satisfied.
   • Responses > 2s and ≤ 8s → Tolerating.
   • Responses > 8s → Frustrated.

For cloud-based performance monitoring, Tencent Cloud's Application Performance Monitoring (APM) service can help track Apdex scores by analyzing response times and providing insights into user experience. It supports customizable thresholds and real-time alerts for performance degradation.