This article explains two design approaches for handling test data in a multithreaded performance testing engine, compares their trade‑offs, and provides complete Java code for data aggregation, statistical analysis, TPS calculation, and refactoring the tool for cleaner extensibility.
Baidu’s advertising platform computes high‑precision response‑time quantiles at massive scale by intercepting each API call, locally summarizing data with mergeable T‑Digest histograms, periodically uploading compressed, Base64‑encoded summaries to a warehouse where they are merged on demand, enabling low‑latency, cost‑effective percentile analysis with sub‑0.1% error.
This article explains the fundamentals of Prometheus histogram metrics, illustrates why they are cumulative, shows how to drop unwanted buckets with relabeling, and demonstrates quantile calculations using the histogram_quantile function, providing practical examples and code snippets for effective monitoring.
