#load-testing

Load testing a web API with k6

Bài viết hướng dẫn kiểm thử tải (load testing) API web bằng công cụ k6, bao gồm các kịch bản kiểm thử dưới lưu lượng khói, trung bình và đột biến, đồng thời tích hợp checks, thresholds, scenarios và CI.

Lập trình viên phát triển API nên đọc bài này để hiểu cách kiểm tra hiệu suất và độ bền của ứng dụng dưới áp lực traffic thực tế, từ đó tối ưu hóa performance và tránh lỗi khi triển khai sản phẩm.

Vaadin 25.2: Build UIs in plain language, and call the browser from Java

Vaadin 25.2 introduces three major additions for Java-based UI development. First, AI controllers (GridAIController, ChartAIController, FormAIController) let end users build data grids, charts, and fill forms using natural-language prompts, with data never sent to the LLM for safety. Second, seven native browser APIs — Geolocation, Clipboard, Fullscreen, WakeLock, Page Visibility, WebShare, and Screen Orientation — are now accessible from server-side Java without writing JavaScript. Third, existing TestBench or Playwright end-to-end tests can be converted into Grafana k6 load tests via a Maven plugin. The release also graduates several components (Slider, Badge, Master-Detail Layout, Modular Upload) to GA, deepens Signals integration, adds security hardening (safe-by-default URLs, clickjacking protection, supply-chain delay for npm packages), and enhances Vaadin Copilot with an annotation/review workflow, customizable palette, and EU-hosted option.

How to generate real-world load tests using Grafana Cloud k6 and production telemetry

Production load tests often fail to reflect real traffic because they rely on arbitrary assumptions. By querying Prometheus/Mimir metrics in Grafana Cloud, teams can extract actual request rates, p95/p99 latency baselines, and traffic shape patterns to build data-driven k6 test configurations. The tutorial walks through four steps: finding real request rates, establishing latency thresholds, identifying traffic patterns (constant, stress, spike, endurance), and wiring everything into a k6 ramping-arrival-rate scenario. Results feed back into the same Grafana dashboards used to derive the test parameters, closing the observability-testing loop. Grafana Assistant can also automate this process using natural language to generate k6 scripts from production telemetry.