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- Testing Load Designer
testing-load-designer_skill
- Python
5
GitHub Stars
1
Bundled Files
2 months ago
Catalog Refreshed
4 months ago
First Indexed
Readme & install
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Installation
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npx veilstrat add skill williamzujkowski/cognitive-toolworks --skill testing-load-designer- SKILL.md16.9 KB
Overview
This skill designs repeatable load testing scenarios for k6, JMeter, Gatling, or Locust, including ramp-up patterns, think time modeling, and SLI validation. It produces executable test scripts, a concrete test configuration, assertion thresholds, and an execution plan tailored to the chosen tool and test type.
How this skill works
Provide a target service URL, desired test type (load, stress, spike, soak), SLI requirements, and optional tool choice. The skill validates inputs, selects sensible defaults (k6 if unspecified), maps test type to a ramp pattern, models realistic think time, and emits a tool-specific script plus JSON configs and an execution checklist. It also flags abort conditions and suggests distributed or observability integrations when relevant.
When to use it
- Validate performance before a production release or major traffic event
- Establish baselines and capacity planning for backend services
- Simulate peak, spike, stress, or extended soak conditions
- Verify SLI/SLO compliance for latency, throughput, and error rates
- Exercise distributed system resilience under sustained load
Best practices
- Verify target URL accessibility and avoid running against production without approval
- Model think time with randomized distributions to mimic real users
- Start with a smoke test and low VU counts, then scale via staged ramps
- Map SLIs to tool-native assertions (k6 thresholds, JMeter assertions, Gatling assertions, Locust custom checks)
- Use synthetic data and never include hardcoded credentials or production PII
- Integrate metrics (Prometheus/Grafana or CloudWatch/Datadog) and set clear abort criteria
Example use cases
- k6 scripted load test for e-commerce checkout with gradual ramp-up and p95 latency threshold
- JMeter stress run to find breaking point using multi-stage ramps and duration assertions
- Gatling capacity test for JVM-based service with percentile assertions and CSV parameterization
- Locust soak test to detect memory leaks over multi-hour runs with master-worker distribution
- Spike test for flash-sale simulation: instant jump to peak VUs, short sustain, and rapid drop
FAQ
k6 is recommended for modern APIs due to its JavaScript scripting, built-in thresholds, and easy CI integration. Choose Gatling for JVM-heavy environments, JMeter for complex protocol coverage, and Locust if you prefer Python.
How do I translate SLIs into VUs?
Use the VU formula: VUs = (target_RPS × response_time_seconds) / (1 - think_time_ratio). Validate assumptions with a small pilot run and adjust think time and response-time estimates.