Glossary
Performance testing terms, without vendor fog.
Short definitions for the metrics, run artifacts, and reliability concepts you will meet while planning and reading a Maxoperf test.
engines
- Taurus
Taurus is an open-source automation-friendly test runner format that can orchestrate tools such as JMeter and other performance engines.
load testing
- BYOC
BYOC means bringing your own compute or private location so runners execute near systems that should not be public.
- Run artifacts
Run artifacts are the files a performance run needs or produces, such as scenario bundles, logs, result exports, manifests, and reports.
- Virtual users (VUs)
Virtual users are simulated users or clients that execute a test scenario concurrently to create controlled load against an authorized target.
maxoperf concepts
- Real-User Monitoring (RUM)
RUM — passive measurement of real browser sessions via a small JS beacon that reports page-views, Core Web Vitals, JS errors, and slow XHR calls.
- Synthetic monitor
Synthetic monitor — a continuous probe that fires periodic checks (HTTP, API workflow, browser flow, DNS, SSL, …) from one or more regions and alerts when the target fails.
metrics
- Core Web Vitals
Core Web Vitals — Google's standard set of user-experience metrics: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS).
- p95 and p99 latency
p95 and p99 latency show the slow tail of response times: 95% or 99% of requests were at or below that value.
- Requests per second (RPS)
RPS measures how many requests a system or test sends each second; it is useful only when paired with latency, errors, and request mix.
reliability
- Error budget
Error budget — the slice of allowed unavailability under an SLO (e.g. 99.9 % over 30 days = ~43 minutes of allowed downtime).
- Service Level Objective (SLO)
SLO — a target percentage (uptime, latency p95, error rate) measured over a rolling or calendar window, with an associated error budget.
- Uptime
Uptime — the percentage of time a service is responding correctly to its consumers, typically measured by a continuous synthetic monitor.