Performance Testing at Scale

From Locust to K6 Migration Strategy

In performance testing, choosing the right tool impacts scalability and reliability. This technical guide analyzes migrating from Locust to K6, focusing on architectural differences and implementation patterns.

Photo by Joshua Sortino on Unsplash

Tool Comparison Matrix

Key technical differences between Locust and K6:

Protocol Support

• Locust: HTTP/HTTPS, WebSocket with custom implementations
• K6: HTTP/HTTPS, WebSocket, gRPC native support

Scripting Language

• Locust: Python
• K6: JavaScript (ES6+)

Resource Utilization

• Locust: Python GIL limitations
• K6: Go runtime, better CPU utilization

Metrics Collection

• Locust: In-memory with CSV export
• K6: Prometheus, InfluxDB, Cloud integrations

Implementation Examples

Let’s examine equivalent test scenarios in both tools.

Performance Test Implementation Comparison

# Locust Implementation
from locust import…