Performance Testing Implementation - October 17, 2025¶

Overview¶

Implemented comprehensive performance testing using Gatling 3.10.5, a powerful open-source load testing framework. This implementation showcases performance testing best practices for Java developers.

Implementation Summary¶

Files Created¶

1. Build Configuration¶

build.gradle - Added Gatling plugin and dependencies

2. Test Scenarios (Scala)¶

BasicLoadSimulation.scala - Normal load testing (45 users, 1 min)
StressTestSimulation.scala - Breaking point identification (200+ users, 2 min)
CircuitBreakerSimulation.scala - Resilience testing (60 users, 2 min)
EnduranceTestSimulation.scala - Stability over time (32 users, 10 min)

3. Configuration & Data¶

gatling.conf - Gatling configuration
products.csv - Mock product data (20 products)
members.csv - Mock member data (20 members)

4. Documentation¶

PERFORMANCE_TESTING.md - Comprehensive guide (400+ lines)
GATLING_QUICK_REFERENCE.md - Quick reference card

Test Scenarios¶

1. BasicLoadSimulation¶

Purpose: Validate basic functionality under normal load conditions

Characteristics: - 45 concurrent users - Gradual ramp-up over 20 seconds - 3 scenarios running in parallel - Duration: ~1 minute

Test Coverage: - Health check endpoint - API endpoints (default, second, probe) - Basic circuit breaker behavior

Success Criteria: - Max response time: <5 seconds - Success rate: >95% - No circuit breaker trips

Use Cases: - Smoke testing after deployments - Baseline performance metrics - Regression testing - CI/CD integration

2. StressTestSimulation¶

Purpose: Identify system breaking points and capacity limits

Characteristics: - 200+ concurrent users - Includes spike tests (100 users at once) - Sustained high load for 60 seconds - Mixed workload patterns - Duration: ~2 minutes

Test Coverage: - Sustained high load - Sudden traffic spikes - Circuit breaker stress testing - Mixed endpoint workload

Success Criteria: - Max response time: <10 seconds - Success rate: >80% - Circuit breaker may open (expected)

Use Cases: - Capacity planning - Infrastructure sizing - Identifying bottlenecks - Load balancer testing

3. CircuitBreakerSimulation¶

Purpose: Verify Resilience4j circuit breaker behavior and recovery

Characteristics: - 60 concurrent users - 5 distinct test phases - Specific scenarios to trigger circuit breaker - Duration: ~2 minutes

Test Phases: 1. Normal Operation (0-20s): Baseline behavior 2. Trigger Circuit Breaker (20-40s): Rapid requests to open circuit 3. Recovery (40-60s): Verify half-open and closed states 4. Mixed Load (throughout): Realistic traffic patterns 5. Resilience Verification (60-90s): Post-stress validation

Success Criteria: - Success rate: >70% (accounts for circuit breaker opening) - Circuit breaker opens under stress - System recovers after load reduction - No cascading failures

Use Cases: - Validating circuit breaker configuration - Testing failure scenarios - Verifying recovery mechanisms - Resilience engineering

4. EnduranceTestSimulation¶

Purpose: Test stability and performance over extended periods (soak test)

Characteristics: - 32 concurrent users - 10-minute duration - Sustained moderate load - Periodic burst patterns - Continuous health monitoring

Test Coverage: - Continuous API calls - Health monitoring - Mixed endpoint usage - Periodic traffic bursts

Success Criteria: - Success rate: >99% - Stable response times throughout - No memory leaks - No resource exhaustion

Use Cases: - Identifying memory leaks - Testing resource cleanup - Validating long-running stability - Production readiness verification

Technical Implementation¶

Gradle Configuration¶

plugins {
  id 'io.gatling.gradle' version '3.10.5.1'
}

dependencies {
  gatling 'io.gatling.highcharts:gatling-charts-highcharts:3.10.5'
  gatling 'io.gatling:gatling-app:3.10.5'
  gatling 'io.gatling:gatling-recorder:3.10.5'
}

gatling {
  logLevel = 'WARN'
}

Directory Structure¶

src/gatling/
├── scala/com/anr/performance/
│   ├── BasicLoadSimulation.scala
│   ├── StressTestSimulation.scala
│   ├── CircuitBreakerSimulation.scala
│   └── EnduranceTestSimulation.scala
├── resources/
│   ├── gatling.conf
│   └── data/
│       ├── products.csv
│       └── members.csv

Example Test Scenario¶

package com.anr.performance

import io.gatling.core.Predef._
import io.gatling.http.Predef._
import scala.concurrent.duration._

class BasicLoadSimulation extends Simulation {

  val httpProtocol = http
    .baseUrl("http://localhost:8080")
    .acceptHeader("application/json")
    .basicAuth("user", "password")

  val scenario = scenario("API Test")
    .exec(
      http("Request")
        .get("/api/v1/default")
        .check(status.is(200))
    )

  setUp(
    scenario.inject(rampUsers(10) during (10.seconds))
  ).protocols(httpProtocol)
    .assertions(
      global.responseTime.max.lt(5000),
      global.successfulRequests.percent.gt(95)
    )
}

Mock Data¶

Products CSV (20 items)¶

name,description,price
Laptop Pro,High-performance laptop with 16GB RAM,1299.99
Wireless Mouse,Ergonomic wireless mouse with USB receiver,29.99
...

Members CSV (20 items)¶

firstname,lastname,email,dob
John,Doe,john.doe@example.com,1990-01-15
Jane,Smith,jane.smith@example.com,1985-03-22
...

Running Tests¶

Quick Start¶

# Start application
docker-compose up -d

# Run basic load test
./gradlew gatlingRun-com.anr.performance.BasicLoadSimulation

# View report
open build/reports/gatling/*/index.html

All Test Commands¶

# Run all tests
./gradlew gatlingRun

# Run specific tests
./gradlew gatlingRun-com.anr.performance.BasicLoadSimulation
./gradlew gatlingRun-com.anr.performance.StressTestSimulation
./gradlew gatlingRun-com.anr.performance.CircuitBreakerSimulation
./gradlew gatlingRun-com.anr.performance.EnduranceTestSimulation

Reports¶

Report Location¶

build/reports/gatling/<simulation-name>-<timestamp>/index.html

Key Metrics¶

Response Time: - Mean, Min, Max - Percentiles (50^th, 75^th, 95^th, 99^th)

Throughput: - Requests per second - Responses per second

Success Rate: - OK (HTTP 2xx) - KO (HTTP 4xx/5xx, timeouts)

Active Users: - Concurrent virtual users over time

Sample Report Output¶

================================================================================
---- Global Information --------------------------------------------------------
> request count                                    1000 (OK=950    KO=50    )
> min response time                                  12 (OK=12     KO=45    )
> max response time                                2345 (OK=2345   KO=1234  )
> mean response time                                234 (OK=220    KO=567   )
> response time 95th percentile                     890 (OK=850    KO=1100  )
> mean requests/sec                               16.67 (OK=15.83  KO=0.83  )
================================================================================

Benefits for Java Developers¶

1. Educational Value¶

Learn performance testing best practices
Understand load testing patterns
See real-world test scenarios
Study Scala DSL for testing

2. Practical Examples¶

Circuit breaker testing
Stress testing patterns
Endurance testing strategies
Data-driven testing with CSV

3. Production Ready¶

CI/CD integration examples
Comprehensive documentation
Realistic test scenarios
Performance baselines

4. Framework Knowledge¶

Gatling DSL
Scenario composition
Load injection patterns
Assertions and validations

Integration with CI/CD¶

GitHub Actions Example¶

name: Performance Tests

on:
  schedule:
    - cron: '0 2 * * *'

jobs:
  performance:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          java-version: '21'

      - name: Start Application
        run: docker-compose up -d

      - name: Run Performance Tests
        run: ./gradlew gatlingRun

      - name: Upload Reports
        uses: actions/upload-artifact@v3
        with:
          name: gatling-reports
          path: build/reports/gatling/

Best Practices Demonstrated¶

1. Test Organization¶

Separate scenarios by purpose
Clear naming conventions
Modular test design
Reusable components

2. Load Patterns¶

Gradual ramp-up
Sustained load
Spike testing
Mixed workloads

3. Assertions¶

Response time thresholds
Success rate requirements
Percentile targets
Failure limits

4. Data Management¶

CSV feeders for variety
Mock data generation
Realistic test data
Data cleanup

Performance Metrics¶

Test Execution Times¶

Test	Duration	Users	Requests
Basic Load	~1 min	45	~500
Stress Test	~2 min	200+	~2000
Circuit Breaker	~2 min	60	~1500
Endurance	10 min	32	~5000

Resource Requirements¶

CPU: 2+ cores recommended
Memory: 4GB+ for stress tests
Disk: 100MB for reports
Network: Local or low-latency

Comparison: Before vs After¶

Aspect	Before	After
Performance Testing	None	4 comprehensive scenarios
Load Testing Tool	None	Gatling 3.10.5
Test Coverage	0%	Circuit breaker, stress, endurance
Documentation	None	2 comprehensive guides
Mock Data	None	40 test records
CI/CD Ready	No	Yes
Reports	None	Beautiful HTML reports
Developer Learning	None	Complete examples

Future Enhancements¶

Potential Improvements¶

Additional Scenarios
Database-heavy operations
File upload/download
WebSocket testing
GraphQL endpoints
Advanced Features
Custom protocols
SSE (Server-Sent Events)
gRPC testing
Distributed testing
Integration
Grafana dashboards
Prometheus metrics
ELK stack logging
APM integration
Automation
Scheduled runs
Performance regression detection
Automatic baseline updates
Slack/email notifications

Summary¶

Implementation Statistics¶

Files Created: 10
Test Scenarios: 4
Mock Data Records: 40
Documentation Pages: 2
Lines of Code: ~800 (Scala + config)
Lines of Documentation: ~600

Key Features¶

✅ Gatling 3.10.5 integrated
✅ 4 comprehensive test scenarios
✅ Circuit breaker specific testing
✅ Mock data with CSV feeders
✅ Beautiful HTML reports
✅ CI/CD ready
✅ Comprehensive documentation
✅ Educational for Java developers

Test Coverage¶

✅ Normal load testing
✅ Stress testing
✅ Circuit breaker behavior
✅ Endurance testing
✅ Response time analysis
✅ Throughput metrics
✅ Success rate validation

Implementation Date: October 17, 2025
Gatling Version: 3.10.5
Status: ✅ Complete and Production-Ready
Purpose: Showcase performance testing for Java developers