Belajar Quality Engineer - Reliability & Chaos Testing

#Pendahuluan

Setelah di episode 13 kita mempelajari security quality engineering, pada episode ini kita mempelajari reliability & chaos testing — bagaimana menguji ketahanan sistem menggunakan chaos engineering. Reliability engineering memastikan sistem bisa bertahan dari failure dan recover dengan cepat.

Mengapa reliability & chaos testing penting? Karena di production, hal yang tidak terduga pasti terjadi: server crash, network failure, database down. Dengan chaos testing, kalian bisa memastikan sistem bisa bertahan dari failure dan recover dengan cepat.

#Chaos Engineering

#Konsep Chaos Engineering

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Chaos Engineering:
├── Definition:
│   ├── Deliberately inject failures
│   ├── Observe system behavior
│   └── Improve resilience
├── Principles:
│   ├── Build hypothesis
│   ├── Run experiments
│   ├── Analyze results
│   └── Improve system
└── Benefits:
    ├── Find weaknesses before production
    ├── Build confidence in system
    └── Improve incident response

#Chaos Experiments

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Chaos Experiments:
├── Infrastructure:
│   ├── Kill random server
│   ├── Network partition
│   ├── Disk failure
│   └── CPU/memory stress
├── Application:
│   ├── Service failure
│   ├── Database failure
│   ├── Cache failure
│   └── External dependency failure
└── Network:
    ├── Latency injection
    ├── Packet loss
    ├── DNS failure
    └── Bandwidth limitation

#Resilience Testing

#Resilience Patterns

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Resilience Patterns:
├── Circuit Breaker:
│   ├── Stop calling failing service
│   ├── Fallback behavior
│   └── Auto-recovery
├── Retry:
│   ├── Retry failed requests
│   ├── Exponential backoff
│   └── Max retry limit
├── Timeout:
│   ├── Set request timeout
│   ├── Graceful degradation
│   └── Fallback behavior
├── Bulkhead:
│   ├── Isolate failures
│   ├── Resource allocation
│   └── Graceful degradation
└── Fallback:
    ├── Alternative behavior
    ├── Cached data
    └── Default response

#Game Days

#Game Day Planning

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Game Day:
├── Definition:
│   ├── Scheduled chaos experiment
│   ├── Team coordination
│   └── Learning opportunity
├── Planning:
│   ├── Define scope
│   ├── Set success criteria
│   ├── Prepare rollback plan
│   └── Notify stakeholders
├── Execution:
│   ├── Inject failure
│   ├── Observe behavior
│   ├── Document findings
│   └── Restore normal
└── Post-mortem:
    ├── What went well?
    ├── What needs improvement?
    └── Action items

Note

Game days harus dilakukan di environment staging, bukan production. Mulai dengan failure yang kecil dan bertahap tingkatkan. Yang penting adalah belajar dari experiment, bukan breaking things.

#Practical: Chaos Test Plan

yaml

chaos_test_plan:
  experiment_1:
    name: "Server Failure"
    scope: "Web server cluster"
    hypothesis: "System can handle single server failure"
    method: "Kill random web server"
    success_criteria: "No user impact, auto-recovery"
  experiment_2:
    name: "Database Failure"
    scope: "Primary database"
    hypothesis: "System can failover to replica"
    method: "Shutdown primary database"
    success_criteria: "Auto-failover within 30 seconds"
  experiment_3:
    name: "Network Latency"
    scope: "API Gateway"
    hypothesis: "System handles latency gracefully"
    method: "Add 2s latency to all requests"
    success_criteria: "Timeout handling, graceful degradation"

Tip

Mulai dengan chaos testing sederhana seperti killing random server. Setelah familiar, tingkatkan ke complexity yang lebih tinggi seperti network partition atau database failure.

#Penutup

Pada episode 14 ini, kalian telah mempelajari reliability & chaos testing.

Inti yang harus dibawa pulang:

Chaos engineering: deliberately inject failures, observe behavior, improve.
Resilience patterns: circuit breaker, retry, timeout, bulkhead, fallback.
Game days: scheduled chaos experiments untuk learning.
Chaos testing harus dilakukan di staging, bukan production.

Di episode 15 selanjutnya, kita akan membahas observability for quality — bagaimana menggunakan observability untuk memantau kualitas di production. Sampai jumpa di episode 15!