Reliability (Pillar: Reliability)
The Reliability pillar of WAF++ defines requirements, principles and measurable controls to operate cloud workloads in a resilient, recoverable and demonstrably available manner.
Reliability is not accidental. It is an architecture outcome achieved through measurable goals, technical enforcement and continuous testing – not through hope.
What does Reliability mean in WAF++?
Reliability means that an organization has demonstrable control over the following dimensions:
| Dimension | What is controlled? | WAF-REL Control |
|---|---|---|
SLO & SLA Governance |
Are availability and latency targets documented, measured and covered by alerts? |
WAF-REL-010 |
Health Monitoring |
Are health checks and readiness probes configured for all services? |
WAF-REL-020 |
High Availability |
Are all production workloads distributed across at least 2 Availability Zones? |
WAF-REL-030 |
Backup & Recovery |
Are automated backups configured and recovery procedures demonstrably tested? |
WAF-REL-040 |
Resilience Patterns |
Are circuit breakers, timeouts and retry logic configured for all dependencies? |
WAF-REL-050 |
Incident Response |
Are documented runbooks, on-call rotation and MTTR tracking in place? |
WAF-REL-060 |
Disaster Recovery Testing |
Are DR tests conducted at least twice a year and documented? |
WAF-REL-070 |
Dependency Resilience |
Are all critical dependencies inventoried and equipped with fallback behavior? |
WAF-REL-080 |
Chaos Engineering |
Are structured chaos experiments used to validate resilience claims? |
WAF-REL-090 |
Reliability Debt |
Are known reliability debts documented, assessed and provided with a remediation plan? |
WAF-REL-100 |
Why is Reliability its own pillar?
Reliability is cross-cutting: it emerges from Security, Operations, Architecture and Governance. Nevertheless, Reliability is an independent discipline because:
-
It has its own measurement dimension: SLOs, MTTR, RTO/RPO, Error Budget
-
It requires specific technical controls that no other pillar covers
-
It addresses reliability debt as a structural risk – analogous to technical debt
-
Reliability must be anchored as a strategic basis for decision-making in architecture processes
-
Brownfield and greenfield scenarios require fundamentally different approaches
| Reliability without measurement is wishful thinking. Backups without restore tests are untested hopes. Multi-AZ without a failover test is an architectural claim, not a proven guarantee. |
Demarcation from other pillars
-
Security addresses: access control, encryption, incident response from a security perspective.
-
Operations addresses: change management, deployment processes, operational excellence.
-
Architecture addresses: system design, patterns, quality of technical decisions.
-
Reliability addresses: measurable availability, recoverability, resilience against failures.
Reliability presupposes that infrastructure exists and is monitored, and extends this with fault tolerance, recovery capacity, resilience patterns and structured failure management.
Controls Overview
The Reliability pillar is operationalized by 10 measurable controls (WAF-REL-010 to WAF-REL-100).
| Control ID | Title | Severity | Automatable |
|---|---|---|---|
SLA & SLO Definition Documented |
Critical |
Medium |
|
Health Checks & Readiness Probes Configured |
High |
High |
|
Multi-AZ High Availability Deployment |
High |
High |
|
Backup & Recovery Validation |
Critical |
High |
|
Circuit Breaker & Timeout Configuration |
High |
High |
|
Incident Response & Runbook Readiness |
High |
Medium |
|
Disaster Recovery Testing |
High |
Partial |
|
Dependency & Upstream Resilience Management |
Medium |
Medium |
|
Chaos Engineering & Fault Injection |
Medium |
Medium |
|
Reliability Debt Register & Quarterly Review |
Medium |
Low–Medium |
Quick Start
New to the Reliability pillar? Recommended reading order:
-
Definition – What is Reliability as a discipline?
-
Scope – Brownfield vs. Greenfield, what is in scope?
-
Reliability Principles – 7 core principles
-
Design Principles – 8 technical architecture principles
-
Controls – The 10 measurable controls
-
Maturity Model – Where does my organization stand?
-
Best Practices – How to implement it concretely?