/google-cloud-waf-reliability

name: google-cloud-waf-reliability
metadata:
  category: WellArchitectedFramework
description: >-
  Generates guidance for reliability, resilience, availability, redundancy,
  fault-tolerance, and disaster recovery (DR) for Google Cloud workloads based
  on the design principles and recommendations in the Google Cloud
  Well-Architected Framework. Use when the user asks to evaluate, design, or
  improve the reliability, resilience, availability, or disaster recovery
  capabilities of Google Cloud workloads.

Google Cloud Well-Architected Framework skill for the Reliability pillar

Overview

The Reliability pillar of the Google Cloud Well-Architected Framework provides principles and recommendations to help you design, deploy, and manage reliable, resilient, and highly available workloads in Google Cloud. A reliable system consistently performs its intended functions under defined conditions, is resilient to failures, and recovers gracefully from disruptions, thereby minimizing downtime, enhancing user experience, and ensuring data integrity.

Core principles

The recommendations in the reliability pillar of the Well-Architected Framework are aligned with the following core principles:

• **Define reliability based on user-experience goals**: Measurement of

reliability should reflect the actual experience of the system's users rather than merely relying on infrastructure metrics. Focus on outcomes that matter most to users. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/define-reliability-based-on-user-experience-goals.md.txt

• **Set realistic targets for reliability**: Determine appropriate Service

Level Objectives (SLOs) that balance the cost and complexity of maximizing availability against business requirements. Provide guidance on defining Service Level Objectives (SLOs) based on monitoring signals, error budgets, and user experience goals. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/set-targets.md.txt

• **Build highly available systems through resource redundancy**: Eliminate

single points of failure by duplicating critical components across zones and regions to maintain operations during localized outages. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/build-highly-available-systems.md.txt

• **Take advantage of horizontal scalability**: Design system architectures to

scale horizontally (adding more instances) to seamlessly accommodate load fluctuations and improve overall fault tolerance. Incorporate proactive capacity planning to monitor and adjust project quotas and resource availability anticipating sudden load spikes. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/horizontal-scalability.md.txt

• **Detect potential failures by using observability**: Implement thorough

monitoring, logging, and alerting systems to proactively detect, diagnose, and address anomalies before they cause user-facing issues. Monitor the golden signals (latency, traffic, errors, and saturation) and set up alerts for when the signals cross specified thresholds. Use Cloud Monitoring to build comprehensive dashboards for the golden signals. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/observability.md.txt

• **Design for graceful degradation**: Architect systems to maintain critical

functionality, even if at reduced performance or with limited features, when dependencies fail or the system experiences extreme stress. To avoid cascading failures, recommend setting up alerts to detect failures early, using the circuit-breaker pattern, handling timeouts effectively to release blocked resources, utilizing retries with exponential backoff and jitter to avoid overwhelming recovering backend systems, and returning custom error responses or static fallback pages. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/graceful-degradation.md.txt

• **Perform testing for recovery from failures**: Build confidence in system

resilience by continuously simulating failures and verifying the effectiveness of automated and manual recovery procedures. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/perform-testing-for-recovery-from-failures.md.txt

• **Perform testing for recovery from data loss**: Regularly test backup and

restore protocols to ensure rapid recovery from data corruption or loss, remaining within the defined Recovery Time Objective (RTO) and Recovery Point Objective (RPO). Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/perform-testing-for-recovery-from-data-loss.md.txt

• **Conduct thorough postmortems**: Foster a blameless culture by investigating

outages comprehensively to understand root causes, followed by implementing measures that prevent recurrence. Grounding document: https://docs.cloud.google.com/architecture/framework/reliability/conduct-postmortems.md.txt

Relevant Google Cloud products

The following are _examples_ of Google Cloud products and features that are relevant to reliability:

• **Compute**: Compute Engine Managed Instance Groups (MIGs), Google Kubernetes

Engine (GKE), Cloud Run

• **Networking**: Cloud Load Balancing, Cloud CDN, Cloud DNS
• **Storage and databases**: Cloud Storage (multi-region), Cloud SQL High

Availability, Spanner, Filestore, Firestore

• **Operations**: Cloud Monitoring, Cloud Logging, Google Cloud Managed Service

for Prometheus

• **Disaster recovery**: Backup and DR Service, Filestore backups

Workload assessment questions

Ask appropriate questions to understand the reliability-related requirements and constraints of the workload and the user's organization. Choose questions from