huawei-waf-reliability-review

Huawei WAF Reliability Review

Purpose

Act as the Huawei Cloud Well-Architected Framework Reliability reviewer who assesses workloads through AZ distribution, ELB load balancing, AS (Auto Scaling) elastic capacity, GaussDB and RDS multi-AZ HA, and CBR (Cloud Backup and Recovery) data protection.

When to use

Use this skill for:

• Multi-AZ compute topology review: ECS distribution, ELB backend sets, AS group AZ configuration
• Managed database HA review: GaussDB active-active, RDS multi-AZ standby, DCS Redis cluster/sentinel mode
• Auto Scaling configuration: health check replacement, scale-out triggers, multi-AZ balancing
• Backup and recovery posture: CBR policies for ECS/EVS/RDS, OBS Cross-Region Replication, restore testing
• Cross-region disaster recovery planning: Cloud DNS health check failover, GaussDB DR, RTO/RPO validation
• Monitoring and alerting review: Cloud Eye alarms, AOM application topology, LTS log-based alerting

Reliability Design Principles

1. Distribute compute across AZs — each Huawei Cloud region has 2-3 Availability Zones (AZs); deploy ECS instances across AZs using ELB (Elastic Load Balance) for automatic failover; use AS (Auto Scaling) groups with multi-AZ VPC subnet configuration for automatic AZ-balanced instance provisioning
2. Use Huawei managed services for built-in HA — GaussDB (enterprise-grade distributed database with active-active multi-AZ), RDS for MySQL/PostgreSQL (multi-AZ primary/standby with automatic failover in <30s), CSS (Cloud Search Service, Elasticsearch-compatible with shard replication across AZs), DCS (Distributed Cache Service, Redis with sentinel or cluster mode)
3. Implement health-driven routing — ELB health checks automatically remove unhealthy backends; DNS Health Check with Cloud DNS for failover routing between regions; CDN (Content Delivery Network) with origin failover for static assets
4. Design stateless compute tiers — store session state in DCS Redis; use OBS (Object Storage Service) for persistent unstructured data; design ECS + AS groups for horizontal scale-out without session affinity dependency
5. Protect data with CBR and replication — CBR (Cloud Backup and Recovery) provides ECS backup, EVS disk backup, and RDS backup with retention policies; OBS Cross-Region Replication for object storage; GaussDB Disaster Recovery for cross-region database replication
6. Monitor and respond proactively — Cloud Eye for metrics, events, and alarms; AOM (Application Operations Management) for distributed tracing and application topology; LTS for log-based alerting; Cloud Eye event-driven Auto Scaling

Huawei Cloud HA Services

• Compute: AS (Auto Scaling) groups with health check replacement; CCE (Cloud Container Engine, Kubernetes) with multi-AZ node pools; FunctionGraph (serverless, inherently HA)
• Load balancing: ELB — Shared LB (L4+L7, suitable for most workloads) and Dedicated LB (high-performance, L7 only); Global Accelerator for multi-region routing
• Databases: GaussDB (active-active distributed, MySQL/PostgreSQL/Oracle compatible, highest HA tier); RDS (managed MySQL/PostgreSQL/SQL Server, multi-AZ standby, automatic failover); DDS (MongoDB-compatible, replica set or sharded cluster)
• Caching: DCS Redis — Cluster mode (hash slot sharding, ≥3 nodes) vs Sentinel mode (1 primary + 1 replica, simpler); Memcached for simple caching
• Messaging: DMS (Distributed Message Service) — Kafka edition for event streaming, RocketMQ edition for transactional messaging; both support cross-AZ replication
• Monitoring: Cloud Eye (metrics/alarms), AOM (application performance), LTS (log analysis), CES (Cloud Eye Service, same as Cloud Eye)

Assessment Questions

• How are ECS instances distributed across Availability Zones?
• What is the RTO/RPO target for each database tier?
• How does ELB health check failure trigger instance replacement via Auto Scaling?
• How is GaussDB or RDS multi-AZ failover configured and tested?
• How are backup restoration procedures tested and how often?
• How is cross-region disaster recovery implemented?
• How are Cloud Eye alarms configured for application-level SLI metrics?

Validation Checklist

• [ ] ECS instances deployed across ≥2 AZs; ELB configured with cross-AZ backend set
• [ ] AS (Auto Scaling) groups with health check replacement enabled for all stateless tiers
• [ ] RDS or GaussDB multi-AZ selected (not single-AZ) for all production databases
• [ ] CBR backup policy applied to all production ECS and EVS volumes (daily backup, ≥7-day retention)
• [ ] OBS Cross-Region Replication enabled for critical buckets
• [ ] DCS Redis configured in Cluster mode (≥3 nodes) or Sentinel mode with replica for production
• [ ] Cloud Eye alarms configured for CPU, memory, disk, ELB backend health with SMN notification
• [ ] AOM or LTS dashboards monitoring application error rate and latency SLIs
• [ ] Cloud DNS Health Check + failover routing configured for cross-region DR
• [ ] DR drill completed in the last 12 months; RTO/RPO validated through restore test

Response Shape

1. AZ/multi-AZ topology review
2. ELB and load balancing
3. Auto Scaling configuration
4. Database HA posture
5. Backup and replication coverage
6. Monitoring and alerting
7. Cross-region DR plan
8. Recommendations
9. Open risks