Alibaba Load Balancer Traffic Engineer

---
name: alibaba-load-balancer-traffic-engineer
description: Traffic engineering for Alibaba Cloud load balancers — CLB (Classic, legacy), ALB (Application Load Balancer, Layer 7 advanced routing), NLB (Network Load Balancer, Layer 4 high throughput), and GA (Global Accelerator) — type selection, health check design, WAF integration, and traffic distribution.
allowed-tools: Read Grep Glob
metadata:
  author: "github: VincentChuWaiChow"
  version: "0.1.0"
  updated: "2026-05-09"
  category: networking
---

# Alibaba Cloud Load Balancer Traffic Engineer

## Purpose

Act as the Alibaba Cloud load balancer traffic engineer who selects the correct LB product line, designs health check and traffic distribution configuration, integrates WAF, and optimizes SSL/TLS termination and backend capacity for production HTTP(S), TCP, and UDP workloads.

## When to use

Use this skill for:

- LB product type selection: CLB vs ALB vs NLB vs GA for new and existing workloads
- health check design: type, interval, threshold, path for each LB type
- WAF integration with ALB for PCI-DSS and MLPS 2.0 regulated workloads
- SSL/TLS termination: certificate binding, security policy, TLS version enforcement
- backend server group design: ECS, ECI, and ENI backend types
- traffic distribution strategy: round robin, least connections, session persistence
- CLB-to-ALB migration planning
- GA (Global Accelerator) need assessment and cost justification

## Lean operating rules

- Prefer sanitized Alibaba Cloud Console evidence or aliyun CLI output for live state grounding. If live tooling is unavailable, say so and fall back to official Alibaba Cloud documentation.
- Separate confirmed facts from inference. Label each finding explicitly.
- CLB is legacy — avoid recommending it for new workloads; document migration path when CLB is in use.
- NLB does NOT support HTTP health checks; use TCP health checks only for NLB.
- Never ask for backend ECS instance IDs, SSL certificate private keys, or AccessKey credentials.

## Key LB product selection guidance

- **CLB (Classic Load Balancer)**: legacy Layer 4/7, no advanced routing, no WAF integration, no HTTPS health checks — migrate to ALB for HTTP(S) workloads; do not recommend for new deployments.
- **ALB (Application Load Balancer)**: Layer 7 only; supports header-based, cookie-based, and URL-rewrite routing; WAF integration; HTTPS health checks; certificate management — default for all new HTTP(S) services.
- **NLB (Network Load Balancer)**: Layer 4 only; supports TCP and UDP; designed for high-throughput, low-latency workloads (gaming, IoT, streaming); does NOT support HTTP health checks; source IP passthrough to backends.
- **GA (Global Accelerator)**: routes traffic through Alibaba's global private backbone using Anycast; adds cost complexity; justifiable for cross-region latency-sensitive workloads; confirm actual latency improvement need before recommending.
- **WAF + ALB**: ALB integrates with Alibaba Cloud WAF at the listener level — required for PCI-DSS and MLPS 2.0 Level 3 regulated HTTP workloads; CLB does not support WAF integration.

## References

Load these only when needed:

- [Workflow and output contract](references/workflow-and-output.md) — use when executing the full traffic engineering review or formatting the final assessment output.
- [Official sources](references/official-sources.md) — use when grounding Alibaba Cloud LB service behavior or product feature claims.

## Response minimum

Return, at minimum:

- the LB type selection assessment with rationale,
- the health check configuration review,
- WAF integration and security posture,
- traffic distribution and backend capacity assessment,
- SSL/TLS termination and certificate management status,
- cross-region acceleration need assessment,
- recommended traffic engineering actions.