Table of Contents
Why Zero-Downtime Matters
Every minute of downtime during deployments has a cost — lost sales, damaged reputation, violated SLAs. A properly architected deployment pipeline eliminates deployment-related downtime entirely.
Blue-Green Deployment
Maintain two identical production environments (blue and green). Deploy to the inactive environment. Test. Switch traffic. Blue-green enables instant rollback — just switch traffic back to the previous environment.
Canary Release
Route a small percentage of traffic (1-5%) to the new version while most traffic continues to the old version. Monitor error rates. Gradually increase traffic to the new version. Canary releases detect issues before they affect all users.
Rolling Update
Replace old instances with new ones gradually. In a 4-server cluster, take one server down, deploy new code, bring it back, repeat. Always maintains N-1 capacity during deployment.
Health Checks
All strategies depend on reliable health checks. Configure NGINX or load balancer to only route traffic to instances passing health checks: returning 200 OK from /health endpoint.
FAQ
What is the simplest zero-downtime strategy?
Blue-green deployment. It requires only two servers and is straightforward to implement with NGINX upstream switching or DNS-level traffic routing.
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Scalable VPS for Zero-Downtime Architecture
Multiple VPS instances, load balancing, NVMe storage — deploy without downtime.
