Selecting the Right Backup Data Center for Your Web Application

Designing DR Infrastructure for Web Applications

Imagine: at 3 AM, the primary AWS region fails, your service is down, and each hour of downtime costs thousands of dollars. Without a backup data center (DR Site), recovery could take hours. We design and implement Disaster Recovery solutions that minimize downtime. Implementing a DR Site is crucial for business continuity and disaster recovery planning. Over 5 years, we have delivered more than 20 projects for e-commerce and fintech. We know how to achieve RTO as low as 5 minutes.

Clients are often surprised that cold standby costs only 10% of production. For a medium project, that's $200 to $500 per month (20,000–50,000 rubles). However, recovery takes up to 8 hours. Warm standby offers the sweet spot: RTO 30–60 minutes at 30–50% of production cost ($600–$1,500 monthly or 60,000–150,000 rubles). As a concrete example, a medium-sized web application with warm standby typically requires an additional $800–$1,200 per month in cloud costs. Contact us — we will help you choose the optimal balance for your budget and RTO/RPO requirements.

How to Choose the Type of DR Readiness?

For cold standby, infrastructure is not running. Data is replicated, and configuration is stored as IaC. On failure: spin up the environment from Terraform, then restore data from backup, then launch the application. RTO: 2–8 hours.

Warm standby means basic infrastructure is running in reduced size (1 instance instead of 10). Data is current via replication. On failure: scale to production size, then switch DNS. RTO: 15–60 minutes.

Hot standby — a full infrastructure copy runs continuously. Data synced with sub-minute lag. On failure: switch DNS/load balancer. RTO: 1–5 minutes.

Warm standby is 3–5 times cheaper than hot standby. It offers RTO up to 60 minutes. Therefore, it is the optimal choice for most web applications.

Choosing the DR Site Location

Key requirements:

• Physically independent power grid and internet channels
• At least 100 km from the primary site (protection against regional disasters)
• Compliance with regulations (user data from Russia must stay in Russia, GDPR for Europe)

Options:

• Second AWS/GCP/Azure region (simplest)
• Different cloud provider (protection against vendor outage)
• Own or rented colocation (for regulated industries)

Why Infrastructure as Code Is the Foundation of a DR Site

The entire DR Site is described in Terraform. Primary and DR environments use different workspaces or separate configuration directories. They are parameterized via variables:

module "app_cluster" {
  source        = "./modules/app"
  region        = var.region
  instance_type = var.dr_mode ? "t3.medium" : "c6i.2xlarge"
  replica_count = var.dr_mode ? 1 : 5
}

Cold standby: terraform apply only when DR is activated. Warm standby: terraform apply immediately with dr_mode = true. IaC ensures environment identity and prevents configuration drift.

Data Replication

PostgreSQL to DR Site: Streaming replication with asynchronous standby in DR. For critical data, use synchronous_commit = remote_apply. This guarantees data availability on standby after primary failure. However, it increases write latency.

Monitor replication lag:

SELECT now() - pg_last_xact_replay_timestamp() AS replication_lag;

Alert if lag > 30 seconds.

File storage: S3 Cross-Region Replication (AWS) — automatic, RPO < 15 minutes; Rclone sync on schedule — for rarely changed objects; Lsyncd for real-time filesystem sync between servers.

Redis: Redis Sentinel with a replica in DR or Redis Cluster with geo-distribution.

Network Connectivity

A dedicated channel for data replication is required between the primary site and DR Site. Options include AWS VPC Peering or Transit Gateway within AWS. For on-premises to cloud, use AWS Direct Connect or GCP Interconnect. Site-to-site VPN is a budget option but less reliable.

The replication channel must be isolated from user traffic. Peak application load must not affect replication.

How to Ensure Minimal RTO?

To achieve RTO in minutes, use hot or warm standby with automatic DNS failover. Also, configure health checks that trigger the recovery procedure. Store Terraform state in a remote backend accessible from both data centers.

DR Site Activation Procedure

A documented runbook with exact commands, not generalities:

1. Confirm the primary site failure (not a false alarm)
2. Declare a DR incident, assign an incident manager
3. Check database replication lag before switching
4. If warm/hot: promote the DB replica (pg_promote())
5. Update DNS (Route 53 / Cloudflare) to DR addresses
6. Verify functionality through the DR Site
7. Notify the team and, if necessary, users
8. Record RTO time

What Is Included in DR Site Setup

Deliverables: infrastructure audit report, DR architecture diagram, data replication configuration, IaC code repository, runbook documentation, team training session, and 30 days of post-setup support.

Implementation Timeline

• Analysis of current infrastructure and strategy selection — 2–3 days
• Data replication setup — 3–7 days
• DR infrastructure deployment in IaC — 5–10 days
• Network connectivity and security — 2–5 days
• Procedures, runbook, testing — 3–5 days

Total: 2–5 weeks depending on infrastructure complexity and DR type.

Estimated Cost

Cost is calculated individually based on the chosen standby type, data volume, and infrastructure complexity. We will help you find the optimal balance between budget and recovery time.

Request a consultation — we will assess your project and propose a solution with the required RTO and RPO.

Disaster Recovery is not a luxury but a necessity for any serious service.

We regularly encounter a situation: "The site is not opening" at 3 a.m. — and it turns out that the VPS disk is full because nginx logs haven't been rotated for six months. Or the server went down under load on the day of an advertising campaign launch because the shared hosting had a limit of 50 concurrent connections. Setting up hosting and deployment is not about "where it's cheaper" but about what happens when something goes wrong. Our team helps avoid such incidents by designing infrastructure that accounts for real load patterns.

When to choose Vercel and Netlify?

Vercel is built for Next.js — deploy in one push, preview deployments for every PR, automatic CDN, Edge Functions, ISR without configuration. For frontend projects and JAMstack, it's the optimal choice: no operational overhead, time-to-deploy measured in minutes.

Real limitations: Vercel Serverless Functions run in us-east-1 by default (latency for Europe +80–100ms), Function timeout 300 seconds on Pro, Bandwidth 1TB/month on Pro. For heavy backend, you need workers or a separate server.

Netlify is closer to static sites and Edge Functions based on Deno Deploy. Build minutes are the main limitation on the free tier.

Why is Docker the foundation of predictable deployment?

"It works on my machine" — classic. Docker solves this through environment containerization. But a bad Dockerfile creates new problems.

A typical mistake: copying everything into the image without .dockerignore, resulting in an 800MB image instead of 80MB. node_modules inside the image weighs as much. Correct approach: multi-stage build.

FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build

FROM node:20-alpine AS runner
WORKDIR /app
COPY --from=builder /app/.next ./.next
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./package.json
EXPOSE 3000
CMD ["npm", "start"]

Final image: 180MB instead of 1.2GB. CI build time is reduced due to layer caching — if package.json hasn't changed, the layer with npm ci is taken from cache.

Docker Compose for local development and simple production scenarios: application + PostgreSQL + Redis in one configuration. For production on a single server, it's a perfectly viable option if there's no requirement for horizontal scaling.

More about containerization — Wikipedia: Docker.

How to set up Nginx as a reverse proxy?

Nginx in front of the application is standard for VPS and dedicated servers. Main functions: SSL termination, gzip, static files, rate limiting, upstream load balancing.

A configuration often done incorrectly: worker_processes auto — number of processes equals CPU count. worker_connections 1024 — that's 1024 per worker process. With 4 CPUs and 1024 connections = 4096 concurrent connections. For a high-traffic site, you need worker_connections 4096 and set keepalive_timeout 65.

For static assets with hash in the filename:

location ~* \.(js|css|woff2|png|webp)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
}

immutable tells the browser: don't revalidate this file even on hard refresh. This only works correctly with content-hashed filenames (which Vite/webpack do by default). Documentation — Wikipedia: Nginx.

AWS: flexibility and complexity

EC2 + Auto Scaling Group — classic for horizontal scaling. AMI with pre-installed application, Launch Template, ASG with min/desired/max instances, Application Load Balancer. When CPU > 70% for 3 minutes — scale out, when CPU < 30% for 15 minutes — scale in. Health check via ALB removes unhealthy instances from rotation.

ECS Fargate — containers without managing EC2. Deploy a Docker image, specify CPU/memory (512 CPU units = 0.5 vCPU, from 512MB memory), Fargate launches it. More expensive than Lambda, but no cold start and no timeout limitations. Suitable for long-running processes, WebSocket servers, heavy workers.

RDS for PostgreSQL with Multi-AZ: automatic failover in 1–2 minutes when primary fails. Read Replicas for scaling reads. RDS Proxy for connection pooling — Lambda functions cannot hold long-term connections, the proxy buffers this.

Kubernetes: when it is justified

K8s adds significant operational complexity. Justified when: multiple teams deploy independent services, fine-grained resource allocation per service is needed, canary deployments and blue/green without downtime are required.

AWS EKS, GKE, or managed k8s from Hetzner (cheaper). Helm charts for standard services. Horizontal Pod Autoscaler based on CPU and custom metrics (RPS via Prometheus).

For most startups and medium-sized projects, Kubernetes is overkill. ECS or Fly.io provide 80% of the capabilities with 20% of the operational complexity.

Monitoring and alerting

A server without monitoring is waiting for an incident. Minimal stack: Prometheus + Grafana (or Grafana Cloud for managed), alerting on disk > 80%, memory > 85%, CPU > 90% over 5 minutes, error rate > 1%. Uptime via Better Uptime or Upptime (self-hosted).

Logs: Loki + Grafana or CloudWatch Logs Insights. Structured JSON logs (winston, pino) are mandatory — otherwise, log searching becomes a pain.

What is included in hosting setup

• Audit of current infrastructure and load profiling
• Selection of target architecture (VPS, AWS, serverless, Kubernetes)
• Setting up CI/CD pipeline (GitHub Actions, GitLab CI) with automatic deployment
• IaC via Terraform or Pulumi (infrastructure as code)
• Configuration of Nginx, SSL certificates, HTTP/2, brotli
• Monitoring and alerting (Prometheus + Grafana, PagerDuty)
• Documentation of runbooks and team training

Additionally, contact us if you need migration from current hosting or integration with external services.

Work process

1. Audit of current infrastructure (2–5 days)
2. Selection of target architecture with load and budget justification (1–3 days)
3. Setting up CI/CD pipeline (GitHub Actions, GitLab CI) (2–5 days)
4. IaC via Terraform or Pulumi (3–10 days)
5. Setting up monitoring and alerting (2–5 days)
6. Documentation of runbooks and team training (1–3 days)

Our experience — 7 years on the market, over 50 projects, guarantee of operability after deployment.

Timeline

• Basic deployment on VPS with Docker + Nginx + CI/CD: 1–2 weeks.
• Setting up AWS infrastructure with Auto Scaling, RDS, CDN: 3–6 weeks.
• Migration to EKS from scratch: 6–12 weeks.
• Setting up Vercel/Netlify for JAMstack: 3–5 days.

The cost is calculated individually depending on complexity and scope of work. Get a consultation — we'll evaluate your architecture in one day.