Koha on AWS: Comparing Deployment Architectures

AWS offers multiple deployment architectures for Koha, ranging from simple single-server setups to enterprise-grade high-availability configurations. This guide compares available options to help you select the appropriate architecture for your library’s size, budget, and reliability requirements.

Architecture Options at a Glance

Basic Architecture: Single EC2 Instance

Design Overview

Internet → EC2 Instance (Koha + MySQL + Apache + Zebra)
             ↓
          EBS Volume

All components run on a single EC2 instance with data stored on an attached EBS volume.

Internet → EC2 Instance (Koha + Apache)
              ↓
          RDS MySQL (Managed Database)

Components

• 1-2 EC2 instances (application tier)
• RDS MySQL instance (db.t3.medium)
• Elastic Load Balancer (optional)
• S3 bucket for backups and file storage
• CloudWatch for monitoring

Improvements Over Basic

Managed Database (RDS):

• Automated backups
• Point-in-time recovery
• Automated patching
• Better performance tuning
• Easier scaling

Separation of Concerns:

• Database independent of web server
• Can upgrade/restart web server without DB downtime
• Easier to scale each tier independently

Cost Estimate

• EC2 (t3.medium): $30/month
• RDS (db.t3.medium): $60/month
• EBS storage: $20/month
• Load balancer (if used): $20/month
• Total: ~$130-$200/month

Best For

✅ Libraries with 5,000-25,000 patrons
✅ Organizations wanting managed database benefits
✅ Planning for future growth
✅ Better uptime requirements

Enterprise Deployment: High Availability

Architecture

Internet → Route 53 (DNS)
              ↓
       Application Load Balancer
         ↓            ↓
    EC2 (AZ-1)    EC2 (AZ-2)  ← Auto-scaling group
         ↓            ↓
       RDS MySQL (Multi-AZ with read replica)
              ↓
         ElastiCache (Memcached for sessions)
              ↓
       S3 (File storage) + CloudFront (CDN)

Components

• Auto Scaling Group: 2-10 EC2 instances
• Application Load Balancer (ALB)
• RDS Multi-AZ: Automatic failover
• ElastiCache: Session/data caching
• S3 + CloudFront: Asset delivery
• Route 53: DNS with health checks
• CloudWatch + SNS: Monitoring/alerts

Features

High Availability:

• Multi-AZ deployment (survives datacenter outage)
• Automatic failover for database
• Load balancer distributes traffic
• No single point of failure

Scalability:

• Auto-scaling based on load
• Handles traffic spikes automatically
• Read replicas for heavy reporting

Performance:

• Memcached for caching
• CloudFront CDN for static assets
• Optimized database queries

Cost Estimate (Medium Library)

• EC2 instances (2x t3.large): $150/month
• RDS Multi-AZ (db.t3.large): $200/month
• Load Balancer: $25/month
• ElastiCache: $50/month
• S3 + CloudFront: $20/month
• Total: ~$445-$600/month

Best For

✅ Large libraries or consortia (25K+ patrons)
✅ Mission-critical operations
✅ Budget for professional infrastructure
✅ High traffic (100K+ monthly sessions)
✅ Require 99.95%+ uptime

Using AWS Marketplace (Easiest Option)

KohaSupport AWS Marketplace AMI provides one-click deployment:

• Pre-configured Koha installation
• Optimized for AWS
• Choose Basic or Advanced at launch
• Built-in backup automation
• Professional support available

Launch via:

1. Visit AWS Marketplace - Koha
2. Search “Koha Library System”
3. Subscribe and launch
4. Follow CloudFormation wizard

See detailed guide: How to Deploy Koha with CloudFormation

Decision Matrix

Choose Basic if:

• Small library (<5K patrons)
• Limited budget
• Simple requirements
• Small IT staff
• Can tolerate occasional downtime

Choose Advanced if:

• Medium library (5K-25K patrons)
• Want managed database
• Planning growth
• Better uptime needed
• Can allocate $200-$400/month

Choose Enterprise if:

• Large library or consortium (25K+)
• Mission-critical system
• High traffic volume
• Budget for HA infrastructure
• Require 99.95%+ uptime SLA

Migration Path

Most libraries follow this progression:

Year 1: Basic (single instance)
Year 2-3: Advanced (add RDS)
Year 4+: Enterprise (full HA if needed)

You can upgrade without data loss by:

1. Taking snapshot of current instance
2. Launching new architecture
3. Migrating database
4. Testing thoroughly
5. Switching DNS

Cost Optimization Tips

1. Use Reserved Instances: Save 30-50% vs on-demand
2. Right-size Resources: Monitor and adjust instance types
3. Automate Backups: Use S3 Lifecycle policies to archive old backups
4. Use Spot Instances: For development/testing environments
5. Clean Up Unused Resources: Stop instances when not needed

Conclusion

AWS offers flexibility to match infrastructure to needs:

• Basic deployment works great for most small-medium libraries
• Advanced deployment adds reliability without excessive complexity
• Enterprise deployment provides enterprise-grade infrastructure for large operations

Don’t over-architect early. Start simple, monitor performance, and upgrade when genuinely needed. The beauty of cloud infrastructure is the ability to scale incrementally.

Need help designing or deploying Koha on AWS? We specialize in AWS-based Koha deployments from simple to complex. Contact us for a free consultation.

Related Articles:

• How to Deploy Koha via CloudFormation
• Koha Performance Optimization
• How to Backup Koha Database