Introduction
DNS for cloud applications determines how users connect to your servers. Without proper DNS configuration, your infrastructure becomes inaccessible.
DNS (Domain Name System) translates domain names into IP addresses, allowing users to access services easily.
In this guide, you will learn DNS records, TTL behavior, propagation, and failover strategies.
DNS Core Concepts
DNS maps domain names to server IP addresses.
Common DNS Records
- A → IPv4 mapping
- AAAA → IPv6 mapping
- CNAME → Alias
- MX → Mail routing
- TXT → Metadata
TTL and Propagation
TTL defines how long DNS data is cached.
- Low TTL → Faster updates
- High TTL → Better performance
Note
DNS propagation can take time due to distributed caching.
DNS Failover Strategies
Active-Passive
Primary server with backup.
Active-Active
Multiple servers serve traffic.
Geo Routing
Routes users to closest server.
Comparison of Failover Approaches
| Strategy | Complexity | Availability |
|---|---|---|
| Active-Passive | Low | Medium |
| Active-Active | Medium | High |
| Geo Routing | High | Very High |
Best Practices
- Use low TTL for migrations
- Monitor DNS health
- Avoid single points of failure
Raff-Specific Context
Raff infrastructure supports DNS-based architectures using:
Conclusion
DNS is critical for reliable cloud applications. Understanding TTL and failover improves system availability.
Next steps:
- Learn load balancing: Load balancing explained
- Explore networking: Private networking guide