Information Security and High Availability

Importance of Uptime and Availability

• Key focus in information security: maintaining system uptime and availability.

High Availability (HA)

• Provides enhanced system resiliency.
• Systems are always on and available.
• If one system fails, another takes over immediately.
• Costs: Additional components and systems increase costs.

Engineering for High Availability

• Multiple Systems: Necessary for redundancy.
• Upgraded Power: Required for continuous operation.
• Higher Quality Components: Adds to overall costs.

Server Clustering

• Definition: Multiple servers acting as one large server.
• Scalability: Ability to add/remove servers as needed.
• Interoperability: Servers typically run identical operating systems.
• Shared Storage: Servers use a shared directory for data synchronization.

Load Balancing

• Function: Distributes load across multiple servers.
• Independence: Servers unaware of each other.
• Flexibility: Can run different operating systems.
• Dynamic Allocation: Allows adding/removing servers.

Site Resiliency

• Definition: Recovery sites in different locations for disaster recovery.
• Types of Recovery Sites:
  • Hot Site: Exact replica of main data center.
  • Cold Site: Empty building; requires setup during disaster.
  • Warm Site: Mid-point with some equipment and data.
• Geographical Dispersion: Sites should be far enough apart to avoid simultaneous disaster impact.

Platform Diversity

• Vulnerability Mitigation: Use different OS to avoid systemic vulnerabilities.
• Example: Mixing Windows, Linux, and macOS.

Cloud Resilience

• Multiple Providers: Use different cloud providers for redundancy (e.g., AWS, Azure, Google Cloud).
• Security Perspective: Reduces risk if one provider is compromised.

Continuity of Operations Planning (COOP)

• Non-Technical Alternatives: Prepare for service provision without technology.
• Examples:
  • Manual transaction completion.
  • Paper receipts.
  • Phone-based credit card approvals.

Conclusion

• Planning for high availability and disaster recovery is crucial.
• Implementing diverse and redundant systems minimizes downtime and ensures continuity.