Case Study: Achieving 99.999% Uptime With Enterprise-Grade PowerHA Clustering

Industry: Healthcare (Customer Anonymous)

Services Provided: AIX Engineering, PowerHA Cluster Design, High Availability Architecture, SAN Integration, Performance Tuning

Outcome: Billing platform reliability increased to 99.999% sustained uptime

Background

A large national healthcare organization was experiencing reliability issues with its enterprise billing platform. The system processed millions of dollars in transactions and needed near-continuous availability. Even small outages disrupted operations, delayed billing cycles, and impacted downstream financial systems.

They required a robust, fault-tolerant, and fully redundant AIX-based infrastructure capable of delivering five nines (99.999%) of uptime.

The organization engaged our consultant (Christian Patterson, PatTechLLC) to architect and deploy a highly available AIX infrastructure using IBM PowerHA.

Challenges

The existing environment had several issues:

  • Single points of failure in compute, storage, and application layers
  • Aging AIX infrastructure with inconsistent configurations
  • Limited failover capability, resulting in manual recovery procedures
  • No standardized build process, making system drift and outages more common
  • High availability requirements for mission-critical financial workloads

The goal was to design and implement a modern, resilient, and automated clustering solution that eliminated downtime risks and stabilized the billing platform.

Solution Approach

1. Architecture & Design

A full high-availability redesign was completed, centered around IBM PowerHA clusters running on PowerVM. Deliverables included:

  • A multi-node active/passive PowerHA cluster design
  • Standardized OS and middleware configuration across nodes
  • Automated failover for application, database, and networking layers
  • Redundant SAN-backed storage using enterprise-class arrays
  • Strict network redundancy using LACP and VLAN segmentation
  • Comprehensive documentation, testing plans, and disaster recovery runbooks

This architecture eliminated single points of failure across the entire platform.

2. AIX Build Standardization

To ensure consistency and resilience, each AIX system was rebuilt using:

  • Standardized LPAR configurations
  • Hardened OS baselines
  • Automated installs via NIM
  • Consistent storage layouts and multipath settings
  • Tuned kernel parameters for the billing application’s workload profile

This not only reduced deployment time but significantly increased stability and performance.

3. Deployment of PowerHA Clusters

Multiple PowerHA clusters were built to support various roles within the billing platform, including:

  • Application servers
  • Database servers
  • Message-handling nodes
  • Supporting middleware components

Each cluster included:

  • Automated verification of resource availability
  • Node failover policies to prevent split-brain scenarios
  • Live failover testing to validate performance under real conditions

Comprehensive clustering logic ensured seamless failovers—even during patching, upgrades, or hardware maintenance.

4. Storage & SAN Integration

Given the sensitivity of billing data, SAN reliability was essential. Work included:

  • Integration with enterprise SAN arrays
  • Multipath configuration for redundancy
  • Tuning for high I/O workloads
  • Testing of storage failover and recovery sequences

This ensured the billing system could continue operating even during storage controller or path failures.

5. Performance Tuning & Reliability Engineering

Once the cluster solution was online, extensive tuning was performed:

  • CPU and memory allocation adjustments
  • I/O subsystem tuning
  • Network throughput optimization
  • Bottleneck elimination and application performance profiling

As part of ongoing support, detailed monitoring and alerting strategies were implemented to detect issues before they became outages.

Results

The new PowerHA-based billing platform delivered remarkable reliability and performance improvements:

  • 99.999% uptime achieved across the fiscal year
  • Dramatically reduced unplanned outages
  • Improved transaction throughput and processing speed
  • Simplified maintenance thanks to automated and reliable failovers
  • Newly established disaster recovery processes with documented RTO/RPO targets
  • Standardized systems that were easier to support, patch, and secure

The healthcare organization experienced enhanced stability, smoother billing cycles, faster recovery times, and greater overall confidence in their enterprise systems.

Key Technologies Used

  • IBM AIX 5.x/6.x
  • IBM PowerHA (HACMP)
  • PowerVM / VIO / LPAR architectures
  • Enterprise SAN
  • KornShell, Bash, Perl scripting
  • NIM for automated AIX deployment
  • Standardized OS hardening and compliance toolsets