Protecting Production Continuity Through PI Server Redundant High Availability Modernization
1. Executive Summary
The existing PI System currently operates on a single PI Server, creating a potential single point of failure for production historian data availability.
This modernization will implement a PI Server Redundant High Availability (HA) architecture to improve system resilience, maintain continuous access to production data, and reduce the operational impact of server failure.
The migration will follow a Parallel Build and Controlled Cutover approach so the existing production environment can remain operational throughout the transition.
2. Existing Environment and Key Risk
The current PI System relies on a single PI Server connected to existing production data sources through OPC DA Servers.
While the current system remains operational, failure of the PI Server could result in temporary loss of historian services and production data visibility.
The existing Tosmap OPC Server is also a critical component because it continues to supply production data during the migration.
Key considerations:
- Avoid production interruption during migration.
- Maintain continuous OPC data acquisition.
- Prevent excessive additional load on the existing Tosmap OPC Server.
- Preserve the existing PI System as a rollback option until migration is successfully completed.
3. Target Architecture
The target environment will introduce PI Server Redundant High Availability, eliminating dependency on a single PI Server.
The redundant architecture is designed to provide:
- Higher historian system availability.
- Automatic failover capability.
- Improved production data continuity.
- Reduced risk from individual server failure.
- Better maintainability for future PI System operations.
The existing production data sources will remain operational while connections are gradually transitioned to the new PI environment.
4. Migration Strategy
The migration will use a Parallel Build and Controlled Cutover approach.
The new PI Server Redundant HA environment will first be built and configured in parallel with the existing PI Server.
Tags and production data connections will then be migrated gradually instead of performing a single large cutover.
During this process, the following systems will be continuously monitored:
- Tosmap OPC Server performance and resource utilization.
- Existing PI Server performance.
- New PI Server data collection.
- Tag communication and data quality.
- Historian data continuity.
The most critical migration consideration is the temporary additional load on the Tosmap OPC Server while both the existing and new PI environments are collecting data.
Therefore, tag migration will be performed in controlled batches. Migration will only continue when OPC and PI Server performance remains within acceptable operating conditions.
5. Validation, Cutover, and Go-Live
Before final go-live, the new PI Server Redundant HA environment will undergo complete operational validation.
Validation will confirm:
- Production tags are communicating correctly.
- Historian data is continuously recorded.
- No significant production data gaps exist.
- PI Server redundancy operates correctly.
- Automatic failover functions as designed.
- Client applications can access the new PI environment.
- System performance remains within acceptable limits.
The existing PI Server will remain available as a controlled rollback path during the stabilization period.
Final cutover and decommissioning of the legacy environment will only proceed after the new PI Server Redundant HA system is confirmed stable and formally accepted.
Expected Business Outcome
The modernization transforms the PI System from a single-server dependency into a resilient historian platform designed to support continuous production operations.
The key outcome is not only improved server redundancy, but also greater confidence that critical production data remains available during equipment failure, maintenance, and future system upgrades.