Transparent Host Relocation via Name Resolution in Redundant Control Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing supervisory process control systems face challenges in maintaining reliable and uninterrupted data access due to the complexity of industrial processes, which requires sophisticated data management and visualization techniques, and the cost and complexity of implementing redundancy in host systems to prevent single path/machine failures.
Innovation Solution
A system that provides transparency between fail-over host partners by using a name resolution table for mapping location-independent reference names to network location-specific addresses, allowing clients to reference data using the same name regardless of which host is active, and includes a messaging infrastructure for minimal interruption during fail-over, enabling synchronization of data between active and standby hosts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundancy is implemented in host systems to prevent single path/machine failures, then system reliability is improved, but device complexity and implementation cost increase
Solution Approach 1:
A name resolution service acts as an intermediary between clients and redundant host systems. Clients reference data using location-independent names through this service, which automatically resolves them to the current active host's address. This mediator abstracts the complexity of redundancy management from clients while maintaining simple client configurations.
Solution Approach 2:
The name resolution service provides multiple functions: it resolves location-independent names to host addresses, manages failover transparency, and maintains client awareness of the active host without requiring clients to implement their own redundancy logic. This universal service handles multiple aspects of redundancy management in a single system component.
2Reliability
If redundancy is implemented with distinct identified active and standby systems, then failover capability is achieved, but configuration and deployment complexity increases
Solution Approach 1:
The complexity of managing distinct identified active and standby systems is extracted from the client applications and centralized in the name resolution service. Clients only need to use location-independent names without worrying about host identification or failover logic, while the name resolution service handles the complex mapping and failover management internally.
3Loss of information
If clients are made aware of distinctly identified active and standby systems, then system transparency is reduced, but client awareness of system state is improved
Solution Approach 1:
The name resolution service mediates between clients and the redundant host systems, providing clients with location-independent names that abstract away the complexity of active/standby identification. Clients maintain awareness of the active host through the resolution service without needing to directly identify or manage distinct system states, preserving operational simplicity.
Data Source
AI summary
A system is disclosed for providing transparency between fail-over host partners for data acquisition clients of a redundancy-enabled host in a supervisory process control data acquisition application runtime environment. The system includes a name resolution table for mapping location-independent reference names to network location-specific addresses. A location-independent name is assigned to the redundancy-enabled host comprising an active host partner and a standby host partner. A messaging infrastructure serves clients of the redundancy-enabled host. The messaging infrastructure maintains a name to address translation for each reference of the client to subscribed data on the redundancy-enabled host such that a same name is used to reference data on the redundancy-enabled host without regard to which one of the redundancy-enabled host partners is presently active.