Evaluating High Availability for Your Business: Key Considerations

Even if high availability is not required by your business today, you should have an understanding of its benefits and limitations, and how it works so that your system architecture can easily be expanded in the future to enable a highly available AVEVA™ PI System™ without complete reinstallation and moving of various system components.

Consider the following:

• How long can your business afford to have the PI System down?

• What is the business impact?

• Are parts of your process more critical than others from an availability standpoint?

• How much cost and performance you are willing to trade for scalability and high availability?

• The cost of your infrastructure is directly linked to the level of component and data availability. Evaluate the business loss that comes with infrastructure downtime, and ensure that the business case justifies the costs.

• What parts of your architecture are important from an availability standpoint? Interfaces? Data Archive servers? PI AF? Analytics? Data Access? Visualization? Client applications? All?

• Implementing redundancy raises a number of concerns: increased size, complexity, power consumption, cost, as well as additional design, verification, and testing time. Both fault-tolerant components and redundant components tend to increase cost. The more complex your system, the more carefully you must consider and prepare for all possible interactions between components. Therefore, a number of choices have to be examined to determine which components should be fault-tolerant:

  • How critical is the component?

  • How likely is the component to fail?

  • How expensive is it to make the component fault-tolerant?

To find the answers to these business questions, your IT department and PI System administrator need to engage with your business departments and your end users. You can then match the high availability options to meet your business requirements.