Learn about high availability

A successful AVEVA™ PI System™ requires data that is always available with minimal if any planned outages, and the system must be scaled quickly and easily as business requirements change.

Today PI System is being used for and integrated with more and more business critical functions. Because PI System plays such a growing role in an enterprise, its more common usage across a variety of tasks and business functions, and the fact that PI data is being consumed by a larger population of users ranging from operators to executives, the availability of data coming from the PI System has become increasingly vital. From a systems perspective, this means having uninterrupted access to PI data and continuous availability of various PI System components that are collecting data, performing calculations, sending critical notifications, and displaying data to users in the form of displays, reports, and web applications. For these reasons, we recommend implementing a PI System with an architecture that meets the goal of high availability for all critical system components so you can mitigate the risk of data loss.

A highly available PI System provides continuous access to data during planned and unplanned outages. Planned outages include scheduled maintenance of software or hardware. Unplanned outages are unexpected system failures such as power interruptions, network outages, hardware failures, and operating system or other software errors. In the event of a disaster, there is the possibility of extensive system failure. Basically, PI System high availability features provide redundancy for your system to prevent planned or unplanned interruptions.

Redundant system components allow you to bring down one component and upgrade, maintain, or repair it while a secondary component continues to perform critical system functions. This flexibility enables IT departments to perform rolling upgrades at more convenient hours without impacting production. In most cases, upgrades do not need to be tied to the production schedule or performed during yearly plant shutdowns. If routine maintenance such as a "Microsoft Patch Tuesday" shuts down a Data Archive server, there is no need for late night heroics to restore a backup because a secondary server can always take over.

You can use PI high availability features in conjunction with PI backups and virtualization. High availability capabilities complement but are not a substitute for a solid backup and recovery plan. You must perform regular data backups following documented backup procedures for your organization.