While the PI System can prevent data loss during planned maintenance, lack of access to data during a maintenance period may be unacceptable. Unplanned downtime represents another potential source of data loss. With the HA release, there is greater assurance that data will always be gathered, stored and available to everyone across the organization at all times. Existing OSIsoft customers can upgrade from PI to PI HA using point-and-click tools that leverage existing operational investments and infrastructure.
New release details include:
• Redundant PI Servers including a primary and one or more secondary servers, together referred to as a “collective.” The PI server configuration tables will be replicated across the collective.
• All interfaces will write time-series data directly to members of the collective, buffering data temporarily for those unable to receive it for a period of time and assuring that time-series data stored in each archive is an exact duplicate of the others.
• Changes to the PI interface design to accommodate HA include the ability to have a pair of PI interface nodes connected to a PI Server or to the collective. If the primary interface node fails to deliver data to the PI Servers, it will fail-over to the secondary PI interface to run in “hot standby” mode. PI interfaces can now be started without a connection to the PI server.
![Mps035 Sm 1200x628 D[2]](https://img.automationworld.com/files/base/pmmi/all/image/2021/03/MPS035_SM_1200x628_D_2_.604a4a336bc60.png?auto=format%2Ccompress&bg=fff&fill-color=fff&fit=fill&h=146&pad=5&q=70&w=340)
