Historian Server redundancy for InTouch

AVEVA Historian Server redundancy provides high availability for historical data by configuring a Primary Historian node and a Partner node. This setup ensures that data remains accessible even if one node becomes unavailable.

When redundancy is enabled, InTouch automatically retrieves data from the currently active Historian node without requiring any user intervention or changes to trends configuration. In this configuration, the Partner Historian acts as a hot standby, providing backup support if the Primary Historian goes offline.

For more information about configuring a redundant historian node, see Use a redundant Historian.

Workflow

Historian redundancy is based on two nodes:

• Primary node: The default active Historian.

• Partner node: A standby Historian that takes over handling data retrieval if the primary becomes unavailable

At any given time, only one node is active. The system monitors availability and if the active node fails, automatic failover occurs. After failover, the Partner node becomes the active node and InTouch, connects to the active node.

• Configure HistorianPartner on the Primary node with the Partner node name, and configure HistorianPartner on the Partner node with the Primary node name.

• When the InTouch $System Tag $HistoricalLogging is enabled on the Primary node, alarms are logged to the Historian in Primary node. When the InTouch $System Tag $HistoricalLogging is disabled, the alarms are not logged to Historian.

• If Historian on the Primary node is turned off, any subsequent queries will retrieve historical data from the Partner node.

Behaviour in InTouch

• When Historian redundancy is configured, InTouch trends automatically connects to the active Historian node and retrieve historical data without interruption.

• No changes are required for trend configuration, pen setup, and scripts or bindings.

• This is applicable to Multi-pen trends, Historical data queries, and any feature using Historian data.

For more information about enabling storage to the Historian, see Configure general logging properties storage to Historian.