Collector Redundancy

Historian includes support for collector redundancy, which decreases the likelihood of lost data due to soft- ware or hardware failures. Implementing collector redundancy ensures that collection of your data remains uninterrupted. Collector redundancy makes use of two or more collectors, gathering data from a single source. Two or more collectors may be configured in a redundant group.

All collectors in the group actively gather the same tags from a data source but only the "active" collector forwards its samples to the Historian server. The non-active collectors buffer their data against failover of the active collector. The Historian server actively monitors the health of the redundant collectors and will automatically switch to a backup if certain user-configurable trigger conditions are met.

Synchronized Configuration

The configuration for each redundant collector is managed by the Historian server. If you change the configuration on one redundant collector, all other collectors will be updated by the Historian server with the new configuration.
Note: Redundant collectors must be of the same collector type.

Offline Collectors

To reduce the possibility of lost data, a collector will immediately send its buffered data to the Historian archiver when brought online. The Historian server will ignore any data already collected to the Historian archive.

Adding Tags to a Redundant Collector

To add tags in a redundant collector system, you must add them to the primary collector. If tags are added to a redundant collector, they will not be collected until the redundant collector is taken out of the redundant system. If the primary collector is not available, you will have to add the tag manually, choosing the primary collector from the Collectors list.
Note:

  • Use Polled tags only as watchdog tags.

  • Historian redundant collector configuration does not force the active Historian collector to run on the active iFIX SCADA, since both redundant collectors provide data and alarms. Also, when both iFIX SCADAS become active, they lose connection with each other.