UniInt End User
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- UniInt Failover Scheme
Deleting Cache FilesOSIsoft recommends renaming or moving the cache files to a backup directory. Delete cache files only if absolutely necessary. To delete the cache files created by the interface. The following procedure is recommended. Stop the interface. Verify the location and names of the cache files belonging to the interface. There are two files: a point cache file and digital cache file. The location and exact name of these files will be listed in the pipc.log file for the interface instance. Delete the cache files. Restart the interface to generate new cache files. UniInt Failover SchemeIntroductionThe UniInt failover scheme provides for a hot failover, no data loss solution given a single point of failover. The scheme requires the data source be able to communicate and service data to two interfaces simultaneously. Additionally, the failover configuration requires the interface supports outputs. UniInt interface level failover may be configured to send data to a H.A. PI server collective. The H.A. PI server basically provides redundant PI servers to allow for the un-interuppted collection and presentation of PI time series data while a single PI server can be taken down for maintenance or in the case of a hardware error that causes a single PI server to become unavailable. The H.A. PI server collective is described in the PI Server Reference Guide. When configured for UniInt failover, the interface routes all data that needs to be sent to PI through a state machine. The state machine determines whether to queue the data or send the data to PI depending on current state of the interface. When the interface is in the primary state, any data sent through the interface will be routed to PI. When in the backup state, any data sent through the interface will be queued for a short period. The data being queued by the backup interface ensures a no-data loss failover under normal circumstances. The same algorithm is used for output data. Figure 1: Failover Architecture The failover architecture is shown in Figure 1. The figure above shows a typical network setup. This by no means includes the myriad of configurations that are supported, it is meant to be used for an example. The figure is repeated and explained in greater detail after the discussion of the required start-up parameters, data source points and PI tags. Download 1.93 Mb. Share with your friends:
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