Migrate from Read-Write to Read-Only

Complete the following steps to migrate from an existing Read-Write option of an interface to the recommended Read-Only option:

1. Install the Read-Only interface.

2. Find all relevant .bat files in the current Read-Only/Read-Write directory.

3. Copy those .bat files over to the Read-Only directory.

4. Edit each of the .bat files to change the directory path and executable name of the interface to use the _ReadOnly option of the interface.

   Here is an example, using the OPC interface, of the change made in the directory path:

   • Old Read-Write directory: C:\Program Files (x86)\PIPC\Interfaces\OPCInt \OPCInt.exe

   • New Read-Only directory: C:\Program Files (x86)\PIPC\Interfaces\OPCInt_ReadOnly\OPCInt_ReadOnly.exe

5. Load each of the new .bat files that are now in the Read-Only directory into the PI ICU.

6. If the Read-Only interface will participate in failover scenarios, be sure to add the failover configuration via the ICU.

7. If the interfaces are in failover, make sure to point the _ReadOnly interface to its new failover partner.

   Note: When you load a migrated .bat file into PI ICU, the UniInt > Failover settings revert to Phase I failover. As this is deprecated, the reversion clears previously-filled fields. After installing the Read-Only version of the interface, load that version's .bat file into PI ICU on the failover partner node. Specify the failover sync file in PI ICU to restore your preferred failover setting.

8. Configure the services to use the optimal, least-privileged account as a service log on an account.

9. Create the service for the Read-Only instance(s) of the interface.

10. Verify trusts are in place for Read-Only interfaces.

11. Stop the Read-Write interface and start the Read-Only interface.

    Note: When you stop the Read-Write interface and then immediately start the Read-Only there will be a small gap in data during which neither interface is sending data to PI. You should not run two interfaces (Read-Write and also Read-Only) at the same time. Technically, you could do that for a short time if both are running on the same interface computer. As pibufss handles compression, data should not be doubled ([-11414] errors). However, if both interfaces send the same data at the same time stamps, you may see [-109] Value at This Time Already Exists messages in the interface logs.

12. Remove the old services for the read/write interfaces or set them to "disabled".

    Note: After migrating all interface instances to Read-Only, OSIsoft recommends that you uninstall the Read-Write interface to avoid sending any output tags from the installed machine.