Because the interface can process both measurement data files and alarm message file, the interface supports two sets of performance points, one for each file type.
It is not necessary to specifically configure the interface for failover. However, by configuring a X_LATEST_TIMESTAMP performance point (where X is DATA or ALARM), it will help minimize the amount the out-of-order data sent to PI.
When the interface sees a file to process, but it hasn’t processed a file for more than a minute, it assumes that it has been on standby and it becoming the active interface. If a X_LATEST_TIMESTAMP performance point has been configured and the connection to the PI server is good, then the interface will read the value of the performance point and use that time as a cut-off for the events it reads from the file. Any event with a timestamp prior to the cut-off time will be dropped.
If the X_LATEST_TIMESTAMP point is not configured or it is not able to read the value of the timestamp then the interface will send all the events to PI. This will mean some out-of-order events may be sent to PI, but this is not a major issue. The PI server can handle these, although the events will not be compressed and it can affect the performance of the PI server. For this reason, if the interfaces are run with failover, it is recommended that a X_LATEST_TIMESTAMP performance point is configured.
For more information on configuring interface-specific performance points, see section Interface Specific Performance Points.
When using failover, both instances of the interface will be writing to the same set of interface specific performance points. This is not a problem, because only one instance of the interface should be processing files at any one time. However, if there is a problem with the Power TG failover mechanism, it is possible for both interfaces to write different values at the same time into the performance points, which could cause some confusion.
When using failover interface with the UniInt performance points, each instance of the interface should be configured with its own set of UniInt performance points. The points use location3 and the UniInt -uht_id= argument to differentiate the two sets of points. See the UniInt Interface User Manual for more information.
Interface Node Clock
The correct time and time zone must be configured on the interface node. Also, the interface node should be configured to automatically adjust for daylight saving time for locations that use daylight saving time. The correct local settings should be used even if the interface node runs in a different time zone than the PI Server node.
Windows and UNIX
The PI Firewall Database and the PI Proxy Database must be configured so that the interface is allowed to write data to the PI Server. See “Modifying the Firewall Database” and “Modifying the Proxy Database” in the PI Server manuals.
Note that the Trust Database, which is maintained by the Base Subsystem, replaces the Proxy Database used prior to PI version 3.3. The Trust Database maintains all the functionality of the proxy mechanism while being more secure.
If the interface cannot write data to the PI Server because it has insufficient privileges, a 10401 error will be reported in the pipc.log file. If the interface cannot send data to a PI2 Server, it writes a -999 error. See the section Appendix A: Error and Informational Messages for additional information on error messaging.
PI Server v3.3 and Higher
Security configuration using piconfig
For PI Server v3.3 and higher, the following example demonstrates how to edit the PI Trust table:
Ensure that the PI API processes are running
NAME PID TIME %CPU VSZ
bufserv 2260 00:00:00 0.0 5480
bufserv 2261 00:00:00 0.0 7672
bufserv 2263 00:00:00 0.0 7672
WARNING: multiple instances of bufserv are running
mqmgr 2252 00:00:00 0.0 4356
mqsrv 2246 00:00:00 0.0 4360
ioshmsrv 2269 00:00:00 0.0 4360
iorates 2275 00:00:00 0.0 8640
WARNING: PISIPowerTG is NOT running
The above is configured for buffering to 2 replicated PI servers, which is why there are 3 bufserv processes running. When buffering is configured there should be n+1 bufserv processes. Ignore the WARNING in the apiverify output.
Change to the interface directory
Run the interface startup script
Output file is "/opt/piapi/dat/PISIPowerTG.out"
Renamed existing "PISIPowerTG.out" as "PISIPowerTG.old"
Starting interface "PISIPowerTG"
This should start the interface as a background process. The stdout and stderr messages will be redirected to the $PIHOME/dat/PISIPowerTG.out file. The interface messages will also be logged into the $PIHOME/dat/pimesslogfile file.