An openUTM client with UPIC as the carrier system can communicate with a UTM cluster application in the same way as with a standalone UTM application.
A cluster is a number of computers (nodes) connected over a fast network. openUTM runs on a cluster in the form of a UTM cluster application. From a physical perspective, a UTM cluster application is made up of several identically generated UTM applications (the node applications) that run on the individual nodes.
The client requires a list of the associated node applications. An arbitrary node application is then selected from this list to be used for the next communication operation.
If communication is not possible with the selected node application, the system automatically attempts to establish a connection to the next node application in the list. This process is repeated until communication can be successfully established to a running node application or until the system detects that none of the node applications in the list can be accessed.
Figure 6: Communication with a UTM cluster application
The list of node applications for each UTM cluster application is passed in the side information file (upicfile). For details, see the section “Side information for UTM cluster applications”.