gtpd2m13Data Communications Services Reference

Application Recovery Support

Application recovery support is an option of the TPF system environment. This package uses the application recovery table, AR0RT, as a vehicle for providing a user (application) with message recovery capability.

The integrity of the application recovery table (ART) is maintained by the system; this package provides the application with the means by which an ART item can be obtained, referenced, keypointed, and deleted. At any point in its processing cycle, an application can save input, output, or user data on file and reference it via its associated ART item, and/or it can save data in the optional data area of the ART item. The maximum block size processed by ART is 1055 bytes. An ART item, once obtained by an application, will be maintained, until deleted by the application. Should application processing be interrupted because of application or system error, this package provides a timeout function that reactivates the application using Routing Control data (RC0PL) maintained in the ART item.

This package is a tool that the user (application) can use to supplement existing system message recovery capability and/or to combine message recovery function with data base recovery function. This type of implementation can lead to shortened transaction path length and/or improved data integrity. The application can choose the point of recovery the location and contents of log records, if any, and the tracking (timeout) period. This function is independent of line disciplines, and, thus, can be used with BSC or SNA devices. The user determines the extent of and provides for this recovery capability. The Application Recovery (AR) package provides the interface to a system maintained data area.

Note:
The application interface program, referenced in the Routing Control Application Table, cannot be corefast.