Procedure for the execution sequencing of distributed application programs at predetermined times in a SNA LU 6.2 network environment.

摘要

A method for scheduling time initiated tasks from an Intelligent Work Station (IWS) of an SNA network in which a host processor has created a plurality of run ready virtual machines which are assigned under control of a Virtual Machine Pool Manager in response to an LU 6.2 Allocate verb to establish an LU 6.2 conversation between distributed parts of an application program, one part of which is resident at the IWS and the other part of which is resident at the host. A distributed application program named BATCH is provided, Part A of which is resident on the user's IWS and Part B of which is resident on the host processor. Part B is functionally a component of Virtual Machine Pool Manager (VMPM) The BATCH program allows the user to transfer information regarding the task that is to be initiated at a designated time, to the host processor. The user invokes the BATCH program which prompts the user for the name of the application program which is to be time initiated, the time that the program is to be initiated, and the name of the processor on which the named application is to be executed. When the named application is to be executed on a host processor other than the host processor assigned to the IWS, the user may specify a transfer time for the local processor to forward the information to the target host processor. The user may also specify a plurality of host locations where the application is to be run. The method also provides at the host processor a Time Application Information Table. The function of the TAIT is to maintain information on time initiated tasks that are frequently scheduled so that the user may be relieved of much of the data entry. The Time Function (TF) component of the VMPM creates a Time Control Block Entry (TCBE) for each scheduled execution of the named application program. A queue of TCBEs are maintained by the VMPM-TF component which is also responsible for activating the tasks at the proper time. The VMPM-TF employs the normal timer services of the host operating system to alert the VMPM-TF that the time has arrived for one or more of the TCBEs to be activated. When the appointed time arrives, the VMPM-TF employing the information in the TCBE, issues an LU 6.2 ALLOCATE verb to the specified host, from the specified USERID for the named application. The ALLOCATE appears to the host to have been issued by the user from his terminal. The VMPM assigns an idle virtual machine from the pool to service the request from the VMPM-TM and the scheduled task is then executed in a conventional manner as if the ALLOCATE request had come from the user's IWS.