V-Share

V-Share allows multiple programs to update the same VSAM file simultaneously. To accomplish this, V-Share intercepts batch VSAM requests and ships the requests to a CICS/VSE region (hereafter just "CICS region"). CICS then updates the file on behalf of the batch jobs. By giving batch jobs the ability to update files within CICS, V-Share makes CICS the VSAM data manager.

V-Share consists of three basic components:

• The first component executes in the batch program’s area. It intercepts the I/O requests and ships them to the second component of V-Share residing in CICS.

• The second component of V-Share resides in the CICS region owning the VSAM files. It performs all of the VSAM I/O on behalf of the batch job. The first and second components communicate through VTAM or through VSE Cross Memory Services. VTAM may be used when the batch job and the CICS region reside either on the same CPU or on different CPUs. Cross Memory Services provides a performance boost but the batch job and the CICS region must be on the same CPU.

• The third component of V-Share also resides in the CICS region. It is comprised of a series of on-line screen programs providing the following functions:

--Define CICS regions to use V-Share

--Define jobs eligible to use V-Share

--Monitor active jobs currently using V-Share

--Suspend a job that is currently active

--Restart a job previously suspended

--Cancel a job

--Reduce the rate of I/O requests being sent to CICS in the event of heavy on-line activity

--Review prior executions of batch jobs

Active Job Status Display

Job Maintenance Status Display