The batch request utility first opens the input data set that contains
the commands and then performs validation on all the commands, checking
for syntax errors. When the utility has determined that there are
no syntax errors, it starts to process each command sequentially,
preparing to send the commands to the appropriate CICS® region
(if CICS BAC is active in the region). As the batch
request utility processes each command, it checks for a change in CICS applid. If there is no change, and to optimize performance,
each command is moved into a buffer ready for sending to the target CICS region. The
CICS BAC batch request utility sends the commands
stored in the buffer when it detects:
- A new CICS applid specified on a command
- A new DEFAULT CICS(applid) that changes
the CICS applid
- The end of the commands input stream.
After it has sent a batch of buffered commands to a CICS region, the CICS BAC batch request utility waits until control
is returned from the EXCI DPL request, then resumes with the next
command in sequence in the input data set. If the previous buffer
sent was full, the next command could be for the same target region
as the request sent previously. This process, and what happens when
the request server receives a set of buffered commands from the utility
is described in the next topic.