Michael Caplin wrote:

> The need is to move information from the MPE files on SYS C to/from the files 
> on SYS A.  At this time there’s an application running on the 3000 that waits 
> for information to show up in certain MSG files.  When this happens, it reads 
> the file, writes it to a separate flat file and then runs PCLINK3 (reflection) as a 
> son process to move this file to SYS A.  It then pauses and runs PCLINK3 
> again to get the new file created by the app on SYS A and moves the data in 
> it to the 3000.

Michael,

another possible approach for the file sharing between the Windows system A
and the MPE system C might the use of a Samba file share on the 3000, i.e.
make a dedicated HP 3000 directory available to Windows so that the Windows
machine could map it as a network drive.

The MPE program monitoring the MSG file would then simply move its output
file to the shared directory instead of invoking the PCLINK file transfer.
Windows could pick up the file, perform its processing and place its result
file in the shared directory where your MPE program could see it and pick
it up.

The above approach might help avoiding the overhead associated with many
PCLINK process creations, file transfer socket connections, etc. When you
mount an HP 3000 Samba share as a Windows network drive persistently, the
3000 side will have a single server process and socket connection for it,
which stays alive all the time and will just have to wake up for the file
existence checking or "transfer" operations.

You'd need to test this setup to verify if / how much more efficient it is.

When copying the files to/from the shared directory, the MPE programs
might need to take care for writing binary or bytestream files, as fixed
ASCII format, for example, does not cooperate well with Posix/Samba.

You might also want to not poll for file existance more frequently than
neccessary, as the polling will add overhead. It might be wise to keep
the number of files in the directory as small as possible.

To prevent incomplete files from being picked up by the other side, it
might be good to copy to a "temporary name" (or subdirectory) and then
rename (or move) to the final name expected by the receiving side.

As I said, would need some testing to see if / how much better it works.

Regards, Lars.

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