[Info-vax] Programming languages on VMS

[DaveFroble]

seasoned_geek wrote:
> On Wednesday, January 31, 2018 at 8:42:24 PM UTC-6, Stephen Hoffman wrote:
> 
>> Somebody please explain the use case for versions on OpenVMS?
>>
> 
> Nice rant!
> 

> There are many production systems which have various feeder systems dropping
> transaction files, all with the same name, into a processing directory and
> the processing application consumes the lowest version number first. The
> systems I know of operating in this manner process millions of dollars worth
> of orders per day. They are not one-offs or isolated. NO, they are not bad
> design either so don't try to play that card. They are what happens when you
> have systems from different vendors running on a cluster which is scattered
> around the country/world.

While there may be applications doing this, I'm going to claim that it's a poor 
design, and one prone to unknown failures.

We're talking communications here.  My biggest priority with communications is 
verification that things actually happened.

If I'm going to transmit data, perhaps a file, I want byte counts, perhaps a 
checksum, and a response that the data was received.  Until that is verified, 
the sender cannot be sure that the data made it to the next step.

What I do these days is have listener sockets waiting for connection requests. 
When a request comes in, the data is processed.  If it's not what is expected, 
the data is discarded and the connection terminated.  Should the data be 
acceptable, a response is sent back to the sender, so that it can log the 
response as proof that the transmission was a success.  After that, the data and 
any processing is the responsibility of the received.

As for taking orders, yep, that's how it's done, including the confirmation that 
the order was received and accepted.

Inventory inquiries, the requestor gets back the data as part of the communication.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
DFE Ultralights, Inc.
170 Grimplin Road
Vanderbilt, PA  15486