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Problems with sending messages via tcp/ip to backend OpenVMS alpha

Darren Cheong
Occasional Visitor

Problems with sending messages via tcp/ip to backend OpenVMS alpha

Hi all,

Before I ask my question I'd just like to let you guys know our current system setup. Currently we have a message router software written in C running on OpenVms alpha that routes message from our front end application running on windows to the backend(Fortran app)which is also running on OpenVMS Alpha.

The communication between the front end application and the message router is facilitated via x.42 and the message router send messages to the backend via TCP/IP. I am currently trying to change that communication path to IP as such I am rewriting the Message Router software to run on either a Windows or Linux PC.

The problems is that only occasionally my messages are able to get to the backend from the message router and in the rare occurence that it does, a few messages will get through but after that it stops again.

I've been trying to look into a few things and I noticed that both the backend app and the current message router uses ast to read/write tcp messages. Could that be whats causing the problem? If it is, is there any way I can emulate that?


Robert Gezelter
Honored Contributor

Re: Problems with sending messages via tcp/ip to backend OpenVMS alpha


ASTs are, IMHO, the most efficient User Mode mechanisms for an OpenVMS program to process externally sequenced events.

The semantic of a process' AST handling is a queue of events that are processed in a First In, First Out manner, with no possibility of premption by other events arriving in the queue.

Implementing this functionality on Linux or Windows is dependant on which, and on which other toolsets are involved.

The behavior you describe could be caused by any number of issues, including long lived latent bugs in the other parts if your system.

- Bob Gezelter, http://www.rlgsc.com