Re: Subsystems and ODP

Hi Charles,

But a data queue server is a blocking server. It can process only one
request at the time.

That's true, but you can have several jobs all waiting on the same data queue. Then, each request that's sent to the queue is handled by whichever data queue server happens to read the queue first. (There's no danger of two jobs reading the same data queue entry.)

That way, you can have several jobs all processing data queue entries, and therefore it's handling several requests concurrently.

Another way is a TCP server, with one parent process and many
children processes. So the parent process waits for a request. Once
it receives a request, it dispatches this request to one of its
children processes. Then, the child process returns the result.
Because the server is a never ending job, all the ressources allocated in QILE will stay open until I stop the job, including ODP.

That depends on how you structure the server. If you use what I call a "handoff server" then it will work the way you describe.

I've actually written a service program that's intended to make it easy to write a handoff server (among other things). (Assuming that you're working with RPG code, that is...)

Actually, now that I'm thinking about it, I have a bunch of bug fixes that need to be made to my TCP service program. I keep forgetting to make them... sigh.

If this interests you, I can provide links to my articles on the subject -- but I'll have to remember to fix the bugs, first. :)

Is there something simpler to do what I want to do? Sharing ODP between
calls of my process, considering that each call can be done by different
users / jobs?

Not that I know of... also, I'm not sure that SQL is capable of sharing an ODP. I know you can share ODPs with traditional RPG native I/O, but I'm not sure how possible it is with SQL. Personally, I think a "server" approach is the way to go. I wonder if you're making this out to be more complicated than it really is? It's pretty darned simple.