topic Question about SYS$ICC_OPEN_ASSOCIATION in Operating System - OpenVMS

Question about SYS$ICC_OPEN_ASSOCIATION

John McL — Tue, 09 Apr 2013 00:27:30 GMT

When calling SYS$ICC_OPEN_ASSOCIATION what does the error code SS$_DUPLNAM refer to? Association name? Logical name? Something else?

I'm trying to create associations with the same name on multiple cluster nodes and access each by specifiying the node name in the call to SSY$ICC_CONNECT. Should this work okay in principle?

Re: Question about SYS$ICC_OPEN_ASSOCIATION

John Gillings — Tue, 09 Apr 2013 02:46:50 GMT

John,

According to the SSRM

SS$_DUPLNAM Specified association name is already registered (already exists), or default association is already open.

> I'm trying to create associations with the same name on multiple cluster nodes

This doesn't make much sense to me. I thought the whole point of ICC was to be cluster wide. I've fairly sure the name space is cluster wide, so attempting to create the same association multiple times will fail with SS$_DUPLNAM.

> specifiying the node name in the call to SSY$ICC_CONNECT

I haven't ever used that parameter. Each time I've used ICC it's been to have a server running on any cluster node, with any process on any other node able to reach it without having to know where it is. I think you can run multiple servers listening on the same association, but the idea is more for load balancing than as independent entities.

If you want to have independent servers, one on each node, I'd have thought a better design would be to incorporate the node name in the association name.

Contact me directly if you want to discuss further.

Re: Question about SYS$ICC_OPEN_ASSOCIATION

John McL — Tue, 09 Apr 2013 05:31:05 GMT

Problem solved by making the nodename part of the association name and using that for SYS$ICC_OPEN_ASSOCIATION and SYS$ICC_CONNECT(W).

PS. The documentation isn't very good for ICC. Maybe one day we'll see a Tech Journal article describing the internals and we'll get a better understanding of it all.