What makes a complex implementation.... no, serious, what does make an environment complex. Is it the number of servers, number of ORACLE_HOMEs, number of different products, maybe size of database, number of databases...
To me, (and I'm not putting my hand up as any kind of expert in this), it's a combination of all of the above.
I reckon there's a few different levels to it though. Let me explain:
If you've just installed eBusiness Suite on a single server, that's not complex. If it's High Availability, ie RAC and Shared Application Tier, then it's kinda complex, (you've probably got at least 4 servers). Add Single SignOn in HA and you're now talking 6 servers, 2 RAC databases and a load balancer... semi complex. Add Portal and Collaboration Suite (both in HA) and now you're talking 14 servers, 4 RAC databases, 11 O_H's... fairly complex. Stick BPEL in there (HA of course) to throw the data around, ContentDB to store the data in, and then dataguard the lot, and you're talking very complex.
But that's just what I think. Anybody have a better/different complexity scale? Anybody Anybody.
So unless anyone has any objections, I'll be talking about the fairly complex to very complex environments. And maybe dabble in the theory of seriously complex.
I realise there's people out there that might stumble across this blog and go "that's not complex, THIS is complex" (to paraphrase Mick Dundee.) If so, please comment when and where neccessary in the next few entries so we can all learn something.
First thing I want to talk about is layout, whether it be hardware, network, SAN, ORACLE_HOMEs, ports etc, it's all pretty much the same. For me it's all about finding the best way to make sure the environment is easy to navigate across, while maintaining fault tolerance and scalability. Once you figure out a pattern for the layout, then it doesn't matter how many servers you have, how many products you're installing, you just need the key and off you go.
But we can talk about that later.