I don’t envy the IBM labs’ job of deciding which versions of their products to test together and support. There are lots of combinations, lots of odd permutations possible and you almost certainly can’t please everyone. This isn’t usually a problem when you’re just dealing with a single product – WebSphere Portal, say – but when you start having several products in the mix, things get complicated pretty quickly.
The most complicated case of this I’ve seen recently came from one of our customers who already uses WebSphere Portal, Lotus Connections and Tivoli Directory Server. They wanted to bring portal up to version 6.1 and start using Tivoli Access Manager, preferably 6.1. Oh, and everything should be at the latest possible level and there should be a single database server. Ouch.
So how to work it out? Can we really get to a totally supported configuration or are we going to have live with a compromise somewhere along the line?
To approach this kind of problem, I generally first lay out the major components and look for their immediate dependencies, usually on a big bit of paper, Infocenter(s) to hand. Then I work through each component in turn figuring out whether I can resolve the dependencies into a single version that everything’s happy with or whether I’m going to have to compromise.
While reaching a totally supported configuration is a fine aspiration, once you start having three or four headline products this can get pretty tough to attain. For some reason this is harder if the products don’t all come from a single software brand.
In this case, there were lots of things to think about. Both Connections 2.0 and Portal 6.1 supported TDS 6.1 but only Tivoli Access Manager 6.1. Both wanted DB2 9.1FP4. However getting the right level of database for Portal, Connections and TDS to use the same physical platform was complicated, because even TDS 6.1 wanted an older DB2 than that…
…and so it went on, all around the infrastructure, until we finally hit on just the right combination of software. In some cases we had to compromise by not using quite the latest version of the software (eg TAM 6.0 versus 6.1). In other cases we had to try out a “nearly” supported version (Connections wants TDS 18.104.22.168, Portal just wants 6.0).
Clearly, if the configuration deviates from the officially supported levels then IBM support can (and usually will) ask you to upgrade. The other lesson is, of course, that if the version dependencies are proving complicated then maybe there’s something questionable in the architecture. Is it really a good idea to share databases between LDAP, Portal and Connections, for example?
One thing we also noticed was that new products’ Infocenters are quietly updated without much fanfare. It pays to keep your eyes on them, especially when you’re working in the first few months after a product is released.