UX, AIX, FLAYX...

[Sridhar Ayengar]

Liam Proven wrote:
>> It's not that there's a lot of mainframes out there, it's that they're
>> quite pervasive.
> 
> All right, conceded.
> 
> But I suspect that there is a user count involved somewhere for
> licensing purposes!

Well, sort of.  There are actually different ways of doing it, but if 
memory serves, the most popular is by prcoessor-load.  There's even 
still a small but enthusiastic group of users who trade compute time.

> Re your point about accessing a mainframe - that would generally be
> very indirectly, though, no? They access a web server or an ATM or
> something, that probably talks to another server, that talks to a
> mainframe.

Yes.  Definitely.

> Most of the tedious IT management press that I read seems to consider
> the client/server model obsolete now and talks of at least 3-layer
> models instead.

The benefit of recent mainframe software architecture is that you can 
run all of the upstream layers on one machine.  Run the web server on 
Linux, with transaction management or application backend running on VSE 
with the backend database on MVS.  Run the whole rigamarole in LPARs or, 
most popularly, in VM guests.  Each OS doing what it does best.  Without 
that advance, I don't think there would be nearly as many mainframes out 
there as there are.

Peace...  Sridhar