Author here, I might write a blog article about that because it is really quite interesting.
The TL;DR is that some might want to rather run 1 or 2 systems (mainframe) instead of 100 physical machines (conventional distributed cattle system).
Now, IBM does make it quite expensive but the mainframe has some pretty cool features like pay-for-what-you-use (which you of course get with the cloud, but not so much if you also want your data in-house).
Anyway, it is a fun beer topic if nothing else :-)
Well...you sort of “pay for what you use”. I believe the extremely simplified version is you pay for the peak CPU usage (excluding specialty processors like ZIIP) in a moving 4 hour average window.
Context:
I work for a large organization that used to run several physical Z13 mainframes, all of them containing several sysplexes. If we had issues, an IBM consultant would fly in within the day. We were definitely not IBM’s biggest customer but we were not insignificant for them either.
We had a lot of mainframe support staff (so not people programming for mainframe but people maintaining storage, DB2, z/OS upgrades etc.) and I think even for them, the IBM bill was more or less: we see a large number, no idea why it’s this amount, but we cannot prove it is not right, so I guess we’ll just pay it.
The TL;DR is that some might want to rather run 1 or 2 systems (mainframe) instead of 100 physical machines (conventional distributed cattle system).
Now, IBM does make it quite expensive but the mainframe has some pretty cool features like pay-for-what-you-use (which you of course get with the cloud, but not so much if you also want your data in-house).
Anyway, it is a fun beer topic if nothing else :-)