Re: P9, Linux and RDP like desktop virtualization

Hello Nathan,

Am 07.04.2020 um 07:47 schrieb Nathan Andelin <nandelin@xxxxxxxxx>:

Marco did not say that he was testing with Windows Terminal Server. I did
not assume that he was referring to such. Rather it seemed more likely that
he was speaking of testing with a couple of PCs running Windows Remote
Desktop. Perhaps Marco can clarify what he was using to test performance?

True. Assumptions are often seeds for misunderstandings.

In regard to to "sessions", my understanding is that the resource
requirements are fairly comparable on the host, whether you're connecting
to a remote PC, or whether you're connecting to a Windows Terminal Server.

Yes, today this is sadly true.

Similarly, Microsoft suggests that the number of CPU cores be proportional
to the number of "sessions" that Windows Terminal Server needs to support.

https://docs.microsoft.com/en-us/windows-server/administration/performance-tuning/role/remote-desktop/session-hosts#selecting-the-proper-hardware-for-performance

This highly depends on workload, obviously.

No, Frank Soltis was not referring to single-tasking.

Then, what was he referring to?

On the other hand, he didn't view Unix task-switching capability to be server class.

I know. The same is true for Mainframe OS' also. But both are used as servers anyway.
Often, decisions are made on the base of "good enough", not "perfect". Sometimes sad.

He also noted that Unix was designed for workstations.

I disagree. Considering the roots of Unix, fridge-sized DEC PDP machines were all but workstations. Or is this perception because of the very early availability of roff for high quality text processing?

(Even today, the output of troff looks superior to the same document set in the same font, size and adjustment in Word.)

And he made a point that task-switching within IBM i was superior.

Yes, that's an outstanding achievement. I never questioned that.

I see tens of thousands of processes supported under IBM i with time-sharing and task-swapping that appear to be unequaled in any other platform.

Yes. I know also from (early) experience that with Kernel 2.4 on Pentium II class hardware, Linux process scheduler was easily struggling when dealing with many thousands of processes. I didn't repeat this stress test, though.

There are other, more… creative ways to achieve something similar. Example is how CICS handles many users.

I think you have a point about the communication protocols, which are used
primarily for screen, keyboard, and mouse sharing. But I was referring to
the resource requirements of multiple sessions vs. single sessions, again
thinking that Marco was likely referring to testing performance with a
single remote desktop session, rather than multiple sessions being handled
by Windows Terminal Server.

Okay, granted. It wasn't obvious to me as by your statements what you're really referring to.

:wq! PoC

PGP-Key: DDD3 4ABF 6413 38DE - https://www.pocnet.net/poc-key.asc