Re: Inside an IBM z17

Lawrence D'Oliveiro  <ldo@nz.invalid> wrote:

On Sat, 03 May 2025 13:51:35 -0400, Dan Espen wrote:
>

Try connecting thousands of users to a single linux box.  You'll soon
see the utility of block mode terminals.

>
A client of mine just got a machine with 40-something CPU cores (each
multithreaded), and something close to a terabyte of RAM. And a couple
dozen hot-swap slots for multi-terabyte hard drives.
>
Of course we’re going to run Linux. I don’t think we’ll have trouble
handling thousands of users on that ...

Depends what you're doing.  The more cores you put on one memory buss, the
more memory contention gets to be an issue.  The more data has to be shared
by processes, the more that bandwidth gets to be an issue too.  So for
simple web service stuff where each web server process is completely
independent and there isn't a central database everyone has to refer to,
that kind of architecture can be great.  But make all those web servers
refer to a central Oracle database and watch everything slow to a crawl.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."