[Discuss] Whence distributed operating systems?

Jack Coats jack at coats.org
Thu Apr 21 10:14:37 EDT 2016


In many ways, we do have a single system signon, with a 'single system
image' for well developed systems today.

This is not true for everything, but within many companies web presence,
the user (who we are in in business to support, right?) sees a 'single
system image', whether it is implemented on a single system or a complex
system or a 'cloud' (basically an obscured set of cooperating systems).

Most often we just ask for users to sign in once to access all aspects of
their 'user experience', even if the systems do re-authorization behind the
curtains.

For supporting the systems that provide this illusion to the users, we are
still lacking on making that as smooth as it needs to be eventually.

The cost of computing has kept going down for years.  And to make it
economical to provide seamless experience for users, the cost of networking
and computing in general has had to go way down. ... Even on a single
platform, let's talk word processing.  Today Word or equivalent is the
standard.  It generates a very flexible document.  Not just text anymore,
but colors, multiple fonts, graphics, and much more, let alone the
programability built into the macro type functions.

This is all great, but it comes at a price.  Just look at the difference in
size between a text only ASCII file that says "The little brown fox jumps
over the lazy dog." and the word processing document that does that.

The price?  Complexity in the programming, the size of files to store and
shuffle from place to place (and associated network traffic).  Bigger
systems (not individual but think all the aspects it takes to run things)
take more administration, maintenance, power, people effort as developers,
admins, system maintainers, let alone the overhead that comes with that and
keeping things semi-organized.

Is all this worth it?  Today the market has said it is.

This whole computing thing is to provide users with a way for them to be
more profitable in their lives.  Whether it is to lower stress, communicate
easier, process information in a way than makes sense to them (not
necessarily us), at a price that the end customer can tolerate and many of
us 'middlemen' can still make a living (some better than others).

Back toward the original subject, the reason that Single System Image was a
big deal was to simplify life for customers and to reduce overhead for the
customers.  Single Sign On was part of the whole thing too.

So back to the question: Is SSI still a thing?  Yes. ... Just re-branded,
revamped, re-released under a label saying it is all 'New and Improved'.


On Thu, Apr 21, 2016 at 7:11 AM, Dan Ritter <dsr at randomstring.org> wrote:

> On Thu, Apr 21, 2016 at 04:50:35AM +0000, Mike Small wrote:
> >
> > After the meeting I was discussing this issue with a friend. It's not an
> > original criticism I didn't suppose, so I found someone with better
> > words to sum up my reaction:
> >
> > "Sadly it seems that we now need to either wait for Linux or Windows to
> > catch up with the 1980s state of the art in distributed systems (think
> > Locus or AFS). What went wrong? Products like DataSynapse’s FabricServer
> > look like an interesting attempt to address the problem, at least for
> > the Java world, but it feels to me that mainstream operating systems
> > designers seem to have lost the plot somewhere along the way."
> >
> >
> http://discovery.bmc.com/community/blog-post/whatever-happened-to-distributed-operating-systems3/
> >
> > Is single system image still a thing?
>
> No, because you need to deal with parallelism issues on a single server.
> Pocket computers now have four simultaneously working cores. It got really
> hard for CPUs to get faster -- how long has the state of the art hovered
> around 4GHz -- so the process improvements lead to more cores, instead.
>
> 80 cores used to be called a cluster, now it's a moderately expensive
> 1U box. If your problems are smaller than that, you use virtualization
> to gain efficient utilization. If your problems are bigger than that,
> you need to coordinate lots of machines anyway, which will be managed
> in a manner nearly identical to a swarm of virtual machines even if they
> are containers or real metal.
>
> The easiest answer is to take your problem, split it into a lot of
> cases, and send the cases out to all the [threads, cores, containers,
> VMs, boxes] to be worked on. Hopefully they don't need to interact much
> during the case work, and hopefully they don't need to coordinate much
> afterwards. Most of the work involves figuring out what to do for those
> interactions and coordinations.
>
> -dsr-
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>



-- 
><> ... Jack

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