On Tue, Oct 09, 2001 at 09:46:37AM -0500, Chad C. Walstrom wrote:
> The discussion comparing Linux/{Intel/Sun/HP/IBM/Mac} Sun/Solaris may
> be interesting, but it boils down to what you need in a server and who
> delivers it.
Very true.
> The term "mission critical" itself is misleading. Factory
> device/machine controllers are far different mission critical
> operations than RDBMS transactions or packet routing.
The term mission critical is a buzzword. CNC milling machines and those
sorts of applications are why the PDP-11 is still manufactured by Mentec.
And UNIX isn't even on the radar as an OS for much of that business.
> Would I use Linux for "mission critical" applications? Certainly.
> I've worked with multiple business that have successfully deployed
> very dependable Linux environments. Is it the right solution for
> every problem domain? Absolutely not. Why?
>
> "When you have a hammer, everything looks like a nail."
Again, define mission critical. To me, mission critical is an application
where human lives are hanging off the buss. *No* business application
is truly mission critical. Maybe I should say I mean MIL-spec, to differen-
tiate between that and "high-reliability, high-availability."
Nuclear power station control. Space flight. Fly-by-wire systems.
The problem with Linux in these applications is the very thing that
makes it appealing for many of us. See, the difference is when you have
to sign off and *guaranty* performance and assume liability, you don't
want to incorporate code that has come from anywhere you haven't explicitly
verified.
And to refer to Carl's post, there do exist OS's that will handle an
out-of-memory condition, but they aren't of the Unix family. VMS or NSK,
and maybe MPE will, I believe.
So it's semantics again -- define mission critical, and you have determined
your functional spec and probably made it a lot more clear what OS. Chewie
hit the nail on the head saying nothing is the right solution for
everything. I just want to point out that there's a level of reliability
that we don't ever really get to hear of, or play with much, in the open
source world. And it's not driven by business.
--
I used to like HP before computers, and once I even liked Compaq,
but I liked DEC better than HP and Compaq put together.