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[nos-bbs] My response - JNOS not being a race car, having stress problems.

Steven Stimpson steven2 at gwi.net
Fri Jun 1 20:32:41 UTC 2007


----- Original Message ----- 
From: "Maiko Langelaar (ve4klm)" <maiko at pcs.mb.ca>
To: "(Skip) K8RRA" <k8rra at ameritech.net>
Cc: "TAPR xNOS Mailing List" <nos-bbs at lists.tapr.org>
Sent: Thursday, May 31, 2007 12:19 AM
Subject: [nos-bbs] My response - JNOS not being a race car,having stress
problems.


> Hi all,
>
> I personally do not want everyone on this list to be distracted or scared
> away from using JNOS to it's full potential, just because of a few recent
> observations and comments, which if misread, will leave new and potential
> NOS users with a not so great impression of what it is truly capable of.

 My apologies if my snitty comments about winlink/linux added to that Maiko,
 "Say what you mean, but don't say it mean".


> Most of the comments have to do with NOS on DOS, but the jist can be taken
> to any O/S for that matter. Let me add that running JNOS on LINUX actually
> removes alot of the possible stress causers that DOS could bring on, for
> instance, the availmem(). That's not an issue in LINUX !
>


 Well, first you commented that running excessive servers and features in
NOS slows it down, so you run only the packet switching features.
But when it comes to mentioning Linux, because it allows unlimited
memory, all of a sudden a 5 megabyte NOS executable is okay?

 You also said the performance issues are the same for all OS/s.


> --------- INFO SNIPPETS BELOW ------------
>
>    Actually, it depends on what kind of "stress" is being applied. The
>    worst stress that DOS-NOS experiences is when new processes are spawned
>    to handle connections for application sockets. The more "user"
connections
>    there are to NOS, the more processes there are and the more "stressed"
>    the machine becomes.
>
>    Any machine which experiences a high degree of memory fragmentation
>    within NOS during the normal course of its uptime is being "over-
>    taxed".  Remember:  NOS on a DOS platform, for all its good (and
>    bad) points, with its non-pre-emptive multitasking capabilities,
>    does not even begin to approach the functionality of a pre-emptive
>    multitasking operating system like UNIX.
>
>    Real multitaskers are "pre-emptive", meaning they will interrupt the
>    current machine task to service another one if necessary. NOS is *not*
>    pre-emptive, but rather, "looks like" a multitasking system because it
>    is constantly polling a "ready process" linked list looking for
processes
>    that are ready to run. It does this through the magic of pwait(), which
>    as you know contains the context switching call, and psignal(), which
>    are the heart and soul of the NOS "kernel". This was ingeniously
devised
>    by Phil Karn, KA9Q in an effort to devise a TCP/IP packet switching
>    program that required being "aware" of multiple threads that work ok
>    on a DOS platform.  The idea was that each process would get a time
>    slice when it was "ready to run".
>
>    THIS IS AN IMPORTANT POINT - NOS performs best when it has the fewest
>    number of processes running and it performs worst when it has the most
>    number of processes running.  The relationship is directly
proportional.

 Basically what this says to me is "Any software that does more, IE has more
processes/threads
is going to slow down. Hmmm...Now that the obvious has been stated...It is
clear to any modern computer
user that the Linux kernel is going to be more efficient with multitasking.

I question I ask is "Does Jnos REALLY Require so much computing power as to
justify a 2.6 kernel with 1 gig of ram and a 4 GHZ dual core 64 bit CPU?
I know a lot of NOS computer enthusiasts are running such hardware, but it
seems
to me somewhere along the line of NOS going from DOS to Linux some people
have become convinced that type of hardware is necessary.

>  Ran my first JNOS box on a 386 40MHz with only ONE meg of RAM.  That
> was Hamgate.Merit.EDU and the machine had 4 radio ports plus a very busy
> ethernet port.  It pushed MOST of the Internet mailing lists such as
> NOS-BBS, various lists from TAPR, Kep tables, and the usual load of
> bulletins and personnal email for Hams living in Eastern Michigan from
> Port Huron down to Toledo, Ohio.  Daily logs showed well in excess of 500
> messages per day, some SMTP and some heirarchical mail being passed to
> conventional BBS's.  I'd say it was chugging along quite well, race car or
> not!

I would dare say that setup was loaded down 200 times more than most
NOS switches, especially when they are situated behind a hardware
firewall/router,
then further seperated by the TUN to the linux NOS.

 Point being all of this ran fine on a 386 with one meg. My first DOS NOS
machine was an 4.7 MHZ 8088 XT, wid 640k, I still own it and I still compile
111f using bcc 3.1 for it.

This is not yet more DOS preaching, this is an example of the extremely
small
amounts of computing resouces needed to run Jnos.

>    How many telnet, FTP and SMTP connections can joe user make before
>    availmem() gets dangerously close to the 'memory threshold' setting
>    and the program slows down to a garbage collecting crawl. Well of
course
>    NOS is going to "stress out" under these conditions. The applications
are
>    all add ons and people want to have everything under the hood of the
same
>    car. Eventually, NOS says, "enough".

 The number of telnet, FTP and SMTP connection
Joe can run before availmem() gets dangerously low is
dependent on availmem(). I run DOS machines that have
630K free at the C:\ prompt. It is amazing what you can
cram in that little space from 640K to 1024K.

 My latest NOS.exe has NNTP client, SMTP client, ftp client, telnet client
and server, and AX.25 BBS. When I kick NNTP to giganews.com,
it processes hundreds of messages a minute. I then like to
start an FTP to download.nvidia.com, and then add
a telnet to k1eu.dynip.com. Then I block tracing on my
internet connection, start tracing on my 2 AX.25 ports, and I watch
the activity on VHF APRS and my H.F. forwarding
networks while all this is going on. I find I rarely drop
below 90k free.

 The concept that everyone wants to have everything under the hood
of the same car mainly applies to Linux. DOS users having been picking and
choosing
within config.h for years, however it seems 5 or 6 meg Linux executables
that literally have "Everything" under the hood is the biggest argument
for using NOS under Linux in the first place.


>
>    I have a system that is living proof of the less processors the better.
>    There's no mailbox, no smtp, no http... it just switches packets where
>    they need to go. Uptimes are in terms of over half a year.
>

Jnos as a switch is one tiny segment of the population. It is one
of many different reasons to run and use NOS. On network
105 you find find Jnos that have up to 10 ports, with convers,
AXIP, ax.25 to internet gates, full functioning BBS (With FBB forwarding).

This a classic sysop gateway intended for end users and it is the very
reason all this stuff was added to Jnos in the first place. Claiming
Jnos only performs well as an AXIP AX.25 switch under *NIX
is just as scary as suggesting it is a horribly broken, undocumented
project on it's way to first beta.


Steven - N1OHX





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