[FreeNX-kNX] A Fix for the problem of multiple attempts needed to login to FreeNX after a re-boot
Antoine Martin
antoine at nagafix.co.uk
Fri Apr 9 00:00:12 UTC 2010
chris at ccburton.com wrote:
>
> Antoine Martin <antoine at nagafix.co.uk> wrote on 07/04/2010 22:40:00:
>
> [snip]
>
>> > To emulate synchronous launching, a delay must be introduced.
>> Well spotted! I had hit this bug too.
>> Generally happened when I was doing a well rehearsed demo.. ;)
>>
>> The solution that I have used successfully (and is also used in neatx)
>> is to watch the output of the nxagent process: once the line saying
>> "Waiting for connection from ..." shows up, you can be certain that the
>> socket is ready.
>> I have also previously used a tcp-connect loop (with a 1 second
>> timeout), but the log parsing is both quicker and more proper.
>>
>> The "sleep 4" that you have added may work in most cases,
>
> It will work unless the machine is maxed out . . .
Exactly.
>> but you can't
>> guarantee that it is the correct delay.
>
> No ! it will only do for about 99.99% of first logins after a reboot.
Probably.
(99.99%, that's very precise! ;)
>> Too short and it causes the
>> aforementioned bug, too long is also problematic as it slows down
>> session startup unnecessarily. (4 extra seconds is pretty long when you
>> don't actually need it in most cases)
>
> No one will notice !!
I do. Ok, maybe I'm the 0.01% then!
But when my desktop PC boots in 10 seconds, I expect virtual sessions to
be significantly quicker than that!
>
> <Snip>
>
>
>>
>> My 2p
>> Cheers
>> Antoine
>>
>
>
> So we differ.
>
> Here is my view.
>
> I am concerned with live systems staying live.
So am I.
> I am unconcerned with log in times of 8 seconds ( which
> is the time my machines take ).
4 to 8 seconds, is 100% more, not negligable IMO: I can start a full
desktop and connect to it under 3 seconds now with my solution.
> I want a fix that can be understood by people who can't solve
> the problem for themselves, that is to say ordinary users.
Meaning that "waiting only as long as necessary" can't be understood?
Or that this is just a quick fix to test if this fixes it?
If it is the former, I think your average NX administrator is cleverer
than you think. If the latter, I apologize: I thought you were a
maintainer and that this was going to be the final solution merged.
> I want something that they can type in easily without making
> mistakes.
patch < file.patch
> I want something which will will be benign in the event a
> mistake is make ie. no unterminated loops or "
Simple: then don't write unterminated loops!
for i in `seq 1 20`; do
if grep thething
success!
> I want minimum intervention patching, following the coding
> style used by the original developer, right or wrong (which
> is of course standard practice throughout the industry).
>
> More elegant and quicker solutions are for the maintainers
That is what I meant: a "sleep 4" is quick patch, not a long term solution.
So, who/where are the maintainers?
Do you know where the release schedule is?
> to include for thorough testing in the next version, after a
> complete review of the surrounding code and associated
> algorithms.
I don't think it is that complex a problem.
> Your solution is to write a new product, which is perfectly
> valid and of course I wish you good luck.
It's already written. Thanks!
> But that won't help an overworked and underpaid systems
> manager supporting for a charity, who is getting flak about a
> system which appears cronky or badly configured and is
> giving a shaky "user experience" to that senior manager
> who is always first in the office on the monday after reboot
> sunday, and views things like this as a test of competence
> or feels he needs to push people along . . .
Yes, I can totally understand, I've been there!
(this is exactly why I moved in a different direction)
> Antoine, did you send me an out of band email a bit back
> asking about printing ??
Yes I did.
> There was a thread going about cups re-direction for a
> bit, but I've been a bit too busy since December to bother
> with anything else, and NX printing is a bit of a convoluted
> pass the parcel.
Indeed.
(like the recent posts "helping printing" prove)
> If you are writing a new application with a new CLIENT
> then you can do what you want and don't have to follow
> the nomachine client.
That's what I did.
Backwards compatibility was just a drag for me, which is where neatx
also failed IMO: trying to re-implement an old design with new tools.
> Looking back at the thread though , my advice is still
> to run the userland cupsd on the NX server, so all sessions
> are the same regardless, and to spool postcript as far
> along the line as you can if you are using a non postscript
> printer rather than having the .ppd on the NX server
> and spooling raster down a remote link.
Thanks, your advice is much appreciated.
> Whatever you do . . .
>
> . . . the main userbase will stay with FreeNX, because
> it works OK, and almost no organisations will gain
> overall benefit from the cost of a project to move
> to one of the other new nxagent launchers
Did you take a look at the link I sent you privately?
The target audience isn't the same as freenx, although it could be used
in a similar fashion. It aims at making it trivial to setup and use
virtual desktops: it is done via a desktop applet which allows you to
start/stop/resume sessions, send them to other clients, it has mDNS
server detection, auto-connect, auto-resume, etc
And it supports VNC, NX, xpra, ssh-X, libvirt backends.. Not just NX.
But, enough astro-turfing ;)
> ( whichis what FreeNX is, though it does also aim
> to pass ipp and samba printing and samba drive
> mapping over the link).
I am building supporting in filesystem agnostic way: not just samba, but
nfs, glusterfs, etc.. will be supported.
Sound support is more limited unfortunately, as Pulseaudio is pretty
much the only game in town nowadays.
> I don't see there is much demand for remote printing
> especially to windows work stations, though I use it
> quite a bit to put ooo-writer on remote XP with local
> USB printers and mapped drives.
I disagree: I do think printing is very important (more so when the
servers are further away - say across the Interweb). And as you pointed
out it is still hit&miss unfortunately.
> The truisms are :-
>
> 99% of the work on any of these projects has been
> done by Nomachine, building and maintaining the
> libraries, nxagent
It also supports VNC and xpra besides NX, so the situation is a bit
different.
>
> and
>
> the client software, which deals with all the caching
> on the workstation and provides an X server for
> windows.
>
> In adition there is ssh/sshd doing the encrypted link.
Which I only use as an option. (if needed or desired)
> All the other stuff runs once at login, again at logout
> and is irrelevant during the operation session.
And this is where I think there is some value to add, like making it
easy to start individual apps in seamless mode, as shown here in XP:
http://shifter.devloop.org.uk/screenshots/xp1.png
But this depends on your use cases: if your users only use one full
remote desktop each without sharing, that's probably not very relevant.
Cheers
Antoine
>
> cb
>
>> >
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>> ________________________________________________________________
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>> Then please write up the solution in the FreeNX Wiki/FAQ:
>>
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>>
>> Don't forget to check the NX Knowledge Base:
>> http://www.nomachine.com/kb/
>>
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>
>
> ------------------------------------------------------------------------
>
> ________________________________________________________________
> Were you helped on this list with your FreeNX problem?
> Then please write up the solution in the FreeNX Wiki/FAQ:
>
> http://openfacts2.berlios.de/wikien/index.php/BerliosProject:FreeNX_-_FAQ
>
> Don't forget to check the NX Knowledge Base:
> http://www.nomachine.com/kb/
>
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