Hi Nick,

Thank you for your feedback.
I understand and I totally agree with everything you wrote.

On that note, I am very happy with Guacamole, its features, and its 
performances so far.
At my company, we manage servers hosted all around the world from the same 
Guacamole instance and this « cat » issue is the only latency problem I have 
encountered so far. I am impressed by this product and the work that has been 
done on it.

As you said, the real way to fix my problem is to kindly remind my colleagues 
not to use « cat » on big files. That’s bad practice.
This latency latency I wrote about is only a technical symptom of this human 
problem.
Nonetheless, I am excited to work with Guacamole and to understand it inside 
out. I felt digging into this latency issue would be a great opportunity to 
learn about this product. And I felt sharing it was a nice way to connect to 
this project’s community.

Best regards,

Julien Lejeune
IT administrator

+32(0) 81 33 11 11
www.actia.be<http://www.actia.be/> [Linkedin] 
<https://www.linkedin.com/company/actia-telematics-services>



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De : Nick Couchman <[email protected]>
Envoyé : mercredi 18 octobre 2023 01:42
À : [email protected]
Objet : Re: Slow output - Linux connections

On Tue, Oct 17, 2023 at 2:23 PM Julien Lejeune 
<[email protected]<mailto:[email protected]>> wrote:
Hi all!

Luke and Mark, thank you for your helpful insights.

I haven't solved the problem yet, but I give you a little feedback anyway.


To be clear, if you connect directly via SSH without Guacamole, the cat takes 
4s. When using Guacamole with a defined SSH connection, it takes 1 minute 37 
seconds.

It's probably worth noting that we don't make any specific claims (that I can 
recall) about Guacamole being faster than a native SSH (or RDP) connection - 
or, at least, not without some better definitions of the characteristics of 
those connections. If I'm wrong about that, and we have made those claims 
somewhere, then please someone jump in and correct me :-). Guacamole is 
designed to perform reasonably well over connections that have elevated latency 
and lower bandwidth, as it can adapt to those conditions, usually better than 
the native protocols. It's also designed to give the user a single clientless 
interface using only a web browser, with no additional software, and is able to 
make those connections available via HTTP/HTTPS/WSS, which are pretty standard 
ports and protocols to have open across network boundaries. And, while, most of 
the time, performance should be comparable to - and may be faster than - other 
SSH clients, there are definitely some situations you're going to hit where the 
nature of the connection and what you're trying to do is better-suited for a 
native client.

If your client computer is relatively "close" to the SSH server (in the 
single-digit ms range), and you're doing some very display-intensive things 
(cat /dev/urandom, or tailing a very verbose log file, etc.), I would fully 
expect that the platform-native SSH client is going to render the output of the 
SSH connection much more efficiently than the Guacamole combination where the 
SSH protocol has to be turned into Guacamole (series of images going one-way 
and keystrokes and mouse movements going the other way) and then rendered by a 
web browser.

Now, the difference you're seeing is quite a bit - 4s -> 1m37s is something 
like a 2400% increase. That said, I'm not sure there's all that much that can 
be done - use "less" instead of cat, so that you're not attempting to stream 
the entire contents of the file all at once?

Aside from the "cat /var/log/huge.log" situations, are there other areas where 
you're consistently  seeing increased latency as compared to the native SSH 
client?

-Nick

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