[paramiko] How to improve paramiko performance

[Deepak Rokade]

Thanks for your suggestions.
I had already used prefetch for 'receiving files' and 'set_pipelined' for
sending files.

Robey,
You are correct HPN patches needs to be applied on both the sides. and I
compared
HPN performance using HPN client and HPN server.

To the surprise FTP takes only 0.4 seconds to transfer a file whereas SFTP
takes 25 seconds.
I understand the difference between two protocols but it's a huge gap
between transfer rates.



On Feb 18, 2008 11:35 AM, Robey Pointer <robey at lag.net> wrote:

> On 15 Feb 2008, at 6:24, Deepak Rokade wrote:
>
> > Hi All,
> > With this mail I want to know "how to improve performance of
> > paramiko for transferring files over the internet through VPN"
> >
>
> This sounds really similar to the HPN thread, so you might check the
> HPN patches.
>
> > Brief about what we are doing.
> >
> > I want to transfer files of size 5MB which are compressed with gzip
> > format over the VPN. This experiment is being carried out between
> > two cities located 1000km apart ()
> >
>
> For fast, latent pipes, you'll want large window sizes, but also note
> that SFTP is *terrible* over high latency links. The folks at the
> bazaar project found this out the hard way.
>
> The problem is that SFTP requires you to send a block of data, then
> wait for an ack. The stop-and-wait wastes a lot of time if you have
> long round-trip times.
>
> Paramiko can "cheat" a little if you use 'set_pipelined' (for sending
> files) or 'prefetch' (for receiving files).
>
> Also note that I think the HPN window improvements require each side
> (client & server) to be running with the HPN patches. (Someone correct
> me if I'm wrong?)
>
> robey
>
>


-- 
Thanx & Regards,
Deepak Rokade

Do what u Enjoy &
               Enjoy what u Do...........
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