Hi Gary/Daniel
Que: what's the RTT (ping time) from the client to the server?
Ans: I tried pinging the server and got a "Request timed out" message. I was
not able to connect through the browser also since it is a SFTP connection. The
browser gives a message saying it cannot get the following URL and that it
needs a specific software for handling SFTP connection (In my case this was
WinSCP).
Please let me know if there is any other way I can find out the ping time for a
SFTP connection.
Que: Have you analyzed the network packets to determine the duration of each
phase of the transaction? Where is the time being spent?.
We have analyzed the time taken for upload into a server without SFTP and the
time taken is a little less.
Que: What libcurl version are you using? Did you build it yourself?
What SSL library are you using? What version?
Ans: curl-7.21.6. Yeah I built libcurl by downloading/building the following:
ActivePerl-5.12.3 Build 1204 ,
libssh2-1.2.8,
nasm-2.09.08 and
openssl-1.0.0d
Que : How does the performance of your application compare to
the same SFTP transaction using a different client?
Ans : I have tried with WinSCP and comparison of time between libcurl and
WinSCP is as below
LibCurl WinSCP
Size Time taken Size Time taken
2 MB 8 seconds 2 MB 1 seconds
5 MB 19 seconds 5 MB 2 seconds
15 MB 50 seconds 15 MB 7 seconds
22.5 MB 90 seconds 22.5 MB 20 seconds
43.7 MB 3 minutes 50 MB 55 seconds
65 MB 4.5 minutes 65 MB 2 minutes
90 MB 6 minutes 90 MB 3.5 minutes
141 MB 11 minutes 145 MB 5 minutes
194 MB 14 minutes 194 MB 7 minutes
250 MB 20 minutes 247 MB 9 minutes
500 MB 36 minutes 500 MB 15 minutes
I am following "Using-libcurl-with-SSH-support-in-Visual-Studio-2008.pdf" by
Andrei Jakab ([email protected]<mailto:[email protected]>).
I also had a doubt whether we need to install (compile) the libcurl library in
the front end machines as well, or do we have a run-time library that we can
obtain ?
I really appreciate any responses for the same.
Regards,
Srikanth
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Gary Maxwell
Sent: Wednesday, June 15, 2011 12:56 PM
To: libcurl development
Subject: RE: Performance issue with libcurl library for SFTP upload
> From: Srikanth Ramaprasad08
> Sent: Tuesday, June 14, 2011 23:28
> Subject: Performance issue with libcurl library for SFTP upload
> I am using libcurl library in our C++ code (IDE: Microsoft
> Visual Studio 2008) for uploading files to an SFTP server.
> Below you can find the time taken for upload of a few files.
> ...
> As you can see the time taken for upload is very high.
"High" is a subjective term. Depending on the environment,
250KBytes/second may be reasonable.
> Is there any way to reduce the time taken to upload to SFTP
> or is this the normal time taken ?
> How can I improve the performance ?
Unfortunately, you provide very little information for the list
to consider, only that you are using VS2008 and SFTP. I would
suggest performing some more investigations on your part:
- What libcurl version are you using? Did you build it yourself?
- What SSL library are you using? What version?
- Have you analyzed the network packets to determine the duration
of each phase of the transaction? Where is the time being spent?
- How does the performance of your application compare to
the same SFTP transaction using a different client?
- Finally, if it still looks like a libcurl problem, please
let us know with as much information as possible.
> Please get back to me ASAP.
This is not the type of request that volunteers for an open
source project like to see. We have real lives and jobs, too.
Cheers,
GaryM @ Broadsoft
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