Slow SFTP transfers

[cyberduck]

11e0fc1 created the issue

If I use the command line sftp client on the local network, I can get transfer speeds of several MB/s.

If I use CyberDuck, the fastest it gets is 600KB/s, which was after I tried increasing the buffer size to 65536.

Is this a known problem? Cyberduck is still nice, but useless for local networks...

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Attachments

• Ciphers.patch (10.8 KiB)
• Upload_with_status_queue.patch (9.4 KiB)
• patch_upload_poc.diff (5.7 KiB)

[cyberduck]

@dkocher commented

Duplicate for #12072.

[cyberduck]

3db2538 commented

This is not a dupe of #12072. That one says that CyberDuck doesn't support compression, resulting in slower transfers. While that may be true for WAN transfers, adding compression over LAN transfers will actually slow them down.

The issue is that CyberDuck is about 10x slower than the sftp client on a LAN, with compression disabled.

Isn't this a really easy one to verify?

[cyberduck]

Michael Schubart commented

I noticed the same thing. Cyberduck: A few 100 KByte/s. Command line scp: a few MByte/s.

[cyberduck]

mfichtner commented

The problem still seems to exist in the latest pre-release 2.5.5. Download speed through SFTP is still approx. 10% of the available bandwidth.

[cyberduck]

analogue commented

Same for me, using the 2.5.5, I get ~85KB/s using Cyberduck, and ~400KB/s using the command line sftp client.

[cyberduck]

@dkocher commented

This is a bug in the SSH I/O code and has nothing to do with the Java language used. Java has a very good network performance in general; e.g. see FTP transfers in Cyberduck. Please don't write any silly annonymous postings here, please.

[cyberduck]

doml commented

Ditto.

Fugu transfers files at 11-12MBps whereas CyberDuck transfers up to about 3MBps if I'm transfering multiple items at once or ~1-1.2 MBps for a single transfer.

Also, CyberDuck crashes on large file transfers (4-20GB per file) which may or may not be a symptom of the same problem.

[cyberduck]

43a8818 commented

I concur on this one. ~88 kBps with Cduck, and ~7.8MB (yes, that's bytes) with scp.

[cyberduck]

15b0e70 commented

I'm experiencing the same problem, 240KB/s with Fugu... 20KB/s with Cyberduck...

Any idea when this is going to be fixed?

[cyberduck]

anonymous commented

I confirm it, 200KB/s with Cyberduck, 1.8MB/s by scp on terminal.

[cyberduck]

efa8001 commented

I may have just entered a duplicate of this bug at http://trac.cyberduck.ch/ticket/656

My symptoms appears to be the same. My connection is not inside a LAN, though.

[cyberduck]

@dkocher commented

I will do a prototype replacing the current SSH implementation with Ganymed.

[cyberduck]

@dkocher commented

The latest nightly build (2844) featueres Ganymed SSH2. Performance issues still exist, but at least uploads reach here 1MB/s over the loopback interface. This issue will only be resolved by using parallel requests as OpenSSH does. See d5ae7a7 and aff28eb.

[cyberduck]

@dkocher commented

Refer to the latest nightly builds at (http://update.cyberduck.ch/nightly/). Try Preferences > SFTP > File Transfers > Use SCP.

[cyberduck]

anonymous commented

Hi,

I'm very thankful that this is fixed however I would STRONGLY suggest that the default setting is set to SCP for SFTP transfers instead of having to dig into these forums to try to determine that this in fact solves the problem.

ALSO if someone elects SFTP as the transfer protocol it would be nice to have a message stating that there are issues with large transfers and the order of magnitude may be 10x slower as an FYI due to underlying libraries (not Cyberduck).

--Nikolaos