Unreliable-network issues


#1

I have Duplicacy backing up large database dump files from a server in Dubai to a machine in the UK, using SFTP.

The network route is long and winding, and this seems to be the cause of the database backups quite often hanging with no apparent activity, and then errors like:

ERROR UPLOAD_CHUNK Failed to upload the chunk xxxxx: failed to send packet header: write tcp ###.###.###.###:59190->###.###.###.###:22: write: connection timed out

ERROR UPLOAD_CHUNK Failed to upload the chunk xxxxx: failed to send packet header: EOF

and others talking about EOF and the like (I’ll copy them here when I next see them).

Could be a similar problem to Uploaded file but failed to store EOF perhaps?

Any things I can try to reduce this problem?


#2

I’ve scripted retries into my duplicacy job such that if I see EOF in the logfile… I try again up to 10 times.

This is a very sub-par workaround. It doesnt help all that much.

We’ve been promised built in retries on SFTP transfers but it hasn’t happened yet and I am not sure if it ever will at this point… without it though… it makes Duplicacy hard to use with SFTP… sadly.


#3

Oddly, looking into the issue further, I see that backing up the same server in Dubai to my local PC in the office is fine. And massively faster, too!

It’s only the backup to a Linux (CentOS 7) machine in a datacentre that’s causing problems. Hmmmm…


#4

I have two machines at home, they both backup to a local NAS and they both backup to remote machines… all via SFTP.

One of them at home has the SFTP EOF fails even to the local NAS. I can usually get it to complete with a few retries. The other computer never has SFTP EOF fails locally but DOES when going remote.

I dont know why it does it… surely it is due to some network issue but we need a system robust to this issue someday :slight_smile:


#5

PS- We were in Dubai earlier this year for a visit… very interesting place.


#6

Problem for me is now fixed, I think is was a network issue leading to extremely slow connection speeds. Perhaps DDOS protection or something like that.