B2 connectivity errors

What is the problem you are having with rclone?

Recently when performing B2 server side copies using rclone, we've observed various connectivity errors. The following errors have been observed quite regularly in the last while on different machines on different networks:

2020/11/17 19:09:14 ERROR : path/to/file.xyz: Failed to copy: connection pool timed out for https://f003.backblazeb2.com/b2api/v2/b2_download_file_by_id?fileId=abc (901 connection_pool_timed_out)

2020/11/17 18:47:27 ERROR : path/to/file.xyz: Failed to copy: javax.net.ssl.SSLException: Read timed out talking to https://f003.backblazeb2.com/b2api/v2/b2_download_file_by_id?fileId=abc (904 io_exception)

2020/11/17 18:58:00 ERROR : path/to/file.xyz: Failed to copy: socket timed out talking to https://f003.backblazeb2.com/b2api/v2/b2_download_file_by_id?fileId=abc (903 socket_timeout)

Has anybody else maybe seen these errors recently? Any ideas what could be causing this?

What is your rclone version (output from rclone version)

rclone v1.52.2-232-gff843516-beta

  • os/arch: windows/amd64
  • go version: go1.14.6

Which OS you are using and how many bits (eg Windows 7, 64 bit)

Windows 10, 64 bit

Which cloud storage system are you using? (eg Google Drive)


The command you were trying to run (eg rclone copy /tmp remote:tmp)

rclone copy (server-side copy)

The rclone config contents with secrets removed.


A log from the command with the -vv flag

See errors above in problem description


best to update to lastest stable and test again.

Hi @asdffdsa, understood, but not quite so easy as I don't have control over all the machines where this is happening. But we've been using this version for a while already without seeing these errors until recently...

in that case, seems to me that only variable that changed is b2 itself.
and those are very specific error values.

Those look like Java error messages and so can't generated by rclone which is written in Go!

So I think something must be up at B2.

Did rclone retry successfully?

Yeah, the errors also looked strange to me. So in your view, the B2 API is failing internally and then returning those errors to rclone via http?

I usually set retries to 1 for server-side copies since I do not expect errors, but if rclone had retried, it may have had more success the second or third time I assume. There were 19 of those errors altogether in the first attempt though...

Would you propose to log an issue with Backblaze?


If it happens regularly, then yes. Those are internal errors which shouldn't be escaping to customers I think.

Ok, thank you as always for your insight @ncw!

1 Like

Hi @ncw, just as a follow up question, does the following kind of error also look like internal to B2, or does it look more like an rclone or local OS error?

2020/12/24 11:01:14 Failed to create file system for ":b2:bucket-name/path/to/folder": Post "https://api003.backblazeb2.com/b2api/v1/b2_list_file_names": dial tcp connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

I think that one looks like a network connectivity problem, so could be local or could be remote. Maybe a local firewall interfering?

I'd only worry about it if you see it regularly.

Ok, makes sense. It does occur consistently on a certain machine, so I suppose checking for a firewall would be good. Thanks @ncw!

1 Like

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.