I’ve been having timeout trouble (lots of reports filed here) for a long time on Backblaze B2, and was curious if their S3 works better. Unfortunately my bucket is too old and migration is some work (I’d probably rclone in hopes of server-side copy). Does yours look S3 enabled?
I’ve also been wondering how to observe behavior, given a lack of Duplicati or .NET logging and the challenges of HTTPS. After looking at external tools, I’m just guessing in Wireshark.
was the idea long ago, and possibly it’s invalid now, but to raise the failure rate from my prior half at default 30 second timeout (I switched to 5 minutes, but 3 was working OK), I reduced the timeout to 15 seconds, got ample timeouts, and looked at one quite closely.
From packet log, this starts at 19:16:24 and ends at 19:16:59. From profiling log, there is
2025-07-21 19:16:23 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Started: duplicati-bf346b005a8934a7ba3e4d5673dac47fa.dblock.zip.aes (9.94 MiB)
2025-07-21 19:16:39 -04 - [Profiling-Duplicati.Library.Main.Backend.PutOperation-UploadSpeed]: Uploaded 9.94 MiB in 00:00:15.1426118, 671.85 KiB/s
2025-07-21 19:16:39 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Completed: duplicati-bf346b005a8934a7ba3e4d5673dac47fa.dblock.zip.aes (9.94 MiB)
2025-07-21 19:16:39 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Started: duplicati-ia215b46c24cc49c78082ab426a1557f5.dindex.zip.aes (5.37 KiB)
2025-07-21 19:16:39 -04 - [Profiling-Duplicati.Library.Main.Backend.PutOperation-UploadSpeed]: Uploaded 5.37 KiB in 00:00:00.1822640, 29.47 KiB/s
2025-07-21 19:16:39 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Completed: duplicati-ia215b46c24cc49c78082ab426a1557f5.dindex.zip.aes (5.37 KiB)
2025-07-21 19:16:40 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Started: duplicati-b907243c763ee4658b188bf445c95e46d.dblock.zip.aes (9.94 MiB)
2025-07-21 19:16:59 -04 - [Information-Duplicati.Library.Main.BasicResults-BackendEvent]: Backend event: Put - Failed: duplicati-b907243c763ee4658b188bf445c95e46d.dblock.zip.aes ()
with the second dblock starting about 17 seconds in. Remote volume size is 10 MB, so graph of 20 MB transfers is probably showing both dblocks, with other work in between.
From the web UI for the bucket, this looks like all files in profiling log actually made it up:
even though Duplicati closed the TCP connection with a FIN when it claimed a timeout.
I saw this on an earlier run too, where a dblock got a timeout, and next run uploaded its dindex. This surprised me, but I verified dblock in DB list data at start of second run.
Key question for development is: where’s the connection that is stalled for 15 seconds?
EDIT 1:
Latest test is actually on 2.1.1.0 Experimental. I set one parallel upload to simplify study.
EDIT 2:
Backblaze IP Addresses told me what I should be filtering on when setting up Wireshark.