Issues to address to get out of beta

Alternative FTP failure? seems like a good place to discuss because I think we might be talking about a retry on the PR that tried to workaround the issue, and the “get out (of|a) beta” topic here is getting long.

Summary of my current thoughts on proposed PR retry is it’s an improvement, but if the issue is actually premature finish from FluentFTP, and not some bug in Duplicati’s async code – and I’m NOT an expert, then I’d prefer trying to get to the bottom of it rather than, for example, have to tune the upload delay for dblock even if a much smaller file is uploaded. Note that use of UploadAsync was added for concurrent uploads, but exposed the FluentFTP bug that did get fixed, and might have added premature finish bug. There’s also the question of whether a poll workaround should be SIZE based, or LIST/MLST as before.