Comment 6 for bug 1734144

What Joris states can be correct. The version of swift that is running is quite vintage with 'customizations'. Varnish is however not used for authenticated requests (boss-backup, thus duplicity), that is bypassed directly to the swift proxy servers.

I've got no control over swift or the backend, since that's a different team. I do however have around 5% of over 8000 duplicity backups reporting this issue every day.

It would make duplicity more resillient, since both a retry of the version check, or a retry of the upload (as specified with numretries) would solve the issue. This backend might be wonky sometimes, and yes that should be fixed, but so might other backends. (https://aws.amazon.com/s3/faqs/ Amazon S3 Standard and Standard - IA are designed to provide 99.999999999% durability of objects over a given year. This durability level corresponds to an average annual expected loss of 0.000000001% of objects. For example, if you store 10,000 objects with Amazon S3, you can on average expect to incur a loss of a single object once every 10,000,000 years. In addition, Amazon S3 is designed to sustain the concurrent loss of data in two facilities.).