So your cron job, which has been dutifully stuffing away into s3 your backups nightly or hourly or whatever, just stops working. s3put just breaks with the unhelpful complaint, “broken pipe.”
You can try running s3put with “–debug 2” added to your flags, and watch the lower protocol-level stuff seem to go along just fine until it barfs with the same error.
Check the size of your file. If you’ve got a backup that’s been slowing creeping up in size and is now over 5.0 GB, that’s your issue. AWS apparently has a 5 GB s3 limit for single-part HTTP PUT.
s3put accepts a “–multipart” option, but only if it can find the necessary Python libraries including “filechunkio,” so install filechunkio and try again. With any luck, you can just add –multipart to your s3put command and it will Just Work.