restic/changelog/unreleased/issue-3397

Enhancement: Improve accuracy of ETA displayed during backup

Restic's `backup` command displayed an ETA that did not adapt when the rate of
progress made during the backup changed during the course of the backup.

Restic now uses recent progress when computing the ETA. It is important to
realize that the estimate may still be wrong, because restic cannot predict
the future, but the hope is that the ETA will be more accurate in most cases.

https://github.com/restic/restic/issues/3397
https://github.com/restic/restic/pull/3563
doc: Polish changelog 2023-07-29 00:30:40 +00:00			`Enhancement: Improve accuracy of ETA displayed during backup`
Improve the ETA displayed during backup The ETA restic displays was based on a rate computed across the entire backup operation. Often restic can progress at uneven rates. In the worst case, restic progresses over most of the backup at a very high rate and then finds new data to back up. The displayed ETA is then unrealistic and never adapts. Restic now estimates the transfer rate based on a sliding window, with the goal of adapting to observed changes in rate. To avoid wild changes in the estimate, several heuristics are used to keep the sliding window wide enough to be relatively stable. 2021-11-01 22:13:23 +00:00
doc: Polish changelog 2023-07-29 00:30:40 +00:00			Restic's `backup` command displayed an ETA that did not adapt when the rate of
			`progress made during the backup changed during the course of the backup.`

			`Restic now uses recent progress when computing the ETA. It is important to`
			`realize that the estimate may still be wrong, because restic cannot predict`
			`the future, but the hope is that the ETA will be more accurate in most cases.`
Improve the ETA displayed during backup The ETA restic displays was based on a rate computed across the entire backup operation. Often restic can progress at uneven rates. In the worst case, restic progresses over most of the backup at a very high rate and then finds new data to back up. The displayed ETA is then unrealistic and never adapts. Restic now estimates the transfer rate based on a sliding window, with the goal of adapting to observed changes in rate. To avoid wild changes in the estimate, several heuristics are used to keep the sliding window wide enough to be relatively stable. 2021-11-01 22:13:23 +00:00
			`https://github.com/restic/restic/issues/3397`
Address review comments 2023-06-08 18:24:21 +00:00			`https://github.com/restic/restic/pull/3563`