While searching for lock file from concurrently running restic
instances, restic ignored unreadable lock files. These can either be
in fact invalid or just be temporarily unreadable. As it is not really
possible to differentiate between both cases, just err on the side of
caution and consider the repository as already locked.
The code retries searching for other locks up to three times to smooth
out temporarily unreadable lock files.
Restic continued e.g. a backup task even when it failed to renew the
lock or failed to do so in time. For example if a backup client enters
standby during the backup this can allow other operations like `prune`
to run in the meantime (after calling `unlock`). After leaving standby
the backup client will continue its backup and upload indexes which
refer pack files that were removed in the meantime.
This commit introduces a goroutine explicitly monitoring for locks that
are not refreshed in time. To simplify the implementation there's now a
separate goroutine to refresh the lock and monitor for timeouts for each
lock. The monitoring goroutine would now cause the backup to fail as the
client has lost it's lock in the meantime.
The lock refresh goroutines are bound to the context used to lock the
repository initially. The context returned by `lockRepo` is also
cancelled when any of the goroutines exits. This ensures that the
context is cancelled whenever for any reason the lock is no longer
refreshed.
Some backends generate additional files for each existing file, e.g.
1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef.sha256
For some commands this leads to an "multiple IDs with prefix" error when
trying to reference a snapshot.
`restic unlock` now only shows `successfully removed locks` if there were locks to be removed.
In addition, it also reports the number of the removed lock files.
Sending data through a channel at very high frequency is extremely
inefficient. Thus use simple callbacks instead of channels.
> name old time/op new time/op delta
> MasterIndexEach-16 6.68s ±24% 0.96s ± 2% -85.64% (p=0.008 n=5+5)
sort.Sort is not guaranteed to be stable. Go 1.19 has changed the
sorting algorithm which resulted in changes of the sort order. When
comparing snapshots with identical timestamp but different paths and
tags lists, there is not meaningful order among them. So just keep their
order stable.
Also make the errors a bit less verbose by not prepending the operation,
since pkg/xattr already does that. Old errors looked like
Listxattr: xattr.list /myfiles/.zfs/snapshot: invalid argument
Use runtime.GOMAXPROCS(0) as worker count for CPU-bound tasks,
repo.Connections() for IO-bound task and a combination if a task can be
both. Streaming packs is treated as IO-bound as adding more worker
cannot provide a speedup.
Typical IO-bound tasks are download / uploading / deleting files.
Decoding / Encoding / Verifying are usually CPU-bound. Several tasks are
a combination of both, e.g. for combined download and decode functions.
In the latter case add both limits together. As the backends have their
own concurrency limits restic still won't download more than
repo.Connections() files in parallel, but the additional workers can
decode already downloaded data in parallel.
Previously, SaveAndEncrypt would assemble blobs into packs and either
return immediately if the pack is not yet full or upload the pack file
otherwise. The upload will block the current goroutine until it
finishes.
Now, the upload is done using separate goroutines. This requires changes
to the error handling. As uploads are no longer tied to a SaveAndEncrypt
call, failed uploads are signaled using an errgroup.
To count the uploaded amount of data, the pack header overhead is no
longer returned by `packer.Finalize` but rather by
`packer.HeaderOverhead`. This helper method is necessary to continue
returning the pack header overhead directly to the responsible call to
`repository.SaveBlob`. Without the method this would not be possible,
as packs are finalized asynchronously.
github.com/pkg/errors is no longer getting updates, because Go 1.13
went with the more flexible errors.{As,Is} function. Use those instead:
errors from pkg/errors already support the Unwrap interface used by 1.13
error handling. Also:
* check for io.EOF with a straight ==. That value should not be wrapped,
and the chunker (whose error is checked in the cases changed) does not
wrap it.
* Give custom Error methods pointer receivers, so there's no ambiguity
when type-switching since the value type will no longer implement error.
* Make restic.ErrAlreadyLocked private, and rename it to
alreadyLockedError to match the stdlib convention that error type
names end in Error.
* Same with rest.ErrIsNotExist => rest.notExistError.
* Make s3.Backend.IsAccessDenied a private function.
These commands filter the snapshots according to some criteria which
essentially requires loading the index before filtering the snapshots.
Thus create a copy of the snapshots list beforehand and use it later on.
Load tree blobs with more than 50MB only from a single goroutine. Very
large tree blobs with for example 400 MB size can otherwise require
roughly 1GB * streamTreeParallelism memory.
This ensures that restic won't create lots of new lock files without
deleting them later on.
In some cases a Delete operation on a backend can return a "File does
not exist" error even though the Delete operation succeeded. This can
for example be caused by request retries. This caused restic to forget
about the new lock file and continue trying to remove the old (already
deleted) lock file.
Currently, `restic backup` (if a `--parent` is not provided)
will choose the most recent matching snapshot as the parent snapshot.
This makes sense in the usual case,
where we tag the snapshot-being-created with the current time.
However, this doesn't make sense if the user has passed `--time`
and is currently creating a snapshot older than the latest snapshot.
Instead, choose the most recent snapshot
which is not newer than the snapshot-being-created's timestamp,
to avoid any time travel.
Impetus for this change:
I'm using restic for the first time!
I have a number of existing BTRFS snapshots
I am backing up via restic to serve as my initial set of backups.
I initially `restic backup`'d the most recent snapshot to test,
then started backing up each of the other snapshots.
I noticed in `restic cat snapshot <id>` output
that all the remaining snapshots have the most recent as the parent.
This enables the backends to request the calculation of a
backend-specific hash. For the currently supported backends this will
always be MD5. The hash calculation happens as early as possible, for
pack files this is during assembly of the pack file. That way the hash
would even capture corruptions of the temporary pack file on disk.
Ensure that only snapshots made in the past are taken into account when running restic forget with the within switches (--keep-within, --keep-within- hourly, and friends)
Allow keeping hourly/daily/weekly/monthly/yearly snapshots for a given time period.
This adds the following flags/parameters to restic forget:
--keep-within-hourly duration
--keep-within-daily duration
--keep-within-weekly duration
--keep-within-monthly duration
--keep-within-yearly duration
Includes following changes:
- Add tests for --keep-within-hourly (and friends)
- Add documentation for --keep-within-hourly (and friends)
- Add changelog for --keep-within-hourly (and friends)
This assigns an id to each tree root and then keeps track of how many
tree loads (i.e. trees referenced for the first time) are pending per
tree root. Once a tree root and its subtrees were fully processed there
are no more pending tree loads and the tree root is reported as
processed.
Michael Eischer
Miles Liu
Jerome Küttner
DRON-666
Leo R. Lundgren
Alexander Weiss
greatroar
Alexander Neumann
Alexander Neumann
gum3ng
Greg
Aneesh Agrawal
Juergen Hoetzel
David le Blanc
Magnus Thor Torfason
greatroar
Quentin Lemaire