Previously, a bug was introduced that added a `LIST` operation
on every replica sync which significantly increased the cost of
running Litestream against S3. This changes the behavior to only
issue the `LIST` operation when the generation has changed.
This commit fixes a bug introduced by parallel restore (03831e2)
where snapshot-only restores were not being handled correctly and
Litestream would hang indefinitely. Now the restore will check
explicitly for snapshot-only restores and exit the restore process
early to avoid WAL handling completely.
This commit reattempts a change to remove the write lock that was
previously tried in 998e831. This change will reduce the number of
locks on the database which should help reduce error messages that
applications see when they do not have busy_timeout set.
In addition to the lock removal, a passive checkpoint is issued
immediately before the read lock is obtained to prevent additional
checkpoints by the application itself. SQLite does not support
checkpoints from an active transaction so it cannot be done afterward.
This commit fixes a bug where restoring to a specific index will
incorrectly choose the latest snapshot instead of choosing the
latest snapshot that occurred before the given index.
This commit changes the `replicate` command so that it performs a
final DB sync & replica sync before it exits to ensure it has
backed up all WAL frames at the time of exit.
This commit removes short-lived `os.Open()` calls on the database
file because this can cause locks to be released when `os.File.Close()`
is later called if the operating system does not support OFD
(Open File Descriptor) locks.
This commit adds the ability to periodically perform snapshots on
an interval that is separate from retention. For example, this lets
you retain backups for 24 hours but you can snapshot your database
every six hours to improve recovery time.
This commit reverts 4e469f8 which was used for debugging the validation
stall corruption issue. It can cause the disk to fill with temporary
files though so it is being reverted.
This commit fixes a timing bug that occurs in a specific scenario
where the shadow wal sync stalls because of an s3 validation and
the catch up write to the shadow wal is large enough to allow a
window between WAL reads and the final copy.
The file copy has been replaced by direct writes of the frame
buffer to the shadow to ensure that every validated byte is exactly
what is being written to the shadow wal. The one downside to this
change is that the frame buffer will grow with the transaction
size so it will use additional heap. This can be replaced by a
spill-to-disk implementation but this should work well in the
short term.
Previously, there were excessive log messages for checkpoints and
retention. These have been removed or combined into a single log
message where appropriate.
This commit refactors the commands to allow a replica URL when
restoring a database. If the first CLI arg is a URL with a scheme,
the it is treated as a replica URL.
