Switching FOREIGN_KEY_CHECKS back on does not check the rows loaded
meanwhile, and DDL would commit halfway, so on MySQL every foreign key is
checked with a query for rows that point at nothing, before the commit.
The recorded table structure now keeps index options (the prefix lengths
MySQL needs for long text columns) and foreign keys; tables the restore
creates get their foreign keys after the commit.
The full-restore test also runs on MariaDB.
Backups now record each table's structure in the dump manifest. The full
restore creates tables that do not exist on the new instance (left behind
by apps that were removed or are switched off), lists all problems at
once, and no longer stops on apps that are missing. Foreign keys are not
checked while rows are loaded in name order, and checked again before the
restore commits (PostgreSQL: dropped and added back in the transaction).
--install-apps installs or enables the apps that were enabled at backup
time; --skip-missing-tables leaves out tables of older backups whose
structure is unknown. nextcloud-aio is never required.
backup:target:add without a key points to backup:key:import, and says that
connecting can take a while. Removing a location drops its cached index;
a migration removes the cache of locations that are gone.
The full-restore test now also runs on PostgreSQL with Mail (foreign keys)
and a disabled app.
On S3, index files and the tree segments read back when a snapshot is
written are fetched 16 at a time through the storage's S3 client
(IBackend::getRanges(), getMany()). Blobs that follow each other in a pack
are read as one range on every location. The snapshot is written in a step
of its own and the run shows "commit" meanwhile. On a 1 TB production
repository the check went from about 4 hours to 3.5 minutes.
backup:status and the web interface list the runs of the last 7 days,
running ones and at least the newest 5; --all / "Show older runs" list
all. Durations of a day or more show the days.
Each 30-second step opened the location again and read its list of
index files. Over SMB that cost a request per file, so on a large
repository opening took longer than the step: each step stored one
4 MiB pack and the list grew further. A first backup of nc01 to a
Storage Box over SMB managed 12 GiB in 35 hours.
occ backup:run and system cron now keep the repository open for the
whole run (reopened when another process took a step or the location
was edited), opening no longer counts towards the step's time, and
SMB folders are listed in one request.
occ backup:cancel stops a running backup: no new step starts and the
step in progress finishes first. A run of an earlier version, which
does not hold back its next step, is marked cancelled after two
minutes unless it is recording its snapshot.
With few packs a request per pack is fewer requests than 256 listings. On
FTP every listing takes a data connection; the FTP server of the integration
tests has ten passive ports, and 256 listings in a row slowed it down until a
read failed ("Not found: snapshots/...").
A Hetzner Storage Box drops an SFTP connection that carried a lot of data
and then stayed quiet for a few minutes; files_external keeps using the dead
client, on which every file looks missing. StorageBackend now checks the
connection after a minute without requests, and replaces a connection that
is dead after a failed request (once per request; put, move and delete are
not repeated). SftpReadStream closes a connection it left in an unknown state.
The verify cache refresh took more than 6 minutes on PostgreSQL for 27,547
packs, one autocommitted insert per pack: putMany()/replaceAll() write in one
transaction. After a verify the cache holds the index files as they are, so a
blob in two packs stays cached for both.