SST scripts for Galera should use the new mariabackup interface
instead of the innobackupex interface, which is currently only
supported for compatibility reasons.
This commit converts the SST script for mariabackup to use the
new interface. It does not need separate tests, as any problems
will be seen as failures when running multiple tests for the
mariabackup-based SST.
The mariabackup interface currently supports passing a password
through an explicit command line variable, but does not support
passing a password through the MYSQL_PWD environment variable.
At the same time, the Galera SST script for mariabackup uses
the environment variable to pass the password, which leads
(in some cases) to an unsuccessful launch of mariabackup and
to the inability to start the cluster. This patch fixes this
issue. It does not need a separate test, as the problem is
visible in general testing on buildbot.
During the prepare phase of restoring backups, "mariabackup" does
not seem to allow (or recognize) the option "innodb_force_recovery"
for the embedded InnoDB server instance that it starts.
If page corruption observed during page recovery, the prepare step
fails. While this is indeed the correct behavior ideally, allowing
this option to be set in case of emergencies might be useful when
the current backup is the only copy available. Some error messages
during "--prepare" suggest to set "innodb_force_recovery" to 1:
[ERROR] InnoDB: Set innodb_force_recovery=1 to ignore corruption.
For backwards compatibility, "mariabackup --innobackupex --apply-log"
should also have this option.
Signed-off-by: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
Setting "streamfmt=mbstream" in the "[sst]" section causes SST to fail
because the format automatically switches to 'tar' by default (insead
of mbstream).
To fix this, we need to add mbstream to the list of valid values for
the format, making it synonymous with xbstream. This must be done both
in the SST script and when parsing the options of the corresponding
utilities.
Use GET_STR instead of GET_STR_ALLOC, so that the memory will
cannot be leaked. For some reason, calling my_cleanup_options()
on xb_server_options or xb_client_options would not work.
InnoDB I/O and buffer pool interfaces and the redo log format
have been changed between MariaDB 10.1 and 10.2, and the backup
code has to be adjusted accordingly.
The code has been simplified, and many memory leaks have been fixed.
Instead of the file name xtrabackup_logfile, the file name ib_logfile0
is being used for the copy of the redo log. Unnecessary InnoDB startup and
shutdown and some unnecessary threads have been removed.
Some help was provided by Vladislav Vaintroub.
Parameters have been cleaned up and aligned with those of MariaDB 10.2.
The --dbug option has been added, so that in debug builds,
--dbug=d,ib_log can be specified to enable diagnostic messages
for processing redo log entries.
By default, innodb_doublewrite=OFF, so that --prepare works faster.
If more crash-safety for --prepare is needed, double buffering
can be enabled.
The parameter innodb_log_checksums=OFF can be used to ignore redo log
checksums in --backup.
Some messages have been cleaned up.
Unless --export is specified, Mariabackup will not deal with undo log.
The InnoDB mini-transaction redo log is not only about user-level
transactions; it is actually about mini-transactions. To avoid confusion,
call it the redo log, not transaction log.
We disable any undo log processing in --prepare.
Because MariaDB 10.2 supports indexed virtual columns, the
undo log processing would need to be able to evaluate virtual column
expressions. To reduce the amount of code dependencies, we will not
process any undo log in prepare.
This means that the --export option must be disabled for now.
This also means that the following options are redundant
and have been removed:
xtrabackup --apply-log-only
innobackupex --redo-only
In addition to disabling any undo log processing, we will disable any
further changes to data pages during --prepare, including the change
buffer merge. This means that restoring incremental backups should
reliably work even when change buffering is being used on the server.
Because of this, preparing a backup will not generate any further
redo log, and the redo log file can be safely deleted. (If the
--export option is enabled in the future, it must generate redo log
when processing undo logs and buffered changes.)
In --prepare, we cannot easily know if a partial backup was used,
especially when restoring a series of incremental backups. So, we
simply warn about any missing files, and ignore the redo log for them.
FIXME: Enable the --export option.
FIXME: Improve the handling of the MLOG_INDEX_LOAD record, and write
a test that initiates a backup while an ALGORITHM=INPLACE operation
is creating indexes or rebuilding a table. An error should be detected
when preparing the backup.
FIXME: In --incremental --prepare, xtrabackup_apply_delta() should
ensure that if FSP_SIZE is modified, the file size will be adjusted
accordingly.
due to different packaging issues.
Also, Percona thinks that tar support has many limitations
and should be removed as well( see discussion in
https://bugs.launchpad.net/percona-xtrabackup/+bug/1681721)
there is an alternative streaming format xbstream that is supported and
does not have these limitations.
