Dear MySQL users,
MySQL Enterprise Backup v3.12.4, a new version of the online MySQL backup
tool, is now available for download from the My Oracle Support (MOS) website
as our latest GA release. This release will be available on eDelivery (OSDC)
after the next upload cycle. MySQL Enterprise Backup is a commercial
extension to the MySQL family of products.
A brief summary of the changes in MySQL Enterprise Backup (MEB)
version 3.12.4 is given below.
Changes in MySQL Enterprise Backup 3.12.4 (2019-02-15)
* Functionality Added or Changed
* Bugs Fixed
Functionality Added or Changed
* Information on the executed GTIDs is now includfed in the
mysqlbackup output and the backup log when the backed-up
server has GTIDs enabled. (Bug #25978803)
* A backup became corrupted if, during the backup process,
a DDL operation that took advantage of MySQL server's
online DDL feature
(http://dev.mysql.com/doc/refman/5.6/en/innodb-online-ddl.html)
occurred. This was because mysqlbackup did not
support the server feature---and it still does not. This
fix avoids the error by having mysqlbackup turn the
server's system variable old_alter_table to "1" at the
beginning of a backup if it is "0," so that any DDL
operations that take place during the backup are handled
with the old table copy method. mysqlbackup then turns
the variable back to "0" near the end of the backup
operation.
Important
Notice that in cases where mysqlbackup quits unexpectedly
and does not turn old_alter_table back to its original
value, the user will have to turn the value back to "0"
manually on the server, in order to return the server to
its original configuration. This should be performed if
the statement "Server system variable 'old_alter_table'
was set to '0'. Setting it to '1'" appears in the early
output of mysqlbackup, but the statement "Setting server
system variable 'old_alter_table' back to '0'" does not
appear before mysqlbackup quits.
(Bug #25217215)
* A new option, --skip-final-rescan, makes mysqlbackup skip
the final rescan for InnoDB tables that are modified by
DDL operations after the database has been locked near
the end of a backup operation. This potentially shortens
the duration for the lock and reduces the backup's impact
on the server's normal operation. See the description for
--skip-final-rescan for details. (Bug #21094221)
* The output by mysqlbackup, which goes to the stderr
stream and the message log, has now been improved to
include the timestamps and thread IDs for all steps taken
by mysqlbackup, in order to provide more information for
debugging purposes. (Bug #20142619)
* When there were no tables matching the regular expression
specified with the --include-tables option during a
backup operation, mysqlbackup still created a backup,
which contained an empty folder for each database on the
server. mysqlbackup now throws an error when
--include-tables selects no tables to be backed up. (Bug
#18114353)
* During the final stage of a backup when MySQL Enterprise
Backup tried to temporarily put the database into a
read-only state using the FLUSH TABLES WITH READ LOCK
statement in order to copy non-InnoDB files, if a long
query was running on the server at the same time, the
FLUSH TABLES WITH READ LOCK statement could be taking too
long to finish, holding up further queries and eventually
bringing down the server.
A new mysqlbackup option --lock-wait-timeout can now be
used to specify the timeout in seconds for the FLUSH
TABLES WITH READ LOCK statement. If the timeout is
exceeded, the statement is failed and the lock on the
tables is released, so that queries held up by the lock
can then be executed. mysqlbackup then retries the
statement and continues with the backup. Default value
for --lock-wait-timeout is 60 [seconds]. (Bug #14339483)
* In order to minimize the impact of a hot backup on the
MySQL server, the copying of the buffer pool dump files
and some of the metadata files is now performed before
the final phase of the backup in which the server
instance is locked. This shortens the duration for the
lock and reduces the backup's impact on the server's
normal operation.
Also, to minimize the resource used on a backup, the
copying of the buffer pool dump files is no longer
performed for partial and offline backups, for which the
buffer pool dump is usually not very useful.
Bugs Fixed
* While MySQL Server interprets the system variable setting
--innodb_checksum_algorithm=0 to mean
--innodb_checksum_algorithm=crc32, a mysqlbackup
operation (except for backup) failed when
--innodb_checksum_algorithm=0 was set as a configuration
option. With this fix, mysqlbackup now accepts
--innodb_checksum_algorithm=0 as valid and interprets it
as --innodb_checksum_algorithm=crc32. (Bug #28295519)
* On macOS, mysqlbackup failed to determine the relay log
file name correctly if the relay log index file name was
not specified. (Bug #25574605)
* The Release number for the RPM packages of MySQL
Enterprise Backup always said "1," instead of giving the
release number of the Linux distribution for which the
package was built. (Bug #25538798)
* When the option --only-innodb-with-frm or --no-locking
was used during a backup operation, the backup sometimes
failed with mysqlbackup complaining that the highest LSN
was larger in a copied page than on the backed-up server.
It was because mysqlbackup did not perform a log flushing
before copying the redo log when either of the mentioned
options was used. With this fix, log flushing was always
performed to prevent the error. (Bug #25412655)
* When creating a full image backup with the --no-locking
option, mysqlbackup failed to write the binary log
information to the backup history table and the
backup_variables.txt file. The result was that when
creating an incremental image backup based on the full
backup, the attempt to copy the binary log files from the
server into the incremental image backup (which is the
default behavior) would fail, causing the incremental
backup to stop. With this fix, the binary log information
is no longer missing after the full backup, so the
incremental image backup no longer fails." (Bug
#25296324)
References: See also: Bug #19915713.
* After restoring an incremental backup of a slave server,
the file ibbackup_slave_info was missing from the meta
folder under the backup directory on the target server.
(Bug #25097753)
* mysqlbackup logged double entries with wrong information
into the backup_history table for optimistic backups.
(Bug #24502876)
* Backups for a slave server in a multi-source replication
setup using the --slave-info option failed. (Bug
#24444950)
References: See also: Bug #21830316.
* Attempts to restore an image backup from the cloud using
the --skip-binlog option failed with a "global tail magic
mismatch" error. This was because mysqlbackup failed to
perform a non-sequential read from the cloud with gaps
caused by the skipping of the binary logs. This fix makes
sure mysqlbackup can perform such reads. (Bug #23534700)
* An extract operation for an image backup failed with a
checksum mismatch error in cases when, during the backup,
an InnoDB tablespace file kept growing in size, and
mysqlbackup failed to put the correct file size in its
file header. (Bug #22905984)
References: This issue is a regression of: Bug #22613568.
* After an apply-incremental-backup operation on a full
backup, mysqlbackup printed to the output stream and the
message log file the old instead of the updated binary
log position. (Bug #22085034, Bug #78898)
* When running the backup-and-apply-log command without a
connection to the MySQL server, mysqlbackup could not
know the correct binary log file name and binary log
position for the backup; yet, at the end of the
backup-and-apply-log operation, mysqlbackup still printed
out some values for the binary log file name and
position, which were random in nature. (Bug #21623089)
* Occasionally, some files were missing from an image
backup created by the --backup-to-image command. It was
due to an internal race condition, which this fix
eliminates. (Bug #19600687)
On Behalf of MySQL Release Engineering Team,
Surabhi Bhat
