The binary log files that the server generates are written in binary format. To examine these files in text format, use the
mysqlbinlog
utility. It is available as of MySQL 3.23.14. You can also use
mysqlbinlog
to read relay log files written by a slave server in a replication setup. Relay logs have the same format as binary log files.
Invoke
mysqlbinlog
like this:
shell> mysqlbinlog [options] log_file ...
For example, to display the contents of the binary log file named
binlog.000003, use this command:
shell> mysqlbinlog binlog.0000003
The output includes all events contained in
binlog.000003. Event information includes the statement executed, the time the statement took, the thread ID of the client that issued it, the timestamp when it was executed, and so forth.
The output from
mysqlbinlog
can be re-executed (for example, by using it as input to
mysql) to reapply the statements in the log. This is useful for recovery operations after a server crash. For other usage examples, see the discussion later in this section.
Normally, you use
mysqlbinlog
to read binary log files directly and apply them to the local MySQL server. It is also possible to read binary logs from a remote server by using the
--read-from-remote-server
option. When you read remote binary logs, the connection parameter options can be given to indicate how to connect to the server. These options are
--host,
--password,
--port,
--protocol,
--socket, and
--user; they are ignored except when you also use the
--read-from-remote-server
option.
Binary logs and relay logs are discussed further in
Section 10.4, lqThe Binary Logrq, and
Section 3.4, lqReplication Relay and Status Filesrq.
mysqlbinlog
supports the following options:
- *
-
--help,
-?
Display a help message and exit.
- *
-
--character-sets-dir=path
The directory where character sets are installed. See
Section 9.1, lqThe Character Set Used for Data and Sortingrq.
- *
-
--database=db_name,
-d db_name
List entries for just this database (local log only).
- *
-
--debug[=debug_options],
-# [debug_options]
Write a debugging log. A typical
debug_options
string is often
'd:t:o,file_name'.
- *
-
--disable-log-bin,
-D
Disable binary logging. This is useful for avoiding an endless loop if you use the
--to-last-log
option and are sending the output to the same MySQL server. This option also is useful when restoring after a crash to avoid duplication of the statements you have logged. This option is available as of MySQL 4.1.8.
This option requires that you have the
SUPER
privilege. It causes
mysqlbinlog
to include a
SET SQL_LOG_BIN=0
statement in its output to disable binary logging of the remaining output. The
SET
statement is ineffective unless you have the
SUPER
privilege.
- *
-
--force-read,
-f
With this option, if
mysqlbinlog
reads a binary log event that it does not recognize, it prints a warning, ignores the event, and continues. Without this option,
mysqlbinlog
stops if it reads such an event.
- *
-
--host=host_name,
-h host_name
Get the binary log from the MySQL server on the given host.
- *
-
--local-load=path,
-l path
Prepare local temporary files for
LOAD DATA INFILE
in the specified directory.
- *
-
--offset=N,
-o N
Skip the first
N
entries in the log.
- *
-
--password[=password],
-p[password]
The password to use when connecting to the server. If you use the short option form (-p), you
cannot
have a space between the option and the password. If you omit the
password
value following the
--password
or
-p
option on the command line, you are prompted for one.
Specifying a password on the command line should be considered insecure. See
Section 7.6, lqKeeping Your Password Securerq.
- *
-
--port=port_num,
-P port_num
The TCP/IP port number to use for connecting to a remote server.
- *
-
--position=N,
-j N
Deprecated. Use
--start-position
instead (starting from MySQL 4.1.4).
- *
-
--protocol={TCP|SOCKET|PIPE|MEMORY}
The connection protocol to use. Added in MySQL 4.1.
- *
-
--read-from-remote-server,
-R
Read the binary log from a MySQL server rather than reading a local log file. Any connection parameter options are ignored unless this option is given as well. These options are
--host,
--password,
--port,
--protocol,
--socket, and
--user.
- *
-
--result-file=name,
-r name
Direct output to the given file.
- *
-
--short-form,
-s
Display only the statements contained in the log, without any extra information.
- *
-
--socket=path,
-S path
For connections to
localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use.
- *
-
--start-datetime=datetime
Start reading the binary log at the first event having a timestamp equal to or later than the
datetime
argument. The
datetime
value is relative to the local time zone on the machine where you run
mysqlbinlog. The value should be in a format accepted for the
DATETIME
or
TIMESTAMP
data types. For example:
shell> mysqlbinlog --start-datetime="2005-12-25 11:25:56" binlog.000003
This option is available as of MySQL 4.1.4. It is useful for point-in-time recovery. See
Section 8.2, lqExample Backup and Recovery Strategyrq.
- *
-
--stop-datetime=datetime
Stop reading the binary log at the first event having a timestamp equal or posterior to the
datetime
argument. This option is useful for point-in-time recovery. See the description of the
--start-datetime
option for information about the
datetime
value. This option is available as of MySQL 4.1.4.
- *
-
--start-position=N
Start reading the binary log at the first event having a position equal to the
N
argument. This option applies to the first log file named on the command line. Available as of MySQL 4.1.4 (previously named
--position).
- *
-
--stop-position=N
Stop reading the binary log at the first event having a position equal or greater than the
N
argument. This option applies to the last log file named on the command line. Available as of MySQL 4.1.4.
- *
-
--to-last-log,
-t
Do not stop at the end of the requested binary log from a MySQL server, but rather continue printing until the end of the last binary log. If you send the output to the same MySQL server, this may lead to an endless loop. This option requires
--read-from-remote-server. Available as of MySQL 4.1.2.
- *
-
--user=user_name,
-u user_name
The MySQL username to use when connecting to a remote server.
- *
-
--version,
-V
Display version information and exit.
You can also set the following variable by using
--var_name=value
syntax:
- *
-
open_files_limit
Specify the number of open file descriptors to reserve.
It is also possible to set variables by using
--set-variable=var_name=value
or
-O var_name=value
syntax.
This syntax is deprecated.
You can pipe the output of
mysqlbinlog
into the
mysql
client to execute the statements contained in the binary log. This is used to recover from a crash when you have an old backup (see
Section 8.1, lqDatabase Backupsrq). For example:
shell> mysqlbinlog binlog.000001 | mysql
Or:
shell> mysqlbinlog binlog.[0-9]* | mysql
You can also redirect the output of
mysqlbinlog
to a text file instead, if you need to modify the statement log first (for example, to remove statements that you do not want to execute for some reason). After editing the file, execute the statements that it contains by using it as input to the
mysql
program.
mysqlbinlog
has the
--start-position
option, which prints only those statements with an offset in the binary log greater than or equal to a given position (the given position must match the start of one event). It also has options to stop and start when it sees an event with a given date and time. This enables you to perform point-in-time recovery using the
--stop-datetime
option (to be able to say, for example,
lqroll forward my databases to how they were today at 10:30 a.m.rq).
If you have more than one binary log to execute on the MySQL server, the safe method is to process them all using a single connection to the server. Here is an example that demonstrates what may be
unsafe:
shell> mysqlbinlog binlog.000001 | mysql # DANGER!!
shell> mysqlbinlog binlog.000002 | mysql # DANGER!!
Processing binary logs this way using different connections to the server causes problems if the first log file contains a
CREATE TEMPORARY TABLE
statement and the second log contains a statement that uses the temporary table. When the first
mysql
process terminates, the server drops the temporary table. When the second
mysql
process attempts to use the table, the server reports
lqunknown table.rq
To avoid problems like this, use a
single
connection to execute the contents of all binary logs that you want to process. Here is one way to do so:
shell> mysqlbinlog binlog.000001 binlog.000002 | mysql
Another approach is to write all the logs to a single file and then process the file:
shell> mysqlbinlog binlog.000001 > /tmp/statements.sql
shell> mysqlbinlog binlog.000002 >> /tmp/statements.sql
shell> mysql -e "source /tmp/statements.sql"
In MySQL 3.23, the binary log did not contain the data to load for
LOAD DATA INFILE
statements. To execute such a statement from a binary log file, the original data file was needed. Starting from MySQL 4.0.14, the binary log does contain the data, so
mysqlbinlog
can produce output that reproduces the
LOAD DATA INFILE
operation without the original data file.
mysqlbinlog
copies the data to a temporary file and writes a
LOAD DATA LOCAL INFILE
statement that refers to the file. The default location of the directory where these files are written is system-specific. To specify a directory explicitly, use the
--local-load
option.
Because
mysqlbinlog
converts
LOAD DATA INFILE
statements to
LOAD DATA LOCAL INFILE
statements (that is, it adds
LOCAL), both the client and the server that you use to process the statements must be configured to allow
LOCAL
capability. See
Section 5.4, lqSecurity Issues with LOAD DATA LOCALrq.
Warning:
The temporary files created for
LOAD DATA LOCAL
statements are
not
automatically deleted because they are needed until you actually execute those statements. You should delete the temporary files yourself after you no longer need the statement log. The files can be found in the temporary file directory and have names like
original_file_name-#-#.
Before MySQL 4.1,
mysqlbinlog
could not prepare output suitable for
mysql
if the binary log contained interlaced statements originating from different clients that used temporary tables of the same name. This is fixed in MySQL 4.1. However, the problem still existed for
LOAD DATA INFILE
statements until it was fixed in MySQL 4.1.8.
SEE ALSO
isamchk(1),
isamlog(1),
msql2mysql(1),
myisam_ftdump(1),
myisamchk(1),
myisamlog(1),
myisampack(1),
mysql(1),
mysql.server(1),
mysql_config(1),
mysql_fix_privilege_tables(1),
mysql_zap(1),
mysqlaccess(1),
mysqladmin(1),
mysqlcheck(1),
mysqld(1),
mysqld_multi(1),
mysqld_safe(1),
mysqldump(1),
mysqlhotcopy(1),
mysqlimport(1),
mysqlshow(1),
pack_isam(1),
perror(1),
replace(1),
safe_mysqld(1)
For more information, please refer to the MySQL Reference Manual,
which may already be installed locally and which is also available
online at http://dev.mysql.com/doc/.
AUTHOR
MySQL AB (http://www.mysql.com/).
This software comes with no warranty.