4.6.7 mysqlbinlog — Utility for Processing Binary Log Files

The server's binary log consists of files containing events that describe modifications to database contents. The server writes these files in binary format. To display their contents in text format, use the mysqlbinlog utility. You can also use mysqlbinlog to display the contents of relay log files written by a slave server in a replication setup because relay logs have the same format as binary logs. The binary log and relay log are discussed further in Section 5.2.3, “The Binary Log”, and Section 16.2.2, “Replication Relay and Status Logs”.

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 events contained in binlog.000003. Event information includes the SQL statement, the ID of the server on which it was executed, the timestamp when the statement was executed, how much time it took, and so forth.

Events are preceded by header comments that provide additional information. For example:

# at 141
#100309  9:28:36 server id 123  end_log_pos 245
  Query thread_id=3350  exec_time=11  error_code=0

In the first line, the number following at indicates the file offset, or starting position, of the event in the binary log file.

The second line starts with a date and time indicating when the statement started on the server where the event originated. For replication, this timestamp is propagated to slave servers. server id is the server_id value of the server where the event originated. end_log_pos indicates where the next event starts (that is, it is the end position of the current event + 1). thread_id indicates which thread executed the event. exec_time is the time spent executing the event, on a master server. On a slave, it is the difference of the end execution time on the slave minus the beginning execution time on the master. The difference serves as an indicator of how much replication lags behind the master. error_code indicates the result from executing the event. Zero means that no error occurred.

Note

When using event groups, the file offsets of all events are grouped together and the comments of all events are grouped together. For example:

# at 587
# at 630
# at 5662
#140627 13:16:52 server id 1  end_log_pos 630     Table_map: `test`.`t1` mapped to number 41
#140627 13:16:52 server id 1  end_log_pos 5662     Write_rows: table id 41
#140627 13:16:52 server id 1  end_log_pos 10694     Write_rows: table id 41 flags: STMT_END_F
	      

The three file offsets do not represent blank events.

The output from mysqlbinlog can be re-executed (for example, by using it as input to mysql) to redo 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 and in Section 7.5, “Point-in-Time (Incremental) Recovery Using the Binary Log”.

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. To 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.

mysqlbinlog supports the following options, which can be specified on the command line or in the [mysqlbinlog] and [client] groups of an option file. For information about option files, see Section 4.2.6, “Using Option Files”.

Table 4.10 mysqlbinlog Options

FormatOption FileDescriptionIntroduced
--character-sets-dir=pathcharacter-sets-dirThe directory where character sets are located 
--database=db_namedatabaseList entries for just this database 
--debug[=debug_options]debugWrite a debugging log 
--defaults-extra-file=file_name Read option file in addition to the usual option files 
--defaults-file=file_name Read only the given option file 
--defaults-group-suffix=str Option group suffix value5.0.10
--disable-log-bindisable-log-binDisable binary logging 
--force-readforce-readIf mysqlbinlog reads a binary log event that it does not recognize, it prints a warning 
--help Display help message and exit 
--hexdumphexdumpDisplay a hex dump of the log in comments5.0.16
--host=host_namehostConnect to the MySQL server on the given host 
--local-load=pathlocal-loadPrepare local temporary files for LOAD DATA INFILE in the specified directory 
--no-defaults Do not read any option files 
--offset=#offsetSkip the first N entries in the log 
--password[=password]passwordThe password to use when connecting to the server 
--port=port_numportThe TCP/IP port number to use for the connection 
--position=#positionDeprecated. Use --start-position 
--print-defaults Print defaults 
--protocol=typeprotocolThe connection protocol to use 
--read-from-remote-serverread-from-remote-serverRead binary log from MySQL server rather than local log file 
--result-file=nameresult-fileDirect output to the given file 
--set-charset=charset_nameset-charsetAdd a SET NAMES charset_name statement to the output5.0.23
--short-formshort-formDisplay only the statements contained in the log 
--socket=pathsocketFor connections to localhost, the Unix socket file to use 
--start-datetime=datetimestart-datetimeRead binary log from first event with timestamp equal to or later than datetime argument 
--start-position=#start-positionRead binary log from first event with position equal to or greater than argument 
--stop-datetime=datetimestop-datetimeStop reading binary log at first event with timestamp equal to or greater than datetime argument 
--stop-position=#stop-positionStop reading binary log at first event with position equal to or greater than argument 
--to-last-logto-last-logDo not stop at the end of requested binary log from a MySQL server, but rather continue printing to end of last binary log 
--user=user_name,userMySQL user name to use when connecting to server 
--version Display version information and exit 

You can also set the following variable by using --var_name=value syntax:

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 events contained in the binary log. This technique is used to recover from a crash when you have an old backup (see Section 7.5, “Point-in-Time (Incremental) Recovery Using the Binary Log”). For example:

shell> mysqlbinlog binlog.000001 | mysql -u root -p

Or:

shell> mysqlbinlog binlog.[0-9]* | mysql -u root -p

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:

shell> mysqlbinlog binlog.000001 > tmpfile
shell> ... edit tmpfile ...
shell> mysql -u root -p < tmpfile

When mysqlbinlog is invoked with the --start-position option, it displays only those events 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, roll forward my databases to how they were today at 10:30 a.m.).

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 -u root -p # DANGER!!
shell> mysqlbinlog binlog.000002 | mysql -u root -p # DANGER!!

Processing binary logs this way using multiple 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 unknown table.

To avoid problems like this, use a single mysql process 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 -u root -p

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 -u root -p -e "source /tmp/statements.sql"

mysqlbinlog can produce output that reproduces a 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 with the LOCAL capability enabled. See Section 6.1.6, “Security Issues with LOAD DATA LOCAL.

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-#-#.

The --hexdump option produces a hex dump of the log contents:

shell> mysqlbinlog --hexdump master-bin.000001

The hex output consists of comment lines beginning with #, so the output might look like this for the preceding command:

/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
# at 4
#051024 17:24:13 server id 1  end_log_pos 98
# Position  Timestamp   Type   Master ID        Size      Master Pos    Flags
# 00000004 9d fc 5c 43   0f   01 00 00 00   5e 00 00 00   62 00 00 00   00 00
# 00000017 04 00 35 2e 30 2e 31 35  2d 64 65 62 75 67 2d 6c |..5.0.15.debug.l|
# 00000027 6f 67 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |og..............|
# 00000037 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00 |................|
# 00000047 00 00 00 00 9d fc 5c 43  13 38 0d 00 08 00 12 00 |.......C.8......|
# 00000057 04 04 04 04 12 00 00 4b  00 04 1a                |.......K...|
#       Start: binlog v 4, server v 5.0.15-debug-log created 051024 17:24:13
#       at startup
ROLLBACK;

Hex dump output currently contains the following elements. This format is subject to change.