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 5.2.4, “The Binary Log”, and Section 17.2.2, “Replication Relay and Status 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 events contained in binlog.000003. For statement-based logging, 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. For row-based logging, the event indicates a row change rather than an SQL statement. See Section 17.1.2, “Replication Formats”, for information about logging modes.

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 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.

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 6.5, “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] option file groups. mysqlbinlog also supports the options for processing option files described at Section 4.2.3.3.1, “Command-Line Options that Affect Option-File Handling”.

Table 4.11. mysqlbinlog Options

FormatOption FileDescriptionIntroductionDeprecatedRemoved
--base64-output[=value]base64-outputPrint binary log entries using base-64 encoding   
--bind-address=ip_addressbind-addressUse the specified network interface to connect to the MySQL Server5.5.8  
--character-sets-dir=pathcharacter-sets-dirThe directory where character sets are installed   
--database=db_namedatabaseList entries for just this database   
--debug[=debug_options]debugWrite a debugging log   
--debug-checkdebug-checkPrint debugging information when the program exits   
--debug-infodebug-infoPrint debugging information, memory and CPU statistics when the program exits   
--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 comments   
--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   
--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   
--protocol=typeprotocolThe connection protocol to use   
--read-from-remote-serverread-from-remote-serverRead the binary log from a MySQL server rather than reading a local log file   
--result-file=nameresult-fileDirect output to the given file   
--server-id=idserver-idExtract only those events created by the server having the given server ID   
--set-charset=charset_nameset-charsetAdd a SET NAMES charset_name statement to the output   
--short-formshort-formDisplay only the statements contained in the log   
--socket=pathsocketFor connections to localhost   
--start-datetime=datetimestart-datetimeStart reading the binary log at the first event having a timestamp equal to or later than the datetime argument   
--start-position=#start-positionStart reading the binary log at the first event having a position equal to or greater than the argument   
--stop-datetime=datetimestop-datetimeStop reading the binary log at the first event having a timestamp equal to or greater than the datetime argument   
--stop-position=#stop-positionStop reading the binary log at the first event having a position equal to or greater than the argument   
--to-last-logto-last-logDo 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   
--user=user_name,userThe MySQL user name to use when connecting to the server   
--verbose Reconstruct row events as SQL statements   
--version Display version information and exit   
  • --help, -?

    Display a help message and exit.

  • --base64-output[=value]

    This option determines when events should be displayed encoded as base-64 strings using BINLOG statements. The option has these permissible values (not case sensitive):

    • AUTO ("automatic") or UNSPEC ("unspecified") displays BINLOG statements automatically when necessary (that is, for format description events and row events). If no --base64-output option is given, the effect is the same as --base64-output=AUTO.

      Note

      Automatic BINLOG display is the only safe behavior if you intend to use the output of mysqlbinlog to re-execute binary log file contents. The other option values are intended only for debugging or testing purposes because they may produce output that does not include all events in executable form.

    • ALWAYS displays BINLOG statements whenever possible. If the --base64-output option is given without a value, the effect is the same as --base64-output=ALWAYS.

    • NEVER causes BINLOG statements not to be displayed. mysqlbinlog exits with an error if a row event is found that must be displayed using BINLOG.

    • DECODE-ROWS specifies to mysqlbinlog that you intend for row events to be decoded and displayed as commented SQL statements by also specifying the --verbose option. Like NEVER, DECODE-ROWS suppresses display of BINLOG statements, but unlike NEVER, it does not exit with an error if a row event is found.

    For examples that show the effect of --base64-output and --verbose on row event output, see Section 4.6.7.2, “mysqlbinlog Row Event Display”.

  • --bind-address=ip_address

    On a computer having multiple network interfaces, this option can be used to select which interface is employed when connecting to the MySQL server.

    This option is supported beginning with MySQL 5.5.8.

  • --character-sets-dir=path

    The directory where character sets are installed. See Section 9.5, “Character Set Configuration”.

  • --database=db_name, -d db_name

    This option causes mysqlbinlog to output entries from the binary log (local log only) that occur while db_name is been selected as the default database by USE.

    The --database option for mysqlbinlog is similar to the --binlog-do-db option for mysqld, but can be used to specify only one database. If --database is given multiple times, only the last instance is used.

    The effects of this option depend on whether the statement-based or row-based logging format is in use, in the same way that the effects of --binlog-do-db depend on whether statement-based or row-based logging is in use.

    Statement-based logging.  The --database option works as follows:

    • While db_name is the default database, statements are output whether they modify tables in db_name or a different database.

    • Unless db_name is selected as the default database, statements are not output, even if they modify tables in db_name.

    • There is an exception for CREATE DATABASE, ALTER DATABASE, and DROP DATABASE. The database being created, altered, or dropped is considered to be the default database when determining whether to output the statement.

    Suppose that the binary log was created by executing these statements using statement-based-logging:

    INSERT INTO test.t1 (i) VALUES(100);
    INSERT INTO db2.t2 (j)  VALUES(200);
    USE test;
    INSERT INTO test.t1 (i) VALUES(101);
    INSERT INTO t1 (i)      VALUES(102);
    INSERT INTO db2.t2 (j)  VALUES(201);
    USE db2;
    INSERT INTO test.t1 (i) VALUES(103);
    INSERT INTO db2.t2 (j)  VALUES(202);
    INSERT INTO t2 (j)      VALUES(203);
    

    mysqlbinlog --database=test does not output the first two INSERT statements because there is no default database. It outputs the three INSERT statements following USE test, but not the three INSERT statements following USE db2.

    mysqlbinlog --database=db2 does not output the first two INSERT statements because there is no default database. It does not output the three INSERT statements following USE test, but does output the three INSERT statements following USE db2.

    Row-based logging.  mysqlbinlog outputs only entries that change tables belonging to db_name. The default database has no effect on this. Suppose that the binary log just described was created using row-based logging rather than statement-based logging. mysqlbinlog --database=test outputs only those entries that modify t1 in the test database, regardless of whether USE was issued or what the default database is.

    If a server is running with binlog_format set to MIXED and you want it to be possible to use mysqlbinlog with the --database option, you must ensure that tables that are modified are in the database selected by USE. (In particular, no cross-database updates should be used.)

  • --debug[=debug_options], -# [debug_options]

    Write a debugging log. A typical debug_options string is 'd:t:o,file_name'. The default is 'd:t:o,/tmp/mysqlbinlog.trace'.

  • --debug-check

    Print some debugging information when the program exits.

  • --debug-info

    Print debugging information and memory and CPU usage statistics when the program exits.

  • --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 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.

  • --hexdump, -H

    Display a hex dump of the log in comments, as described in Section 4.6.7.1, “mysqlbinlog Hex Dump Format”. The hex output can be helpful for replication debugging.

  • --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.

    Important

    These temporary files are not automatically removed by mysqlbinlog or any other MySQL program.

  • --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, mysqlbinlog prompts for one.

    Specifying a password on the command line should be considered insecure. See Section 5.3.2.2, “End-User Guidelines for Password Security”. You can use an option file to avoid giving the password on the command line.

  • --port=port_num, -P port_num

    The TCP/IP port number to use for connecting to a remote server.

  • --position=N

    Deprecated. Use --start-position instead. --position was removed in MySQL 5.5.3.

  • --protocol={TCP|SOCKET|PIPE|MEMORY}

    The connection protocol to use for connecting to the server. It is useful when the other connection parameters normally would cause a protocol to be used other than the one you want. For details on the permissible values, see Section 4.2.2, “Connecting to the MySQL Server”.

  • --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.

    This option requires that the remote server be running. It works only for binary log files on the remote server, not relay log files.

  • --result-file=name, -r name

    Direct output to the given file.

  • --server-id=id

    Display only those events created by the server having the given server ID.

  • --set-charset=charset_name

    Add a SET NAMES charset_name statement to the output to specify the character set to be used for processing log files.

  • --short-form, -s

    Display only the statements contained in the log, without any extra information or row-based events. This is for testing only, and should not be used in production systems.

  • --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 useful for point-in-time recovery. See Section 6.3, “Example Backup and Recovery Strategy”.

  • --start-position=N, -j N

    Start reading the binary log at the first event having a position equal to or greater than N. This option applies to the first log file named on the command line.

    This option is useful for point-in-time recovery. See Section 6.3, “Example Backup and Recovery Strategy”.

  • --stop-datetime=datetime

    Stop reading the binary log at the first event having a timestamp equal to or later than 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 useful for point-in-time recovery. See Section 6.3, “Example Backup and Recovery Strategy”.

  • --stop-position=N

    Stop reading the binary log at the first event having a position equal to or greater than N. This option applies to the last log file named on the command line.

    This option is useful for point-in-time recovery. See Section 6.3, “Example Backup and Recovery Strategy”.

  • --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.

  • --user=user_name, -u user_name

    The MySQL user name to use when connecting to a remote server.

  • --verbose, -v

    Reconstruct row events and display them as commented SQL statements. If this option is given twice, the output includes comments to indicate column data types and some metadata.

    For examples that show the effect of --base64-output and --verbose on row event output, see Section 4.6.7.2, “mysqlbinlog Row Event Display”.

  • --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.

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 6.5, “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 5.3.5, “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-#-#.

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