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 , "The Binary Log", and , "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. 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 , "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 , "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 MariaDB 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. mysqlbinlog also supports the options for processing option files described at , "Command-Line Options that Affect Option-File Handling".

Table 4.11. mysqlbinlog Options

Format Option File Description Introduction Deprecated Removed
--base64-output[=value] base64-output Print binary log entries using base-64 encoding
--bind-address=ip_address bind-address Use the specified network interface to connect to the MariaDB Server
--binlog-row-event-max-size=# binlog-row-event-max-size Binary log max event size
--character-sets-dir=path character-sets-dir The directory where character sets are installed
--database=db_name database List entries for just this database
--debug[=debug_options] debug Write a debugging log
--debug-check debug-check Print debugging information when the program exits
--debug-info debug-info Print debugging information, memory and CPU statistics when the program exits
--default-auth=plugin default-auth=plugin The authentication plugin to use 5.6.2
--disable-log-bin disable-log-bin Disable binary logging
--force-read force-read If mysqlbinlog reads a binary log event that it does not recognize, it prints a warning
--help Display help message and exit
--hexdump hexdump Display a hex dump of the log in comments
--host=host_name host Connect to the MariaDB server on the given host
--local-load=path local-load Prepare local temporary files for LOAD DATA INFILE in the specified directory
--offset=# offset Skip the first N entries in the log
--password[=password] password The password to use when connecting to the server
--plugin-dir=path plugin-dir=path The directory where plugins are located 5.6.2
--port=port_num port The TCP/IP port number to use for the connection
--protocol=type protocol The connection protocol to use
--raw raw Write events in raw (binary) format to output files
--read-from-remote-server read-from-remote-server Read the binary log from a MariaDB server rather than reading a local log file
--result-file=name result-file Direct output to the given file
--server-id=id server-id Extract only those events created by the server having the given server ID
--set-charset=charset_name set-charset Add a SET NAMES charset_name statement to the output
--short-form short-form Display only the statements contained in the log
--socket=path socket For connections to localhost
--start-datetime=datetime start-datetime Start reading the binary log at the first event having a timestamp equal to or later than the datetime argument
--start-position=# start-position Start reading the binary log at the first event having a position equal to or greater than the argument
--stop-datetime=datetime stop-datetime Stop reading the binary log at the first event having a timestamp equal to or greater than the datetime argument
--stop-never stop-never Stay connected to server after reading last binary log file
--stop-never-slave-server-id=# stop-never-slave-server-id Slave server ID to report when connecting to server
--stop-position=# stop-position Stop reading the binary log at the first event having a position equal to or greater than the argument
--to-last-log to-last-log Do not stop at the end of the requested binary log from a MariaDB server, but rather continue printing until the end of the last binary log
--user=user_name, user The MariaDB user name to use when connecting to the server
--verbose Reconstruct row events as SQL statements
--version Display version information and exit

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

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 , "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

If the statements produced by mysqlbinlog may contain BLOB values, these may cause problems when mysql processes them. In this case, invoke mysql with the --binary-mode option.

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 MariaDB 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 , "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-#-#.

Retornar