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 replica 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 7.4.4, “The Binary Log”, and Section 19.2.5, “Relay Log and Replication Metadata Repositories”.

Invoke mysqlbinlog like this:

mysqlbinlog [options] log_file ...

For example, to display the contents of the binary log file named binlog.000003, use this command:

mysqlbinlog binlog.000003

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 19.2.1, “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 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 replica 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 replication source server. On a replica, it is the difference of the end execution time on the replica minus the beginning execution time on the source. The difference serves as an indicator of how much replication lags behind the source. 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 an unexpected server exit. For other usage examples, see the discussion later in this section and in Section 9.5, “Point-in-Time (Incremental) Recovery”. To execute the internal-use BINLOG statements used by mysqlbinlog, the user requires the BINLOG_ADMIN privilege (or the deprecated SUPER privilege), or the