The command probes are executed before and after a client
command is executed, including any SQL statement that might be
executed during that period. Commands include operations such as
the initialization of the DB, use of the
COM_CHANGE_USER
operation (supported by the
MySQL protocol), and manipulation of prepared statements. Many
of these commands are used only by the MySQL client API from
various connectors such as PHP and Java.
command-start(connectionid, command, user, host) command-done(status)
command-start
: Triggered when a command is submitted to the server.connectionid
: The connection ID of the client executing the command.command
: An integer representing the command that was executed. Possible values are shown in the following table.Value Name Description 00 COM_SLEEP Internal thread state 01 COM_QUIT Close connection 02 COM_INIT_DB Select database ( USE ...
)03 COM_QUERY Execute a query 04 COM_FIELD_LIST Get a list of fields 05 COM_CREATE_DB Create a database (deprecated) 06 COM_DROP_DB Drop a database (deprecated) 07 COM_REFRESH Refresh connection 08 COM_SHUTDOWN Shutdown server 09 COM_STATISTICS Get statistics 10 COM_PROCESS_INFO Get processes ( SHOW PROCESSLIST
)11 COM_CONNECT Initialize connection 12 COM_PROCESS_KILL Kill process 13 COM_DEBUG Get debug information 14 COM_PING Ping 15 COM_TIME Internal thread state 16 COM_DELAYED_INSERT Internal thread state 17 COM_CHANGE_USER Change user 18 COM_BINLOG_DUMP Used by a replication slave or mysqlbinlog to initiate a binary log read 19 COM_TABLE_DUMP Used by a replication slave to get the master table information 20 COM_CONNECT_OUT Used by a replication slave to log a connection to the server 21 COM_REGISTER_SLAVE Used by a replication slave during registration 22 COM_STMT_PREPARE Prepare a statement 23 COM_STMT_EXECUTE Execute a statement 24 COM_STMT_SEND_LONG_DATA Used by a client when requesting extended data 25 COM_STMT_CLOSE Close a prepared statement 26 COM_STMT_RESET Reset a prepared statement 27 COM_SET_OPTION Set a server option 28 COM_STMT_FETCH Fetch a prepared statement user
: The user executing the command.host
: The client host.
command-done
: Triggered when the command execution completes. Thestatus
argument contains 0 if the command executed successfully, or 1 if the statement was terminated before normal completion.
The command-start
and
command-done
probes are best used when
combined with the statement probes to get an idea of overall
execution time.