This section describes the server options and system variables
      that you can use on slave replication servers. You can specify the
      options either on the command
      line or in an option
      file. Many of the options can be reset while the server is
      running by using the CHANGE MASTER
      TO statement. You can specify system variable values
      using SET.
    
Server ID. 
        On the master and each slave, you must use the
        server-id option to establish a
        unique replication ID. For each server, you should pick a unique
        positive integer in the range from 1 to
        232 – 1, and each ID must be
        different from every other ID. Example:
        server-id=3.
      
      Some slave server replication options are handled in a special
      way, in the sense that each is ignored if a
      master.info file exists when the slave starts
      and contains a value for the option. The following options are
      handled this way:
    
As of MySQL 4.1.1, the following options also are handled specially:
      The master.info file format in 4.1.1 changed
      to include values corresponding to the SSL options. In addition,
      the 4.1.1 file format includes as its first line the number of
      lines in the file. (See Section 14.3.1, “Replication Relay and Status Files”.) If you
      upgrade an older server to 4.1.1, the new server upgrades the
      master.info file to the new format
      automatically when it starts. However, if you downgrade a 4.1.1 or
      newer server to a version older than 4.1.1, you should manually
      remove the first line before starting the older server for the
      first time. Note that, in this case, the downgraded server can no
      longer use an SSL connection to communicate with the master.
    
      If no master.info file exists when the slave
      server starts, it uses the values for those options that are
      specified in option files or on the command line. This occurs when
      you start the server as a replication slave for the very first
      time, or when you have run RESET
      SLAVE and then have shut down and restarted the slave.
    
      If the master.info file exists when the slave
      server starts, the server uses its contents and ignores any
      options that correspond to the values listed in the file. Thus, if
      you start the slave server with different values of the startup
      options that correspond to values in the
      master.info file, the different values have
      no effect because the server continues to use the
      master.info file. To use different values,
      you must either restart after removing the
      master.info file or (preferably) use the
      CHANGE MASTER TO statement to reset
      the values while the slave is running.
    
      Suppose that you specify this option in your
      my.cnf file:
    
[mysqld]
master-host=some_host
      The first time you start the server as a replication slave, it
      reads and uses that option from the my.cnf
      file. The server then records the value in the
      master.info file. The next time you start the
      server, it reads the master host value from the
      master.info file only and ignores the value
      in the option file. If you modify the my.cnf
      file to specify a different master host of
      some_other_host, the change still has
      no effect. You should use CHANGE MASTER
      TO instead.
    
MySQL Enterprise. For expert advice regarding slave startup options subscribe to the MySQL Enterprise Monitor. For more information, see http://www.mysql.com/products/enterprise/advisors.html.
      Because the server gives an existing
      master.info file precedence over the startup
      options just described, you might prefer not to use startup
      options for these values at all, and instead specify them by using
      the CHANGE MASTER TO statement. See
      Section 12.5.2.1, “CHANGE MASTER TO Syntax”.
    
This example shows a more extensive use of startup options to configure a slave server:
[mysqld] server-id=2 master-host=db-master.mycompany.com master-port=3306 master-user=pertinax master-password=freitag master-connect-retry=60 report-host=db-slave.mycompany.com
Startup options for replication slaves. 
        The following list describes startup options for controlling
        replication slave servers. Many of these options can be reset
        while the server is running by using the
        CHANGE MASTER TO statement.
        Others, such as the --replicate-* options, can
        be set only when the slave server starts. Replication-related
        system variables are discussed later in this section.
      
          When this option is set to some positive integer
          value other than 0 (the default) it
          affects replication behavior as follows: After the slave SQL
          thread has started, value log
          events are allowed to be executed; after that, the slave SQL
          thread does not receive any more events, just as if the
          network connection from the master were cut. The slave thread
          continues to run, and the output from
          SHOW SLAVE STATUS displays
          Yes in both the
          Slave_IO_Running and the
          Slave_SQL_Running columns, but no further
          events are read from the relay log.
        
This option is used internally by the MySQL test suite for replication testing and debugging. It is not intended for use in a production setting.
          
          
          --disconnect-slave-event-count
        
This option is used internally by the MySQL test suite for replication testing and debugging.
          Normally, a slave does not log to its own binary log any
          updates that are received from a master server. This option
          tells the slave to log the updates performed by its SQL thread
          to its own binary log. For this option to have any effect, the
          slave must also be started with the
          --log-bin option to enable
          binary logging.
          --log-slave-updates is used
          when you want to chain replication servers. For example, you
          might want to set up replication servers using this
          arrangement:
        
A -> B -> C
          Here, A serves as the master for the slave
          B, and B serves as the
          master for the slave C. For this to work,
          B must be both a master
          and a slave. You must start both
          A and B with
          --log-bin to enable binary
          logging, and B with the
          --log-slave-updates option so
          that updates received from A are logged by
          B to its binary log.
        
          This option causes a server to print more messages to the
          error log about what it is doing. With respect to replication,
          the server generates warnings that it succeeded in
          reconnecting after a network/connection failure, and informs
          you as to how each slave thread started. This option is
          enabled by default as of MySQL 4.0.19 and 4.1.2; to disable
          it, use
          --skip-log-warnings.
          As of MySQL 4.0.21 and 4.1.3, aborted connections are not
          logged to the error log unless the value is greater than 1.
        
Note that the effects of this option are not limited to replication. It produces warnings across a spectrum of server activities.
          
          
          --master-connect-retry=
        seconds
          The number of seconds that the slave thread sleeps before
          trying to reconnect to the master in case the master goes down
          or the connection is lost. The value in the
          master.info file takes precedence if it
          can be read. If not set, the default is 60. Connection retries
          are not invoked until the slave times out reading data from
          the master according to the value of
          --slave-net-timeout. The number
          of reconnection attempts is limited by the
          --master-retry-count option.
        
          The host name or IP number of the master replication server.
          The value in master.info takes precedence
          if it can be read. If no master host is specified, the slave
          thread does not start.
        
          The name to use for the file in which the slave records
          information about the master. The default name is
          master.info in the data directory.
        
          The password of the account that the slave thread uses for
          authentication when it connects to the master. The value in
          the master.info file takes precedence if
          it can be read. If not set, an empty password is assumed.
        
          The TCP/IP port number that the master is listening on. The
          value in the master.info file takes
          precedence if it can be read. If not set, the compiled-in
          setting is assumed (normally 3306).
        
          The number of times that the slave tries to connect to the
          master before giving up. Reconnects are attempted at intervals
          set by the CHANGE MASTER TO
          statement or
          --master-connect-retry option
          and reconnects are triggered when data reads by the slave time
          out according to the
          --slave-net-timeout option. The
          default value is 86400.
        
          
          
          
          
          
          
          
          
          
          
          
          
          --master-ssl,
          --master-ssl-ca=,
          file_name--master-ssl-capath=,
          directory_name--master-ssl-cert=,
          file_name--master-ssl-cipher=,
          cipher_list--master-ssl-key=
        file_name
          These options are used for setting up a secure replication
          connection to the master server using SSL. Their meanings are
          the same as the corresponding
          --ssl,
          --ssl-ca,
          --ssl-capath,
          --ssl-cert,
          --ssl-cipher,
          --ssl-key options that are
          described in Section 5.6.6.3, “SSL Command Options”. The values in the
          master.info file take precedence if they
          can be read.
        
These options are operational as of MySQL 4.1.1.
          The user name of the account that the slave thread uses for
          authentication when it connects to the master. This account
          must have the REPLICATION SLAVE
          privilege. FILE privilege
          instead.) The value in the master.info
          file takes precedence if it can be read. If the master user
          name is not set, the name test is assumed.
        
          Cause the slave to allow no updates except from slave threads
          or from users having the SUPER
          privilege. On a slave server, this can be useful to ensure
          that the slave accepts updates only from its master server and
          not from clients. This variable does not apply to
          TEMPORARY tables.
        
This option is available as of MySQL 4.0.14.
          The basename for the relay log. The default basename is
          .
          The server writes the file in the data directory unless the
          basename is given with a leading absolute path name to specify
          a different directory. The server creates relay log files in
          sequence by adding a numeric suffix to the basename.
        host_name-relay-bin
          Due to the manner in which MySQL parses server options, if you
          specify this option, you must supply a value; the
          default basename is used only if the option is not actually
          specified. If you use the
          --relay-log option without
          specifying a value, unexpected behavior is likely to result;
          this behavior depends on the other options used, the order in
          which they are specified, and whether they are specified on
          the command line or in an option file. For more information
          about how MySQL handles server options, see
          Section 4.2.3, “Specifying Program Options”.
        
          If you specify this option, the value specified is also used
          as the basename for the relay log index file. You can override
          this behavior by specifying a different relay log index file
          basename using the
          --relay-log-index option.
        
          You may find the --relay-log
          option useful in performing the following tasks:
        
Creating relay logs whose names are independent of host names.
              If you need to put the relay logs in some area other than
              the data directory because your relay logs tend to be very
              large and you do not want to decrease
              max_relay_log_size.
            
To increase speed by using load-balancing between disks.
          The name to use for the relay log index file. The default name
          is
          
          in the data directory, where
          host_name-relay-bin.indexhost_name is the name of the slave
          server.
        
          Due to the manner in which MySQL parses server options, if you
          specify this option, you must supply a value; the
          default basename is used only if the option is not actually
          specified. If you use the
          --relay-log-index option
          without specifying a value, unexpected behavior is likely to
          result; this behavior depends on the other options used, the
          order in which they are specified, and whether they are
          specified on the command line or in an option file. For more
          information about how MySQL handles server options, see
          Section 4.2.3, “Specifying Program Options”.
        
          If you specify this option, the value specified is also used
          as the basename for the relay logs. You can override this
          behavior by specifying a different relay log file basename
          using the --relay-log option.
        
          
          
          --relay-log-info-file=
        file_name
          The name to use for the file in which the slave records
          information about the relay logs. The default name is
          relay-log.info in the data directory.
        
          Disable or enable automatic purging of relay logs as soon as
          they are no longer needed. The default value is 1 (enabled).
          This is a global variable that can be changed dynamically with
          SET GLOBAL relay_log_purge =
          .
        N
This option is available as of MySQL 4.1.1.
The size at which the server rotates relay log files automatically. For more information, see Section 14.3.1, “Replication Relay and Status Files”. Default is 1GB.
This option is available as of MySQL 4.0.14.
          This option places an upper limit on the total size in bytes
          of all relay logs on the slave. A value of 0 means “no
          limit.” This is useful for a slave server host that has
          limited disk space. When the limit is reached, the I/O thread
          stops reading binary log events from the master server until
          the SQL thread has caught up and deleted some unused relay
          logs. Note that this limit is not absolute: There are cases
          where the SQL thread needs more events before it can delete
          relay logs. In that case, the I/O thread exceeds the limit
          until it becomes possible for the SQL thread to delete some
          relay logs because not doing so would cause a deadlock (which
          is what happens before MySQL 4.0.13). You should not set
          --relay-log-space-limit to less
          than twice the value of
          --max-relay-log-size (or
          --max-binlog-size if
          --max-relay-log-size is 0). In
          that case, there is a chance that the I/O thread waits for
          free space because
          --relay-log-space-limit is
          exceeded, but the SQL thread has no relay log to purge and is
          unable to satisfy the I/O thread. This forces the I/O thread
          to ignore
          --relay-log-space-limit
          temporarily.
        
          Tell the slave to restrict replication to statements where the
          default database (that is, the one selected by
          USE) is
          db_name. To specify more than one
          database, use this option multiple times, once for each
          database. Note that this does not replicate cross-database
          statements such as UPDATE
           while having selected a different database
          or no database.
        some_db.some_table SET
          foo='bar'
To specify multiple databases you must use multiple instances of this option. Because database names can contain commas, if you supply a comma separated list then the list will be treated as the name of a single database.
          An example of what does not work as you might expect: If the
          slave is started with
          --replicate-do-db=sales and you
          issue the following statements on the master, the
          UPDATE statement is
          not replicated:
        
USE prices; UPDATE sales.january SET amount=amount+1000;
          The main reason for this “check just the default
          database” behavior is that it is difficult from the
          statement alone to know whether it should be replicated (for
          example, if you are using multiple-table
          DELETE or multiple-table
          UPDATE statements that go
          across multiple databases). It is also faster to check only
          the default database rather than all databases if there is no
          need.
        
          If you need cross-database updates to work, make sure that you
          have MySQL 3.23.28 or later, and use
          --replicate-wild-do-table=
          instead. See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        db_name.%
          Tells the slave to not replicate any statement where the
          default database (that is, the one selected by
          USE) is
          db_name. To specify more than one
          database to ignore, use this option multiple times, once for
          each database. You should not use this option if you are using
          cross-database updates and you do not want these updates to be
          replicated. See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        
          An example of what does not work as you might expect: If the
          slave is started with
          --replicate-ignore-db=sales and
          you issue the following statements on the master, the
          UPDATE statement
          is replicated:
        
USE prices; UPDATE sales.january SET amount=amount+1000;
            In the preceding example the statement is replicated because
            --replicate-ignore-db only
            applies to the default database (set through the
            USE statement). Because the
            sales database was specified explicitly
            in the statement, the statement has not been filtered.
          
          If you need cross-database updates to work, use
          --replicate-wild-ignore-table=
          instead. See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        db_name.%
          
          
          --replicate-do-table=
        db_name.tbl_name
          Tells the slave thread to restrict replication to the
          specified table. To specify more than one table, use this
          option multiple times, once for each table. This works for
          both cross-database updates and default database updates, in
          contrast to --replicate-do-db.
          See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        
          
          
          --replicate-ignore-table=
        db_name.tbl_name
          Tells the slave thread to not replicate any statement that
          updates the specified table, even if any other tables might be
          updated by the same statement. To specify more than one table
          to ignore, use this option multiple times, once for each
          table. This works for cross-database updates, in contrast to
          --replicate-ignore-db. See
          Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        
          
          
          --replicate-rewrite-db=
        from_name->to_name
          Tells the slave to translate the default database (that is,
          the one selected by USE) to
          to_name if it was
          from_name on the master. Only
          statements involving tables are affected (not statements such
          as CREATE DATABASE,
          DROP DATABASE, and
          ALTER DATABASE), and only if
          from_name is the default database
          on the master. This does not work for cross-database updates.
          To specify multiple rewrites, use this option multiple times.
          The server uses the first one with a
          from_name value that matches. The
          database name translation is done before
          the --replicate-* rules are tested.
        
          If you use this option on the command line and the
          “>” character is special to
          your command interpreter, quote the option value. For example:
        
shell> mysqld --replicate-rewrite-db="olddb->newdb"
          To be used on slave servers. Usually you should use the
          default setting of 0, to prevent infinite loops caused by
          circular replication. If set to 1, the slave does not skip
          events having its own server ID. Normally, this is useful only
          in rare configurations. Cannot be set to 1 if
          --log-slave-updates is used. Be
          careful that starting from MySQL 4.1, by default the slave I/O
          thread does not even write binary log events to the relay log
          if they have the slave's server id (this optimization helps
          save disk usage compared to 4.0). So if you want to use
          --replicate-same-server-id in
          4.1 versions, be sure to start the slave with this option
          before you make the slave read its own events that you want
          the slave SQL thread to execute.
        
          
          
          --replicate-wild-do-table=
        db_name.tbl_name
          Tells the slave thread to restrict replication to statements
          where any of the updated tables match the specified database
          and table name patterns. Patterns can contain the
          “%” and
          “_” wildcard characters, which
          have the same meaning as for the
          LIKE pattern-matching operator.
          To specify more than one table, use this option multiple
          times, once for each table. This works for cross-database
          updates. See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
        
          Example:
          --replicate-wild-do-table=foo%.bar%
          replicates only updates that use a table where the database
          name starts with foo and the table name
          starts with bar.
        
          If the table name pattern is %, it matches
          any table name and the option also applies to database-level
          statements (CREATE DATABASE,
          DROP DATABASE, and
          ALTER DATABASE). For example,
          if you use
          --replicate-wild-do-table=foo%.%,
          database-level statements are replicated if the database name
          matches the pattern foo%.
        
          To include literal wildcard characters in the database or
          table name patterns, escape them with a backslash. For
          example, to replicate all tables of a database that is named
          my_own%db, but not replicate tables from
          the my1ownAABCdb database, you should
          escape the “_” and
          “%” characters like this:
          --replicate-wild-do-table=my\_own\%db.
          If you use the option on the command line, you might need to
          double the backslashes or quote the option value, depending on
          your command interpreter. For example, with the
          bash shell, you would need to type
          --replicate-wild-do-table=my\\_own\\%db.
        
          
          
          --replicate-wild-ignore-table=
        db_name.tbl_name
Tells the slave thread not to replicate a statement where any table matches the given wildcard pattern. To specify more than one table to ignore, use this option multiple times, once for each table. This works for cross-database updates. See Section 14.9, “How Servers Evaluate Replication Filtering Rules”.
          Example:
          --replicate-wild-ignore-table=foo%.bar%
          does not replicate updates that use a table where the database
          name starts with foo and the table name
          starts with bar.
        
          For information about how matching works, see the description
          of the
          --replicate-wild-do-table
          option. The rules for including literal wildcard characters in
          the option value are the same as for
          --replicate-wild-ignore-table
          as well.
        
          The host name or IP number of the slave to be reported to the
          master during slave registration. This value appears in the
          output of SHOW SLAVE HOSTS on
          the master server. Leave the value unset if you do not want
          the slave to register itself with the master. Note that it is
          not sufficient for the master to simply read the IP number of
          the slave from the TCP/IP socket after the slave connects. Due
          to NAT and other routing issues, that IP may not be valid for
          connecting to the slave from the master or other hosts.
        
This option is available as of MySQL 4.0.0.
          The account password of the slave to be reported to the master
          during slave registration. This value appears in the output of
          SHOW SLAVE HOSTS on the master
          server if the
          --show-slave-auth-info option
          is given.
        
The TCP/IP port number for connecting to the slave, to be reported to the master during slave registration. Set this only if the slave is listening on a nondefault port or if you have a special tunnel from the master or other clients to the slave. If you are not sure, do not use this option.
This option is available as of MySQL 4.0.0.
          The account user name of the slave to be reported to the
          master during slave registration. This value appears in the
          output of SHOW SLAVE HOSTS on
          the master server if the
          --show-slave-auth-info option
          is given.
        
          Display slave user names and passwords in the output of
          SHOW SLAVE HOSTS on the master
          server for slaves started with the
          --report-user and
          --report-password options.
        
          Tells the slave server not to start the slave threads when the
          server starts. To start the threads later, use a
          START SLAVE statement.
        
          
          
          --slave_compressed_protocol={0|1}
        
If this option is set to 1, use compression for the slave/master protocol if both the slave and the master support it. The default is 0 (no compression).
          The name of the directory where the slave creates temporary
          files. This option is by default equal to the value of the
          tmpdir system variable. When
          the slave SQL thread replicates a
          LOAD DATA
          INFILE statement, it extracts the file to be loaded
          from the relay log into temporary files, and then loads these
          into the table. If the file loaded on the master is huge, the
          temporary files on the slave are huge, too. Therefore, it
          might be advisable to use this option to tell the slave to put
          temporary files in a directory located in some file system
          that has a lot of available space. In that case, the relay
          logs are huge as well, so you might also want to use the
          --relay-log option to place the
          relay logs in that file system.
        
          The directory specified by this option should be located in a
          disk-based file system (not a memory-based file system)
          because the temporary files used to replicate
          LOAD DATA
          INFILE must survive machine restarts. The directory
          also should not be one that is cleared by the operating system
          during the system startup process.
        
          The number of seconds to wait for more data from the master
          before the slave considers the connection broken, aborts the
          read, and tries to reconnect. The first retry occurs
          immediately after the timeout. The interval between retries is
          controlled by the CHANGE MASTER
          TO statement or
          --master-connect-retry option
          and the number of reconnection attempts is limited by the
          --master-retry-count option.
          The default is 3600 seconds (one hour).
        
          
          
          --slave-skip-errors=[
        err_code1,err_code2,...|all]
Normally, replication stops when an error occurs on the slave. This gives you the opportunity to resolve the inconsistency in the data manually. This option tells the slave SQL thread to continue replication when a statement returns any of the errors listed in the option value.
Do not use this option unless you fully understand why you are getting errors. If there are no bugs in your replication setup and client programs, and no bugs in MySQL itself, an error that stops replication should never occur. Indiscriminate use of this option results in slaves becoming hopelessly out of synchrony with the master, with you having no idea why this has occurred.
          For error codes, you should use the numbers provided by the
          error message in your slave error log and in the output of
          SHOW SLAVE STATUS.
          Appendix A, Errors, Error Codes, and Common Problems, lists server error codes.
        
          You can also (but should not) use the very nonrecommended
          value of all to cause the slave to ignore
          all error messages and keeps going regardless of what happens.
          Needless to say, if you use all, there are
          no guarantees regarding the integrity of your data. Please do
          not complain (or file bug reports) in this case if the slave's
          data is not anywhere close to what it is on the master.
          You have been warned.
        
Examples:
--slave-skip-errors=1062,1053 --slave-skip-errors=all
System variables used on replication slaves. 
        The following list describes system variables for controlling
        replication slave servers. They can be set at server startup and
        some of them can be changed at runtime using
        SET.
        Server options used with replication slaves are listed earlier
        in this section.
      
          This variable is similar to
          init_connect, but is a string
          to be executed by a slave server each time the SQL thread
          starts. The format of the string is the same as for the
          init_connect variable.
        
            The SQL thread sends an acknowledgement to the client before
            it executes init_slave.
            Therefore, it is not guaranteed that
            init_slave has been
            executed when START SLAVE
            returns. See Section 12.5.2.7, “START SLAVE Syntax”, for more
            information.
          
This variable was added in MySQL 4.1.2.
This variable is unused.
Whether to use compression of the master/slave protocol if both the slave and the master support it. This variable was added in MySQL 4.0.3.
          The name of the directory where the slave creates temporary
          files for replicating
          LOAD DATA
          INFILE statements. This variable was added in MySQL
          4.0.0.
        
The number of seconds to wait for more data from a master/slave connection before aborting the read. This timeout applies only to TCP/IP connections, not to connections made via Unix socket files, named pipes, or shared memory. This variable was added in MySQL 3.23.40.
Normally, replication stops when an error occurs on the slave. This gives you the opportunity to resolve the inconsistency in the data manually. This variable tells the slave SQL thread to continue replication when a statement returns any of the errors listed in the variable value. This variable was added in MySQL 3.23.47.
          If a replication slave SQL thread fails to execute a
          transaction because of an InnoDB
          deadlock or because the transaction's execution time
          exceeded InnoDB's
          innodb_lock_wait_timeout or
          NDBCLUSTER's
          TransactionDeadlockDetectionTimeout or
          TransactionInactiveTimeout, it
          automatically retries
          slave_transaction_retries
          times before stopping with an error. The default in MySQL 4.1
          is 0. You must explicitly set the value to
          greater than 0 to enable the “retry” behavior,
          which is often desirable.
        
The number of events from the master that a slave server should skip. This variable was added in MySQL 3.23.33.
            If skipping the number of events specified by setting this
            variable would cause the slave to begin in the middle of an
            event group, the slave continues to skip until it finds the
            beginning of the next event group and begins from that
            point. For more information, see
            Section 12.5.2.6, “SET GLOBAL SQL_SLAVE_SKIP_COUNTER Syntax”.
          

User Comments
To know more about relay-logs hop onto http://dev.mysql.com/doc/refman/5.0/en/slave-logs.html
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