Syntax:
FLUSH [NO_WRITE_TO_BINLOG | LOCAL]
    flush_option [, flush_option] ...

The FLUSH statement clears or reloads various internal caches used by
MySQL. Some variants acquire locks. To execute FLUSH, you must have the
RELOAD privilege. Specific flush options might require additional
privileges, as described later.

By default, FLUSH statements are written to the binary log so that they
will be replicated to replication slaves. Logging can be suppressed
with the optional NO_WRITE_TO_BINLOG keyword or its alias LOCAL.

*Note*: FLUSH LOGS, FLUSH MASTER, FLUSH SLAVE, and FLUSH TABLES WITH
READ LOCK (with or without a table list) are not written to the binary
log in any case because they would cause problems if replicated to a
slave.

The RESET statement is similar to FLUSH. See [HELP RESET], for
information about using the RESET statement with replication.

URL: http://dev.mysql.com/doc/refman/5.5/en/flush.html

