/** \mainpage MaxScale by SkySQL

The SkySQL MaxScale is an intelligent proxy that allows forwarding of
database statements to one or more database server user complex rules
and a semantic understanding of the database satements and the roles of
the various servers within the backend cluster of databases.

The MaxScale is designed to provided load balancing and high avilability
functionality transparantly to the applications. In addition it provides
a highly scalable and flexibile architecture, with plugin components to
support differnt protocols and routing decissions.

The MaxScale is implemented in C and makes entensive use of the
asynchronous I/O capabilities of the Linux operating system. The epoll
system is used to provide the event driven framework for the input and
output via sockets.

The protocols are implemented as external shared object modules which
can be loaded and runtime. These modules support a fixed interface,
communicating the entries points via a structure consisting of a set of
function pointers. This structured is called the "module object".

The code that routes the queries to the database servers is also loaed
as external shared objects and are referred to as routing modules.

\section Building Building MaxScale

Edit the file build_gateway.inc in your skygateway directory and set
the ROOT_PATH and MYSQL_ROOT/MYSQL_HEADERS variables to the location in which
you checked out the code and the location of your MariaDB include files.

The include files, static e,bedded library and other files may come from the RPMs packages:

MariaDB-5.5.34-centos6-x86_64-common.rpm
MariaDB-5.5.34-centos6-x86_64-compat.rpm
MariaDB-5.5.34-centos6-x86_64-devel.rpm

Please backup any existent my.cnf file before installing the RPMs

Install them this way:

	rpm -i --force --relocate=/usr/=$PREFIX/usr/ MariaDB-5.5.34-centos6-x86_64-*

This README assumes $PREFIX = $HOME.


Build with the dynamic embedded libmysqld from an existent MariaDB setup

set DYNLIB := Y
copy the libmysqld.so in $(HOME)/usr/lib64/dynlib

If DYNLIB is not set MaxScale will be built using the satic library found in $(HOME)/usr/lib64

This libmysqld.a comes from the RPM or it is copied from an existent MariaDB setup

ERRMSG is the variable that point to the errmsg.sys file that is required by the embedded library.

Example:

	ERRMSG := $(HOME)/usr/share/mysql

	(/home/jdoe/usr/share/mysql/errmsg.sys)

Please note the errmsg.sys file is NOT included in the RPMs at the moment at it must be taken from an existent MariaDB setup:
it's mandatory to get it from the same MariaDB server version we took the dinamyc library or MariaDB devel RPM for the static one.
You may get the one in the 'english' folder:

Example /usr/local/mariadb/share/english/errmsg.sys


Go to the sky gateway directory and do:

	make depend

to update all the dependency files and then do:

	make

	make install

You may set the DEST variable for the target install location, example:

	make DEST=/some/path

	make DEST=/some/path install


If DEST is not set the default install location is:

	DEST=$(HOME)/usr/local/skysql

This should get you all the things built that you need.

Other make targets are available

clean	- Removes compiled code and shared objects
install - Installs the binary and the modules in the location defined by the
make variable DEST

ctags - Build tags files for the vi editor

documentation - Build the doxygen documentation

depend - Update the dependencies used by the makefiles

Two files are required for the libmysqld library that is used within MaxScale,
errmsg,sys and a my.cnf file with the following:

[mysqld]
max_connections=4096

Please check errmsg.sys is found in the MaxScale install_dir DEST/MaxScale/mysql

\section Running  Running MaxScale

The gateway consists of a core executable and a number of modules that implement
the different protocols and routing algorithms. These modules are built as
shared objects that are loaded on demand. In order for the gateway to find these
modules it will search using a predescribed search path. The rules are:

1. Look in the current directory for the module

2. Look in $MAXSCALE_HOME/modules

3. Look in /usr/local/skysql/MaxScale/modules

Configuration is read by default from the file
$MAXSCALE_HOME/etc/MaxScale.cnf, /etc/MaxScale.cnf, an example file
is included in the root of the source tree. The default value of
MAXSCALE_HOME can be overriden by use of the -c flag on the command
line. This should be immediately followed by the path to the MaxScale
home directory.

The -f flag can be used to set the name and the location of the configuration 
file. Without path expression the file is read from $MAXSCALE_HOME/etc directory.
*/