Configuring MySQL

The following sections describe how to replace the default H2 databases with MySQL.

Step 1: Setting up a MySQL database

Follow the steps below to set up a MySQL database.

Download and install MySQL on your computer using the following command:

For instructions on installing MySQL on MAC OS, go to Homebrew.
```
sudo apt-get install mysql-server mysql-client
```
Start the MySQL service using the following command:
```
sudo /etc/init.d/mysql start
```
Log in to the MySQL client as the root user (or any other user with database creation privileges).
```
mysql -u root -p
```
Enter the password when prompted.

In most systems, there is no default root password. Press the Enter key without typing anything if you have not changed the default root password.
In the MySQL command prompt, create the database using the following command:
```
create database wso2_mb;
```
For users of Microsoft Windows, when creating the database in MySQL, it is important to specify the character set as latin1. Failure to do this may result in an error (error code: 1709) when starting your cluster. This error occurs in certain versions of MySQL (5.6.x), and is related to the UTF-8 encoding. MySQL originally used the latin1 character set by default, which stored characters in a 2-byte sequence. However, in recent versions, MySQL defaults to UTF-8 to be friendlier to international users. Hence, you must use latin1 as the character set as indicated below in the database creation commands to avoid this problem. Note that this may result in issues with non-latin characters (like Hebrew, Japanese, etc.). The database creation command should be as follows:
```
mysql> create database <DATABASE_NAME> character set latin1;
```
For users of other operating systems, the standard database creation commands will suffice. For these operating systems, the database creation command should be as follows:.
```
mysql> create database <DATABASE_NAME>;
```

Give authorization of the database to the regadmin user as follows:

GRANT ALL ON wso2_mb.* TO regadmin@localhost IDENTIFIED BY "regadmin";

Once you have finalized the permissions, reload all the privileges by executing the following command:
```
FLUSH PRIVILEGES;
```
Log out from the MySQL prompt by executing the following command:
```
quit;
```

Step 2: Connecting the server to a MySQL database

Once you have setup the physical database as explained in the previous step, the next step is to enable the connectivity between your MB server and the database. This can be done by simply copying the relevant database drivers to your server, and then configuring the datasources in MB to link to the new database. See the instructions given below.

Copying the database drivers

Download the MySQL Java connector JAR file, and copy it to the <MB_HOME>/repository/components/lib/ directory.

Setting up datasource configurations

The connection between physical databases and the server is established through datasources. The master-datasources.xml file (stored in the <MB_HOME>/repository/conf/datasources directory) is the default datasource configuration file that is shipped with WSO2 products. In the case of WSO2 MB, since we use two databases (Carbon database for registry/user management data and the MB-specific database for storing MB data), the master-datasources.xml file should contain two separate datasource configurations corresponding to the two databases.

If you check the default master-datasources.xml file in the product, you will see that the configurations point to the embedded H2 databases. The following instructions explain how you can divert the default configurations to point to the external MySQL database you created in step 1.

Follow the steps given below to replace the MB-specific datasource configuration with a new connection to a MySQL database:

Open the <MB_HOME>/repository/conf/datasources/master-datasources.xml file. This is where datasources are configured to point to the databases used by the Message Broker. This file consists of commented out configurations for datasources. The datasource configuration for MySQL is among these. The changes made to this file must be done in both broker nodes.

You simply have to update the url pointing to your MySQL database, the username and password required to access the database and the MySQL driver details as shown below. Further, be sure to set the <defaultAutoCommit> element to false for the MB database.

<datasource>
  <name>WSO2_MB_STORE_DB</name>
  <jndiConfig>
     <name>WSO2MBStoreDB</name>
  </jndiConfig>
     <definition type="RDBMS">
         <configuration>
            <driverClassName>com.mysql.jdbc.Driver</driverClassName>
            <url>jdbc:mysql://localhost:3306/wso2_mb</url>
            <username>root</username>
            <password>root</password>
            <maxActive>50</maxActive>
            <maxWait>60000</maxWait>
            <minIdle>5</minIdle>
            <testOnBorrow>true</testOnBorrow>
            <validationQuery>SELECT 1</validationQuery>
            <validationInterval>30000</validationInterval>
            <defaultAutoCommit>false</defaultAutoCommit>
         </configuration>
      </definition>
</datasource>

The elements in the above configuration are described below:

Element	Description
url	The URL of the database. The default port for a DB2 instance is 50000.
username and password	The name and password of the database user
driverClassName	The class name of the database driver
maxActive	The maximum number of active connections that can be allocated at the same time from this pool. Enter any negative value to denote an unlimited number of active connections.
maxWait	The maximum number of milliseconds that the pool will wait (when there are no available connections) for a connection to be returned before throwing an exception. You can enter zero or a negative value to wait indefinitely.
minIdle	The minimum number of active connections that can remain idle in the pool without extra ones being created, or enter zero to create none.
testOnBorrow	The indication of whether objects will be validated before being borrowed from the pool. If the object fails to validate, it will be dropped from the pool, and another attempt will be made to borrow another.
validationQuery	The SQL query that will be used to validate connections from this pool before returning them to the caller.
validationInterval	The indication to avoid excess validation, and only run validation at the most, at this frequency (time in milliseconds). If a connection is due for validation, but has been validated previously within this interval, it will not be validated again.
defaultAutoCommit	It is recommended to disable auto committing by setting this property to `false` for the MB database. This means that each SQL statement will be committed to the database as individual transactions, as opposed to committing multiple SQL statements as one transaction.

For more information on other parameters that can be defined in the <MB_HOME>/repository/conf/datasources/ master-datasources.xml file, see Tomcat JDBC Connection Pool.

Open the <MB_HOME>/repository/conf/broker.xml file. This is the root configuration file of WSO2 MB. The changes made to this file must be done in all the MB nodes.
In the broker.xml file we need to use the MySQL message store and Andes context store. To do this, uncomment or add the following configuration.
```
...
<persistence>
  <messageStore class="org.wso2.andes.store.rdbms.RDBMSMessageStoreImpl">
        <property name="dataSource">jdbc/MySQLMessageStore</property>
  </messageStore>

  <andesContextStore    class="org.wso2.andes.store.rdbms.RDBMSAndesContextStoreImpl">
        <property name="dataSource">jdbc/MySQLMessageStore</property>
  </andesContextStore>
...
</persistence>
```
The elements in the above configuration are described below.
- The fully qualified name of the respective implementation class should be defined under the class attributes of messageStore and andesContextStore elements. This implementation class will be used by MB to persist relevant information.
- The <property> elements are used to define different properties for each store. The minimal property for starting each store is the dataSource property. Depending on the implementation, the required properties may differ.

Step 3: Creating database tables

To create the database tables, connect to the database that you created earlier and run the following scripts:

To create tables in the MB-specific database (wso2_mb), use the below script:

You may have to enter the password for each command when prompted.
```
mysql -u root -p -Dwso2_mb < '<WSO2MB_HOME>/dbscripts/mb-store/mysql-mb.sql ';
```
Restart the server.
You can create database tables automatically when starting the product for the first time by using the -Dsetup parameter as follows:
- For Windows: <MB_HOME>/bin/wso2server.bat -Dsetup
- For Linux: <MB_HOME>/bin/wso2server.sh -Dsetup