CloverETL Server requires MySql 5.x

For modification Tomcat context params, add to context config file (and modify according to your credentials):

<Parameter name="jdbc.driverClassName" value="com.mysql.jdbc.Driver" override="false" />
<Parameter name="jdbc.url" value="jdbc:mysql://127.0.0.1:3306/clover?useUnicode=true&amp;characterEncoding=utf8" override="false" />
<Parameter name="jdbc.username" value="root" override="false" />
<Parameter name="jdbc.password" value="" override="false" />
<Parameter name="jdbc.dialect" value="org.hibernate.dialect.MySQLDialect" override="false" />

Or If you use properties file for configuration:

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/clover?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=
jdbc.dialect=org.hibernate.dialect.MySQLDialect

Since 3.0 JDBC driver isn't included in CloverETL Server web archive, thus it must be added to the application server classpath.

Create DB with proper charset, like this:

CREATE DATABASE IF NOT EXISTS clover DEFAULT CHARACTER SET 'utf8';