Setting up Embedded H2

The following sections describe how to replace the default H2 databases with Embedded H2:

Setting up the database

Download and install the H2 database engine in your computer.

For instructions on installing DB2 Express-C, see H2 installation guide.

Setting up the drivers

WSO2 currently ships H2 database engine version h2-1.2.140.* and its related H2 database driver. If you want to use a different H2 database driver, take the following steps:

Delete the following H2 database-related JAR file, which is shipped with WSO2 products:
<PRODUCT_HOME>/repository/components/plugins/h2-database-engine_1.2.140.wso2v3.jar
Find the JAR file of the new H2 database driver (<H2_HOME>/bin/h2-*.jar, where <H2_HOME> is the H2 installation directory) and copy it to your WSO2 product's <PRODUCT_HOME>/repository/components/lib/ directory.

Setting up datasource configurations

A datasource is used to establish the connection to a database. By default, WSO2_CARBON_DB datasource is used to connect to the default H2database, which stores registry and user management data. After setting up the Embedded H2 database to replace the default H2 database, either change the default configurations of the WSO2_CARBON_DB datasource, or configure a new datasource to point it to the new database as explained below.

Changing the default WSO2_CARBON_DB datasource

Follow the steps below to change the type of the default WSO2_CARBON_DB datasource.

Edit the default datasource configuration in the <PRODUCT_HOME>/repository/conf/datasources/m aster-datasources.xml file as shown below.

<datasource>
    <name>WSO2_CARBON_DB</name>
    <description>The datasource used for registry and user manager</description>
    <jndiConfig>
         <name>jdbc/WSO2CarbonDB</name>
    </jndiConfig>
    <definition type="RDBMS">
         <configuration>
             <url>jdbc:h2:repository/database/WSO2CARBON_DB;DB_CLOSE_ON_EXIT=FALSE;LOCK_TIMEOUT=60000</url>
             <username>wso2carbon</username>
             <password>wso2carbon</password>
             <driverClassName>org.h2.Driver</driverClassName>
             <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	This property is not applicable to the Carbon database in WSO2 products because auto committing is usually handled at the code level, i.e., the default auto commit configuration specified for the RDBMS driver will be effective instead of this property element. Typically, auto committing is enabled for an RDBMS drivers by default. When auto committing is enabled, each SQL statement will be committed to the database as an individual transaction, as opposed to committing multiple statements as a single transaction.

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

Configuring new datasources to manage registry or user management data

Follow the steps below to configure new datasources to point to the new databases you create to manage registry and/or user management data separately.

Add a new datasource with similar configurations as the WSO2_CARBON_DB datasource above to the <PRODUCT_HOME>/repository/conf/datasources/ master-datasources.xml file. Change its elements with your custom values. For instructions, see Setting up datasource configurations.
If you are setting up a separate database to store registry-related data, update the following configurations in the <PRODUCT_HOME>/repository/conf/ registry.xml file.
```
<dbConfig name="wso2registry">
	<dataSource>jdbc/MY_DATASOURCE_NAME</dataSource>
</dbConfig>
```
If you are setting up a separate database to store user management data, update the following configurations in the <PRODUCT_HOME>/repository/conf/ user-mgt.xml file.
```
<Configuration>
	<Property name="dataSource">jdbc/MY_DATASOURCE_NAME</Property>
</Configuration>
```

Creating database tables

To create the database tables, connect to the database that you created earlier and run the following scripts in the H2 shell or web console:

To create tables in the registry and user manager database (WSO2CARBON_DB), use the below script:
```
<PRODUCT_HOME>/dbscripts/h2.sql
```

Follow the steps below to run the script in Web console:

Run the ./h2.sh command to start the Web console.
Copy the script text from the SQL file.
Paste it into the console.
Click Run.
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: <PRODUCT_HOME>/bin/wso2server.bat -Dsetup
- For Linux: <PRODUCT_HOME>/bin/wso2server.sh -Dsetup

Changing the WSO2 ML DB

If you set up a separate H2 database for WSO2 ML related data, and you want to use it instead of the default H2 database which stores ML-specific data the instructions are the same. In summary:

Add the datasource to the master-datasources.xml file, and change the configurations (values of the <url>, <username>,<password> and <driverClassName> properties) accordingly.
Create the database tables using the following script: <ML_HOME>/dbscripts/ml/h2.sql