Setting up IBM DB2

The following sections describe how to replace the default H2 databases with IBM DB2:

Creating The Database

Follow the instructions below to set up a database in IBM DB2:

Preparing DB2 database

Download the latest version of DB2 Express-C and install it on your computer.

For instructions on installing DB2 Express-C, see this ebook.

Setting up the database and users

Create the database using either DB2 command processor or DB2 control center as described below.

Using the DB2 command processor

Run DB2 console and execute the db2start command in CLI to open DB2.
Create the database using the following command:
create database <DB_NAME>
Before issuing a SQL statement, establish the connection to the database using the following command:
connect to <DB_NAME> user <USER_ID> using <PASSWORD>
Grant required permissions for users as follows:
```
connect to DB_NAME
grant <AUTHORITY> on database to user <USER_ID>
```
For example:

For more information on DB2 commands, see the DB2 Express-C Guide.

Using the DB2 control center

Open the DB2 control center using the db2cc command as follows:
Right-click All Databases in the control center tree (inside the object browser), click Create Database, and then click Standard and follow the steps in the Create New Database wizard.
Click User and Group Objects in the control center tree to create users for the newly created database.
Give the required permissions to the newly created users.

Setting up DB2 JDBC drivers

Copy the DB2 JDBC drivers (db2jcc.jar and db2jcc_license_c0u.jar) from <DB2_HOME>/SQLLIB/java/ directory to the <PRODUCT_HOME>/repository/components/lib/ directory.

<DB2_HOME> refers to the installation directory of DB2 Express-C, and <PRODUCT _HOME> refers to the directory where you run the WSO2 product instance.

Creating database tables

Create the database tables either manually by running the script or automatically by using a startup parameter as described below.

Using the script

You can create database tables manually by executing the following scripts in the DB2 Express-C command editor:

Use the scripts given in the following locations to change the respective database and then restart the server.
- To create tables for the registry and user manager database, run the below command:
```
<PRODUCT_HOME>/dbscripts/db2.sql
```
- To create tables for the product specific databases, run the below command:
```
<PRODUCT_HOME>/dbscripts/<PRODUCT_NAME>/db2.sql
```
```
 
```
After executing the script, start the server as follows:
- For Linux:
  wso2server.sh
- For Windows:
  wso2server.bat

Using a startup parameter

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

Creating A Datasource For The Database

After creating the database, you create a datasource to point to it in the following files:

Edit the default datasource configuration defined in the master-datasources.xml file, which is located in the <PRODUCT_HOME>/repository/conf/datasources/ directory, as shown below. The database configurations in registry.xml and user-mgt.xml refer to this datasource.

Replace the url, username, password and driverClassName settings with your custom values and also the other values accordingly in the master-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:db2://SERVER_NAME:PORT/DB_NAME</url>
                <username>regadmin</username>
                <password>regadmin</password>
                <driverClassName>com.ibm.db2.jcc.DB2Driver</driverClassName>
                <maxActive>80</maxActive>
                <maxWait>360000</maxWait>
                <minIdle>5</minIdle>
                <testOnBorrow>true</testOnBorrow>
                <validationQuery>SELECT 1</validationQuery>
                <validationInterval>30000</validationInterval>
            </configuration>
      </definition>
</datasource>
```
The datasource configuration options in the above configuration are as follows:
- url - The URL of the database.
  
  The default port for a DB2 instance is 50000.
- username - The name of the database user.
- password - The 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.
For more information on other parameters that can be defined in the master-datasources.xml file, see Tomcat JDBC Connection Pool.