Changing the Default Databases for BPMN and BPEL

When you use the Business Process profile in WSO2 EI, two separate databases are required for storing data specific to BPMN and BPEL. This is in addition to the default Carbon database. By default, the Business Process profile is shipped with embedded H2 databases for this purpose:

activiti.h2.db: For BPMN-specific data.
jpadb.h2.db: For BPEL-specific data.

These databases are stored in the <EI_HOME>/wso2/business-process/repository/database directory.

For instructions on changing the default Carbon database, see Changing the Carbon Database in the WSO2 Product Administration Guide.

Given below are the steps you need to follow in order to change the default BPMN and BPEL databases.

Setting up the database

You can set up two databases of the following types:

Creating the datasource connection

A datasource is used to establish the connection to a database. By default, datasource connections for the BPEL and BPMN databases are configured in the activiti-datasources.xml and bps-datasources.xml files respectively. These datasource configurations point to the default H2 databases, which are shipped with the product. After setting up new databases to replace the default H2 databases, you can either change the default configurations in the above-mentioned files or configure new datasources.

Creating the datasource connection for the BPEL database

Follow the steps below.

Open the <EI_HOME>/wso2/business-process/conf/datasources/bps-datasources.xml file and locate the <datasource> configuration element.
You simply have to update the url pointing to your database, the username and password required to access the database. See the following examples:

Optionally, you can update the configuration elements given below for your database connection.

Element	Description
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	Specifies whether each SQL statement should be automatically committed when it is completed. It is recommended to disable auto committing by setting this property to `true`.

For more information on other parameters that can be defined in the <EI_HOME>/wso2/business-process/conf/datasources/master-datasources.xml file, see Tomcat JDBC Connection Pool.

Creating the datasource connection for the BPMN database

Follow the steps below.

Open the <EI_HOME>/wso2/business-process/conf/datasources/activiti-datasources.xml file and locate the <datasource> configuration element.
You simply have to update the url pointing to your database, the user name and password required to access the database. See the following examples:

Optionally, you can update the configuration elements given below for your database connection.

Element	Description
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	Specifies whether each SQL statement should be automatically committed when it is completed. It is recommended to disable auto committing by setting this property to `true`.

For more information on other parameters that can be defined in the <EI_HOME>/wso2/business-process/conf/datasources/master-datasources.xml file, see Tomcat JDBC Connection Pool.

Creating database tables

To create the database tables, connect to the databases that you created earlier and run the scripts provided in the product pack.

Creating database tables in the BPEL database

Several db scripts are provided to create the necessary tables in the BPEL database:

Create: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpel/create directory.
Drop: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpel/drop directory.
Truncate: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpel/truncate directory.
Upgrade: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpel/upgrade directory.

To create the necessary database tables:

Connect to the database and run the above scripts. For example, shown below is how to create data in a MySQL database.
```
mysql -u root -p -DBPS_DS < '<EI_HOME>/wso2/business-process/dbscripts/bps/bpel/create/mysql.sql';
```
Restart the server.

Creating database tables in the BPMN database

Several db scripts are provided to create the necessary tables in the BPMN database:

Create: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpmn/create directory.
Drop: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpmn/drop directory.
Metadata: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpmn/metadata directory.
Upgrade: These scripts are stored in the <EI_HOME>/wso2/business-process/dbscripts/bps/bpmn/upgrade directory.

To create the necessary database tables:

Connect to the database and run the above scripts. For example, execute the following scripts to create data in a MySQL database.
- activiti.mysql.create.engine.sql
- activiti.mysql.create.history.sql
- activiti.mysql.create.identity.sql
- activiti.mysql.create.substitute.sql
Shown below is how the script for creating identity data is executed:
```
mysql -u root -p -DBPS_DS < '<EI_HOME>/wso2/business-process/dbscripts/bps/bpmn/create/activiti.mysql.create.identity.sql';
```
Restart the server.

Create database tables when the server starts

You can create database tables automatically when starting the product for the first time by using the -Dsetup parameter as follows:

For Windows: <EI_HOME>/wso2/business-process/bin/wso2server.bat -Dsetup
For Linux: <EI_HOME>/wso2/business-process/bin/wso2server.sh -Dsetup