> # SequeLink® Configuration Example

> The examples show the configuration tools used on Windows and UNIX.

> In this example, the ODBC Client has been installed on multiple Windows workstations and the SequeLink Server for DB2 has been installed on a z/OS server.

> Four user applications use the SequeLink Server for DB2 to connect to a DB2 database. One application is an order-entry application that needs the ability to update the database. The other applications are reporting applications that must not have the ability to update; therefore, they must connect with read-only functionality to the database.

> We have decided to place an added layer of security on the order-entry application because it allows updates. The security mechanism that will be used is application IDs (see "Planning Security"). By using the application ID security mechanism, we can ensure that if one of the reporting applications is modified to use the same client data source as the order-entry application, the reporting application will be unable to update the database because it is not configured with an application ID.

> To configure SequeLink for use with the report applications, we will modify the default server data source to make it read-only by setting the DataSourceReadOnly attribute to Select, which means only SQL Select statements are allowed. Also, we will create a client data source that uses the default data source. We will name the client data source DB2ReadOnly. The reporting applications will connect to the DB2 database using the DB2ReadOnly client data source.

> Also, we will configure SequeLink for use with the order-entry application. To make sure that the application is certified to the server, we will assign it an application ID, and set the DataSourceApplID service attribute to the value of the order-entry application's ID. We must create and configure a server data source that sets the DataSourceApplID attribute; we will name the server data source DB2Update. In addition, we must create and configure a client data source that references the DB2Update server data source. We will name the client data source DB2OrderEntry.

> The following summary lists the components that must be configured:

> - A new server data source named DB2Update must be created. This server data source uses application IDs to certify the order-entry application to the server.
> - The default server data source must be modified to make it read-only.
> - An ODBC client data source named DB2OrderEntry must be created. This client data source will reference the newly created server data source, DB2Update. The order-entry application must connect to this ODBC client data source. For information about how to connect ODBC applications to SequeLink Client data sources, refer to the SequeLink Administrator's Guide.
> - An ODBC client data source named DB2ReadOnly must be created. This client data source will reference the default server data source. The reporting applications must connect to this ODBC client data source.

> Figure 3-2 shows how all of the components fit together.

> Figure 3-2. Example Configuration

> ### Creating a Server Data Source

> This example shows how to use the SequeLink Manager Snap-in to create a server data source. You could also use the SequeLink Manager Command-Line tool or the SequeLink Manager for tool. Refer to the SequeLink Administrator's Guide for complete instructions on using the SequeLink Manager tools.

> To create a server data source:

> 1. Start the SequeLink Manager MMC Snap-in by clicking Start / Run. In the Run field, type `mmc` and click OK. An MMC console window appears.

> 2. From the Console menu, select Console / Open. Select the SequeLink Manager console you want to start; then, click Open. The SequeLink Manager appears in the MMC console window.

> 3. Connect to the SequeLink Server.

> 4. Open the following nodes:
> - Connected to MVSDB28
> - SequeLink Services
> - MVSDB28
> - Configuration

> 5. Click Data Source Settings to display the existing data sources in the Details pane (right pane).

> 6. Right-click the Data Source Settings node and select New / Data source. A new server data source appears in the left pane as an editable field.

> 7. To name the server data source, type `DB2Update`, and press ENTER.
> 8. Add the DataSourceApplId attribute to the DB2Update data source. Right-click the DB2Update data source and select New / Attribute. The New Attribute window appears.
> 9. In the Attribute drop-down list, select DataSourceApplID.

> 10. In the Value field, type the application ID that the order-entry application will use to identify itself to the SequeLink service. Refer to the SequeLink Developer's Reference for information about specifying application IDs for ODBC client applications.
> 11. Click OK. The attribute is added to the server data source.

> For a description of SequeLink service attributes, refer to the SequeLink Administrators Guide.

> ### Modifying the Default Server Data Source

> NOTE: This procedure assumes that the SequeLink Manager is running and that you have completed the previous procedure.

> 1. Select the Data Source Settings node to display the existing data sources in the Details pane (right pane).
> 2. Add the DataSourceReadOnly attribute to the Default data source. Right-click Default in the Details pane and select New / Attribute. The New Attribute window appears.

> 3. In the Attribute drop-down list, select DataSourceReadOnly.
> 4. In the Value field, select Select, which means only Select statements are allowed.
> 5. Click OK. The attribute is added to the default server data source.

> ### Configuring ODBC Client Data Sources

> 1. Start the ODBC Administrator by selecting its icon from the DataDirect SequeLink 6.0 Client for ODBC program group. Click the User DSN tab to view a list of existing user data sources.

> 2. Create and configure the first data source by clicking Add. The Create New Data Source window appears. Select DataDirect SequeLink 6.0 from the list of installed drivers; then, click Finish.

> The SequeLink for ODBC Driver Setup window appears.

> 3. Provide the following information; then, click OK.

> Data Source Name: Type `DB2ReadOnly`.

> Description: Type `DB2 read-only connection for Accounting`. This field is optional.

> SequeLink Server Host: Type `speedy.na.DataDirect.com`. This field identifies the TCP/IP host name of the SequeLink service to which you want the ODBC Client to connect.

> SequeLink Server Port: Type `19996`, which is the default TCP/IP port the SequeLink service is listening on for incoming connection requests. The port that you specify must be the same as the one that was specified for the SequeLink service when the SequeLink Server was installed.

> SequeLink Data Source: Leave this field blank. This client data source is to use the default server data source; therefore, a server data source does not have to be specified.

> NOTE: This example does not use LDAP. If you wanted to configure the ODBC Client to retrieve connection information from an LDAP directory, you would select the Use LDAP check box. The fields change on the lower half of the screen to accommodate the information required to query an LDAP server for connection information.

> 4. Create and configure the second data source by clicking Add. The Create New Data Source window appears. Select DataDirect SequeLink 6.0 from the list of installed drivers; then, click Finish.

> The SequeLink for ODBC Driver Setup window appears.

> 5. Provide the following information; then, click OK.

> Data Source Name: Type `DB2OrderEntry`.

> Description: Type `DB2 update connection`. This field is optional.

> SequeLink Server Host: Type `speedy.na.DataDirect.com`. This field identifies the TCP/IP host name of the SequeLink service to which you want the ODBC Client to connect.

> SequeLink Server Port: Type `19996`, which is the default TCP/IP port the SequeLink service is listening on for incoming connection requests. The port you specify must be the same as the one that was specified for the SequeLink service when the SequeLink Server was installed.

> SequeLink Data Source: Type `DB2Update`, which is the name of the server data source that was created for update capabilities and the use of application IDs, or select the value from the drop-down list.

> The configuration of SequeLink client and server data sources is complete. The reporting applications can now use the DB2ReadOnly client data source, and the order-entry application can use the DB2OrderEntry client data source.

> For information about how to configure the order-entry application to specify an application ID, refer to the SequeLink Developer's Reference.