Section 6.1. Client and Server Connectivity: The Big Picture

6.1. Client and Server Connectivity: The Big Picture

Figure 6.1 illustrates a simplified overview of what is required to connect from a DB2 client to a DB2 server.

Figure 6.1. The big picture of client and server connectivity

To connect to a remote database (a database that resides in a machine other than the client machine), follow this two-step process.

1.

At the server, enable it to accept client connections by turning on listener processes. In Figure 6.1, the information required from the database servers is on the right side below the server machine. For example, if you are using the TCP/IP protocol, you need to set the DB2COMM registry variable to tcpip to start the DB2 TCP/IP listeners. In addition, you must specify the port that the databases of a given instance are listening to in the SVCENAME Database Manager Configuration parameter. This is the information you need to give to the client machine in step 2.

2.

At the client, make sure to enter the connection information (obtained from the first step) correctly into the system and node directories using the catalog command. In Figure 6.1, on the left side below the DB2 client you can see the system database and node directories where you need to store the information obtained in step 1.

To connect to a local database (a database that resides in the same machine as the client machine), the create database command stores the required information in the system and local database directories automatically for you.

In the next sections you will also learn about the Database Connection Services (DCS) directory, which is required to connect to a DB2 server on the z/OS, OS/390, and iSeries platforms.

We first show you how to enter the information in the DB2 directories using DB2 commands. Once you are familiar with the commands, we show you how to configure client-server connectivity using the Configuration Assistant (CA), which populates these directories behind the scenes.

NOTE

The Configuration Assistant and the Configuration Advisor (introduced in Chapter 5, Understanding the DB2 Environment, DB2 Instances, and Databases) are different tools. The Configuration Assistant is mainly used to set up client-server connectivity, while the Configuration Advisor is used exclusively to configure database manager and database configuration parameters.