Setting Up an IOM Bridge Connection

Introduction

An IOM Bridge connection enables client applications to access a server using the IOM Bridge for COM or IOM Bridge for Java.

The IOM Bridge for COM is a software component of SAS Integration Technologies that is used (transparently) to enable native COM/DCOM applications to access server data on either Windows platforms or on platforms other than Windows such as a UNIX or z/OS. The IOM Bridge for Java is used (transparently) when a Java client accesses an IOM server. This bridge allows developers to write Java applications that access server data.

For more information about the IOM Bridge for COM and the IOM Bridge for Java, refer to Connecting Clients to IOM Servers in the SAS Integration Technologies Technical Overview.

This section covers the following topics:

• When to Use an IOM Bridge Connection
• Components of a Client-Server Configuration (IOM Bridge Connection)
• How Clients Use an IOM Bridge Connection to Access Servers

When to Use an IOM Bridge Connection

You must use an IOM Bridge connection if any of the following is true:

• The server will run on a platform other than Windows (for example, UNIX).

• The server will be accessed by Java client applications.

• The server will use load balancing.

You can also use an IOM Bridge connection if the server will run on a Windows machine and will be accessed by Windows clients. In this situation, clients will connect to the server using the IOM Bridge connection instead of the COM/DCOM connection.

Components of a Client-Server Configuration

When you configure a server with an IOM Bridge connection, the client-server configuration consists of the following:

• a server machine that hosts the Base SAS 9.1 software and the SAS 9.1 Integration Technologies software. In addition, if you are using a SAS Workspace Server or SAS Stored Process Server, then the spawner program (which is part of SAS Integration Technologies), must be running on the server machine in order for clients to obtain access. For information about best practices for setting up the four different types of IOM servers (SAS Workspace Server, SAS Stored Process Server, SAS OLAP Server, and SAS Metadata Server), see Best Practices: Server and Spawner Setup.

• a client application, which can run on the same machine as the server or on a remote machine. To connect to the server via TCP/IP, client applications must use the IOM Bridge for COM or IOM Bridge for Java utilities provided with SAS Integration Technologies. To request specific services from the server, client applications use Application Program Interfaces (APIs), also known as distributed objects, which are provided with SAS Integration Technologies.

• a SAS Metadata Server, which is a central repository that client and server software can access in order to obtain metadata (or configuration information) about the server. For IOM Bridge connections, the metadata includes definitions for server objects. Optionally, the metadata can also include definitions for spawner objects (which must be used for SAS Workspace Servers and SAS Stored Process Servers); user, group, and login objects (which can be used to provide credentials for various definitions); pooled logical server objects (which associate workspace servers and puddles for pooling security); and load balancing logical server objects (which associate workspace or stored process servers and spawner-to-spawner logins for load balancing).

  Note: If your configuration is very simple (that is, consisting of only one or two servers and clients) and does not require strict security, you can supply the server parameters for the configuration directly in the application program.

How Clients Use an IOM Bridge Connection to Access Servers

When a client application uses an IOM Bridge connection to access a server, the following actions occur:

1. The client application uses Integration Technologies distributed objects to request a server object. The requested server object can be defined in the client application, or a definition can be retrieved from a metadata server.

2. When the client application requests a server object, an IOM Bridge connection is made to the server.

   • If the server configuration uses a spawner, the spawner must be running. The spawner authenticates the client, launches the server, and connects the client to the server.
     
     
   • If the server configuration does not use a spawner, the server must be running. The server authenticates the client before continuing.

   After a connection is established, the server object is created.

3. The client application uses SAS Integration Technologies distributed objects to request services from the server object. The server object can provide services such as SAS language services and publishing services, depending on the type of server object.

4. When the client application is finished using the server object, it issues a request to close the object. Any server or spawner connections associated with the object are closed.

For details about other server and spawner setup, see Best Practices: Server and Spawner Setup.