Overview of Pooling

A workspace pool is a group of workspaces that are created and ready for use on one or more servers. Workspace pooling improves the efficiency of connections between clients and servers because SAS processes remain active between uses of SAS and can be reused by multiple clients within the same client process. For both the pooling and non-pooling cases, the client uses the workspace as long as required. With pooling, when the client is finished with the workspace, the process that supports the workspace stays active and can be used by another client. Without pooling, a new SAS process must be created for each client connection.

An authorized application (such as the SAS Information Delivery Portal), which will be referred to here as the pool administrator, runs and controls access to the pool. The pool administrator uses its credentials to connect and authenticate itself to the LDAP directory, giving it authorization to create workspaces. The method that the pool administrator uses to authorize clients to use workspaces depends upon whether the pool is set up for exclusive use by a single client or shared access by many clients.

If a pool is set up for use by a single client, the client uses its own credentials to access the SAS server and SAS login definitions the client is allowed to see. The client can then use attributes on these objects to create a workspace or a pool of workspaces. This scenario is useful for development environments.

If the pool is to be used by many different clients, two main problems arise:

• Workspaces may need to be created before the clients are known
• Workspaces created with one client's login may be accessible by other clients

To ensure security, the pool administrator must have some method of verifying authorization. The method provided with the Integration Technologies Administrator is the use of the Client DN attribute on the SAS login. When the pool administrator issues the request for the workspace, it includes the client's distinguished name as part of the request. The request is accepted only if the client's distinguished name either exactly matches the Client DN attribute or is a member of a group specified in the Client DN attribute. Regardless of the method used, when the client has been authorized to the pool administrator, the administrator uses the pool manager to allocate a workspace from the pool to the client. When the client is finished with the workspace, it releases the workspace to return to the pool, where it is then available for other clients.

A workspace pool consists of a SAS login and one or more SAS servers that have a common

• Base distinguished name
• Logical name
• Domain name

In addition, the servers must all be accessible under the same access credentials.

Note: For Windows clients, you can choose between Integration Technologies pooling or COM+ pooling. For details, see Choosing IT or COM+ Windows Client Pooling in the Developer's Guide.

For information about where to specify the parameters that are needed to set up Integration Technologies pooling, see Locations for Specifying Pooling Parameters.