(ZOS) Connection optimization

Characteristics of a configuration in which the Domain Name Server cooperates with workload management (WLM) to route client requests throughout a cell are:

• The DNS is replicated by setting up a secondary DNS on more than one system in the cell.
• The client must know the host name and port of the name server to connect to WebSphere Application Server for z/OS .
• Each system in the cell has the same location service daemon IP name. Workload management and the domain name server determine the actual system that receives client requests. The client sees the cell as a single system, though its requests might be balanced across systems in the cell.
• As part of workload balancing and maximizing performance goals, workload management also routes work requests to systems in the cell. This function is possible because WAS for z/OS cooperates with workload management. Because the system references that a client sees are indirect, even requests from that same client might be answered by differing systems in the cell.
• The implication for clients is that they should not cache IP addresses unless they can recover from failed connections. That is, if a connection fails, a client should be able to reissue a request, but, because the IP address is an indirect address, a reissue of the request can be answered by another system in the cell.

For additional details on setting up servers for connection optimization, see z/OS Communications Server: IP Configuration Reference.