Prepare Clients for Migration

Configure and prepare your clients such that the transition of HTTP clients from the old deployment to the new deployment is smooth and happens by switching the Domain Name System (DNS) entry.

These changes can be done gradually over time because after these changes are completed everything continues to work as before the changes. This includes some changes to the source environment.

To prepare clients:

  1. Get a DNS name issued from DNS issuing authority. Point this DNS name to the source environment load balancer.

    If you are already using a DNS name in clients, skip this step.

  2. Create a new port in the source environment load balancer that matches the target port number. Add routing rule to this new port to route to the original load balancer port in the source environment.
  3. Change all clients to use the DNS name and new port.

    For SSL, it might be required that the trust certificate for the target environment server has to be pre-configured at the client so that transition from the source to the target environment works smoothly.

  4. If you were already set up to use a global DNS name, ensure that the Oracle WebLogic Server front end host points to the load balancer and not the DNS name.

    Ensure that the loopback HTTP invokes point to the Oracle WebLogic Server front end host/port. For SOA, also ensure that the loopback abstract WSDL/Schema references point to the WebLogic FE host/port.

    These changes ensure that:

    • Callbacks come back to the source domain that issued the request, after transitioning to the target.

    • Loopbacks in the source domain come back to the source domain after transitioning to the target.