IBM SG24-6320-00 manual Switch-Over migration scenario

6320ch_planning.fm Draft Document for Review July 28, 2004 7:33 pm

sufficient capacity to operate both of the instances (and software stacks, for single node install) at the same time.

Note: This approach is not supported for Microsoft Windows platforms.

In-place migration scenario- migration is done on one system (but a test server is highly recommended).

3.5.1 Switch-Over migration scenario

This approach is suitable when the necessary hardware to duplicate the current runtime environment is available to create a test environment where the migration takes place. Once this test environment is fully migrated and tested this test environment becomes the new production environment and the old production environment is taken off line.

With this approach the server downtime is kept to a minimum. The migration is carried out and tested on the test environment while the production servers remain running in parallel. By the time the migration and testing are complete, the database from the migrated environment will be out of sync with the production database. To reconcile the data, the production environment (still on WebSphere Commerce Suite V5.1) must be taken off-line and the database re-migrated based on the already learnt lessons. Once the migration is complete the test environment will be switched-over as the production environment.

Turning the newly migrated environment into production is a relatively simple task to do. Figure 3-1depicts a high level layout of the Switch-Over migration scenario approach implementation. Once the test environment has been fully tested and the database reconciled, at the firewall or router level, depending on the configuration used, the NAT (Network Address Translation) rules are changed to route all the user traffic to the new runtime. The original WebSphere Commerce Suite V5.1 runtime remains active to serve as the contingency environment in the case of any problems after may occur turning the migrated environment into production.

46Keeping Commerce Applications Updated WebSphere Commerce 5.1 to 5.6 Migration Guide