Advantages of Parallel vs. In-place Upgrade:
Parallel upgrades are highly recommended and a best practice. Parallel upgrades minimize down time and offer a roll back plan. In addition, parallel upgrades offer easier troubleshooting ie. if there are issues with the newer version environment, we can lose all the corresponding logs and configuration for troubleshooting in case of rollback. With a parallel upgrade, the logs and configuration are untouched and can be used for troubleshooting issues.
Inherent risks associated with an in-place upgrade are:
1. Extended outage window – servers must be taken offline to upgrade – this means account authentication and authorization are non-operational.
2. Lengthy rollback process – with parallel upgrades, customers can quickly roll back by switching the Load Balancer to redirect to the old version environment. An in-place upgrade requires removing the new environment and restoring the old environment using backups to restore the old version – this can be lengthy.
3. Unknown issues encountered – parallel deployments of a newer environment offer the ability to identify issues through functional tests before cutting over from the older environment. In-place upgrades may present unexpected issues that are time-consuming to troubleshoot/resolve.
4. License management – Since the newer version environment will be operational going forward, the customer agrees to decommission the older environment. In such cases, we provide Temporary licenses to set up the newer version environment, OR customer may use the original license keys provided via email when initially purchased.
NOTE: Copying License keys from one machine to another will NOT work.