Replatform

Overview

A replatform is where we make some significant changes to the technology platform - but we make as little change to the code as possible. This allows for a migration where testing can be limited to regression testing and performance testing and so a shorter overall migration duration.

We include in the definition of a platform; the OS, the middleware platform, and server-cluster frameworks such as K8.

In a cloud context, a platform change would also include a switch between self-install software and a PaaS service. A migration from an on-premises Oracle database to an OCI database service (e.g. oracle Database Cloud Service) would be considered to be a platform change. While, in contrast, a move between self-install on premises to a self-install database on OCI bare-metal would be a simple rehost.

Benefits

Time to migrate Score
Technical difficulty Score
Strategic Value Score

The advantage of a replatform over a rehost is that this is the first level at which the technology of the cloud can be brought to bear to improve an application. The advantages are focused on the non-functional aspects of the application :

Each of these aspects can be improved by a replatform of the middleware to cloud-native middleware services. In general, the greater the degree of change that is accepted, then the greater the benefits. For example, moving to a managed service will accrue a certain degree of benefit, while moving to a service explicitly designed as cloud-native will likely deliver a much higher level of benefit. As Oracle, we offer both approaches. For example, Oracle Database Cloud Service focusing on compatibility with self-install, while our Autonomous Database breaks some of that compatibility but as a consequence is able to deliver far greater benefits on all the non-functional elements.

As another example, for a java application running on Weblogic, Websphere or JBoss then the simplest re-hosting would be to simply install those middleware technologies. A first level replatform would be embed the middleware in a cloud-native framework such as Kubernetes (see (Oracle Weblogic on OKE)[https://docs.oracle.com/en/solutions/deploy-wls-on-oke/index.html])

Challenges

The main challenges that any replatform brings are driven by the degree of change or incompatibility between source and target architectures. However, as we saw above, the more you invest in making the change, the greater the long-term benefits that are possible. .

One of the defining characteristics of a replatform compared to a rehosting is that a replatform will typically incur some significant changes to operational processes as a result of the change in platform. Typically, the impact is for backup and recovery, monitoring, patching, upgrading etc. In many cases the processes will be significantly improved (greater automation etc) and some operational processes may be eliminated altogether. However, while these changes are beneficial, they also require changes to roles, and may need staff retraining and organizational change.

Use Cases