blueprints/doc/source/caf/plan/cloud-migration-plan-and-implementation.rst
Kyriakos Akriotis 8f13cc9a18 - CAF draft
2023-11-23 16:56:19 +01:00

118 lines
4.6 KiB
ReStructuredText

Cloud Migration Plan and Implementation
=======================================
Cloud migration is planned and implemented based on the infrastructure,
technical platform and key applications on the live network, along with
the cloud migration scope and key capability objectives specified in the
migration blueprint.
Our experts have summarized the following four steps based on its experience
in cloud migration:
- **Step 1**: Apps improving external user experience
- **Step 2**: Apps improving workplace productivity
- **Step 3**: IT apps supporting enterprise core business processes
- **Step 4**: Apps supporting innovation in business and product forms
|
.. image:: ../../assets/caf/image11_1.png
|
Cloud migration strategies
**************************
- **Retire**: Back up and decommission application systems that are no
longer used to reduce resource waste.
- **Retain**: Retain applications deemed unnecessary or unsuitable for
cloud migration off the cloud due to resource costs, application
lifecycles, or enterprise service policies. However, communication
and data integration with other applications on the cloud are often
required.
- **Rehost**: Directly migrate applications to the cloud without changing
the application running environment. The common migration operations
are Physical to Virtual (P2V) and Virtual to Virtual (V2V).
- **Replatform**: Replace the cloud-based PaaS platform, such as middleware
and database, used by on-premises applications without changing the
core application architecture. This lowers platform technical
resource investment required, makes management less expensive, and
enhances efficiency.
- **Rearchitect**: Change the application architecture and development mode
to build cloud-native capabilities. For example, monolithic
applications are broken down into microservices. This strategy is
used to support the long-term development of enterprise services on
the cloud when existing applications cannot support subsequent
function, performance, and scalability requirements.
- **Repurchase**: Decommission legacy applications and replace them with
new ones, such as newly developed SaaS applications or third-party
SaaS services.
|
.. image:: ../../assets/caf/image12_2.png
Cloud migration approach
************************
Before determining the cloud migration approach, prioritize applications
based on the following factors:
- **Value and urgency**: For example, applications that have high
requirements on elastic scaling and agility iteration in Internet
services are of high value. If application servers are about to reach
End of Life (EOL) or require cloud-based DR capabilities, cloud
migration is urgent.
- **Risk or service impact**: Low-latency applications (such as
manufacturing applications) and core financial systems requires high
performance, availability and data security control. Cloud migration
has great impact on these services.
- **Difficulty or service complexity of technical solutions**: If
applications are not decoupled by layer and are complex with high
dependency on peripheral equipment, the migration solution is
difficult.
The following principles, which have been identified based on Open Telekom
Cloud's robust experience with system migration and application
reconstruction, can help ensure a smooth migration:
- **Determine the migration sequence**: Evaluate the complexity and
importance of applications. Preferentially migrate applications with
high value, low migration impact, and low complexity.
- **Migrating from edge to core**: Separately migrate services of different
types, such as test services, office services, production services,
and billing services. Start your migration with supporting
applications and then move on to core applications.
- **Independent applications first**: Migrate simple applications with few
peripheral dependencies first.
- **Integrity of application migration**: Ensure the integrity of the
migration scope, objects, and process. Make sure that services are
running properly after migration.
- **Minimal impacts**: Consider all possible impacts of cloud migration on
the running of the destination systems and take necessary measures to
minimize risks.
Pilot project
*************
Select applications that are easy to migrate to the cloud, which has
strong driving force and great value for pilot projects to achieve quick
wins. During migration practice, build organizations, streamline
processes, build capabilities, and eliminate risks.
.. toctree::
:maxdepth: 1