To start with, migrating your business applications to cloud can be looked upon in the following three ways:
At the outset, it is very important to remember that there should be clear and compelling business reasons for cloud migration; otherwise, the efforts and costs incurred might not deliver the desired results. Not all workloads are candidates for cloud migration.
Various methods like manual and automated data collection tools and conducting requirement workshops with stakeholders are employed to obtain the data for analysis.
Some of the most frequently asked questions are as follows:
The outcome of this phase is generally identification of workloads (web serving, web applications, business intelligence and data warehouse, ERP and SCM, analytics) suitable to be hosted in a given cloud environment, the costs involved and the migration impact.
This step involves detailed planning and design of the target environment (memory, processor, disk storage). It includes taking key architectural decisions and hardware sizing after studying the software stacks and patterns of utilization. The criteria considered include: application criticality, availability / downtime tolerance and business constraints.
Depending upon the types of workload and target cloud environment being considered, there are essentially three scenarios for implementing the actual migration:
It is the easiest and most cost-effective way to migrate workloads from a non-cloud environment to a cloud environment. It usually takes place for like-for-like environments and involves Physical-to-Virtual or Virtual-to-Virtual movements with the same OS in the source and target. In this technique, all applications running in physical servers (or in a virtual machine) are packaged into an image and added to the cloud catalogue and instantiated into a virtual machine on the cloud platform. Technologies such as VMWare Converter and Platespin are used to perform such a migration.
The essential mechanism by which this works is decoupling the application from its OS and encapsulating it along with its dependencies, configuration / registry files, services and runtime libraries into a ‘Virtual Application Appliance’.
Once the customer’s existing instances have been migrated to the target cloud platform, these instances go through an adjustment stage for configuration to the target cloud environment’s architecture standards. Some of these include applying any operating system-level security patches, security policy or regulatory requirements and IP address changes.
This is the final phase where it is confirmed that the migrated workload is performing operating as expected and the cloud platform has now become the production environment for the migrated workload. The old source servers and images are usually decommissioned or re-purposed after a predefined period of monitoring.