Cloud Migration Strategies for On-Prem to Cloud

In this article will see what are the Cloud Migration Strategies. The Cloud Service provider considered in this article is AWS, but it can be any other Cloud Provider. Actual Migration as such requires a few pre-requisite activities, and the migration journey itself varies so vastly from client to client and project to project. Also, migration can be pretty complex eg. On-Prem to Cloud, Cross-Region or Availability Zone, Cross-Cloud, etc. So, we will be considering only On-Prem to Cloud and only a part of it. There are a number of factors like IT Strategy, Run Requirement, Application Portfolio, IT Delivery Model, etc. to be considered within this strategy OR you may follow AWS CAF (Cloud Adoption Framework), OR you may follow the AWS MAP (Migration Acceleration Program). The CAF framework provides all-encompassing guidelines for such migrations. But a more precise method to get started would be the AWS MAP (Migration Acceleration Program). But today we will be looking directly at implementing migration.

????? ‘What’ do we mean by Cloud Migration strategy?

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We define migration as the set of activities used to move existing workloads to the cloud - There are different ways to do this as follows - Retain, Retire, Repurchase, Relocate, and Rehost. A?Cloud Migration Strategy?is the high-level plan an organization adopts to move existing On-Prem and/or co-located application workloads and their associated data into the Cloud using one of the options from the 6R strategy to do so. Most plans include a public Cloud Migration strategy where the target is AWS, GCP, Azure, or any other Public Cloud provider. A successful enterprise Cloud Migration strategy will include prioritizing workloads for migration, determining the correct migration plan for each individual workload, ?testing, and adjusting the strategy based on the test results.

?But there is one caveat in the migration process - although most workloads will benefit from Cloud Migrations, not all workloads are suitable for migration. This we shall soon discuss. In any case, the desired final state is - a seamless transition of the applications from On-Prem to the desired Cloud infrastructure without impacting application services. But this all is easier said than done. Cloud Migration can end up being quite a journey depending on the complexity of existing infrastructure, the complexity of desired outcomes, OR any ongoing subscriptions, licenses, etc. OR many other factors.

One guideline to come up with a strategy is the AWS CAF (Cloud Adoption Framework) provided free by AWS. It is a very exhaustive framework, but we can pick and choose whichever guideline applies to our migration. Also, there is AWS MAP (Migration Acceleration Program) which provides services categorized into which phase they can be used. This reduces costs and automates and accelerates execution.

AWS offers a wide range of migration tools, guidance, services, and programs to help customers assess, migrate, and modernize applications and data from building the business case to leveraging AWS services to deliver new experiences.

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????? ‘Why’ do we use Cloud Migration strategies?

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Adopting a Cloud Migration strategy helps identify and execute the fastest, cheapest, least disruptive transition from On-Prem to Cloud. And, can help determine which existing application workloads can be discontinued or replaced, which should be rewritten, which may remain On-Prem as-is, which should be moved to Cloud as-is or targeted to be augmented with native Cloud services, and which Cloud is the right destination for which application.

Experts say that in the majority of Cloud infrastructures, the client opts for a multi-cloud environment; more than 85% of their customers have multi-cloud setups. This is because each Cloud Provider will have slightly varying pricing models for each service, and better infrastructure or hosting or locations which may be suited only to part of workloads and not all. An enterprise Cloud Migration strategy will include a combination of approaches to address the entire application portfolio.?Since every organization is different, an enterprise Cloud Migration strategy should be tailored exactly to their particular needs and to achieve the desired business and technical outcomes. This requires knowledge of the business goals and the application portfolio that can provide visibility into the TCO and ROI of undertaking a migration.

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????? ‘What’ are the benefits of Cloud Migration strategies for On-Prem?

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·?????? Cloud-compatible application – Enterprises end up having cloud-compatible applications and that means that now they can use cloud-specific features like auto-scaling, security, etc for their applications.?

·?????? Decreased hosting costs -?In the Cloud, you no longer have to worry about the costs and conditions of keeping physical servers running. A third-party data center manages the servers, often on a subscription-based model that cuts out capital expenditure.

·?????? Agility and scalability -?Operational agility is a top driver for Cloud adoption, according to Gartner. Cloud-based services not only automatically scale capacity to growing or fluctuating demand but also allow teams to collaborate on application updates or issues from anywhere instead of on-site. This level of continuity can give businesses a real competitive edge.

·?????? Decreased footprint -?Because server capacity scales up and down to fit your Cloud needs, you only use the energy and resources you need. You could potentially even reduce your pool of data centers to one or even zero for reduced environmental impact.

·?????? Disaster recovery -?This is important to businesses of all sizes, but it is historically expensive for smaller businesses. Today, the Cloud is helping more organizations implement backup and recovery solutions that take less time and upfront investment.

·?????? Security -?The Cloud offers greater security than On-Prem by storing your sensitive data and apps centrally by using cloud-native services. Most Cloud Providers also keep unwanted traffic from accessing your data by providing regular security updates, leaving you free from security threats, and free to take care of what matters to your business.

·?????? Application Availability - The Cloud Providers provide 9 9s availability guarantees of the instances hosted on your platform.

·?????? High-performance computing - High-performance computing, big data, ML, complex event processing, etc are difficult to set up and configure as they can depend on specific costly hardware. Cloud provides the option of pay-as-you-go, so organizations can test, develop, and experiment with these niche technologies. This enables clients to incorporate these niche services into their existing applications without shelling out huge amounts.

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????? How does a Cloud Migration strategy work?

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Your exact roadmap for migrating to the Cloud depends on the size and complexity of your environment. But the following are the recommended steps, at a high level we have 3 all encompassing steps - Assess, Mobilize, and Modernize :

·?????? Assessment -

?? At the start of your journey, you?assess?your organization’s current readiness for operating in the cloud. You need to?assess your On-Prem resources and build a right-sized and optimized cost projection for running applications in AWS. Before getting started, you should be clear on your reasons for the move and which strategy can best support them. Start by assessing your current environment. AWS provides solutions that can provide complete visibility into your environment and all its dependencies while finalizing a strategy as part of the package.

?? Services - Optimization and Licensing Assessment, Migration Evaluator, Application Discovery Service (as shown below).

·?????? Mobilize -

?? Planning your migration -?It is important to calculate your Cloud Server requirements based on current application resource requirements to avoid buying more than you need. At this critical stage, you will need the resources and expertise of a specialist.

?? Choosing your Cloud environment -?You need to decide on which Cloud Provider you need to go with and what kind of Cloud Model you want to adopt. Whether you choose public Cloud, Hybrid Cloud, Private Cloud, or multiCloud (or services like Google, Azure, or AWS) depends on which best serves your current and future needs.

?? Migrating your Apps and Data -?If planned accurately, your actual migration should be quite straightforward. Still, keep in mind Cloud Security concerns, such as complying with security policies and planning for Data Backup and Recovery. Also, be sure to use baseline pre-migration performance and different other parameters/outputs for later comparison in preparation for the actual migration.

?? Following Cloud Compliance?– We need To follow guidelines while moving workloads to the Cloud as regards security, PII, regional compliance, etc.

?? Validating post-move success -?You cannot declare a Cloud Migration successful without evidence that it is working as expected even after the migration. With a solution like AppDynamics Business iQ, you can prove the benefits of Cloud Migration by comparing pre-and post-move application performance and parameters, from both a technical and a business perspective, in a low-risk test environment.

?? Services - Application Migration Service, Migration Hub

·?????? Migrate & Modernize -

?? During the?migration phase each application is designed, migrated, and validated.?Whereas in modernize phase the applications are already running and are converted to native applications.

?? Services - Migration Hub, Application Migration Service, Database Migration Service, AWS Managed Services?

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????? What are the types of Cloud Migration strategies?

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1.?????? Retain

2.?????? Retire

3.?????? Repurchase (Drop and Shop)

4.?????? Rehost (Lift and shift)

5.?????? Replatform (Lift, Tinker, Shift)

6.?????? Refactor (Re-architect)

Let's see each one a bit in detail:

1.?????? Retain - Retain is not truly a migration but it still is a part of the migration activity. It simply means to retain certain identified applications on its existing On-Prem infrastructure.

???????????? i.????? This happens so if there is still a strong ongoing investment in the On-Prem infrastructure and license subscriptions, etc.,

?????????????ii.????? or if a critical application is running on legacy mainframe or minicomputer platforms, the organization may wish to keep those productive applications right where they are, and instead use APIs to integrate with the remaining Cloud-based counterparts.

????????????iii.????? Additionally, there might be compliance factors that might come into play such that you are unable to take the data off-premises for compliance reasons.

??????????? iv.????? Or perhaps the organization is not yet ready to prioritize an app that was recently upgraded, etc.

In all of these scenarios, you should plan to revisit Cloud computing at a later date. You should only migrate what makes sense for your business. This results in a hybrid Cloud Migration strategy with workloads divided between the public and private Clouds.

2.?????? Retire - Over a period of time, applications become obsolete, whether due to redundancy or the availability of better options in a Cloud-based offering. In such scenarios these applications are altogether dropped from the migration process and not considered for any movement to the Cloud.

3.?????? Repurchase (Drop and Shop) - In this strategy, we decommission the existing applications and replace it with a Cloud-based version from the Cloud provider’s marketplace – Effectively, this is a licensing change - instead of using a traditional On-Prem license, you start using the same application as a Cloud service. This approach is often utilized for older On-Prem ERP, CRM, finance, etc which have equivalent functionality either in an app marketplace or as a SaaS application. This is also a good choice for legacy applications not easily virtualized or migrated in other ways. This is a smaller effort than “lift and shift” (see below) because you are not moving anything - just starting a new license agreement in the Cloud.

4.?????? Rehost (Lift and shift) - This is a strategy of rehosting applications to the Cloud without making any changes to the On-Prem application. One can use the “AWS Server Migration Service”, “Application Migration Service”, “Database Migration Service” and/or integrated services in the “AWS Migration Hub” for Discovery, etc., then containerize the application and then migrate it to AWS.

5.?????? Replatform (Lift, Tinker, Shift) - This strategy modifies or replaces certain components to better take advantage of the Cloud provider’s features, for example switching to managed services or replacing commercial off-the-shelf software with an open-source equivalent, etc.

6.?????? Refactor?(Re-architect) - This approach entails an entire re-architecting of an application to take advantage of unique Cloud provider features. When Cloud-native features are required or the agility and scalability of micro-services-based applications call for it, these applications are typically broken up into smaller pieces or services and often deployed in a containerized environment on one or more public Clouds. Although this is the most expensive approach to migration, the resulting benefits can far exceed the potential risks. Over time, many applications that were migrated with another strategy may become refactored as the increased benefits of Cloud-native applications are required.

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????? Other Activities during Cloud Migration

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·?????? Define goals - Obviously, we need to be clear about what we want to achieve out of this activity, so our effort will be focused towards the end goal.

·?????? Measurement - We need to measure how much effort is needed, what the sizing of the servers requires, how much will be saved, and when is the break-even point of this activity, etc so as to fully appreciate the benefits the cloud will provide us.

·?????? Cold Migration - In the cold migration strategy workload is stopped, moved over to your Cloud, and then restarted there. This option may work well for your non-production workloads where you can simply turn it off with minimal business impact (e.g. development or test workloads).

·?????? Live Migration - It means moving a live running VM between your On-Prem environment and your Cloud.

·?????? Reprovision?from scratch - While this might not technically be considered a migration, it may be an option for some of your workloads. Instead of moving them, it might be possible to spin them up as new workloads in the Cloud instead. Simply bring them up as new in the Cloud and turn the old ones off in your On-Prem environment.

·?????? Create Security Strategy - Cloud providers have a shared responsibility model, which means that they provide a lot of security services, but we need to incorporate them into our workloads, architecture, etc so that our application can become robust.

·?????? Creating insights into on-cloud workloads - Once you moved your workloads to the Cloud you need to enable insights by using the Cloud services so we get the exact cause of any workload failure on the first incident itself. This helps in a major way in validating our freshly moved resources.

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????? Principal factors in the Cloud Migration Journey

1.?????? Security - The Cloud offers a shared responsibility model and workloads should be secured using a zero-trust approach by utilizing stateless transactions where possible.

2.?????? Governance & Compliance - Regulations vary widely by geography and industry. Cloud providers can offer physically secure storage of an organization’s data, but the Cloud customer must ensure that regulatory mandates are complied with for things such as retention and privacy of data.

3.?????? Cost Management - Each organization is responsible for ensuring that unused accounts, workloads, and data are deprovisioned, and that applications do not replicate needlessly creating VM sprawl or container sprawl across the Cloud.

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????? Risks in undertaking a Cloud Migration engagement

Cloud infrastructure has been universally adopted because of all the advantages that the Cloud has to offer as discussed earlier. However, the migration process itself comes with risks. Some of the most common issues that organizations face during their Cloud Migration include the following:

1.?????? Not having a Cloud Migration strategy - One of the biggest risks of Cloud Migration is attempting to make the move without a clear, detailed Cloud Migration strategy. When making the move to the Cloud, an organization must make several important decisions surrounding:

o?? IT Asset Distribution: Different data and applications are best suited to being hosted On-Prem or in public or private Cloud environments. Most organizations select a hybrid Cloud model and distribute their assets across private and public Clouds and on-site infrastructure. A Cloud Migration strategy should include a breakdown of the assets that should be hosted in each environment.

o?? Cloud Platform(s) to Use: Several Cloud providers exist and each offers many different options, all of which are designed and optimized for different purposes. Before making the move to the Cloud, an organization should identify the platform(s) best suited to its use cases.

o?? Application Deployment Model: The Cloud provides new application deployment options, such as serverless applications and containers. When preparing to migrate to the Cloud, an organization needs to decide whether it will “lift and shift” applications designed for On-Prem environments to the Cloud or re-architect applications to take full advantage of the benefits of the Cloud.

Not making these and other important decisions in advance can increase the cost, duration, and complexity of a cloud migration process. Also, making the wrong decisions can create significant security risks, such as storing or processing sensitive information in a public cloud environment.

o· Mitigation - Make a clear plan as regards IT Asset Distribution, the Cloud Platform(s) to Use, and Application Deployment Models.

2.?????? Complex existing architecture - In an On-Prem environment, complex architectures are workable. Intra-site network latency is relatively low, so an organization can support a complex array of databases and applications without significant performance impacts. When moving to the cloud, a complex existing infrastructure can put the success of the cloud migration at risk. Some of the potential impacts include:

o?? Extended Migration Process: If an organization’s On-Prem architecture is complex, developing and implementing a migration strategy will be a complex process. Organizations will have to develop a strategy for migrating their IT resources to the cloud without negatively impacting performance or security.

o?? Reduced Performance: If an organization’s infrastructure is distributed between On-Prem architecture and multiple cloud environments, then latency is much higher than in an On-Prem environment. As a result, complex architectures with significant interconnectivity between assets hosted in different locations will suffer degraded performance when moving to the cloud.

Cloud infrastructure offers new architectural options, such as serverless applications. If an organization has a complex architecture, cloud migration provides an opportunity to re-design and re-architect an organization’s complex infrastructure.

o·?Mitigation - The solution here is to audit the infrastructure that you have thoroughly and assess which parts of the architecture are interdependent and which ones make economically no sense to move to the cloud. The part of the legacy system that is impossible or economically impractical to migrate will remain as it is, while everything that can be taken to the cloud is moved. This reduces our scope and thereby complexity

3.?????? Selecting the wrong Cloud service provider (CSP) - Different CSPs have offerings with different features and strengths. For example, organizations looking for a general-purpose cloud might choose AWS, those that use LDAP and Active Directory may benefit from Azure’s built-in integration with these systems, Oracle Cloud specializes in databases and data management, and Google Cloud Platform (GCP) has strong data analytics capabilities.

The “right” cloud for an organization depends on its unique use cases. If an organization chooses a CSP that does not align with its intended uses, then it might not be able to extract the full value from its cloud migration and may face significant performance issues or a complex migration while trying to implement its required functionality in a non-ideal environment. Trying to fix these issues by migrating from one CSP to another can result in additional expenses and overhead.

When planning a cloud migration, an organization should thoroughly research the available options and ensure that their chosen cloud provider implements their required functionality and can support any necessary third-party solutions. Many organizations choose a multi-cloud infrastructure that provides optimal environments for various resources and use cases.

4.?????? Long Migration Process - Many organizations’ IT environments have grown up over several years within an On-Prem environment. Applications and infrastructure designed for On-Prem deployment do not always translate well to a cloud environment.

As a result, an organization’s cloud migration process may be extended as it works to re-architect systems and applications for cloud environments. In general, a cloud migration can take a year or more.

Some impacts of an extended cloud migration include:

o?? Productivity Losses: As companies move through the cloud migration process, their IT infrastructure will pass through intermediate states as some resources are migrated to the cloud while others are still waiting for their turns. Since these intermediate states are unlikely to be optimized, an organization can suffer significant losses to performance and productivity that can hurt it and its customers.

o?? Security Risks: In addition to potential productivity impacts, an organization’s move through intermediate states of cloud migration may carry security risks as well. If security policies and solutions are not updated in sync with cloud migration, corporate data and applications may be exposed to attack.

o?? Resource Utilization: Cloud migration consumes a great deal of time and other resources. An inefficient cloud migration strategy may waste resources, increasing the cost to the business.

An extended migration process can hurt an organization and its customers. Before beginning the migration, a company should carefully consider its migration strategy and attempt to optimize performance and security throughout the entire migration process.

5.?????? Data Breach - Throughout the cloud migration process, an organization must ensure that data and applications are secure. While a company may have a pre-migration and post-migration security strategy, this is not enough to protect its resources.

The organization will transition through numerous intermediate states as data and applications move to the cloud. If an organization’s security strategy does not adapt to provide adequate protection at each of these intermediate steps, then attackers may be able to steal data or exploit applications while the organization is in a vulnerable state.

A corporate cloud migration strategy must incorporate a migration security strategy. This includes plans for ensuring that corporate data and applications are appropriately protected at every stage of the migration process.

6.?????? Unexpected Cloud Costs - Making the move to the cloud can dramatically decrease an organization’s infrastructure costs. By outsourcing the management of an organization’s underlying infrastructure to a third-party provider, an organization can take advantage of the cost savings of its CSP’s optimizations and economy of scale.

However, an organization can only take full advantage of the cost savings of the cloud if its IT infrastructure is designed for the cloud. If an organization “lifts and shifts” legacy applications to cloud environments or purchases oversized service packages, then the cost of the cloud may exceed the cost of hosting the same infrastructure On-Prem.

Additionally, “as a service” infrastructure means that an organization pays for what it uses. It is often difficult and complicated to monitor ongoing cloud costs, so cloud costs often spiral out of expectation, until the monthly bill arrives.

Cloud migration can be a tradeoff between short-term costs and long-term benefits. Designing and optimizing architecture and applications for cloud environments can reduce overhead and costs in the long term.

o Mitigation - To make sure that you are paying for the services your business needs and uses, employ professionals who will control you and not overspend. Another sensible move is having?a cloud readiness assessment?checklist that among many things would include a detailed budget estimation.