Key pillars of successful application migration to the cloud

No matter what business you are in, cloud migration can be a daunting proposition. From choosing the right service provider to deciding a hosting strategy and selecting pricing models, there are many high-stake decisions involved. However, with proper planning, you can navigate these complexities and execute cloud transformation within your stipulated timeframe and budget.

This blog explores the core pillars of a seamless cloud transformation and outlines our journey of helping a top global DNS provider successfully migrate mission-critical applications to the cloud. The customer wanted to upgrade their existing data platform as it offered limited scalability and availability. They were looking for a highly available, scalable, secure, enterprise-grade solution capable of handling rapid business growth. Here is a deeper dive into the factors we took into consideration across the project lifecycle – from pre-migration to post migration.

1. Prerequisites and readiness

To meet the customer’s business needs, we rearchitected their platform into smaller microservices on the cloud. Assessing their applications’ footprints and the associated data helped accelerate the transformation process and avoid risks like SLA violation, security breaches, non-functional issues related to performance, cost, etc. Some important considerations to ensure readiness while rearchitecting are:

  • Team mentoring

    Ensured alignment of key stakeholders across functions (IT, finance, engineering, management, etc.) and provided relevant, quality training in cloud technologies to all team members

  • Security and compliance

    Assessed the geographical footprint and compliance requirements of the business to evaluate the security risks of moving application data to the cloud

  • Application assessment

    • Mapped applications with third-party dependencies including databases, data transfer rate, and size
    • Defined the build, release, and deployment topology of all applications
    • Used a test regression suite with sufficient coverage to validate the functional behavior of applications
    • Prepared a sanity suite to validate the successful deployment of applications in the new environment

  • ROI

    Calculated application hardware, network, and licensing costs factoring in operational and maintenance efforts

  • Operational and capacity assessment

    • Established robust alerting and monitoring processes for all applications
    • Proactively monitored services statistics and utilization metrics
    • Ensured continuous integration and automated deployment are in place for all applications
    • Created a detailed application runbook
    • Assessed key business metrics like SLA response time, application/data availability, acceptable downtime, etc.
    • Assessed application usage metrics including the number of concurrent users, the geographical location of users, and the most frequently used applications
    • Chose right-sized resources with auto-scaling capabilities according to service usage
    • Planned for future growth by ensuring adequate capacity to meet growing business needs in the coming years

This approach helped to create a robust blueprint for the transition, minimize potential risks, and ensure enterprise-readiness for the migration.

2. Hosting strategy and service provider analysis

Choosing the right type of architecture is a critical decision for any cloud migration. While both cloud-native and cloud-agnostic architectures have their merits, the latter gives enterprises flexibility to run applications on any cloud platform. Depending on your specific business needs, you can also choose between public, private, hybrid, or multi-cloud hosting strategies.

Based on these choices, you can evaluate leading cloud providers like AWS, Google, and Microsoft across parameters like cost, SLAs, scalability, availability, geographic coverage, security compliance, customer support, operational maintenance, and application migration tools they offer.

A hybrid cloud hosting strategy was chosen to meet the DNS provider’s requirements of low latency, custom route announcements, and compliance. Certain core services were hosted in a private cloud, while the remaining services were hosted on public/private cloud in AWS.

3. Application and data migration approach

Enterprises need to keep the design and architecture of their applications in mind while creating a migration blueprint. Here’s where we refer to Gartner’s 5R migration strategy – rehost, refactor, revise, rebuild, and replace. In simple terms, this means identifying which of your applications can be easily lifted and shifted to the cloud and which ones need to be rearchitected or replaced.

For the DNS service provider, we adopted the following approach:

  • Migrated simple applications with the least dependencies in the initial phase, and business-critical applications with higher dependencies in later phases
  • Initially lifted and shifted services, database, and workloads to the cloud and leveraged AWS’s extensive offerings to rearchitect/refactor services effectively
  • Refactored certain services to eliminate single points of failure and made them stateless with loose coupling
  • Avoided database as a point of integration and rearchitected to microservices for improving scalability and time-to-market
  • Rebuilt and replaced existing services with cloud-native services to realize capacity, availability, cost, and speed benefits
  • Drafted a detailed rollback strategy in case of failures
  • Identified an appropriate migration window to minimize business disruption
  • Set up internal and external monitoring systems to continuously check application health
  • Set up auto-scaling of resources as per usage to optimize utilization
  • Set up policies for periodically rotating applications, database passwords, and access keys to ensure airtight security
  • Avoided exposing any sensitive information on and performed additional security checks before exposing anything to the internet
  • Ensured redundancy of services and set up data backup policies for all business-critical information
  • Used private IPs for communication within the cloud to avoid internet traffic that would increase cost and network latency
  • Set up auto-recovery policies for critical infrastructure on the cloud to ensure business continuity in case of hardware failure

This approach helped us create a robust migration plan backed by effective disaster management and security strategies to help the client minimize risks and ensure business continuity.

4. Data and workload migration strategy

The location of an enterprise’s database plays a critical role during application migration. If your database is still on-premise, moving your application to the cloud can adversely affect performance. Setting up a new database on the cloud will enable your applications to connect directly to the cloud database. You can also set up replication between the on-premise and cloud databases to ensure up to date synchronization. Once you’ve moved your applications and workloads to the cloud successfully, you can decommission the on-premise database.

This strategy helped the customer minimize data transfer costs and deliver a high performing solution. Their storage space was increased and the database was vertically scalable post migrating to AWS.

5. Validation of migrated workloads

The success of application migration heavily relies on validating migrated workloads in the new environment. For the DNS provider, a wide variety of metrics was created to track non-functional business requirements like availability, reliability, and capacity. A single-click deployment model was used along with blue-green deployment techniques to avoid downtime. Application migration was validated on functional parity, performance, SLAs, alerting and monitoring, security, and compliance, providing complete assurance to the client.

This is just one example of how Impetus manages complex, large-scale cloud transformation projects and helps enterprises automatically migrate mission-critical workloads to the cloud. To learn more about how we can help you achieve your digital transformation goals with zero business disruption, contact us today.

Pushpendra Garg
Technical Architect, Enterprise Solutions