Infrastructure mapping
Define target compute, storage, and network profiles with explicit compatibility checks.
Optimize Rehost Spring Boot with Observability and VM Rightsizing
STACKIT
Understanding Rehost
Section titled “Understanding Rehost”Rehost (lift-and-shift) migrates workloads with minimal application change. It is primarily a run strategy to reduce transition risk and accelerate migration throughput.
In practical terms, Rehost is application-wave oriented: each workload gets a defined target runtime mapping, cutover path, and runbook package for repeatable factory delivery.
Rehost compared to Relocate in STACKIT
Section titled “Rehost compared to Relocate in STACKIT”Relocate and Rehost are often used interchangeably, but in this framework they are separated on purpose.
- Rehost in STACKIT: Application-level lift-and-shift with explicit target runtime mapping, cutover, rollback, and runbook standardization.
- Relocate in STACKIT: Estate-level move of existing virtualization patterns with minimal reshaping of workload runtime behavior.
- When to prefer Rehost: When migration waves require repeatable runbooks and stable run operations at scale across many applications.
- When to prefer Relocate: When urgent movement of VM estates is the primary goal and modernization is deferred by design.
When Rehost is a good fit
Section titled “When Rehost is a good fit”- Strict migration timeline with limited engineering capacity for redesign.
- Legacy workloads that are difficult to refactor in the current program phase.
- Business stability priority where functional behavior must remain largely unchanged.
- Factory scale objective where repeatable migration procedures are required across many systems.
Design considerations in STACKIT context
Section titled “Design considerations in STACKIT context”Data and cutover path
Design transfer windows, consistency checks, and rollback triggers.
Stateful workload handling
Separate application artifact rollout from database migration sequencing to reduce cutover risk.
Security and compliance
Map identity controls, encryption requirements, and evidence checkpoints.
Operational handover
Ensure runbooks cover Day-1 operations and incident workflows after migration.
Recommended design flow
Section titled “Recommended design flow”- Baseline current runtime dependencies and non-functional requirements.
- Define target runtime mapping and migration sequence.
- Design data movement and cutover orchestration.
- Validate runbook quality with dry-run checkpoints.
- Approve production migration with release and business sign-off.
Data migration path in Rehost
Section titled “Data migration path in Rehost”In Rehost scenarios, the data migration path depends on whether the workload is stateless or stateful:
- Stateless workloads: Focus on application deployment and configuration.
- Stateful workloads: Require a coordinated data movement strategy alongside the application migration.
For stateful migration waves, split the path into two streams:
- Infrastructure and application stream: Provision the target environment, deploy the application, and prepare the target data store.
- Data stream: Export source data, transfer to the target, restore, and validate.
Suggested data sequence
Section titled “Suggested data sequence”- Export data from the source system using platform-native or tool-specific methods.
- Transfer data to the target environment or intermediate staging area.
- Configure the target environment to ingest the migrated data.
- Run the restoration process and verify data integrity.
- Validate application connectivity and functional behavior before final cutover.
Required outputs
Section titled “Required outputs”Shared outputs across all migration paths
Section titled “Shared outputs across all migration paths”- Approved design decision record with scope, assumptions, and governance sign-off.
- Validation evidence package for security, compliance, and operational readiness.
- Strategy-specific migration runbook draft from the Design phase.
- Handover package for Migration Factory Setup and wave planning.
Rehost-specific outputs
Section titled “Rehost-specific outputs”- Rehost decision rationale and constraints.
- Target runtime mapping.
- Data movement and cutover plan.
- Runbook with validation and rollback checkpoints.
- Post-wave stabilization checklist.
Diagram step reference
Section titled “Diagram step reference”Define landing zone
Section titled “Define landing zone”Define landing zone requirements and controls as the start point for Rehost run. Clarify network, identity, backup, and monitoring prerequisites before migration sequencing is approved so Rehost waves can run with predictable operations quality.
Use migration tools
Section titled “Use migration tools”Define the automated Rehost path used for repeatable wave throughput. In the automated Rehost path, infrastructure and application setup are provisioned as code so wave delivery stays repeatable and auditable.
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Provision VM target with IaC: Create networks, security groups, compute instances, and base storage through Terraform or OpenTofu.
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Install and configure application with automation: Use Ansible playbooks for package install, service setup, and baseline configuration.
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Apply environment-specific parameters: Inject target variables, secrets references, and endpoint mappings in a controlled automation run.
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Run automated validation and cutover gates: Execute health checks, migration pre-checks, rollback checkpoints, and release approvals before live switch.
- Runbook Blueprint
- Migration Plan
Asset title
Framework
Asset type
Migration
Runbook
Migration
Runbook
Migration
Blueprint
Migration
Runbook
Migration
Blueprint
Migration
Runbook
Migration
Guide
The runbook asset documents the PostgreSQL flags and the optional dump-based data restore path.
Install
Section titled “Install”Describe manual installation steps for exception workloads.
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Create and prepare target VM manually: Provision the VM through Portal or CLI, attach required storage, and apply OS hardening and patch baseline.
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Install runtime and dependencies manually: Install required runtime packages, system libraries, and service users/groups according to product installation guidance.
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Install application in the classic way: Perform guided installation steps (for example installer or setup wizard flow) to reproduce the source deployment model on the target VM.
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Validate base install readiness: Confirm service startup, file permissions, required ports, DNS reachability, and outbound connectivity.
- Cloud Design Patterns
- Runbook Blueprint
Config
Section titled “Config”Define manual runtime configuration and controls.
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Mirror source configuration for target context: Recreate application settings from the source environment and adapt them to target endpoints, DNS, certificates, and service integrations.
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Apply security and access settings: Configure service credentials, secret handling, and least-privilege access for target operation.
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Align operational defaults: Configure logging targets, metrics exporters, backup schedules, and retention baselines.
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Validate configuration parity: Run smoke checks to confirm the target instance behaves as a functional equivalent of the source baseline.
- Runbook Blueprint
Deploy
Section titled “Deploy”Define manual deployment sequencing and release checks.
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Plan final migration window: Align freeze windows, communication checkpoints, and rollback authority for production switch.
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Run final data migration: Execute last data sync or restore steps and confirm consistency checks before go-live.
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Activate production traffic: Perform controlled live switch to the target environment and verify critical user and integration paths.
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Confirm handover readiness: Record evidence, close open risks, and transfer ownership for Day-1 operations.
- Migration Plan
- Runbook Blueprint