Oracle Cloud Infrastructure 2025 Migration Architect Professional Advanced Practice Exam: Hard Questions 2025

A regulated enterprise is migrating a portfolio of 60 applications from an on-premises data center to OCI. The portfolio includes: (1) a 3-tier web app with predictable traffic, (2) a legacy client-server app tightly coupled to a specific OS version, (3) a data warehouse with nightly ETL and heavy I/O, and (4) multiple small internal apps with unknown owners. The CIO mandates: minimize downtime, meet strict data residency, and reduce operational risk by standardizing patterns. Which migration strategy and planning approach best meets these constraints?

During discovery, you identify that several on-prem applications rely on hard-coded IP allowlists from third-party SaaS providers and require consistent egress IPs after migration. The security team also requires inspection of all outbound traffic and centralized control of internet access. Which planning decision best addresses these requirements on OCI while keeping the design scalable across multiple VCNs and compartments?

A customer plans to migrate an on-prem Oracle database used by multiple applications with strict RPO near-zero and RTO under 30 minutes. The applications will be split across two OCI regions for disaster recovery. The customer also requires that application cutover occurs with minimal application downtime and without changing application connection strings. Which architecture best satisfies these requirements?

You are designing the target OCI landing zone for a multi-account enterprise moving from a heavily segmented on-prem network. Requirements include: centralized security controls, separate environments (dev/test/prod), least-privilege access, and the ability for multiple teams to deploy resources independently without accidentally impacting shared network/security services. Which OCI architecture best meets these requirements?

A legacy application uses multicast and relies on layer-2 adjacency between servers. The application cannot be modified in the short term. The migration goal is to move as much as possible to OCI while avoiding an extended dual-run period. Which design decision is most appropriate?

A migration team is moving a mission-critical N-tier application. The on-prem database is 20 TB. The initial plan uses an offline transfer: export, ship, import. During rehearsals, the import into the target database takes much longer than the allowable downtime window. The team wants to keep the same target database engine and minimize application change. What is the best adjustment to the migration approach?

You migrated a set of applications to OCI. Users report intermittent timeouts to an internal API hosted on private subnets. The API is fronted by an OCI Load Balancer, and clients are in multiple spoke VCNs connected via DRG. Health checks show backends are healthy. Packet captures show SYN packets reaching the backends, but some SYN-ACK responses never reach the clients. Which troubleshooting action is most likely to resolve the issue?

A team is migrating hundreds of VMs using an automated pipeline. After cutover, about 10% of VMs fail to boot in OCI with errors related to missing drivers and incorrect network interface naming. The source environment is heterogeneous and includes older operating systems. What is the most effective mitigation to improve success rate while maintaining automation at scale?

After migrating to OCI, an analytics workload experiences sporadic performance degradation. The team notices that the compute instances show low CPU utilization, but storage latency spikes during the same periods. The workload uses attached block volumes and runs parallel queries with high random read I/O. Which post-migration optimization is most appropriate?

A company has completed a phased migration to OCI. They now operate hybrid connectivity to on-prem and have implemented centralized logging. Security discovers that several migrated instances are still using overly permissive security list rules and lack consistent patch compliance. Operations wants to enforce guardrails without breaking production workloads and with auditable change control. Which approach best addresses this?