S90.09 Free Sample Questions

A financial services company is modernizing its legacy SOA, which is built around a central Enterprise Service Bus (ESB) for orchestration, transformation, and routing of SOAP/XML messages between monolithic applications. The new architecture will introduce RESTful microservices running in containers. A key requirement is to expose a subset of both new and legacy services to external mobile applications via a secure, managed API. The company wants to improve agility and reduce the bottleneck caused by the central ESB team. Which architectural approach provides the most effective long-term solution for managing both internal service-to-service communication and external API exposure?

A development team is decomposing a monolithic order processing system into microservices. They have created an `Order` service and a `Shipment` service. When a new order is successfully processed, the `Order` service needs to trigger the creation of a shipment. The lead architect has mandated that the system must be resilient to transient failures of the `Shipment` service and that the `Order` service should not be blocked or fail if the `Shipment` service is temporarily unavailable. Which two design patterns should be implemented to meet these requirements? (Select TWO)

An architect is designing a security model for a microservices-based application deployed in Kubernetes. The requirements are to enforce strong identity for every service, encrypt all service-to-service (east-west) traffic, and apply fine-grained access policies specifying which services can communicate with each other. Manual configuration of certificates for each service is not feasible due to the dynamic nature of the environment. Which technology is best suited to meet all these requirements?

**Case Study:** A large e-commerce company, `ShopSphere`, is re-architecting its monolithic backend into a cloud-native microservices platform on Kubernetes to handle massive seasonal traffic spikes. The current system suffers from tight coupling, making independent deployments impossible and scaling inefficient. **Current Architecture & Problems:** - A single, large Java application handles Products, Inventory, Orders, and Payments. - All teams deploy on a fixed, quarterly schedule. - The entire application must be scaled horizontally, even if only the Payments module is under heavy load. - A failure in the Inventory component can bring down the entire checkout process. **Business & Technical Requirements:** 1. **Independent Deployability:** The Product, Inventory, Order, and Payment services must be developed, tested, and deployed independently. 2. **Elastic Scalability:** Each service must scale independently based on its specific load. 3. **High Availability:** The failure of a non-critical service (e.g., a recommendation engine) must not impact the core user journey of placing an order. 4. **Data Consistency:** An order should only be confirmed if payment is successful and inventory is successfully reserved. This cross-service transaction must be managed reliably. 5. **Observability:** A unified view of logs, metrics, and traces is required for troubleshooting distributed transactions. Which of the following proposed architectures best satisfies all of ShopSphere's requirements?

True or False: In a contract-first approach to service design, the WSDL or OpenAPI specification is generated automatically from the service implementation code.

A DevOps team is building a CI/CD pipeline for a microservice. A key goal is to ensure that any code change passes a series of automated quality gates before it can be deployed to production. The pipeline must support rapid feedback to developers and prevent buggy code from reaching users. The following diagram shows a proposed pipeline structure. Which stage is missing that is critical for enabling a zero-downtime deployment strategy and immediate rollback capability? ```mermaid flowchart LR A[Commit Code] --> B{Build & Unit Test} B --> C{Static Code Analysis} C --> D[Integration Test] D --> E[Deploy to Staging] E --> F{User Acceptance Test} F --> G[Deploy to Production] ```

When designing a new, agnostic utility service for currency conversion, an architect must decide on a versioning strategy. The service will be used by many independent consumer applications across the enterprise. The primary goal is to allow the service to evolve without breaking existing consumers. Which versioning approach best supports this goal?

A cloud architect is deciding between using a container orchestration platform like Kubernetes or a Serverless/FaaS platform like AWS Lambda for a new event-processing service. The service will process uploaded images to extract metadata. The workload is expected to be very spiky, with long idle periods followed by sudden bursts of thousands of concurrent requests. Cost optimization for idle time is a major priority. Which platform is the better choice and why?

An operations team is struggling to troubleshoot performance issues in a distributed microservices environment. When a user reports a slow API call, it's difficult to identify which downstream service is the bottleneck because logs from each service are stored in separate files on different virtual machines. What combination of practices is essential for establishing effective observability in this environment? (Select ALL that apply)

A team is designing a service that aggregates data from two other services, Service A (product details) and Service B (inventory levels), to provide a complete view for a web storefront. Service A has a 99.5% availability SLA, and Service B has a 99.0% availability SLA. Assuming the services fail independently, what is the maximum theoretical availability of the new aggregator service if it relies on synchronous calls to both services to fulfill a single request?