1z0-1084-23 Practice Exam Questions with Answers Oracle Cloud Infrastructure 2023 Developer Professional Certification

Explanation

The correct answer is: "Tightly coupled." Tightly coupling is not a criterion that is usually met by a microservice. In fact, microservices are designed to be loosely coupled. Loosely coupling refers to reducing dependencies and minimizing the direct interactions between different components or services. Microservices promote independence and autonomy, allowing each service to operate independently without being tightly bound to other services. The other options listed are criteria that are typically met by microservices: Organized around business capabilities: Microservices architecture suggests designing services around specific business capabilities or functionalities. This allows for focused and specialized services that align with the organization's business needs. Independently deployable: Microservices are designed to be independently deployable units. Each microservice can be developed, tested, and deployed separately, without impacting other services. This enables agility and scalability in the deployment process. Highly maintainable: Microservices are often designed to be highly maintainable. They are smaller in scope and focused on specific tasks, making it easier to manage and maintain individual services. Additionally, microservices can be updated, patched, or replaced without affecting the entire system, facilitating easier maintenance and evolution of the application. Therefore, the criterion that is NOT typically met by a microservice is being tightly coupled.

Explanation

The correct answer is: "Multiple microservices can run in one process." The statement that is FALSE about microservices is: "Multiple microservices can run in one process." Microservices are designed to be independent and autonomous services that can be deployed, scaled, and managed separately. Each microservice typically runs as its own separate process. This separation allows for loose coupling and independent scalability of individual services. Running multiple microservices in a single process would violate the fundamental principle of microservices architecture, which emphasizes the isolation and independence of services. Combining multiple microservices into a single process would tightly couple them, making it difficult to independently manage, scale, and update each service. The other statements provided are true about microservices: It is fairly common for microservices to communicate with HTTP: Microservices often communicate with each other using lightweight protocols like HTTP/REST. This allows for interoperability, flexibility, and ease of communication between microservices. Microservices are typically designed around business capabilities: Microservices architecture advocates designing services based on specific business capabilities or functionalities. Each microservice focuses on a specific business domain or task, enabling modular and scalable development. They are independently deployable: Microservices are designed to be independently deployable units. This means that each microservice can be developed, tested, deployed, and updated separately without affecting other services. This flexibility allows for faster development cycles and more efficient scalability.

Explanation

The correct answer is: "Adding a custom certificate authority (CA) or custom CA bundle to your gateway's trust store for mTLS is optional unless you need to reject certificates that do not contain particular values (such as a domain name)." The statement that is NOT valid regarding the mTLS options in OCI API Gateway is: "Adding a custom certificate authority (CA) or custom CA bundle to your gateway's trust store for mTLS is optional unless you need to reject certificates that do not contain particular values (such as a domain name)." In OCI API Gateway, adding a custom certificate authority (CA) or custom CA bundle to the gateway's trust store is not optional. It is a necessary step when configuring mTLS authentication. The trust store in the gateway is used to validate the client certificates presented during mTLS authentication. The other options listed are valid regarding the mTLS options in OCI API Gateway: Once the mTLS request policy is enabled, all requests with valid certificates are routed to the backend unless specific values (such as a domain name) are defined. This means that only requests with valid client certificates will be allowed to access the backend microservices. The mTLS request policy can only be enabled at the API deployment specification level, and it applies globally to all routes in that deployment. This ensures consistent mTLS authentication across all routes and endpoints in the API deployment. Custom CA or custom CA bundles can be added to the gateway's trust store, but only if they already exist in the OCI Certificates service. This allows you to include trusted CAs or CA bundles to validate client certificates during mTLS authentication.

An action is a response that you define for the rule to perform when the filter finds a matching event1. The action type specifies the service that you want to invoke by delivering the event message1. The following action types are available in OCI Events rule definition1:

• Streaming: Send to a stream from Oracle Streaming Service.
• Notifications: Send to an Oracle Notification Service topic.
• Functions: Send to an Oracle Functions Service endpoint. Email is not a valid action type for OCI Events rule definition. To send an email as an action, you need to use the Notifications service and subscribe to a topic with an email protocol2.

Explanation

A valid concern that needs to be further investigated in this scenario is whether the OKE cluster has a secret with the credentials of the Oracle Cloud Infrastructure Registry (OCIR) repository and if that secret is being used in the Kubernetes deployment manifest. Here's why this concern is relevant: Access to the OCIR repository: In order for the OKE cluster to pull images from the OCIR repository, it needs proper authentication credentials. These credentials are typically provided in the form of a secret, which contains the necessary information to authenticate with the registry. Secret in the deployment manifest: The Kubernetes deployment manifest defines how the application containers should be deployed. It includes specifications such as the container image, resource requirements, and environment variables. To pull images from a private repository like OCIR, the deployment manifest needs to reference the appropriate secret that contains the registry credentials. If the images are not being pulled from the designated OCIR repository, it suggests that either the secret with the OCIR credentials is missing or it is not properly referenced in the deployment manifest. Further investigation should focus on verifying the presence and correctness of the secret, as well as confirming that it is correctly referenced in the deployment manifest for the application containers. By ensuring the presence of the secret and proper configuration in the deployment manifest, the OKE cluster will have the necessary credentials to access the OCIR repository and successfully deploy the application containers.

Blue/Green deployment strategy allows releasing a new version of an application using two identical environments where one of them is active at a given time. The current version of the application is provisioned on the active environment, whereas the new version gets deployed to the standby environment1. The traffic is shifted from the active to the standby environment by updating the ingress resource2. Therefore, both old and new application versions are deployed to production at the same time, but only one of them receives the traffic. Verified References: Announcing new deployment strategies for OCI DevOps Service, Blue-Green OKE Deployment

Explanation

The necessary configuration to provide access to a private repository in OCI Registry (OCIR) from OCI Container Engine for Kubernetes (OKE) is to create a docker-registry secret for OCIR with an identity Auth Token on the cluster and specify the imagePullSecret property in the application deployment manifest. Here's the breakdown of the steps: Create a docker-registry secret for OCIR with an identity Auth Token: In order to authenticate with the private repository in OCIR, you need to create a secret in your OKE cluster that contains the necessary credentials. This can be done by generating an identity Auth Token from the OCI Console and creating a secret in the cluster using the kubectl command. Specify the imagePullSecret property in the application deployment manifest: In your application's deployment manifest (such as a Kubernetes Deployment or StatefulSet YAML file), you need to include the imagePullSecret property and specify the name of the secret you created in the previous step. This allows the OKE cluster to use the credentials from the secret to pull the docker image from the private repository in OCIR during deployment. By following these steps, you can ensure that your OKE cluster has the necessary access to the private repository in OCIR, and your application can successfully pull the required docker image during deployment.

To prevent images from being deleted from a repository, you can set the global policy of image retention to “Retain All Images”. This policy applies to all repositories in the tenancy and overrides any individual repository settings. You can also lock the policy to prevent any changes to it.Verified References: Using Retention Rules to Preserve Data

Explanation

The option that is NOT available when viewing the Application metrics in the Oracle Cloud Infrastructure (OCI) Console is: "The number of retries made by the function before failing due to an error." When viewing the Application metrics in the OCI Console for Oracle Functions, you can typically see metrics related to the performance and usage of your functions. These metrics provide insights into how your functions are performing and being utilized. The following metrics are usually available: The number of requests to invoke a function that failed due to throttling: This metric indicates the number of requests that were not processed by the function due to reaching the configured concurrency limit or throttling settings. The length of time a function runs for: This metric represents the duration of each function invocation, measuring the time it takes for the function to complete its execution. The number of requests to invoke a function that failed with an error response: This metric counts the number of requests that encountered an error during the function invocation, resulting in a failed response. However, the number of retries made by the function before failing due to an error is not typically available as part of the Application metrics in the OCI Console. The retries made by the function are usually handled at the invoker level, and the specific details of retries may not be captured as part of the application-level metrics. It's important to note that the availability of metrics and their specific details may vary depending on the version and configuration of Oracle Functions and the monitoring setup. It is recommended to refer to the Oracle Functions documentation and consult the official documentation for accurate and up-to-date information on available metrics.

Explanation

The correct answer is: "Edit the tenancy global retention policy." To ensure that container images never get deleted from the Oracle Cloud Infrastructure Registry (OCIR), you should edit the tenancy global retention policy. The tenancy global retention policy is a setting that determines the retention behavior for all the images in the OCIR across the entire tenancy. By editing this policy, you can define the retention behavior that suits your requirements. To edit the tenancy global retention policy, you would typically perform the following steps: Access the Oracle Cloud Infrastructure Console and navigate to the OCIR service. Go to the "Policies" section or "Settings" section in the OCIR service. Locate the tenancy global retention policy settings. Modify the retention policy to specify the desired retention behavior. In this case, you would set the policy to retain all images, ensuring they are never deleted from the repository. By setting the global policy of image retention to "Retain All Images," you can ensure that the container images in your OCIRrepository are permanently retained and not subject to deletion based on any default or automatic retention rules. The other options mentioned are not directly related to ensuring that container images are never deleted from the repository: Creating a group and assigning a policy to perform lifecycle operations on images or writing a policy to limit access to the specific repository in your compartment are access control measures and do not address the retention of images. Setting the global policy of image retention to "Retain All Images" is the correct action to achieve the desired outcome of preventing image deletion from the repository.

Explanation

The statement that accurately describes the Oracle Cloud Infrastructure (OCI) Load Balancer integration with OCI Container Engine for Kubernetes (OKE) is: "OKE service provisions an OCI Load Balancer instance for each Kubernetes service with LoadBalancer type in the YAML configuration." When you define a Kubernetes service in your YAML configuration with the LoadBalancer type, the OKE service automatically provisions an OCI Load Balancer instance specifically for that service. This Load Balancer instance is dedicated to the Kubernetes service and provides traffic balancing functionality. Each Kubernetes service that requires load balancing will have its own OCI Load Balancer instance provisioned by OKE.

Explanation

The correct answer is: In blue/green deployment, both old and new applications are in production at the same time. In canary deployment, the application is deployed incrementally to a select group of people. In a blue/green deployment strategy, two identical environments, referred to as blue and green, are set up. The current production environment (blue) continues to serve live traffic while a new version of the application is deployed in the green environment. Once the new version is tested and deemed stable, traffic is routed from the blue environment to the green environment, making it the new production environment. This approach allows for a seamless switch between the old and new versions of the application. On the other hand, in a canary deployment strategy, the new version of the application is deployed incrementally to a small subset of users or a specific group. This allows for testing the new version in a real production environment while minimizing the impact of any potential issues. If the new version performs well and meets the desired criteria, it can be gradually rolled out to a larger audience or the entire user base. In summary, the main difference between blue/green and canary deployment strategies lies in how the deployment is managed. Blue/green involves simultaneous production of both old and new applications, while canary deployment focuses on incremental deployment to a select group of users.

Explanation

The correct answers are: Amount of RAM used by a function: Oracle Functions collects and reports the amount of memory (RAM) used by a function during its execution. This metric helps in monitoring and optimizing the resource consumption of functions. Length of time a function runs: Oracle Functions captures and provides the duration of function executions. This metric allows you to track the performance and responsiveness of your functions and identify any potential bottlenecks or delays. These metrics provide valuable insights into the resource utilization and performance of your functions, enabling you to monitor and optimize their behavior in the Oracle Cloud Infrastructure (OCI) environment.

Explanation

The Fn Project is an open source serverless computing platform that serves as the engine for Oracle Functions. It provides a runtime environment for executing functions in a serverless architecture. The Fn Project enables developers to build and deploy functions using different programming languages, including Java, Python, Node.js, and more. The Fn Project is designed to be flexible and extensible, allowing developers to define functions as small units of code and execute them in response to events or triggers. It supports event-driven execution, allowing functions to be triggered by various events such as HTTP requests, messages from messaging systems, or changes in data. Oracle Functions leverages the Fn Project as its underlying engine, providing a managed serverless platform within the Oracle Cloud Infrastructure. It allows developers to easily develop, deploy, and manage functions using the familiar Fn Project framework and tooling. With Oracle Functions, developers can focus on writing their function code while leaving the infrastructure management, scaling, and operational tasks to the platform.

Explanation

The correct answer is: "read only." The layers of a Docker image are read-only. Once a layer is created, it cannot be modified. Each layer represents a Dockerfile instruction, and it is stacked on top of the previous layer, forming a stack of immutable layers. These layers are designed to be read-only to ensure consistency and integrity of the image. When a Docker image is built, each instruction in the Dockerfile creates a new layer. Each layer represents the changes made by that instruction relative to the previous layer. The layers are stacked on top of each other to form the complete image. This layer-based approach allows for efficient storage and distribution of Docker images. Because the layers are read-only, any changes or modifications to the image result in the creation of new layers rather than modifying the existing ones. This immutability ensures that each layer remains intact and preserves the integrity of the image. It also enables Docker's caching mechanism, where previously built layers can be reused if the corresponding instructions haven't changed, speeding up the image build process. The other options mentioned, such as "write only," "write once," "movable," and "read mostly," do not accurately describe the permission associated with Docker image layers. Docker image layers are specifically designed to be read-only.

Explanation

The statement that is incorrect is: "The request does not require an Authorization header." In order to POST messages to a stream in the OCI Streaming service using OCI APIs, the request does require an Authorization header. The Authorization header is used to provide authentication and ensure the request is authorized to access the stream. The correct approach is to include the Authorization header in the request, along with other required headers such as x-content-sha256, content-type, and content-length. Therefore, the incorrect statement is that the request does not require an Authorization header.\

Explanation

Which TWO statements are correct regarding Docker images and containers? (Choose two.) Writing and building a new Dockerfile is the only way you can create new Docker images. A container can exist without an image but an image cannot exist without a container. Only one container can be spawned from a given image at a time. If multiple containers are spawned from the same image, then they all use the same copy of that image in memory. (Correct) An image is a collection of immutable layers whereas a container is a running instance of an image. (Correct) ChatGPT The correct statements regarding Docker images and containers are: If multiple containers are spawned from the same image, then they all use the same copy of that image in memory. This statement is correct. When multiple containers are created from the same Docker image, they share the underlying layers of the image in memory. Each container has its own isolated filesystem and runtime environment, but they all use the same base image, which helps in efficient resource utilization. An image is a collection of immutable layers whereas a container is a running instance of an image. This statement is also correct. Docker images are composed of multiple layers, with each layer representing a specific change or addition to the previous layer. These layers are read-only and can be shared among multiple containers. On the other hand, a container is a lightweight and isolated runtime instance created from a specific image. It is a running process that has its own filesystem, network, and runtime configuration. The statements "Writing and building a new Dockerfile is the only way you can create new Docker images" and "A container can exist without an image but an image cannot exist without a container" are incorrect. Docker images can be created in various ways, including using Dockerfiles, importing from existing images, or pulling from registries. Additionally, a container requires an image to run, so an image must exist before a container can be created from it.

Idle-timeout is the parameter that is used to configure the time period during which an idle function will remain in memory before Oracle Functions removes its container image from memory2. The idle-timeout parameter is specified in seconds and can be set when creating or updating a function2. The default value for idle-timeout is 30 seconds and the maximum value is 900 seconds (15 minutes)2. If a function has the --provisioned-concurrency option enabled, the idle-timeout parameter is ignored and the function instances are always kept in memory3.Verified References: Creating Functions, Provisioned Concurrency

Explanation

The correct answer is: fn deploy --app travel-app --allExplanation: To build and deploy multiple Oracle Functions as part of a single application named "travel-app," you can use the fn deploy command with the appropriate options. The command fn deploy --app travel-app --all is the correct syntax. Here's what each part of the command does: fn deploy: This command is used to deploy functions and applications in Oracle Functions. --app travel-app: This option specifies the application name as "travel-app," indicating that you want to deploy functions to this application. --all: This option indicates that you want to deploy all the functions within the application. By using fn deploy --app travel-app --all, you can build and deploy all the functions in your travel application across different programming languages (Java, Python, and Node.js) to the "travel-app" application in Oracle Functions.

Explanation

The correct answer is: "A finely tuned piece of software that performs a single or small collection of tasks." Microservices are a software architectural approach where a system is decomposed into small, independent services that are responsible for performing a specific set of tasks. Each microservice is designed to be focused, finely tuned, and highly cohesive, handling a single or a small collection of related tasks. This granularity allows for better scalability, maintainability, andflexibility in building complex applications. The other options provided do not accurately define microservices: An open-source system for automating deployment, scaling, and management of containerized applications refers to a container orchestration tool like Kubernetes, which can be used to manage microservices but is not a definition of microservices itself. A statically typed and compiled language describes a type of programming language characteristic and is not specific to the concept of microservices. An organized collection of structured information or data, typically stored electronically in a computer system is a definition of a database or data storage system and is unrelated to microservices.

In the shared responsibility model, Oracle is responsible for securing the underlying cloud infrastructure and platform services, while customers are responsible for securing theirdata and applications within the cloud4. For provisioned OKE clusters, Oracle manages the control plane (master nodes) of the Kubernetes cluster, while customers manage the data plane (worker nodes) of the cluster5. Therefore, it is the responsibility of the customer to perform patching, upgrading, and maintaining of the worker nodes in provisioned OKE clusters5. Customers can use tools such as Terraform or kubectl to automate these tasks5.

Explanation

The option that allows changes to a Docker image to be stored in a version control system is: docker commit The docker commit command is used to create a new image from a container's changes. It takes a running container as input, captures the changes made to it, and creates a new image with those changes. This new image can then be tagged and pushed to a registry, or saved locally. By using docker commit, you can effectively capture the changes made to a container as a new image and store it in a version control system along with the Dockerfile and other project files. This allows for reproducibility and traceability of changes to the Docker image over time.

End-to-end testing is a technique that involves checking the entire user flow as well as the moving parts of a cloud native app, ensuring that there are no high-level discrepancies3. End-to-end testing simulates real user scenarios and validates the functionality, performance, reliability, and security of the app from start to finish3. End-to-end testing has several benefits, such as3:

• Comprehensive testing: You can test your app as a whole and verify that all the components work together as expected.
• User-centric testing: You can test your app from the user’s perspective and ensure that it meets the user’s needs and expectations.
• Quality assurance: You can test your app in a realistic environment and identify any issues or defects before releasing it to the users.

Explanation

The term that describes a group formed by a master machine and a worker machine in a Kubernetes architecture is "Cluster". A cluster in Kubernetes consists of one or more master machines and multiple worker machines (also known as nodes). The master machine manages the overall control plane and orchestrates the deployment and management of containers on the worker nodes. The worker nodes are responsible for running the containers and executing the workloads. The cluster is the fundamental unit of organization and management in Kubernetes, providing the infrastructure and resources to run and manage containerized applications. It ensures high availability, scalability, and fault tolerance for the applications deployed within it.

Explanation

The correct statements about deleting a Kubernetes cluster are: If you change the auto-generated name of a worker node and then delete the cluster, the renamed worker node is not deleted. Changing the name of a worker node does not affect its deletion when the cluster is deleted. The cluster deletion process does not consider the renamed worker nodes and will delete all worker nodes associated with the cluster. Upon deleting a cluster, no other resources created during the cluster creation process or associated with the cluster (such as VCNs, Internet Gateways, NAT Gateways, Route Tables, Security Lists, Load Balancers, and Block Volumes) are deleted automatically. These additional resources are not automatically deleted when the cluster is deleted. You need to manage the deletion of these resources separately, if desired. Therefore, the correct statements are that the renamed worker nodes are not deleted when the cluster is deleted, and other associated resources are not automatically deleted when the cluster is deleted.