1Z0-1084-22 Online Practice Questions and Answers

Correct Answer: AC

A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator. PVs are volume plugins like Volumes, but have a lifecycle independent of any individual Pod that uses the PV. A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. If you intend to create Kubernetes persistent volumes, sufficient block volume quota must be available in each availability domain to meet the persistent volume claim. Persistent volume claims must request a minimum of 50 gigabytes You can define and apply a persistent volume claim to your cluster, which in turn creates a persistent volume that's bound to the claim. A claim is a block storage volume in the underlying IaaS provider that's durable and offers persistent storage, enabling your data to remain intact, regardless of whether the containers that the storage is connected to are terminated. With Oracle Cloud Infrastructure as the underlying IaaS provider, you can provision persistent volume claims by attaching volumes from the Block Storage service.

Correct Answer: B

Kubernetes cluster is a group of nodes. The nodes are the machines running applications. Each node can be a physical machine or a virtual machine. The node's capacity (its number of CPUs and amount of memory) is defined when the

node is created. A cluster comprises:

- one or more master nodes (for high availability, typically there will be a number of master nodes)

- one or more worker nodes (sometimes known as minions) Connecting to Worker Nodes Using SSH

If you provided a public SSH key when creating the node pool in a cluster, the public key is installed on all worker nodes in the cluster. On UNIX and UNIX-like platforms (including Solaris and Linux), you can then connect through SSH to the

worker nodes using the ssh utility (an SSH client) to perform administrative tasks.

Note the following instructions assume the UNIX machine you use to connect to the worker node:

Has the ssh utility installed.

Has access to the SSH private key file paired with the SSH public key that was specified when the cluster was created.

How to connect to worker nodes using SSH depends on whether you specified public or private subnets for the worker nodes when defining the node pools in the cluster. Connecting to Worker Nodes in Public Subnets Using SSH Before you

can connect to a worker node in a public subnet using SSH, you must define an ingress rule in the subnet's security list to allow SSH access. The ingress rule must allow access to port 22 on worker nodes from source 0.0.0.0/0 and any

source port To connect to a worker node in a public subnet through SSH from a UNIX machine using the ssh utility:

1- Find out the IP address of the worker node to which you want to connect. You can do this in a number of ways: Using kubectl. If you haven't already done so, follow the steps to set up the cluster's kubeconfig configuration file and (if necessary) set the KUBECONFIG environment variable to point to the file. Note that you must set up your own kubeconfig file. You cannot access a cluster using a kubeconfig file that a different user set up. See Setting Up Cluster Access. Then in a terminal window, enter kubectl get nodes to see the public IP addresses of worker nodes in node pools in the cluster. Using the Console. In the Console, display the Cluster List page and then select the cluster to which the worker node belongs. On the Node Pools tab, click the name of the node pool to which the worker node belongs. On the Nodes tab, you see the public IP address of every worker node in the node pool. Using the REST API. Use the ListNodePools operation to see the public IP addresses of worker nodes in a node pool. 2- In the terminal window, enter ssh opc@ to connect to the worker node, where is the IP address of the worker node that you made a note of earlier. For example, you might enter ssh [email protected]. Note that if the SSH private key is not stored in the file or in the path that the ssh utility expects (for example, the ssh utility might expect the private key to be stored in ~/.ssh/id_rsa), you must explicitly specify the private key filename and location in one of two ways: Use the -i option to specify the filename and location of the private key. For example, ssh -i ~/.ssh/my_keys/my_host_key_filename [email protected] Add the private key filename and location to an SSH configuration file, either the client configuration file (~/.ssh/config) if it exists, or the system-wide client configuration file (/etc/ssh/ssh_config). For example, you might add the following: Host 192.0.2.254 IdentityFile ~/.ssh/my_keys/my_host_key_filename For more about the ssh utility's configuration file, enter man ssh_config Note also that permissions on the private key file must allow you read/write/execute access, but prevent other users from accessing the file. For example, to set appropriate permissions, you might enter chmod 600 ~/.ssh/my_keys/my_host_key_filename. If permissions are not set correctly and the private key file is accessible to other users, the ssh utility will simply ignore the private key file.

Correct Answer: F

Correct Answer: C

https://docs.cloud.oracle.com/en-us/iaas/Content/ResourceManager/Concepts/resourcemanager.htm Following are brief descriptions of key concepts and the main components of Resource Manager. CONFIGURATION Information to codify your infrastructure. A Terraform configuration can be either a solution or a file that you write and upload. JOB Instructions to perform the actions defined in your configuration. Only one job at a time can run on a given stack; further, you can have only one set of Oracle Cloud Infrastructure resources on a given stack. To provision a different set of resources, you must create a separate stack and use a different configuration. Resource Manager provides the following job types: Plan: Parses your Terraform configuration and creates an execution plan for the associated stack. The execution plan lists the sequence of specific actions planned to provision your Oracle Cloud Infrastructure resources. The execution plan is handed off to the apply job, which then executes the instructions. Apply. Applies the execution plan to the associated stack to create (or modify) your Oracle Cloud Infrastructure resources. Depending on the number and type of resources specified, a given apply job can take some time. You can check status while the job runs. Destroy. Releases resources associated with a stack. Released resources are not deleted. For example, terminates a Compute instance controlled by a stack. The stack's job history and state remain after running a destroy job. You can monitor the status and review the results of a destroy job by inspecting the stack's log files. Import State. Sets the provided Terraform state file as the current state of the stack. Use this job to migrate local Terraform environments to Resource Manager. STACK The collection of Oracle Cloud Infrastructure resources corresponding to a given Terraform configuration. Each stack resides in the compartment you specify, in a single region; however, resources on a given stack can be deployed across multiple regions. An OCID is assigned to each stack.

Correct Answer: BE

Oracle Functions is a fully managed, multi-tenant, highly scalable, on-demand, Functions-as-a- Service platform. It is built on enterprise-grade Oracle Cloud Infrastructure and powered by the Fn Project open source engine. Use Oracle Functions (sometimes abbreviated to just Functions) when you want to focus on writing code to meet business needs. The serverless and elastic architecture of Oracle Functions means there's no infrastructure administration or software administration for you to perform. You don't provision or maintain compute instances, and operating system software patches and upgrades are applied automatically. Oracle Functions simply ensures your app is highly-available, scalable, secure, and monitored Applications built with a serverless infrastructure will scale automatically as the user base grows or usage increases. If a function needs to be run in multiple instances, the vendor's servers will start up, run, and end them as they are needed. Oracle Functions is based on Fn Project. Fn Project is an open source, container native, serverless platform that can be run anywhere - any cloud or on-premises. Serverless architectures are not built for long-running processes. This limits the kinds of applications that can cost-effectively run in a serverless architecture. Because serverless providers charge for the amount of time code is running, it may cost more to run an application with long-running processes in a serverless infrastructure compared to a traditional one.

https://docs.cloud.oracle.com/en-us/iaas/Content/Functions/Concepts/functionsconcepts.htm https://www.cloudflare.com/learning/serverless/why-use-serverless/

Correct Answer: C

Token-based authentication for the CLI allows customers to authenticate their session interactively, then use the CLI for a single session without an API signing key. This enables customers using an identity provider that is not SCIM-

supported to use a federated user account with the CLI and SDKs.

Starting a Token-based CLI Session

To use token-based authentication for the CLI on a computer with a web browser:

In the CLI, run the following command. This will launch a web browser.

oci session authenticate

In the browser, enter your user credentials. This authentication information is saved to the .config file.

Correct Answer: C

In the API Gateway service, a back end is the means by which a gateway routes requests to the back- end services that implement APIs. If you add a private endpoint back end to an API gateway, you give the API gateway access to the VCN associated with that private endpoint. You can also grant an API gateway access to other Oracle Cloud Infrastructure services as back ends. For example, you could grant an API gateway access to Oracle Functions, so you can create and deploy an API that is backed by a serverless function. API Gateway service to create an API gateway, you can create an API deployment to access HTTP and HTTPS URLs. https://docs.cloud.oracle.com/en-us/iaas/Content/APIGateway/ Tasks/apigatewayusinghttpbackend.htm API Gateway service to create an API gateway, you can create an API deployment that invokes serverless functions defined in Oracle Functions. https://docs.cloud.oracle.com/en-us/iaas/Content/APIGateway/Tasks/apigatewayusingfunctionsbackend.htm API Gateway service, you can define a path to a stock response back end https://docs.cloud.oracle.com/en-us/iaas/Content/ APIGateway/Tasks/apigatewayaddingstockresponses.htm

Correct Answer: C

A cascading failure is a failure that grows over time as a result of positive feedback. It can occur when a portion of an overall system fails, increasing the probability that other portions of the system fail. the circuit breaker pattern prevents the service from performing an operation that is likely to fail. For example, a client service can use a circuit breaker to prevent further remote calls over the network when a downstream service is not functioning properly. This can also prevent the network from becoming congested by a sudden spike in failed retries by one service to another, and it can also prevent cascading failures. Self-healing circuit breakers check the downstream service at regular intervals and reset the circuit breaker when the downstream service starts functioning properly. https://blogs.oracle.com/developers/getting-started-with-microservices-part-three