Oracle Oracle Certifications 1Z0-1084-21 Questions & Answers

• Question 51:

  In the sample Kubernetes manifest file below, what annotations should you add to create a private load balancer In oracle Cloud infrastructure Container Engine for Kubermetes?

  

  A. service.beta.kubernetes.io/oci-load-balancer-private:"true"

  B. service.beta.kubernetes.io/oci-load-balancer-private: "true" service.beta.kubernetes.io/oci-load-balancer-subnet1: "ocid1.subnet.oc1..aaaaa....vdfw"

  C. service.beta.kubernetes.io/oci-load-balancer-internal: "true"

  D. service.beta.kubernetes.io/oci-load-balancer-internal: "true" service.beta.kubernetes.io/oci-load-balancer-subnet1: "ocid1.subnet.oc1..aaaaa....vdfw"

  Correct Answer: D

  https://docs.cloud.oracle.com/en-us/iaas/Content/ContEng/Tasks/contengcreatingloadbalancer.htm? TocPath=Services%7CExample%2 0Network%20Resource%20Configuration%7CUpgrading%20the% 20Version%20of%20Kubernetes%2 0Running%20on%20a%20Master%20Node%7C_____2 Creating Internal Load Balancers in Public and Private Subnets You can create Oracle Cloud Infrastructure load balancers to control access to services running on a cluster: When you create a 'custom' cluster, you select an existing VCN that contains the network resources to be used by the new cluster. If you want to use load balancers to control traffic into the VCN, you select existing public or private subnets in that VCN to host the load balancers. When you create a 'quick cluster', the VCN that's automatically created contains a public regional subnet to host a load balancer. If you want to host load balancers in private subnets, you can add private subnets to the VCN later.

  Alternatively, you can create an internal load balancer service in a cluster to enable other programs running in the same VCN as the cluster to access services in the cluster. You can host internal load balancers in public subnets and private subnets. To create an internal load balancer hosted on a public subnet, add the following annotation in the metadata section of the manifest file: service.beta.kubernetes.io/oci-load-balancer-internal: "true" To create an internal load balancer hosted on a private subnet, add both following annotations in the metadata section of the manifest file: service.beta.kubernetes.io/oci-load-balancer-internal: "true" service.beta.kubernetes.io/oci-load-balancersubnet1: "ocid1.subnet.oc1..aaaaaa....vdfw" where ocid1.subnet.oc1..aaaaaa....vdfw is the OCID of the private subnet.

• Question 52:

  You have two microservices, A and B running in production. Service A relies on APIs from service B. You want to test changes to service A without deploying all of its dependencies, which includes service B.

  Which approach should you take to test service A?

  A. Test against production APIs.

  B. Test using API mocks.

  C. There is no need to explicitly test APIs.

  D. Test the APIs in private environments.

  Correct Answer: B

  Testing using API mocks Developers are frequently tasked with writing code that integrates with other system components via APIs. Unfortunately, it might not always be desirable or even possible to actually access those systems during development. There could be security, performance or maintenance issues that make them unavailable ? or they might simply not have been developed yet. This is where mocking comes in: instead of developing code with actual external dependencies in place, a mock of those dependencies is created and used instead. Depending on your development needs this mock is made "intelligent" enough to allow you to make the calls you need and get similar results back as you would from the actual component, thus enabling development to move forward without being hindered by eventual unavailability of external systems you depend on

• Question 53:

  You are developing a polyglot serverless application using Oracle Functions. Which language cannot be used to write your function code?

  A. PL/SQL

  B. Python

  C. Node.js

  D. Java

  Correct Answer: A

  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. With Oracle Functions, you can write code in Java, Python, Node, Go, and Ruby (and for advanced use cases, bring your own Dockerfile, and Graal VM). You can then deploy your code, call it directly or trigger it in response to events, and get billed only for the resources consumed during the execution.

• Question 54:

  Which two "Action Type" options are NOT available in an Oracle Cloud Infrastructure (OCI) Events rule definition?

  A. Notifications

  B. Functions

  C. Streaming

  D. Email

  E. Slack

  Correct Answer: DE

  https://docs.cloud.oracle.com/en-us/iaas/Content/Events/Concepts/eventsoverview.htm ACTIONS Event Rules must also specify an action to trigger when the filter finds a matching event. Actions are responses you define for event matches. You set up select Oracle Cloud Infrastructure services that the Events service has established as actions. The resources for these services act as destinations for matching events. When the filter in the rule finds a match, the Events service delivers the matching event to one or more of the destinations you identified in the rule. The destination service that receives the event then processes the event in whatever manner you defined. This delivery provides the automation in your environment. You can only deliver events to certain Oracle Cloud Infrastructure services with a rule. Use the following services to create actions: Notifications Streaming Functions

• Question 55:

  How do you perform a rolling update in Kubernetes?

  A. kubect1 rolling-update

  B. kubect1 upgrade --image=*image:v2

  C. kubect1 update -c

  D. kubect1 rolling-update --image=image

  Correct Answer: A

  https://docs.oracle.com/en/cloud/iaas/wercker-cloud/wercm/quickstarts/platforms/kubernetes/

• Question 56:

  Your Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE) administrator has created an

  OKE cluster with one node pool in a public subnet. You have been asked to provide a log file from one of

  the nodes for troubleshooting purpose.

  Which step should you take to obtain the log file?

  A. ssh into the node using public key.

  B. ssh into the nodes using private key.

  C. It is impossible since OKE is a managed Kubernetes service.

  D. Use the username open and password to login.

  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.

• Question 57:

  Per CAP theorem, in which scenario do you NOT need to make any trade-off between the guarantees?

  A. when there are no network partitions

  B. when the system is running in the cloud

  C. when the system is running on-premise

  D. when you are using load balancers

  Correct Answer: A

  CAP THEOREM

  "CONSISTENCY, AVAILABILITY and PARTITION TOLERANCE are the features that we want in our

  distributed system together"

  Of three properties of shared-data systems (Consistency, Availability and tolerance to network Partitions)

  only two can be achieved at any given moment in time.

• Question 58:

  Which two statements are true for service choreography?

  A. Service choreographer is responsible for invoking other services.

  B. Services involved in choreography communicate through messages/messaging systems.

  C. Service choreography relies on a central coordinator.

  D. Service choreography should not use events for communication.

  E. Decision logic in service choreography is distributed.

  Correct Answer: BE

  Service Choreography Service choreography is a global description of the participating services, which is defined by exchange of messages, rules of interaction and agreements between two or more endpoints. Choreography employs a decentralized approach for service composition. the decision logic is distributed, with no centralized point.

  

  Choreography, in contrast, does not rely on a central coordinator. and all participants in the choreography need to be aware of the business process, operations to execute, messages to exchange, and the timing of message exchanges.

• Question 59:

  Which is NOT a valid option to execute a function deployed on Oracle Functions?

  A. Send a signed HTTP requests to the function's invoke endpoint

  B. Invoke from Oracle Cloud Infrastructure CLI

  C. Invoke from Docker CLI

  D. Trigger by an event in Oracle Cloud Infrastructure Events service

  E. Invoke from Fn Project CLI

  Correct Answer: C

  You can invoke a function that you've deployed to Oracle Functions in different ways:

  Using the Fn Project CLI.

  Using the Oracle Cloud Infrastructure CLI.

  Using the Oracle Cloud Infrastructure SDKs.

  Making a signed HTTP request to the function's invoke endpoint. Every function has an invoke endpoint.

  Each of the above invokes the function via requests to the API. Any request to the API must be

  authenticated by including a signature and the OCID of the compartment to which the function belongs in

  the request header. Such a request is referred to as a 'signed' request. The signature includes Oracle

  Cloud Infrastructure credentials in an encrypted form.

• Question 60:

  What is one of the differences between a microservice and a serverless function?

  A. Microservices are used for long running operations and serverless functions for short running operations.

  B. Microservices always use a data store and serverless functions never use a data store.

  C. Microservices are stateless and serverless functions are stateful.

  D. Microservices are triggered by events and serverless functions are not.

  Correct Answer: A

  microservice is larger and can do more than a function. A function is a relatively small bit of code that performs only one action in response to an event. In many cases, microservices can be decomposed into a number of smaller stateless functions. The difference between microservices and functions is not simply the size. Functions are stateless, and they require no knowledge about or configuration of the underlying server--hence, the term serverless. https://developer.oracle.com/java/fn-project-introduction.html