Correct Answer: B

this pattern isolates an operation that makes calls to multiple back-end microservices, centralizing its logic into a specialized microservice.

Correct Answer: B

check the steps for Creating, Deploying, and Invoking a Helloworld Function https://docs.cloud.oracle.com/ en-us/iaas/Content/Functions/Tasks/functionscreatingfirst.htm in step 7 that will deploy the funcation 7Enter the following single Fn Project command to build the function and its dependencies as a Docker image called helloworld-func, push the image to the specified Docker registry, and deploy the function to Oracle Functions in the helloworld-app: $ fn -v deploy --app helloworld-app The -v option simply shows more detail about what Fn Project commands are doing (see Using the Fn Project CLI with Oracle Functions).

Correct Answer: B

Having deployed the authorizer function, you enable authentication and authorization for an API deployment by including two different kinds of request policy in the API deployment specification: An authentication request policy for the entire API deployment that specifies:The OCID of the authorizer function that you deployed to Oracle Functions that will perform authentication and authorization.The request attributes to pass to the authorizer function.Whether unauthenticated callers can access routes in the API deployment. An authorization request policy for each route that specifies the operations a caller is allowed to perform, based on the caller's access scopes as returned by the authorizer function. Using the Console to Add Authentication and Authorization Request Policies To add authentication and authorization request policies to an API deployment specification using the Console: Create or update an API deployment using the Console, select the From Scratch option, and enter details on the Basic Information page. For more information, see Deploying an API on an API Gateway by Creating an API Deployment and Updating API Gateways and API Deployments. In the API Request Policies section of the Basic Information page, click the Add button beside Authentication and specify: Application in : The name of the application in Oracle Functions that contains the authorizer function. You can select an application from a different compartment. Function Name: The name of the authorizer function in Oracle Functions. Authentication Token: Whether the access token is contained in a request header or a query parameter. Authentication Token Value: Depending on whether the access token is contained in a request header or a query parameter, specify:

Header Name: If the access token is contained in a request header, enter the name of the header. Parameter Name: If the access token is contained in a query parameter, enter the name of the query parameter. https://docs.cloud.oracle.com/en-us/iaas/Content/APIGateway/Tasks/apigatewayaddingauthzauthn.htm

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 opc@192.0.2.254. 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 opc@192.0.2.254 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: C

https://docs.cloud.oracle.com/en-us/iaas/Content/API/Concepts/sdks.htm

Software Development Kits (SDKs) Build and deploy apps that integrate with Oracle Cloud Infrastructure services. Each SDK provides the tools you need to develop an app, including code samples and documentation to create, test, and troubleshoot. In addition, if you want to contribute to the development of the SDKs, they are all open source and available on GitHub. SDK for Java Python SDK Ruby SDK Go SDK

Correct Answer: F

Correct Answer: D

Resiliency and Availability Resiliency and availability refers to the ability of a system to continue operating, despite the failure or suboptimal performance of some of its components. In the case of Oracle Functions: The control plane is a set of components that manages function definitions. The data plane is a set of components that executes functions in response to invocation requests. For resiliency and high availability, both the control plane and data plane components are distributed across different availability domains and fault domains in a region. If one of the domains ceases to be available, the components in the remaining domains take over to ensure that function definition management and execution are not disrupted. When functions are invoked, they run in the subnets specified for the application to which the functions belong. For resiliency and high availability, best practice is to specify a regional subnet for an application (or alternatively, multiple AD- specific subnets in different availability domains). If an availability domain specified for an application ceases to be available, Oracle Functions runs functions in an alternative availability domain.

Correct Answer: BE

https://www.techjini.com/blog/microservices/

Correct Answer: C

Canary deployments are a pattern for rolling out releases to a subset of users or servers. The idea is to first deploy the change to a small subset of servers, test it, and then roll the change out to the rest of the servers. The canary deployment serves as an early warning indicator with less impact on downtime: if the canary deployment fails, the rest of the servers aren't impacted. Blue-green deployment is a technique that reduces downtime and risk by running two identical production environments called Blue and Green. At any time, only one of the environments is live, with the live environment serving all production traffic. For this example, Blue is currently live and Green is idle. A/B testing is a way to compare two versions of a single variable, typically by testing a subject's response to variant A against variant B, and determining which of the two variants is more effective A rolling update offers a way to deploy the new version of your application gradually across your cluster.

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/gettingstarted-with-microservices-part-three