1z0-1084-22 Oracle Cloud Infrastructure 2022 Developer Professional Questions and Answers

Overview ofEvents

Oracle Cloud Infrastructure Events enables you to create automation based on the state changes of resources throughout your tenancy. Use Events to allow your development teams to automatically respond when a resource changes its state.

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 forthese 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 eventthen 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

References:

https://docs.cloud.oracle.com/en-us/iaas /Content/Events/Concepts/eventsoverview.htm

distributed systems of native-cloud like functions that have a lot of benefit like

Resiliency and availability

Resiliency and availability refers to the ability of asystem to continue operating, despite the failure or sub-optimal 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 thatexecutes 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 ceasesto 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.

Concurrency and Scalability

Concurrency refers to the ability of a system to run multiple operations in parallel using shared resources. Scalability refers to the ability of the system to scale capacity (both up and down) to meet demand.

In the case of Functions, when a function is invoked for the first time, the function's image is run as a container on an instance in a subnet associated with the application to which thefunction belongs. When the function is executing inside the container, the function can read from and write to other shared resources and services running in the same subnet (for example, Database as a Service). The function can also read from and write toother shared resources (for example, Object Storage), and other Oracle Cloud Services.

If Oracle Functions receives multiple calls to a function that is currently executing inside a running container, Oracle Functions automatically and seamlessly scales horizontally to serve all the incoming requests. Oracle Functions starts multiple Docker containers, up to the limit specified for your tenancy. The default limit is 30 GB of RAM reserved for function execution per availability domain, although you can request an increase to this limit. Provided the limit is not exceeded, there is no difference in response time (latency) between functions executing on the different containers.

Web Application Firewall (WAF):

Oracle Cloud Infrastructure Web Application Firewall (WAF) is a cloud-based, Payment Card Industry (PCI) compliant, global security service that protects applications from malicious and unwanted internet traffic. WAF can protect any internet facing endpoint,providing consistent rule enforcement across a customer's applications.

WAF provides you with the ability to create and manage rules for internet threats including Cross-Site Scripting (XSS), SQL Injection and other OWASP-defined vulnerabilities. Unwantedbots can be mitigated while tactically allowed desirable bots to enter. Access rules can limit based on geography or the signature of the request.

The global Security Operations Center (SOC) will continually monitor the internet threat landscape acting asan extension of your IT infrastructure.

References:

https://docs.cloud.oracle.com/en-us/iaas/Content/WAF/Concepts/overview.htm

Storing and Viewing Function Logs:

When a function you've deployed to Oracle Functions is invoked, you'll typically want to store the function's logs so that you can review them later. You specify where Oracle Functions storesa function's logs by setting a logging policy for the application containing the function.

You can specify that Oracle Functions:

Stores logs in Oracle Cloud Infrastructure. Until an Oracle Cloud Infrastructure logging service is released, Oracle Functionsstores logs as files in a storage bucket in Oracle Cloud Infrastructure Object Storage.

Note that to view function logs in a storage bucket, the group to which you belong must have been granted access with the following identity policy statements:

Allowgroup to manage object-family in compartment

Allow group to read objectstorage-namespaces in compartment  (Usually created when configuring your tenancy for function development. See Create a Policy to Give Oracle Functions Users Access to Oracle Cloud Infrastructure Registry Repositories.)

Stores logs by exporting them to an external logging destination like Papertrail. Note that to use an external logging destination, you must have set up a VCN with public subnets and an internet gateway (see Create the VCN and Subnets to Use with Oracle Functions, if they don't exist already).

You set application logging policies in the Console.

References:

https://docs.cloud.oracle.com/en-us/iaas/Content/Functions/Tasks/functionsexportingfunctionlogfiles.htm

After a new version of Kubernetes has been released and when Container Engine forKubernetes supports the new version, you can use Container Engine for Kubernetes to upgrade master nodes running older versions of Kubernetes. Because Container Engine for Kubernetes distributes the Kubernetes Control Plane on multiple Oracle-managed master nodes (distributed across different availability domains in a region where supported) to ensure high availability, you're able to upgrade the Kubernetes version running on master nodes with zero downtime.

Having upgraded master nodes to a new version ofKubernetes, you can subsequently create new node pools running the newer version. Alternatively, you can continue to create new node pools that will run older versions of Kubernetes (providing those older versions are compatible with the Kubernetes version running on the master nodes).

Note that you upgrade master nodes by performing an ‘in-place’ upgrade, but you upgrade worker nodes by performing an ‘out-of-place’ upgrade. To upgrade the version of Kubernetes running on worker nodes in a node pool, you replace the original node pool with a new node pool that has new worker nodes running the appropriate Kubernetes version. Having 'drained' existing worker nodes in the original node pool to prevent new pods starting and to delete existing pods, you can thendelete the original node pool.

Upgrading the Kubernetes Version on Worker Nodes in a Cluster:

After a new version of Kubernetes has been released and when Container Engine for Kubernetes supports the new version, you can use Container Engine for Kubernetes to upgrade master nodes running older versions of Kubernetes. Because Container Engine for Kubernetes distributes the Kubernetes Control Plane on multiple Oracle-managed master nodes (distributed across different availability domains in a region where supported) to ensure high availability, you're able to upgrade the Kubernetes version running on master nodes with zero downtime.

You can upgrade the version of Kubernetes running on the worker nodes in a cluster in two ways:

(A) Perform an 'in-place' upgrade of a node pool in the cluster, by specifying a more recent Kubernetes version for new worker nodes starting in the existing node pool. First, you modify the existing node pool's properties to specify the more recent Kubernetes version. Then, you 'drain'existing worker nodes in the node pool to prevent new pods starting, and to delete existing pods. Finally, you terminate each of the worker nodes in turn. When new worker nodes are started in the existing node pool, they run the more recent Kubernetes version you specified. See Performing an In-Place Worker Node Upgrade by Updating an Existing Node Pool.

(B) Perform an 'out-of-place'upgrade of a node pool in the cluster, by replacing the original node pool with a new node pool. First, you create a new node pool with a more recent Kubernetes version. Then, you 'drain' existing worker nodes in the original node pool to prevent new podsstarting, and to delete existing pods. Finally, you delete the original node pool. When new worker nodes are started in the new node pool, they run the more recent Kubernetes version you specified. See Performing an Out-of-Place Worker Node Upgrade by Replacing an Existing Node Pool with a New Node Pool.

Note that in both cases:

The more recent Kubernetes version you specify for the worker nodes in the node pool must be compatible with the Kubernetes version running on the master nodes in the cluster. See Upgrading Clusters to Newer Kubernetes Versions).

You must drain existing worker nodes in the original node pool. If you don't drain the worker nodes, workloads running on the cluster are subject to disruption.

References:

https://docs.cloud.oracle.com/en-us/iaas/Content/ContEng/Tasks/contengupgradingk8sworkernode.htm

Authorization Header

The Oracle Cloud Infrastructure signature uses the "Signature" Authentication scheme (with an Authorization header), and not the Signature HTTP header.

Required Credentials and OCIDs

You need an API signing key in the correct format. See Required Keys and OCIDs.

You also need the OCIDs for your tenancy and user. See Where to Get the Tenancy's OCID and User's OCID.

Summary of Signing Steps

In general, these are the steps required to sign a request:

Form the HTTPS request (SSL protocol TLS 1.2 is required).

Create the signingstring, which is based on parts of the request.

Create the signature from the signing string, using your private key and the RSA-SHA256 algorithm.

Add the resulting signature and other required information to the Authorization header in the request.

References:

https://docs.cloud.oracle.com/en-us/iaas/Content/Streaming/Concepts/streamingoverview.htm

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

Oracle Cloud Infrastructure provides a number of DevOps tools and plug-ins for working with Oracle Cloud Infrastructure services. These can simplify provisioning and managing infrastructure or enable automated testing and continuous delivery.

A/B Testing

While A/B testing can be combined with either canary orblue-green deployments, it is a very different thing. A/B testing really targets testing the usage behavior of a service or feature and is typically used to validate a hypothesis or to measure two versions of a service or feature and how they stack up against each other in terms of performance, discoverability and usability. A/B testing often leverages feature flags (feature toggles), which allow you to dynamically turn features on and off.

Integration Testing

Integration tests are also known as end-to-end(e2e) tests. These are long-running tests that exercise the system in the way it is intended to be used in production. These are the most valuable tests in demonstrating reliability and thus increasing confidence.

Penetration Testing

Oracle regularly performs penetration and vulnerability testing and security assessments against the Oracle cloud infrastructure, platforms, and applications. These tests are intended to validate and improve the overall security of Oracle Cloud Services.

References:

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