Oracle 1z0-1084-22 Exam With Confidence Using Practice Dumps

What Is Cloud Native?

Cloud native technologies arecharacterized by the use of containers, microservices, serverless functions, development pipelines, infrastructure expressed as code, event-driven applications, and Application Programming Interfaces (APIs). Cloud native enables faster software developmentand the ability to build applications that are resilient, manageable, observable, and dynamically scalable to global enterprise levels.

When constructing a cloud-native application, you'll want to be sensitive to how back-end services communicate with each other. Ideally, the less inter-service communication, the better. However, avoidance isn't always possible as back-end services often rely on one another to complete an operation.

While direct HTTP calls between microservices are relatively simple to implement, care should be taken to minimize this practice. To start, these calls are always synchronous and will block the operation until a result is returned or the request times outs. What were once self-contained, independent services, able to evolve independently and deploy frequently, now become coupled to each other. As coupling among microservices increase, their architectural benefits diminish.

Executing an infrequent request that makes a single direct HTTP call to another microservice might be acceptable for some systems. However, high-volume calls that invoke direct HTTP calls to multiple microservices aren't advisable. They can increase latency and negatively impact the performance, scalability, and availability of your system. Even worse, a longseries of direct HTTP communication can lead to deep and complex chains of synchronous microservices calls, shown in Figure 4-9:

A message queue is an intermediary construct through which a producer and consumer pass a message. Queues implement an asynchronous, point-to-point messaging pattern.

Events

Message queuing is an effective way to implement communication where a producer can asynchronously send a consumer a message.

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Adding Request Policies and Response Policies to API Deployment Specifications:

You can control thebehavior of an API deployment you create on an API gateway by adding request and response policies to the API deployment specification:

a request policy describes actions to be performed on an incoming request from a caller before it is sent to a back end

a response policy describes actions to be performed on a response returned from a back end before it is sent to a caller

You can use request policies to:

limit the number of requests sent to back-end services

enable CORS (Cross-Origin Resource Sharing) support

provide authentication and authorization

You can add request and response policies that apply globally to all routes in an API deployment specification, and also (in some cases) request and response policies that apply only to particular routes.

Notethe following:

No response policies are currently available.

API Gateway request policies and response policies are different to IAM policies, which control access to Oracle Cloud Infrastructure resources.

You can add request and response policies to anAPI deployment specification by:

using the Console

editing a JSON file

References:

ateway/Tasks/apigatewayaddingrequestpolicies.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.

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