A 503 Service Unavailable Error is an HTTP response status code indicating that a server is temporarily unable to handle the request. This may be due to the server being overloaded or down for maintenance.
Wednesday, July 29, 2020
Q2 Question 20 Explanation
Autoscaling lets you automatically adjust the number of Compute instances in an instance pool based on performance metrics such as CPU utilization. This helps you provide consistent performance for your end users during periods of high demand, and helps you reduce your costs during periods of low demand.
you can associate a load balancer with an instance pool. If you do this, when you add an instance to the instance pool, the instance is automatically added to the load balancer's backend set . After the instance reaches a healthy state (the instance is listening on the configured port number), incoming traffic is automatically routed to the new instance.
Instance pools let you provision and create multiple Compute instances based off the same configuration, within the same region.
By default, the instances in a pool are distributed across all fault Domains in a best-effort manner based on capacity. If capacity isn't available in one fault domain, the instances are placed in other fault domains to allow the instance pool to launch successfully.
In a high availability scenario, you can require that the instances in a pool are evenly distributed across each of the fault domains that you specify. When sufficient capacity isn't available in one of the fault domains, the instance pool will not launch or scale successfully, and a work request for the instance pool will return an "out of capacity" error. To fix the capacity error, either wait for capacity to become available, or use the UpdateInstancePool operation to update the placement configuration (the availability domain and fault domain) for the instance pool.
during create the instance pool you can select the location where you want to place the instances"
In the Availability Domain list, select the availability domain to launch the instances in.
If you want the instances in the pool to be placed evenly in one or more fault domains, select the Distribute instances evenly across selected fault domains check box. Then, select the fault domains to place the instances in.
Q2 Question 19 Explanation
This is the simplest way
Tag Variables
You can use a variable to set the value of a defined tag. When you add the tag to a resource, the variable resolves to the data it represents. You can use tag variables in defined tags and default tags.
Supported Tag Variables
The following tag variables are supported.
${iam.principal.name}The name of the principal that tagged the resource${iam.principal.type}The type of principal that tagged the resource.${oci.datetime}The date and time that the tag was created.
Consider the following example:
Operations.CostCenter="
${iam.principal.name} at ${oci.datetime}"
Operations is the namespace, CostCenter is the tag key, and the tag value contains two tag variables
${iam.principal.name} and ${oci.datetime}. When you add this tag to a resource, the variable resolves to your user name (the name of the principal that applied the tag) and a time date stamp for when you added the tag.user_name at 2019-06-18T18:00:57.604Z
The variable is replaced with data at the time you apply the tag. If you later edit the tag, the variable is gone and only the data remains. You can edit the tag value in all the ways you would edit any other tag value.
To create a tag variable, you must use a specific format.
${<variable>}
Type a dollar sign followed by open and close curly brackets. The tag variable goes between the curly brackets. You can use tag variables with other tag variables and with string values.
Tag defaults let you specify tags to be applied automatically to all resources, at the time of creation, in a specific compartment. This feature allows you to ensure that appropriate tags are applied at resource creation without requiring the user who is creating the resource to have access to the tag namespaces.
Q2 Question 18 Explanation
GEOLOCATION STEERING
Geolocation steering policies distribute DNS traffic to different endpoints based on the location of the end user. Customers can define geographic regions composed of originating continent, countries or states/provinces (North America) and define a separate endpoint or set of endpoints for each region.
Combine with Oracle Health Checks to fail over from one region to another
Q2 Question 17 Explanation
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. 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.
You can create automation based on state changes for your Oracle Cloud Infrastructure resources by using event types, rules, and actions.
When the function is executing inside the container, the function can read from and write to other resources and services running in the same subnet (for example, Database as a Service). The function can also read from and write to other shared resources (for example, Object Storage), and other Oracle Cloud Services.
Q2 Question 16 Explanation
The Oracle Services Network is a conceptual network in Oracle Cloud Infrastructure that is reserved for Oracle services. These services have public IP addresses that you typically reach over the internet. However, you can access the Oracle Services Network without the traffic going over the internet. There are different ways, depending on which of your hosts need the access:
Hosts in your on-premises network:
- Private access through a VCN with FastConnect private peering or VPN Connect: The on-premises hosts use private IP addresses and reach the Oracle Services Network by way of the VCN and the VCN's service gateway.
- Public access with FastConnect public peering: The on-premises hosts use public IP addresses.
regarding which Fastconnect Public peering: To access public services in Oracle Cloud Infrastructure without using the internet. For example, Object Storage, the Oracle Cloud Infrastructure Console and APIs, or public load balancers in your VCN. Communication across the connection is with IPv4 public IP addresses. Without FastConnect, the traffic destined for public IP addresses would be routed over the internet. With FastConnect, that traffic goes over your private physical connection.
so Answer 4 will be the best answer that meets the customer requirement
A service gateway lets your virtual cloud network (VCN) privately access specific Oracle services without exposing the data to the public internet. No internet gateway or NAT is required to reach those specific services. The resources in the VCN can be in a private subnet and use only private IP addresses. The traffic from the VCN to the Oracle service travels over the Oracle network fabric and never traverses the internet.
Object Lifecycle Management lets you automatically manage the archiving and deletion of objects. By using Object Lifecycle Management to manage your Object Storage and Archive Storage data, you can reduce your storage costs and the amount of time you spend managing data.
Q2 Question 15 Explanation
Oracle Cloud Infrastructure Container Engine for Kubernetes is a fully-managed, scalable, and highly available service that you can use to deploy your containerized applications to the cloud. Use Container Engine for Kubernetes (sometimes abbreviated to just OKE) when your development team wants to reliably build, deploy, and manage cloud-native applications. You specify the compute resources that your applications require, and Container Engine for Kubernetes provisions them on Oracle Cloud Infrastructure in an existing OCI tenancy.
Oracle Cloud Infrastructure Registry is an Oracle-managed registry that enables you to simplify your development to production workflow. Oracle Cloud Infrastructure Registry makes it easy for you as a developer to store, share, and manage development artifacts like Docker images. And the highly available and scalable architecture of Oracle Cloud Infrastructure ensures you can reliably deploy your applications. So you don't have to worry about operational issues, or scaling the underlying infrastructure.