Pivotal Cloud Foundry Interview Questions
1. What Are The Advantages Of Cloud Services?
Some of the advantages of cloud service are given as follows:
Helps in the utilization of investment in the corporate sector; and therefore, is cost-saving.
Helps in developing scalable and robust applications. Previously, the scaling took months, but now, scaling takes less time.
Helps in saving time in terms of deployment and maintenance.
2. How Many Types Of Deployment Models Are Used In Cloud?
There are 4 types of deployment models used in cloud:
1. Public cloud
2. Private cloud
3. Community cloud
4. Hybrid cloud
3. What Essential Things A User Should Know Before Going For Cloud Computing Platform?
Answer: A user should know some parameters by which he can go for the cloud computing services.
The parameters are as follows:
User should know the data integrity in cloud computing.
It is a measure to ensure integrity like the data is accurate, complete and reasonable.
Compliance: user should make sure that proper rules and regulations are followed while implementing the structure.
Loss of data: user should know about the provisions that are provided in case of loss of data so that backup and recovery can be possible.
Business continuity plans: user should think about does the cloud services provide him uninterrupted data resources.
Uptime: user should know about the uptime the cloud computing platform provides and how helpful it is for the business.
Data storage costs: user should find out about the cost which you have to pay before you go for cloud computing.
4. Explain Different Layers Which Define Cloud Architecture?
Answer: Cloud computing architecture consists of many layers which help it to be more organized and can be managed from one place. The layers are as follows:
Cloud controller or CLC is the top most level in the hierarchy which is used to manage the virtualized resources like servers, network and storage with the user APIs.
Walrus is used for the storage and act as a storage controller to manage the demands of the users. It maintains a scalable approach to control the virtual machine images and user data.
Cluster Controller or CC is used to control all the virtual machines for executions the virtual machines are stored on the nodes and manages the virtual networking between Virtual machines and external users.
Storage Controller or SC provides a storage area in block form that are dynamically attached by Virtual machines.
Node Controller or NC is at the lowest level and provides the functionality of a hypervisor that controls the VMs activities, which includes execution, management and termination of many instances.
5. Explain the difference between cloud and traditional datacenters?
Answer: The expenditure of the traditional data center is expensive due to heating and hardware/software issues
Cloud being scaled when there is an increase in demand. Mostly the expenditure is on the maintenance of the data centers, while this issues are not faced in cloud computing.
6. Explain how can I vertically scale an Amazon instance?
Answer: This is one of the essential features of AWS and cloud virtualization. SpinUp a newly developed large instance where we pause that instance and detach the root Ebs volume from the server and discard. Later stop your live instance, detach its root volume connected. Note down the unique device ID and attach the same root volume to the new server. And restart it again. This results in vertically scaled Amazon instance.
7. What is an AMI? How do we implement it?
Answer: AMI stands for Amazon Machine Image. It is basically a copy of the root file system.
Provides the data required to launch an instance, which means a copy of running an AMI server in the cloud. It’s easy to launch an instance from many different AMIs.
Hardware servers that commodities bios which exactly point the master boot record of the first block on a disk. A disk image is created which can easily fit anywhere physically on a disk .Where Linux can boot from an arbitrary location on the EBS storage network.
8. What is the requirement of virtualization platforms in implementing cloud?
Answer: Virtualization is the basis of the cloud computing and there are many platforms that are available like VMware is a technology that provides the provision to create private cloud and provide a bridge to connect external cloud with private cloud. There are three key features that have to be identified to make a private cloud that is:
Cloud operating system.
Manage the Service level policies.
Virtualization keeps the user level and the backend level concepts different from each other so that a seamless environment can be created between both.
9. What are the characteristics of cloud architecture that differs from traditional cloud architecture?
The characteristics are:
The hardware requirement is being provided as per the demand created for cloud architecture.
Cloud architecture is capable of scaling the resource on demand created.
Cloud architecture is capable of managing and handling dynamic workloads without any point of failures.
10. What is Hypervisor in Cloud Computing and its types?
Answer: The hypervisor is a virtual machine monitor (VMM) that manages resources for virtual machines. The name hypervisor is suggested as it is a supervisory tool for the virtual machines.
There are mainly two types of hypervisors :
Type-1: the guest Vm runs directly over the host hardware, e.g Xen, Hyper-V, VmWare ESXi
Type-2: the guest Vm runs over hardware through a host OS, e.g Kvm, Oracle VirtualBox
11. What is Cloud and Cloud Computing?
Cloud: A cloud is a term comprised of hardware, storage, services, and interfaces which helps in providing computing as a service from a remote location it has three kinds of users:
Cloud Service Provider
Business Management Users
Cloud Computing: Cloud computing is a defined as on-demand delivery of computing power, database storage, applications, and other IT resources through a cloud services platform via the internet so that cloud delivers service worldwide.
A user can manipulate, configure, and access the hardware and software resources remotely in cloud computing.
12. Name some basic characteristic of cloud computing?
Below are some of the essential characteristic of cloud computing:
On-demand self-service with a provision of storage, computing etc.
Broad network access can be used in the thin or thick client platform
Support rapid elasticity so that it can grow and shrink as per requirement
Measured Services with pay as you go pricing model.
13. What are the characteristics of Cloud Foundry?
Answer: Cloud Foundry is capable to offer hardware requirement depending on the demand. Without failure, it is capable of handling and controlling aggressive workloads. Also, Cloud Foundry is capable to escalate the resource on demand. There are other characteristics such as scalability and using different languages on a single app.
14. What is Diego Brain?
Answer: Diego Brain distribute Tasks and LRPs to Diego Cells and corrects discrepancies between Actual and Desired counts to ensure fault-tolerance and long-term consistency.
15. What is Diego in CF?
Answer: Diego is a self-healing container management system that attempts to keep the correct number of instances running in Diego Cells to avoid network failures and crashes. Diego schedules and runs Tasks and Long-Running Processes (LRP).
16. List out the components of Cloud Foundry?
The list of Cloud Foundry components:
Cloud Foundry Components
Authentication: OAuth2 Server (UAA) and Login Server
App Lifecycle: Cloud Controller and Diego Brain, nsync, BBS, and Cell Reps
App Storage and Execution: Blobstore, Diego Cell
Services: Service Brokers
Messaging: Consul and BBS
Metrics and Logging: Loggregator
17. What is BOSH in Cloud Foundry?
Answer: BOSH creates and deploys virtual machines (VMs) on top of a physical computing infrastructure, and deploys and runs Cloud Foundry on top of this cloud.
18. What is Cloud Foundry’s container-based architecture?
Answer: Cloud Foundry’s container-based architecture runs apps in any programming language over a variety of cloud service providers. This multi-cloud environment allows developers to leverage the cloud platform that suits specific app workloads and move those workloads as necessary within minutes with no changes to the app.
19. What are the services in Cloud Foundry?
Answer: In a Cloud Foundry platform, all external dependencies such as databases, messaging systems, files systems and so on are considered Services.
20. What is the Cloud Controller?
Answer: The CF Cloud Controller runs the apps and other processes on the cloud’s VMs, balancing demand and managing app lifecycles.
21. What is User Authentication and Authorization in CF?
Answer: CF manages user accounts through two User Authentication and Authentication (UAA) servers, which support access control as OAuth2 services and can store user information internally, or connect to external user stores through LDAP or SAML.
22. What is Open Service Broker API?
Applications deployed to Cloud Foundry access external resources via a Open Service Broker API.
23. What are nsync, BBS, and Cell Reps?
Answer: To keep applications available, cloud deployments must constantly monitor their states and reconcile them with their expected states, starting and stopping processes as required.
The nsync, BBS, and Cell Rep components work together along a chain to keep apps running. At one end is the user. At the other end are the instances of applications running on widely-distributed VMs, which may crash or become unavailable.
24. What is the router?
Answer: The router routes incoming traffic from the world to the VMs that are running the apps that the traffic demands, usually working with a customer-provided load balancer.
25. What are Service Brokers?
Answer: Applications typically depend on services such as databases or third-party SaaS providers. When a developer provisions and binds a service to an application, the service broker for that service is responsible for providing the service instance. (Pivotal Training Online)
26. What are the security features available in Cloud Foundry?
Cloud Foundry implements the following measures to mitigate against security threats:
Minimizes network surface area Isolates customer applications and data in containers
Uses role-based access controls, applying and enforcing roles and permissions to ensure that users can only view and affect the spaces for which they have been granted access
Ensures security of application bits in a multi-tenant environment
Prevents possible denial of service attacks through resource starvation
27. What are Isolation Segments?
Answer: Isolation segments provide dedicated pools of resources to which apps can be deployed to isolate workloads. Using isolation segments separates app resources as completely as if they were in different CF deployments but avoids redundant management components and unneeded network complexity.
28. What measures CF can take for Container Security?
Answer: CF secures containers through the following measures:
Running application instances in unprivileged containers by default
Hardening containers by limiting functionality and access rights Only allowing outbound connections to public addresses from application containers.
This is the original default.
Administrators can change this behavior by configuring ASGs.
29. What is Zipkin Tracing?
Answer: Zipkin is a tracing system that enables app developers to troubleshoot failures or latency issues. Zipkin provides the ability to trace requests and responses across distributed systems.
30. How do you deploy Cloud Foundry?
Answer: If installing Cloud Foundry for the first time, deploy with cf-deployment.
If you have an existing Cloud Foundry deployment that uses cf-release, migrate your deployment to cf-deployment.
31. How do you use Docker in Cloud Foundry?
Answer: By default, apps deployed with the cf push command run in standard Cloud Foundry Linux containers. With Docker support enabled, Cloud Foundry can also deploy and manage apps running in Docker containers.
To deploy apps to Docker, developers run cf push with the –docker-image option and the location of a Docker image to create the containers from.
32. What do you know about cloud foundry?
Answer: Cloud Foundry is basically a multi-cloud application platform which is open source in nature and is generally considered for running, deploying, building as well as scaling applications. It supports PHP, GO, Node.JS, .NET, Ruby on rails and Staticfile. Because of its open source nature, developers can simply code in multiple languages. This is exactly what that eliminates the need of vendor lock-in.
33. How Iaas and PaaS are different terms?
Answer: Infrastructure as a Service (IaaS) basically provides a base infrastructure and the end users are liable for configuration of environment and platform which is significant to expand applications. The common examples of this approach are Microsoft Azure and Amazon Web Service.
Platform as a Service (PaaS) is useful when it comes to cutting down the environment configuration by offering a platform which is always ready-to-use. It is possible to host PAAS services on the top of IAAS infrastructure.
34. What do you know about cloud load balancing?
Answer: Cloud Foundry installation complete this tasks at three different levels
Cloud Foundry controller simply runs the applications and some other operations on the cloud virtual machines simply balancing the demand.
Bosch simply comes out with virtual machines on the head of a computing infrastructure. After this, it expands and run cloud foundry on the top of cloud. A manifest document is followed to simply configure this deployment process.
Router simply route the traffic to Virtual machines that runs the apps in such a way that it start working with a client-provided load balancer.
35. What do you know about using services with Cloud Foundry?
Answer: Generally the apps are dependent on the metered or free services like API or databases. To assimilate these into apps, developers can write a service broker which is basically an API that broadcast to Cloud Controller the provisioning of service, service offering and empower apps to make calls.
36. What Security aspects are available with the Cloud Foundry?
Cloud Foundry assures several security aspects and common ones are:
1. Access Control: Users are provided permission to control the access of others who enter the cloud environment
2. Identity Management: authorizing the application services is done by identity management
3. Authorization and Authentication: To ensure security, cloud Foundry only allows the authenticated and authorized users to access applications, data or any information.
Thus cloud foundry is secure
37. How monitoring and analyzing of Cloud Foundry can be done?
Well, it is not a big deal. As the cloud simply runs, router Virtual machines, cloud controller virtual machines and other apps running on virtual machines develop metrics and logs. Logg-regartor system manages the concerned data in a usable and structured form i.e. the firehouse. It is possible to simply direct the outcome for specific uses like analyzing and monitoring user behavior simply by considering nozzles.
38. Tell about the different modes of Software as a service (SAAS)?
Answer: There are two modes basically and they are “Fine-grain multi-tenancy in which resources are simply shared without limit but functionality doesn’t change. Other mode is “Simple multi-tenancy” in which every user has self-reliant resources and is quite distinct as compared with other users. Generally it is considered as a powerful mode than others.
39. How the components of cloud Foundry communicate?
Answer: By simply posting the messages internally with the help of https protocols and Http, components can communicate with each other. It is also possible that they can send NATS messages directly to each other.
40. As an (IaaS), infrastructure as a service, what resources are provided by Cloud Foundry?
Answer: There are physical as well as Virtual resources that are used to build a cloud. It generally deals with the problems associated with maintaining and expanding of the services.
Tell the different models available for the deployment of Cloud Foundry
Cloud Foundry can simply be deployed through any of the following model depending upon exact need and the type of results:
1. Public cloud
2. Private Cloud
3. Hybrid Cloud
4. Community cloud
41. What is the Cloud Foundry Foundation Developer Training and Certification Program?
Answer: The Cloud Foundry Foundation Developer Training and Certification Program is a suite of training and certification products expressly designed to equip developers with a valuable, marketable skill set across all distributions of the industry-standard cloud application platform (including Huawei Fusion Stage, IBM Blue mix Cloud Foundry, Pivotal Cloud Foundry, SAP Cloud Platform and Swisscom Application Cloud). The program includes:
A free introductory course offered via the edX platform;
A self-paced e Learning Cloud Foundry Developer class;
A training partner program which includes licensed materials for in-person Cloud Foundry developer classes, offered by member companies including DellEMC, Engineer Better, IBM, Pivotal, Resilient Scale, SAP, Stark and Wayne and Swisscom;
“Cloud Foundry Certified Developer” Certification, awarded to individuals who pass a performance-based exam.
42. Where is the program offered? When does it start? How do I sign up?
Find full details on the Training program here and the Certification process here.
The free introductory Massive Open Online Course, or MOOC, is offered in partnership with the Linux Foundation and will be available via edx.org with the title “Introduction to Cloud Foundry and Cloud Native Software Architecture.” It will be available in early May.
The self-paced eLearning “Cloud Foundry for Developers” is offered in partnership with the Linux Foundation. Students interested in enrolling can get more information here. Organizations interested in bulk purchase agreements can contact Michelle McManus at mmcmanus@cloud foundry.org. It will be available on June 13.
The Cloud Foundry Certified Developer certification is a performance-based certification exam designed to verify a candidate’s expertise using the Cloud Foundry platform and building cloud-native applications. The certification exam is offered in partnership with the Linux Foundation and can be accessed here. (You will need a Linux Foundation ID. See below for details.)
Additionally, the exam will be offered in-person at the Cloud Foundry Summit on April 18-20. Register for on-site certification when you sign up for Summit and receive a discount on your ticket.
43. What qualifications are needed by a candidate for Certification in order to take the test?
Answer: Candidates for the Certification exam should have hands-on practical experience building software that runs on Cloud Foundry. Those who do not have this experience should choose a Cloud Foundry training course — either the free introductory MOOC or self-paced eLearning course.
44. How many exams constitute the Certification process? How long will it take? What topics does it cover?
Answer: There is a single exam that includes performance-based questions (complete the work/task) and multiple choice. It can take up to three hours to complete.
Candidates should be comfortable modifying simple Java, Node.js or Ruby applications.
Topics covered in the exam include:
- Cloud Foundry Basics
- Cloud-Native Architectural Principles
- Troubleshooting Applications on Cloud Foundry
- Cloud-Native Application Security
- Working with Services in Cloud Foundry
- Application Management on Cloud Foundry
- Container Management within Cloud Foundry
45. What is the cost of the Certification exam?
Answer: If you are an individual developer who wishes to purchase the Certification exam, you will pay $300. For a pricing list for organizations looking to purchase in bulk, please email Timothy Harris.
46. What Are The Basic Characteristics Of Cloud Computing?
The four basic characteristics of cloud computing are given as follows:
- Elasticity and scalability.
- Self-service provisioning and automatic de-
- Standardized interfaces.
- Billing self-service based usage model.
47. How Would You Save Your Applications, Softwares And Drivers For A Long Term Without Using Any Magnetic Disk?
Answer: I do not have to worry about my computer hardware at home because all my applications, files, games will be present somewhere on the Internet with cloud computing. The necessity is very fast connection.
48. Why Cloud Is Necessary?
Answer: Amongst those who are already using the cloud, 94 % said the infrastructure was an important part of their decision but there is not one universal cloud infrastructure which suits every environment.
49. Explain The Benefits Of Cloud Computing?
Answer: There are numerous benefits of cloud computing including data backup and storage of data, powerful server capabilities, software asa service known as (SaaS), Information technology sandboxing capabilities etc.
50. What Is The Use Of Apis In Cloud Services?
Answer: API stands for Application programming interface is very useful in cloud platforms as it allows easy implementation of it on the system. It removes the need to write full-fledged programs. It provides the instructions to make the communication between one or more applications. It also allows easy to create an application with ease and link the cloud services with other systems.