Google Cloude: Compute Engine

Question 1

What is compute engine?

Answer 1

Compute Engine delivers configurable virtual machines running in Google’s data centers with access to high-performance networking infrastructure and block storage.

Question 2

What is global load balancing?

Answer 2

Global load-balancing technology helps you distribute incoming requests across pools of instances across multiple regions, so you can achieve maximum performance, throughput, and availability at low cost.

Question 3

What is multi-tenancy?

Answer 3

The scheme in which different VMs belonging to different customers run on the same physical machine is called the multi-tenancy model.

Question 4

What are the benefits and downsides to multi-tenancy?

Answer 4

While multi-tenancy delivers better efficiency and economy of scale, a certain type of workloads suffers from the noisy neighbor problem. A VM running in multi-tenancy mode can consume maximum resources depriving other VMs their share. This scenario results in degraded performance of applications that demand unmatched bandwidth, storage throughput, and CPU time.

Question 5

What are the benefits and downsides to single tenancy?

Answer 5

Single-tenancy ensures that customers have control over the placement logic. For workloads that need 100% access to hardware resources, customers can choose to deploy only one VM on the host. Even if they run multiple VMs, it’s guaranteed that all of them run on the same physical host assuring better privacy and security of data.

Question 6

What are the benefits and downsides to single tenancy?

Answer 6

Single-tenancy ensures that customers have control over the placement logic. For workloads that need 100% access to hardware resources, customers can choose to deploy only one VM on the host. Even if they run multiple VMs, it’s guaranteed that all of them run on the same physical host assuring better privacy and security of data.

The downside is that the cost is much higher than multi-tenancy

Question 7

Which opperating systems can be run on a vm?

Answer 7

Any:

Debian, CentOS, CoreOS, SUSE, Ubuntu, Red Hat Enterprise Linux, FreeBSD, or Windows Server 2008 R2, 2012 R2, and 2016.

Question 8

What are the different predefined machine types?

Answer 8

n general purpose
m Optimised for memory and data
c Optimized for computing

Question 9

What are preemptive vm’s?

Answer 9

Low-cost, short-term instances designed to run batch jobs and fault-tolerant workloads. Preemptible VMs provide significant savings of up to 80% while still getting the same performance and capabilities as regular VMs.

Question 10

What is the difference between HDD and SDD persistent disks and the difference betwteen local and persistent disks?

Answer 10

Persistent storage is any data storage device that retains data after power to that device is shut off. GC offers two types of persistent disks HDD and SDD.

Standard HDD persistent disks are efficient and economical for handling sequential read/write operations, but are not optimized to handle high rates of random input/output operations per second (IOPS).

If your applications require high rates of random IOPS, use SSD persistent disks

GC also offers a local SSD. Unlike Persistent Disks, Local SSDs are physically attached to the server that hosts your VM instance. This tight coupling offers superior performance, very high input/output operations per second (IOPS), and very low latency compared to persistent disks.

Question 11

What is live migration?

Answer 11

Compute Engine virtual machines can live-migrate between host systems without rebooting, which keeps your applications running even when host systems require maintenance.

Question 12

What gpu’s are used by Google Cloud?

Answer 12

NVIDIA Tesla

Question 13

Difference between CPU and GPU?

Answer 13

Architecturally, the CPU is composed of just a few cores with lots of cache memory that can handle a few software threads at a time. In contrast, a GPU is composed of hundreds of cores that can handle thousands of threads simultaneously.

CPU’s are good for serial processing, while GPUs are used mainly for parralel processing.

Question 14

When should you add GPU’s to an instance?

Answer 14

Big data and Graphic intensive programs

GPUs can be added to accelerate computationally intensive workloads like machine learning, simulation, medical analysis, and virtual workstation applications.

If you have graphics-intensive workloads, such as 3D visualization, you can create virtual workstations that use NVIDIA GRID® platform

Question 15

Which machine types can support GPU’s?

Answer 15

GPUs are currently only supported with general-purpose N1 machine types.

Question 16

What is per second billing?

Answer 16

Google bills in second-level increments. You pay only for the compute time that you use.

Question 17

What are sustained use discounts?

Answer 17

Sustained-use discounts are automatic discounts for running Compute Engine resources for a significant portion of the billing month.

Question 18

What is the difference between an internal and external ip address?

Answer 18

internal is used to communicate between instances on the same virtual private cloud, whereas external is used to communicated with the internet

Question 19

Difference between static and ephemeral ip address?

Answer 19

Static external IP addresses are assigned to a project long term until they are explicitly released from that assignment, and remain attached to a resource until they are explicitly detached.For VM instances, static external IP addresses remain attached to stopped instances until they are removed.

Ephemeral external IP addresses are available to VM instances and forwarding rules. Ephemeral external IP addresses remain attached to a VM instance only until the VM is stopped and restarted or the instance is terminated. If an instance is stopped, any ephemeral external IP addresses that are assigned to the instance are released back into the general Compute Engine pool and become available for use by other projects. When a stopped instance is started again, a new ephemeral external IP address is assigned to the instance.

Question 20

What can be used, instead of an internal ip, to communicate internally between instances?

Answer 20

internal fully qualified domain name (FQDN)

Question 21

How to setup firewall for a vm instance?

Answer 21

Go to VPC
Create firewall rule and add a target tag
Go to the virtual machine instance, edit and ad the tag.

Question 22

What is a machine image?

Answer 22

A machine image is a Compute Engine resource that stores all the configuration, metadata, permissions, and data from one or more disks required to create a Virtual machine (VM) instance. You can use a machine image in many system maintenance scenarios, such as instance creation, backup and recovery, and instance cloning.

Question 23

How to install git on a linux machine?

Answer 23

sudo apt update
sudo apt upgrade
sudo apt install git

Question 24

What is the difference between App engine and Compute Engine?

Answer 24

App Engine is a Platform-as-a-Service. It means that you simply deploy your code, and the platform does everything else for you. For example, if your app becomes very successful, App Engine will automatically create more instances to handle the increased volume.

Compute Engine is an Infrastructure-as-a-Service. You have to create and configure your own virtual machine instances. It gives you more flexibility and generally costs much less than App Engine. The drawback is that you have to manage your app and virtual machines yourself.