Virtualization

Question 1

What is Load Balancing?

Answer 1

In general, a load balancer:

• is located between a client and application server
• receives a request from a client
• forwards a request to an appropriate server

Question 2

What is a Load Balancer listener?

Answer 2

Sets rules to forward a request to a target group, to 0 or more VMs using different Protocol and port - HTTP 80 - HTTPS 443

It can complete Health Checks ensure requests are sent to running targets

Protocol and Path, e.g., HTTP and / Interval, e.g., 30 seconds

• Scheduling - Round Robin - Least Outstanding Requests

Question 3

What layer does the Application Load Balancer reside on?

Answer 3

Application layer (Layer 7) of OSI model

Question 4

What network features do load balancers have?

Answer 4

• Unique protocols/portswhich listeners check for requests
• One or two listeners,

Listener A checks requests arriving via HTTP 80

Listener B checks requests arriving via HTTPS 443

• At least 2 Availability Zones

An ALB only forwards requests to targets (VMs) in these AZs

• Security Groupto allow traffic on specific protocols/ports, e.g.,

HTTP 80 for web requests

RDP 3389 for remote login

Question 5

If a Load balancer is set to Y & Z availaibility zone, where does the VMs have to be set?

Answer 5

A VM is assigned an Y & Z too

Question 6

What layer of the OSI model does a Network Balancer reside at?

Answer 6

transport layer (Layer 4) of the OSI model which includes TCP, UDP and TLS

Question 7

What values does Network load balancer use?

Answer 7

The selection of a target is based on several values from the UDP (TCP) packet:

protocol, source IP address, source port, destination IP address, destination port, (TCP sequence number)

Question 8

How many Availability Zones do a Network load balancer require?

Answer 8

At least 1 Availability Zone
One or more Target Groups

Question 9

What does a network balancer do?

Answer 9

Sorts TCP and UDP packets

Question 10

What does Virtualisation represent?

Answer 10

the creation of a simulation/emulation of physical hardware

• Access to CPU cycles instead of a physical CPU
• Access to memory storage instead of physical RAM
• Access to disk storage instead of physical disk/s
• Access to network instead of physical network cards, switches, etc

Question 11

What are the abilities of Virtualisation?

Answer 11

• Scaling(in/out, up/down)
• Migrationof running systems
• Improved security

Question 12

what are some advantages of virtualisation?

Answer 12

• Lower physical hardware requirements
• Lower running costs, e.g., power, cooling, etc.
• Potentially reducing administration staff costs
• Rapid deployment templates / cloning
• Automated recovery

Question 13

What are some Virtualisation Disadvantages?

Answer 13

• Loss of single physical server, result in loss of multiple virtual servers
• Measurable overhead, even a server running a single VM will not perform as well as running on direct hardware
• Additional complexity when diagnosing failures

Question 14

What are 3 Virtualisation Platforms?

Answer 14

• Hardware
• Hypervisors
• Paravirtualisation

Question 15

What are 2 hardware technologies that support virtualisation?

Answer 15

Intel VT-xand AMD-V

Question 16

What are type 1 Hypervisors?

Answer 16

• Microsoft Hyper-V
• Parallels Workstation
• VMware ESXi
• Xen Hypervisor

Question 17

What are type 2 Hypervisors?

Answer 17

• Microsoft Virtual PC
• Parallels Desktop
• Virtual Box
• VMware Fusion / Player / Server / Workstation

Question 18

What does Paravirtualisation allow?

Answer 18

• The guest OS to access the VM but also a portion of the hypervisor
• The OS can use accessible hypervisor services to improve performance

Question 19

What is VMware vSphere

Answer 19

• A leader in Virtualisation Management
• vMotionis the technology that supports live migration of VMs from one physical server to another
• Support for virtual switches
• many more features

Question 20

What does ICM represent

Answer 20

Install, confirgure and manage