EC2 Fundamental Flashcards
(103 cards)
1
Q
What is budget
A
A way to cap the usage of services in AWS
2
Q
What are the variations of budget
A
Cost, Usage, Reservation and Savings Plan
3
Q
What is budget threshold
A
The percentage of forecast, exceeding which a notification is triggered
4
Q
What are core 4 services of EC2
A
VM (EC2), Storing Data on Virtual Drive (EBS), Distributing Load Across VM (ELB) and Scaling Service using Auto - Scaling Group (ASG)
5
Q
Which OS can you select for EC2
A
Linux, Windows and Mac
6
Q
Can you choose compute power
A
Yes, via CPU
7
Q
Can you choose RAM
A
Yes
8
Q
What are the storage options
A
Network Based & Instance Based
9
Q
What are network based store
A
EBS & EFS
10
Q
Can you select the network card for EC2
A
Yes
11
Q
What are security groups
A
Firewall rules
12
Q
What is Bootstrap script
A
The start up script for EC2, that runs once at start up
13
Q
How many instance types are there
A
7
14
Q
In the expression m5.2Xlarge what m means
A
instance class
15
Q
In the expression m5.2Xlarge what 5 means
A
generation
16
Q
In the expression m5.2Xlarge what 2Xlarge means
A
size within the instance class
17
Q
what are the things that security group restricts
A
ports, IP (from where the instance is accessed), inbound traffic and outbound traffic
18
Q
can one security group be attached to multiple instances?
A
yes
19
Q
can a security group belong to multiple VPC in same region
A
no
20
Q
can a security group belong to multiple region
A
no
21
Q
inbound traffic are allowed by default - true/false
A
false
22
Q
outbound traffic are allowed by default - true/false
A
true
23
Q
what is 22 port for
A
SSH
24
Q
what is 21 port for
A
FTP
25
what is `22 port also used for
SFTP
26
what is 80 used for
HTTP
27
what is 443 used for
HTTPS
28
what is 3389 used for
remote desktop protocol for windows
29
can a security group refer other security groups
yes
30
what is EC2 Instance Connect
browser based instance connectivity option
31
what type of OS are supported by EC2 Instance Connect
Linux
32
can we block port 22 and still use EC2 Instance Connect to SSH to the machine
no
33
should you use IAM access key and secret key inside a VM to be able to other VM
no, this is dangerous, use IAM role instead
34
how can one EC2 connect with AWS services
using IAMrole
35
how many instance purchase options are there
5
36
what are the options
on - demand, reserved, dedicated - host, spot, dedicated - instance
37
which option is best suited for short - term, unpredictable work load
on - demand
38
on - demand (non - linux) instances are billed per minute - TRUE/FALSE
FALSE, they are billed per hour
39
what is the billing option for linux machines
billing per second after the first minute
40
how much max discount is available for reserved instances
75%
41
what are the reservation periods
1 to 3 years
42
what are the purchasing options for reserved instances
no upfront, partial upfront, all upfront
43
can you change instance type of reserved instance
yes (for convertible reserved instances)
44
what is scheduled reserved instances
the one which can be launched during the prescheduled time period
45
what is max discount for spot instances
90%
46
when can a spot instance be consumed back by aws
when you are not willing to pay for current price of the spot instance
47
what kind of work load is suitable for spot instances
batch jobs, data analysis, image processing, any distributed workload
48
what is a dedicated host
a physical server to host ec2 instances leased to the user for at least 3 years
49
what are the benefits of dedicated host
* regulatory compliance
* bring your own license
50
what are the similarities between dedicated host and dedicated instances
1. both enables availing of dedicated physical server
2. both supports automatic instance placement
51
what are the core differences between dedicated host and dedicated instances
1. dedicated instances all run on same physical server tied to an account with per instance billing, on the other hand dedicated hosts are billed per host.
2. dedicated host gives lot of control on the physical server attributes
52
how does spot instance mechanism works
when current\_spot\_price is \< max price that user is ready to pay, the instances either gets terminated or stopped based on chosen configuration
53
what is a spot block
spot block is a predefined period when the instances will not be consumed despite of the current spot price becoming lesser than max price that one has agreed to pay
54
what is a spot request
spot request is a way to ask for spot instances
55
what comprises of spot requet
1. maximum price
2. desired number of instances
3. launch specification
4. request type (one time/persistent)
5. valid from and valid to
56
what happens with persistent spot request
if the instances are consumed back, they are brought up automatically by aws
57
what is one time spot request
a way to get spot instances one off
58
does canceling a spot request terminate the requests as well
no
59
which states of spot instance support cancellation
active, disabled, and open
60
what is spot fleet
a combination of spot instances and (optional) on - demand instances
61
what are launch pools for spot fleet
set of combinations of instance type, availability zone and OS
62
can the spot fleet choose a pool
yes
63
when does spot fleet stops launching
either after reaching max capacity or budget
64
what are strategies for spot fleet
lowest price, capacity optimized and diversified
65
what is lowest price strategy
provision instances from the pool with lowest price
66
what is capacity optimzed
provision instances from the pool with optimal capacity for the number of instances
67
what is 'diversified' approach for spot fleet instances
the instances are provisioned across available pools, thereby gurantying higher availability
68
Which EC2 Purchasing Option can provide you the biggest discount, but it is not suitable for critical jobs or databases?
Spot Instances are good for short workloads and this is the cheapest EC2 Purchasing Option. But, they are less reliable because you can lose your EC2 instance.
69
What should you use to control traffic in and out of EC2 instances?
Security Group
70
How long can you reserve an EC2 Reserved Instance?
1 or 3 years
71
You would like to deploy a High-Performance Computing (HPC) application on EC2 instances. Which EC2 instance type should you choose?
Compute Optimized
72
Which EC2 Purchasing Option should you use for an application you plan to run on a server continuously for 1 year?
Reserved Instances
73
You are preparing to launch an application that will be hosted on a set of EC2 instances. This application needs some software installation and some OS packages need to be updated during the first launch. What is the best way to achieve this when you launch the EC2 instances?
Build a script that does all required installations. Then use EC2 User Data to bootstrap your EC2 instances using a bash script. This script can contain commands such as installing software/packages, download files from the Internet, or anything you want.
74
Which EC2 Instance Type should you choose for a critical application that uses an in-memory database?
Memory Optimized
75
You have an e-commerce application with an OLTP database hosted on-premises. This application has popularity which results in its database has thousands of requests per second. You want to migrate the database to an EC2 instance. Which EC2 Instance Type should you choose to handle this high-frequency OLTP database?
Storage Optimized
76
Security Groups can be attached to only one EC2 instance.
False
77
You're planning to migrate on-premises applications to AWS. Your company has strict compliance requirements that require your applications to run on dedicated servers. You also need to use your own server-bound software license to reduce costs. Which EC2 Purchasing Option is suitable for you?
Dedicated Host
78
You would like to deploy a database technology on an EC2 instance and the vendor license bills you based on the physical cores and underlying network socket visibility. Which EC2 Purchasing Option allows you to get visibility into them?
Dedicated Host
79
what are the key differences between public and private ip
public ip is exposed over internet vs. private ip needs NAT and IG to expose
public ip can be geo located vs. private ip can not
public ip is never duplicated vs. private ip (within a network) can
80
what are private IP ranges
* Class A: 10.0.0.0 to 10.255.255.255
* Class B: 172.16.0.0 to 172.31.255.255
* Class C: 192.168.0.0 to 192.168.255.255
81
what is elastic ip
elastic ip are those public ip assigned to VMs as long as the VMs are not destroyed
82
what is placement group
a set of strategies to control how the EC2 instances are placed on AWS hardware
83
what are 3 typical placement groups
cluster, spread and partition
84
what is cluster placement group
all EC2 instances stays on same rack of same AZ
85
what is the pros and cons of cluster placement group
pros - very low network latency; cons - single point of failure
86
what is spread placement group
all EC2 instance stays on different availability zone
87
what are benefit of spread placement group
pros - highly available; cons - there can be 7 instances per placement group per availability zone
88
what is partition placement group
partition placement group is a technique where each instances belong to a partition (i.e. a physical rack), across multiple AZ within the same region
89
how many partition placement group can be placed per availability zone
7
90
what is the core benefit of partition placement group
because of the fact that instances do not share racks the risk of failure is very low
91
what is elastic network interfaces
logical component in a VPC that represents virtual network card
92
can ENI have multiple private IPs
yes
93
how many elastic ip can be associated per private ip
one
94
how many security groups can be associated with a ENI
multiple
95
does ENI has a MAC address
yes
96
can ENI be attached on the fly
yes
97
can ENI span across multiple availability zones
no
98
what is hibernate option in EC2
this is a mechanism where the entire state of RAM is written to a file in root partition, so that even when the machine is stopped and restarted, the OS can be put back to where it was at last state
99
is hibernation supported for all instance family
no, there are only selected few - the C, M and R series are the one being used
100
what is the maximum size of instance RAM
150 Gb
101
is hibernation supported on Bare Metal
no
102
what is the characteristic of the ROOT volume
it must be EBS backed, encrypted, non - instance store and significantly large
103
how long instances can be hibernated
not more than 60 days
