AWS EC2 Flashcards

1
Q

EBS - SSD - IOPs

A
  • GP2 16000 IOPS

- IO1 - 64K IOPS

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2
Q

EC2 Hibernation

A
  • preserves in memory RAM on EBS
  • Must be less than 150gb
  • Can’t hibernate > 60 days
  • On-demand and Reserved
  • Windows, Linux AMI, Umbunto
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3
Q

If you delete an ASG, what happens to the instances?

A

The instances will be terminated and the ASG will be deleted.

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4
Q

EC2 ASGs can span AZs and Regions - true or false?

A

False… ASGs only span AZs not regions.

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5
Q

How would you ensure only traffic to EC2 instance from an ELB

A

configure the security group of the ec2 instances to allow only traffic from the ELB

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6
Q

Can you change instance size while running

A

Yes. Simple button push

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7
Q

Two methods for accessing meta data of ec2 instances

A

169.254.169.254/latest/meta-data

Metadata Query Tool

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8
Q

An elastic IP Address is public or private?

A

Public

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9
Q

Easy way to move a private network between two ec2 instances (primary and standby) in failure of the primary?

A

Use an ENI. Move on failure.

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10
Q

How does cross zone load balancing work with 1 instance in az1 and 4 instances in az2

A

All get 20%

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11
Q

How does load balancing work with 1 instance in az1 and 4 instances in az2 without cross zone balancing

A

50% in az1. And 50% in az2 split across 4 instances

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12
Q

Ec2 auto scaling picks the highest capacity policy if two events trigger at the same time. True or false

A

True

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13
Q

You can use an internet gateway ID as the custom source for a security group rule?

A

False

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14
Q

A recovered instance is identical to the original. Including Id. IPs. And metadata

A

True

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15
Q

Allows elb to complete inflight requests?

A

Connection draining

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16
Q

True or false, an ebs volume can be used normally while a snapshot is in progress?

A

True

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17
Q

Load balancer is not sending data to an instance, Why?

A

Instance has failed the elb health check

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18
Q

Can you Create a cloud watch alarm to reboot instances

A

True

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19
Q

Cold Attach

A

Instance is being launched

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20
Q

Hot attach

A

Instance is running

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21
Q

Warm attach

A

Instance is stopped

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22
Q

ASGs are only scaling out a portion of the instances …why?

A

VCPU based limits

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23
Q

You can change the security group when the instance is in a running or stopped state?

A

True

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24
Q

Default Configuration of the default NACL is

A

Allow

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25
Q

Default Configuration of a custom NACL is

A

Deny

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26
Q

Can you change a default security group

A

Yes

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27
Q

Can you delete the default security group

A

No

28
Q

How do you allow a group of developers the ability to assume a role that allows access to aws services?

A

Create a policy that allows certain permissions needed by the devs
Create a role using the policy just created
Create a policy that allows that role to be assumed
Attach the policy to the IAM group for devs

29
Q

Can an IAM group assume a role

A

No

30
Q

Assuming a role gives you permanent access

A

False. Roles grant temp access

31
Q

What aws resources can assume a role

A

A role can be assumed by a human user or a machine principal, such as an Amazon Elastic Computer Cloud (Amazon EC2) instance or an AWS Lambda function

32
Q

Auto scaling cooldown

A

Wait time scaling takes before takings action…. 5mins default

33
Q

Allows a spot instance to run uninterrupted for 1 to 6 hours

A

Spot block

34
Q

Default security group settings

A

Allow inbound from all within same group

Allow all outbound

35
Q

What are the rules of a new security group?

A

Inbound Deny

Outbound Allow All

36
Q

What interfaces get DNS Hostnames using the default VPC?

A

Both Public and Private get Hostnames

37
Q

What interfaces get DNS Hostnames using the non-default VPC?

A

Private gets a DNS Hostname

Public does not get a DNS Hostname

38
Q

You can only attach an instance store to an EC2 instance at launch?

A

True.

39
Q

Do all instance types support encryption?

A

No… all families do, but not all types within those families.

40
Q

How can you optimize the EBS volumes attached to your EC2 instance?

A

Use EBS Optimized Instances

41
Q

Adding an ASG to an ELB… what health checks should be enabled on the ASG?

A
  • EC2 which is by default

- ELB - so that the ASG knows the ELB has marked the instance as unhealthy

42
Q

Used to execute scripts from the console on all target EC2 instances

A

RUN Command

43
Q

How to use a new AMI in a Launch Configuration

A
  • Create a New Launch Config using the new AMI

- Update the ASG to use the new Launch Config

44
Q

Placement group that enables workloads to achieve the low-latency network performance necessary for tightly-coupled node-to-node communication that is typical of HPC applications.

A

Cluster

45
Q

Placement group where instances do not share the underlying hardware with groups of instances….This strategy is typically used by large distributed and replicated workloads, such as Hadoop, Cassandra, and Kafka.

A

Partition

46
Q

Placement group that places a small group of instances across distinct underlying hardware to reduce correlated failures.

A

Spread

47
Q

Do gp2 ebs volumes support multi-attach

A

No. Multi-Attach is supported exclusively on Provisioned IOPS SSD volumes.

48
Q

Does hibernating an ec2 instance preserved an instance store volume or save the data

A

No

49
Q

During rebalancing, asg launches new before termination of old?

A

True

50
Q

Asg terminates unhealthy instances before launching new

A

True

51
Q

You have an asg across 3azs… what is the min capacity to be highly available?

A

2

52
Q

Used to customize dynamic ec2 configuration options

A

User data

53
Q

EC2 instance in an Auto Scaling group is having some issues that are causing it to launch new instances based on the dynamic scaling policy. How to troubleshoot and stop the current scaling…

A

Suspend the scaling processes responsible for launching new instances
Place the EC2 instance that is experiencing issues into the Standby state

you can suspend a scaling process… no need to disable

54
Q

The following are a few reasons why an instance might immediately terminate:

A

– You’ve reached your EBS volume limit.
– An EBS snapshot is corrupt.
– The root EBS volume is encrypted and you do not have permissions
– The instance store-backed AMI that you used to launch the instance is missing a required part (an image.part.xx file).

55
Q

Using IP addresses as targets allows load balancing any application hosted in AWS or on-premises using IP addresses

A

true

56
Q

The logical ID is used to reference the resource in parts of the template for CloudFormation.

A

true

57
Q

Lambda runtimes

A
Java 
C#
Go
Ruby
Power shell
Node is
58
Q

Can instance volumes be used at boot volumes

A

Yes

59
Q

Asg rebalancing launches new before terminating

A

True. Unlike unhealthy

60
Q

Need DB with no write downtime?

A

Aurora multi master

61
Q

Reasons asg might not terminate instances

A

In impaired stas
Health grace period not expired
Failed elb check

62
Q

Asg de-registration delay can do what?

A

Delay the scaling in event allows the target to complete work

63
Q

Can you use a launch configuration with multiple instance types?

A

No. Use a launch template?

64
Q

When to use Enhanced networking

A

High throughput. 10gbs to 100gbs

65
Q

Can you hibernate an ec2 with instance store and keep the data

A

No. You will lose the data

66
Q

Status check failed_instance

A

Problems that require your attention…. Vs. “…_system” that require amz attention