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Q48 & 49

Question 48. What Is A Placement Group In Ec2 ? Answer : AWS provides an option of creating a Placement Group in EC2 to logically group the instances within as single Availability Zone. We get the benefits of low network latency and high network throughput by using a Placement Group. Placement Group is a free option as of now. When we stop an instance, it will run in same Placement Group in restart at a later point of time. The biggest limitation of Placement Group is that we cannot add Instances from multiple availability zones to one Placement Group. Question 49. What Types Of Issues Do You Face While Connecting To An Ec2 Instance ? Answer : Some of the possible connection issues with EC2 instance are: Connection time out Permission denied due to host key not found Unprotected private key file Permission denied due to user key not recognized by server No supported authentication method available Server refused the key AWS Video Training
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Q47

Question 47. What Are The Main Features Of Application Load Balancer (alb) In Amazon Ec2 ? Answer : Main features of Application Load Balancer (ALB) are as follows: Content-Based Routing:  In ALB, we can make use of content in the request to decide the routing of a request to a specific service. HTTP/2:  ALB supports the new version of HTTP protocol. In this protocol, we can send multiple requests on same connection. It also supports TLS and header compression. WebSockets:  ALB supports WebSockets in EC2. With WebSockets, a server can exchange real-time messages with the end-users. Layer-7 Load Balancing:  ALB can also load balance HTTP/HTTPS application with layer-7 specific features. Delete Protection:  ALB also provides Delete Protection option by which we can prevent it from getting deleted by mistake. Containerized Application Support:  We can use ALB to load balance multiple containers across multiple ports on same EC2 instance.
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Q46

Question 46. What Are The Main Features Of Classic Load Balancer In Ec2 ? Answer : Some of the main features of Classic Load Balancer (CLB) in Amazon EC2 are as follows: Health Check:  Based on the result of Health Check, Classic Load Balancer can decide to route the traffic. If any instance has unhealthy results, CLB will not route the traffic to that instance. Security:  We can create security groups for CLB in Virtual Private Cloud (VPC). With these features, it is easy to implement secure load balancing within a network. High Availability:  With CLB, we can distribute traffic among EC2 instances in single or multiple Availability Zones. This helps in providing very high scale of availability for the incoming traffic. Sticky Sessions:  CLB also supports sticky session by using cookies. The sticky sessions make sure that the traffic from a user is always routed to the same instance so that user gets seamless experience. IPv6:  CLB also support Internet Protocol version 6. Operational
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Q45

Question 45. What Is The Difference Between A Spot Instance And A Demand Instance On Ec2 ? Answer : “On-Demand” instances allow the user to use the compute by hour without requiring long term commitment. There are no guarantees that the user will always be able to launch specific instance types in an availability zone, though AWS tries it’s best to meet the needs. This service is preferable for POCs and they do not suffer an interruption of the service(by AWS) like Spot instances. “Spot” instances are a bid_for_low_price version of On-Demand instances, but could be shut down by AWS anytime the Spot instance price goes higher than bid price. Spot price fluctuates based on the supply and demand of the capacity. It’s essentially the leftover capacity of AWS to be used. There is no difference in the performance compared to On-Demand instances and is usually cheaper than On-demand instances as there is no guarantee provided over the availability. The user can choose a start time and end tim
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Q43 & 44

Question 43. What Is The Underlying Hypervisor For Ec2 ? Answer : Xen Question 44. What Are Spot Instances In Amazon Ec2 ? Answer : In Amazon EC2, we can even bid for getting a computing instance. Any instance procured by bidding is a Spot Instance. Multiple users bid for an EC2 Instance. Once the bid price exceeds the Spot price, the user with the highest bid gets it. As long as their bid price remains higher than the Spot price, they can keep using it. Spot price varies with the supply and demand. Once Spot price exceeds Bid price, the instance will be taken back from the user.
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Q42

Question 42. How You Will Change The Root Ebs Device Of My Amazon Ec2 Instance ? Answer : Stop the instance. Detach the root EBS volume. Attach the alternate EBS volume (as the root e.g. /dev/sda1) Start the instance. This presupposes that your alternate EBS volume is bootable, of course – it has to contain the bootable OS image.
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Q41

Question 41. Explain What Happens When I Reboot An Ec2 Instance ? Answer : Rebooting an instance is like rebooting a PC. The hard disk isn’t affected. You don’t return to the image’s original state, but the contents of the hard disks are those before the reboot. Rebooting isn’t associated with billing. Billing starts when you instantiate an image and stops when you terminate it. Rebooting in between hasn’t any effect.
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