AMAZON EC2
Q: What is the difference between stopping and terminating an EC2 instance?
A: While you may think that both stopping and terminating are the same, there is a difference. When you stop an EC2 instance, it performs a normal shutdown on the instance and moves to a stopped state. However, when you terminate the instance, it is moved to a stopped state and the EBS volumes attached to it are deleted and can never be recovered.
Q: What are the different types of EC2 instances based on their costs?
A: The three types of EC2 instances are:
On-demand instance - It is cheap for a short time but not when taken for the long term
Spot instance - It is cheaper than the on-demand instance and can be bought through bidding.
Reserved instance - If you are planning to use an instance for a year or more, then this is the right one for you.
Q: How can you add an existing instance to a new Auto Scaling group?
Here’s how you can add an existing instance to a new Auto Scaling group:
Open EC2 console
Select your instance under Instances
Choose Actions -> Instance Settings -> Attach to Auto Scaling Group
Select a new Auto Scaling group Attach this group to the Instance
Edit the Instance if needed
Once done, you can successfully add the instance to a new Auto Scaling group
Q: How can you recover/login to an EC2 instance for which you have lost the key?
A: Follow the steps provided below to recover an EC2 instance if you have lost the key:
1. Verify that the EC2Config service is running
2. Detach the root volume for the instance
3. Attach the volume to a temporary instance
4. Modify the configuration file
5. Restart the original instance
Q: How do you configure CloudWatch to recover an EC2 instance?
A: Here’s how you can configure them:
Create an Alarm using Amazon CloudWatch
In the Alarm, go to Define Alarm -> Actions tab
Choose Recover this instance option
Q: What are the common types of AMI designs?
A: There are many types of AMIs, but some of the common AMIs are:
Fully Baked AMI
Just Enough Baked AMI (JeOS AMI)
Hybrid AMI
Amazon Route 53
Q: What is the difference between Latency Based Routing and Geo DNS?
A: The Geo Based DNS routing takes decisions based on the geographic location of the request. Whereas, the Latency Based Routing utilizes latency measurements between networks and AWS data centers. Latency Based Routing is used when you want to give your customers the lowest latency possible. On the other hand, Geo Based routing is used when you want to direct the customer to different websites based on the country or region they are browsing from.
Q: What is the difference between a Domain and a Hosted Zone?
A: Domain:- A domain is basically a collection of data describing a self-contained administrative and technical unit. For example, www. facebook.com is a domain and a general DNS concept.
Hosted zone - A hosted zone is a container that holds information about how you want to route traffic on the internet for a specific domain. For example, lms.simplilearn.com is a hosted zone.
Q: How does Amazon Route 53 provide high availability and low latency?
A: Here’s how Amazon Route 53 provides the resources in question:
Globally distributed servers - Amazon is a global service and consequently has DNS services globally. Any customer creating a query from any part of the world gets to reach a DNS server local to them that provides low latency.
Dependency - Route 53 provides a high level of dependability required by important applications
Optimal locations - Route 53 uses a global anycast network to automatically answer queries from the optimal location.
Amazon VPC
Q: Name and explain some security products and features available in VPC?
A: Here is a selection of security products and features:
Security groups - This acts as a firewall for the EC2 instances, controlling inbound and outbound traffic at the instance level.
Network access control lists - It acts as a firewall for the subnets, controlling inbound and outbound traffic at the subnet level.
Flow logs - These capture the inbound and outbound traffic from the network interfaces in your VPC.
Q: How do you monitor Amazon VPC?
A: You can monitor VPC by using: + - CloudWatch and CloudWatch logs - VPC Flow Logs
Q: What are the different types of virtualization in AWS and what are the differences between them?
A: The three major types of virtualization in AWS are:
Hardware Virtual Machine (HVM) - It is a fully virtualized hardware, where all the virtual machines act separate from each other. These virtual machines boot by executing a master boot record in the root block device of your image.
Paravirtualization (PV) - Paravirtualization-GRUB is the bootloader which boots the PV AMIs. The PV-GRUB chain loads the kernel specified in the menu.
Paravirtualization on HVM - PV on HVM actually helps operating systems take advantage in storage and network I/O available through the host.
Q: Name some of the AWS services that are not region specific
A: AWS services that are not region specific are:
IAM
Route 53
Web Application Firewall
CloudFront
Q. What are the factors to consider while migrating to Amazon Web Services?
Here are the factors to consider during AWS migration:
- Operational Costs - These include the cost of infrastructure, ability to match demand and supply, transparency, and others.
Workforce Productivity
Cost avoidance
Operational resilience
Business agility
That's a wrap............