A user has developed an application which is required to send the data to a NoSQL database. The user wants to decouple the data sending such that the application keeps processing and sending data but
does not wait for an acknowledgement of DB. Which of the below mentioned applications helps in this scenario?
Correct Answer:D
Amazon Simple Queue Service (SQS) is a fast, reliable, scalable, and fully managed message queuing service. SQS provides a simple and cost-effective way to decouple the components of an application. In this case, the user can use AWS SQS to send messages which are received from an application and sent to DB. The application can continue processing data without waiting for any acknowledgement from DB. The user can use SQS to transmit any volume of data without losing messages or requiring other services to always be available.
Reference: http://aws.amazon.com/sqs/
You want to have multiple versions of your application running at the same time, with all versions launched via AWS Elastic Beanstalk. Is this possible?
Correct Answer:C
AWS Elastic Beanstalk is designed to support multiple running environments. As an example you could have one for integration testing, one for pre-production, and one for production, with each environment independently configured and running on its own separate AWS resources.
Reference: https://aws.amazon.com/elasticbeansta|k/faqs/
A user is planning to host a web server as well as an app server on a single EC2 instance which is a part of the public subnet of a VPC. How can the user setup to have two separate public IPs and separate security groups for both the application as well as the web server?
Correct Answer:C
If you need to host multiple websites(with different IPs) on a single EC2 instance, the following is the suggested method from AWS.
Launch a VPC instance with two network interfaces
Assign elastic IPs from VPC EIP pool to those interfaces (Because, when the user has attached more than one network interface with an instance, AWS cannot assign public IPs to them.)
Assign separate Security Groups if separate Security Groups are needed
This scenario also helps for operating network appliances, such as firewalls or load balancers that have multiple private IP addresses for each network interface.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/MuItipIeIP.html
Doug has created a VPC with CIDR 10.201.0.0/16 in his AWS account. In this VPC he has created a public subnet with CIDR block 10.201.31.0/24. While launching a new EC2 from the console, he is not able to assign the private IP address 10.201.31.6 to this instance. Which is the most likely reason for this issue?
Correct Answer:C
In Amazon VPC, you can assign any Private IP address to your instance as long as it is: Part of the associated subnet's IP address range
Not reserved by Amazon for IP networking purposes Not currently assigned to another interface Reference: http://aws.amazon.com/vpc/faqs/
A user has configured a website and launched it using the Apache web server on port 80. The user is using ELB with the EC2 instances for Load Balancing. What should the user do to ensure that the EC2 instances accept requests only from ELB?
Correct Answer:B
When a user is configuring ELB and registering the EC2 instances with it, ELB will create a source security group. If the user wants to allow traffic only from ELB, he should remove all the rules set for the other requests and open the port only for the ELB source security group.
Reference:
http://docs.aws.amazon.com/EIasticLoadBaIancing/latest/DeveIoperGuide/using-elb-security-groups.htmI