Exam 2019 Flashcards
Define Amazon Machine Image
Copy of a server with OS and preinstalled software
* Predefined AMIs from Amazon and third-parties, user-defined AMIs
possible
* AMIs are stored in S3
What is an Amazon Instance Type?
An Amazon EC2 instance type is a specific hardware configuration for a virtual machine (VM) in the Amazon Elastic Compute Cloud (EC2) service. It defines the number of virtual CPUs, amount of memory, network performance, and other hardware characteristics of the VM.
You have to deploy a microservice application in the cloud. Which of the following deployment models is best? Give arguements.
- One VM per service
- Multiple services per VM
- One pod per service
- Multiple services per pod
Out of the options given, “Multiple services per pod” is often the best choice for deploying microservice applications in the cloud. Pods in Kubernetes provide a logical host for one or more containers, and allow for fine-grained management and scaling of microservices. Multiple services per pod also allow for better resource utilization, as well as simplified network communication between services.
What is the cost model of Amazon Lambda?
Is infinite scaling of services in the cloud possible assuming an unlimited number of physical servers? Give arguments for your decision marked with (1), (2),
No, infinite scaling of services in the cloud is not possible with an unlimited number of physical servers. (1) Physical resources such as power and cooling have limits, and at some point additional servers will exceed available capacity. (2) Network infrastructure also has limits in terms of bandwidth and latency which can impact performance. (3) Managing an ever-increasing number of servers can become challenging, leading to reduced reliability and increased complexity.
3 Autoscaling approaches
Reactive
Scheduled
Predictive
The step-scaling policy in AWS is different from the simple scaling policy. It takes …………………………………………………….. into account?
Amount of breach
What is the difference between normal reads and strong reads in DynamoDB?
Normal reads in DynamoDB retrieve data with eventually consistent data, while strong reads retrieve data with strongly consistent data. This means that with normal reads, the data returned might not reflect the latest updates, while with strong reads the data returned will reflect the latest updates.
There is a Node.js web application called as myapp whose source code is present in the current directory (.) of your working laptop. You are assigned a task of creating this application’s docker image considering following points:
a. Base image node is to be used with the version as boron.
b. The application source code is to be copied inside /usr/src/myapp directory.
c. index.js is the file which should be run when the container starts.
d. The application uses port 8080.
Complete the below docker file steps (in the right order) which are required for creating this application’s docker image considering all the above points.
RUN mkdir -p /usr/src/myapp WORKDIR /usr/src/myapp
COPY package.json /usr/src/myapp
COPY . /usr/src/myapp
Create directory for the app
RUN mkdir -p /usr/src/myapp
Set the working directory
WORKDIR /usr/src/myapp
Copy the package.json file to the app directory
COPY package.json /usr/src/myapp
Install the dependencies
RUN npm install
Copy the application source code to the app directory
COPY . /usr/src/myapp
Expose port 8080
EXPOSE 8080
Set the command to run when the container starts
CMD [ “node”, “index.js” ]
Set the base image to node with version boron
FROM node:boron
