Cloud Computing : PaaS and SOA

<p>Node.js, Java, Python, Go, and C# (D)</p> Signup and view all the answers

<p>Creating thumbnails from uploaded photos to an S3 bucket (A)</p> Signup and view all the answers

<p>POST (D)</p> Signup and view all the answers

<p>One-to-many decoupled communication (A)</p> Signup and view all the answers

<p>It may slow down client operations (A)</p> Signup and view all the answers

<p>GET (D)</p> Signup and view all the answers

<p>A key/value storage interface (B)</p> Signup and view all the answers

<p>Updates or replaces an existing resource (C)</p> Signup and view all the answers

<p>DELETE (B)</p> Signup and view all the answers

<p>It generally requires additional care for concurrent requests. (C)</p> Signup and view all the answers

<p>Receive a representation of individual students (C)</p> Signup and view all the answers

<p>It always produces the same result regardless of frequency. (C)</p> Signup and view all the answers

<p>Concurrent requests for the same resource may need extra handling. (D)</p> Signup and view all the answers

<p>The variety of development environments and their features. (B)</p> Signup and view all the answers

<p>User interface design quality (B)</p> Signup and view all the answers

<p>Distributed web applications with low response times. (B)</p> Signup and view all the answers

<p>Billed per second with a minimum of one minute charged per hour. (C)</p> Signup and view all the answers

<p>Components are aimed to be stateless and only called upon user requests. (B)</p> Signup and view all the answers

<p>Python, Ruby, Java, PHP, Go, and Node.js. (D)</p> Signup and view all the answers

<p>Containers with arbitrary code/functions managed by Kubernetes. (B)</p> Signup and view all the answers

<p>$0.12 per GB. (A)</p> Signup and view all the answers

<p>Interprocess communication is needed due to the lack of shared state. (B)</p> Signup and view all the answers

<p>They support queries to find drivers close to passengers. (B)</p> Signup and view all the answers

<p>Each service must handle transactions independently without coordination. (D)</p> Signup and view all the answers

<p>Incorporating event-based communication strategies. (C)</p> Signup and view all the answers

<p>No shared state between services. (A)</p> Signup and view all the answers

<p>Interactions between microservices. (D)</p> Signup and view all the answers

<p>Remote Procedure Calls (RPC) or event-based communication. (C)</p> Signup and view all the answers

<p>They can lead to inconsistent states across services. (B)</p> Signup and view all the answers

<p>To serve as a single entry point for clients (A)</p> Signup and view all the answers

<p>Data storage (A)</p> Signup and view all the answers

<p>It orchestrates microservices differently depending on the device (B)</p> Signup and view all the answers

<p>6 or 7 (B)</p> Signup and view all the answers

<p>Knowledge of internal system architecture (A)</p> Signup and view all the answers

<p>Netflix API Gateway (D)</p> Signup and view all the answers

<p>By collating requests and responses optimally (D)</p> Signup and view all the answers

<p>To ensure all requests are processed equally (D)</p> Signup and view all the answers

<p>Microservices architecture (B)</p> Signup and view all the answers

<p>By redirecting to an external authentication service (D)</p> Signup and view all the answers

<p>Separation of concerns and statelessness (A)</p> Signup and view all the answers

<p>Level 2 (B)</p> Signup and view all the answers

<p>Returning URL links for possible actions on a resource (D)</p> Signup and view all the answers

<p>Use of standard HTTP ports 80/443 (D)</p> Signup and view all the answers

<p>JSON (D)</p> Signup and view all the answers

<p>Statefulness allows for easier session management (B)</p> Signup and view all the answers

<p>Large JSON representation including a Token ID (B)</p> Signup and view all the answers

<p>Level 0 (B)</p> Signup and view all the answers

Adds a new element or resource to a collection.

Retrieves a representation of a resource or a list of resources from a collection.

Replaces an existing resource completely with a new representation.

Deletes an existing resource.

Modifies a specific part of an existing resource without replacing it completely.

A resource that represents a group of individual resources.

A specific resource within a collection, identified by its unique identifier.

A unique address that identifies a resource on the web.

Comparing PaaS is more complex than IaaS due to the focus on development and application creation environments and their specific features. Factors like cost, performance, and security are still important, but now we need to consider the environment's strengths and weaknesses.

Programming languages and libraries supported by a PaaS platform.

The availability of database management systems within the PaaS platform.

Communication capabilities within the PaaS, including communication between applications, users, and external systems.

The support provided for deployment and testing processes within the PaaS.

The cost model of the PaaS, potentially more complex than IaaS due to factors like usage-based billing.

A completely managed platform, where the runtime environment, libraries, operating system, and development tools are handled for you. Google App Engine targets distributed web applications.

Google App Engine utilizes a stateless architecture, prioritizing low response time by breaking applications into small, stateless components. These components are only activated when a web request is received.

RESTful APIs allow using arbitrary numbers of server processes for scaling and elasticity by separating concerns and maintaining statelessness.

REST APIs use HTTP verbs like GET, POST, PUT, and DELETE to perform actions, enabling caching for GET requests.

HATEOAS (Hypertext As The Engine Of Application State) enriches REST API responses by including links for all possible actions on a resource, allowing clients to discover available operations.

REST APIs are generally firewall-friendly as they use standard HTTP ports like 80 and 443, which are commonly open for web traffic.

OpenStack is an example of an IaaS management platform that uses a RESTful API to programmatically manage cloud resources like virtual machines and images.

OpenStack API uses JSON format to represent data and authenticate users with token-based authentication, ensuring a stateless session.

Richardson's Maturity Model categorized REST interfaces into levels based on their features and adherence to REST principles.

In Level 0 of Richardson's Maturity Model, clients interact with services through HTTP POST requests to a single URL, with parameters in the body.

The act of designing and building an application as a collection of loosely coupled, independent services that communicate with each other over a network.

A type of communication between microservices where a request is sent from one service to another and a response is received immediately.

A type of communication between microservices where one service sends an event to another without expecting an immediate response.

The ability of a distributed system to operate correctly even when individual services experience failures.

A database architecture where each microservice has its own separate database, preventing data conflicts.

A set of operations performed on a database that must all succeed or fail as a whole. In a partitioned database architecture, transactions involving multiple databases become more complex.

The potential for inconsistencies in the state of different microservices due to failures or delays in communication.

The process of ensuring that multiple services maintain a consistent view of the data even in the presence of failures.

A specialized microservice that acts as the single point of entry for all client requests.

An API Gateway encapsulates the knowledge of the internal architecture of a microservice system, shielding clients from its complexities.

An API Gateway provides a specialized API for each type of client, tailoring the response to their needs.

Netflix's API Gateway orchestrates microservices differently based on the device accessing the service.

An API Gateway often handles common functionalities such as authentication, monitoring, and load balancing.

An API Gateway can significantly improve the overall performance of a microservice system by efficiently routing requests and handling common operations.

The API Gateway may be responsible for dynamically routing requests to different microservices within a system, depending on the specific needs of the client.

The API Gateway can manage the flow of requests to prevent overloading or crashing of microservices, ensuring the system's stability.

The API Gateway can implement authentication mechanisms to verify the identity of clients before granting access to resources.

The API Gateway often collects and analyzes data about requests to monitor the performance and health of the underlying microservices.

AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. It is triggered by events, like HTTP requests or messages from other AWS services.

AWS Lambdas are similar to Heroku dynos in that they are both ways to run code without managing servers. However, AWS Lambdas are more flexible and scalable, and can be triggered by a variety of events.

An AWS Lambda can be triggered by several events, including periodic schedules, incoming HTTP requests, and communication from other AWS components. This allows you to create flexible and scalable applications.

A typical use case for AWS Lambdas is to pair them with communication services like Amazon SQS or Amazon SNS. This allows you to decouple communication and provide more flexibility in your application, as you can send messages to a queue and have lambdas process them asynchronously.

Amazon SQS (Simple Queue Service) is a fully managed message queuing service that allows you to send, store, and receive messages between applications. Amazon SNS (Simple Notification Service) is a fully managed push notification service that allows you to send notifications to mobile devices, email addresses, or other endpoints.

AWS Lambdas have some limitations, such as a maximum memory limit of 3GB and a maximum execution time of 300 seconds. They can also only handle a maximum of 1000 concurrent executions.

AWS Lambdas can be written in several programming languages, including Python, Java, Node.js, Go, and C#. This makes them a very flexible and powerful tool that can be used for a variety of tasks.

Creating image thumbnails is a common use case for AWS Lambdas. By using an S3 bucket to store images, you can trigger a Lambda function whenever a new image is uploaded and have the function resize the image and store it in a new S3 bucket. This allows you to scale your image processing workload without having to worry about managing servers.