Class 16

Resources:

• How the Web Works, HTTP Request/Response Cycle
• Computer Hope
• Software Deployment

Review, Research, and Discussion

1. Describe the Web-Request-Response-Cycle
   • First a user gives a client a URL, the client builds a request for information (or resources) to be generated by a server. When the server receives that request, it uses the information included in the request to build a response that contains the requested information. Once built, that response is sent back to the client in the requested format, to be rendered to the user.
2. Explain what a “server” is, as it relates to the WRRC
   • A server is a software or hardware device that accepts and responds to requests made over a network. The device that makes the request, and receives a response from the server, is called a client. On the Internet, the term “server” commonly refers to the computer system that receives requests for a web files and sends those files to the client.
3. What does it mean to “deploy” an application?
   • Software deployment refers to the process of running an application on a server or device. A software update or application may be deployed to a test server, a testing machine, or into the live environment, and it may be deployed several times during the development process to verify its proper functioning and check for errors.

Vocabulary Terms

1. Server
   • A server is a computer that serves information to other computers. These computers, called clients, can connect to a server through either a local area network or a wide area network, such as the internet.
2. Pub/Sub
   • Architectural design pattern that provides a framework for exchanging messages between publishers and subscribers. This pattern involves the publisher and the subscriber relying on a message broker that relays messages from the publisher to the subscribers. The host (publisher) publishes messages (events) to a channel that subscribers can then sign up to.
3. WRRC
   • The request/response cycle traces how a user’s request flows through the app. Understanding the request/response cycle is helpful to figure out which files to edit when developing an app (and where to look when things aren’t working).