Web Essentials Lecture 2

Questions and Answers

What is a web client?

A type of server that stores web data

Software that accesses web servers via HTTP (correct)

Software used for designing websites

Hardware that connects to the internet

Which browser is recognized for introducing graphical web browsing?

Internet Explorer

Netscape Navigator

Mozilla Firefox

Mosaic (correct)

What event is referred to as the Browser War?

The launch of the first web browser

The release of the first mobile browser

The introduction of HTML5

The competition between Microsoft and Netscape (correct)

Which feature is commonly found in modern web browsers?

Support for HTTP communication Signup and view all the answers

Which of the following browsers is open source?

Mozilla Firefox Signup and view all the answers

What is the primary function of the Navigation Toolbar in a browser?

To include navigation buttons and search bar Signup and view all the answers

Which browser was dominant in the early 2000s as part of the Browser War?

Internet Explorer Signup and view all the answers

What aspect of modern browsers contributes to better standards compliance?

The availability of developer tools Signup and view all the answers

Which component of a URL specifies the domain name?

Authority Signup and view all the answers

What function allows users to search for text within a web page?

Find in Page Signup and view all the answers

Which feature allows browsers to remember user information for faster form filling?

Automatic Form Filling Signup and view all the answers

What action can users take to save a web page for later reference?

Bookmarking Signup and view all the answers

What part of the URL contains parameters that may be sent to the server?

Query String Signup and view all the answers

Which menu option in Mozilla allows users to view the raw HTML source of a document?

View Signup and view all the answers

How can users change the appearance of their browser using Mozilla?

By applying themes Signup and view all the answers

What does the Fragment component of a URL do?

Scrolls to a specific part of an HTML document Signup and view all the answers

What is the primary function of a subtask in server software?

To handle a single client connection Signup and view all the answers

How do virtual hosts operate in relation to the Host header field in an HTTP request?

They indicate which virtual host should handle the request Signup and view all the answers

Which statement is true about the differences between Apache and Microsoft IIS?

Apache can run on Windows, Linux, and macOS, while IIS is limited to Windows Signup and view all the answers

Which programming languages are commonly used with Apache and IIS, respectively?

Perl or PHP for Apache, VBScript for IIS Signup and view all the answers

What does the TCP connection queue refer to in server configuration?

The maximum number of queued requests when the thread limit is reached Signup and view all the answers

Which role does Tomcat serve in server environments?

A popular open-source servlet container capable of running as a standalone server Signup and view all the answers

In server configuration, what does the connection timeout parameter specify?

The time the server waits before closing an inactive TCP connection Signup and view all the answers

What does the client access configuration in server settings control?

Which clients can send HTTP requests to the server Signup and view all the answers

What is the primary function of a web server?

To accept HTTP requests and return resources. Signup and view all the answers

What step involves determining which 'virtual host' should handle the HTTP request?

Determining the Virtual Host Signup and view all the answers

What is the primary purpose of Request-URI Mapping?

To map server resources to request paths Signup and view all the answers

Which component is responsible for managing HTTP communications in Tomcat?

Connector Signup and view all the answers

Which of the following actions does a web server take if the requested resource is a program?

Executes the program and returns its output. Signup and view all the answers

Which step occurs first when a web server is processing an HTTP request?

Listening for Connection Requests Signup and view all the answers

How can new virtual hosts be added in Tomcat?

By creating new Host components Signup and view all the answers

What does the web server use to create an HTTP response with a file?

The file's MIME type Signup and view all the answers

What does the Application Base signify in a virtual host configuration?

The directory where web applications are stored Signup and view all the answers

What does managing persistent connections entail in a web server?

Keeping the connection open until a time limit or request. Signup and view all the answers

In Tomcat's default configuration, what does the Default Hostname setting ensure?

It allows handling of all HTTP requests if no specific host is matched Signup and view all the answers

What does mapping the Request-URI to a resource involve?

Identifying the location of the resource on the server. Signup and view all the answers

What is the role of Caching in server performance?

To determine if resources are stored in server memory Signup and view all the answers

Which of the following best describes a Context within a Host in Tomcat?

It maps specific URL paths to server directories Signup and view all the answers

What type of information does the web server typically log?

The IP address of the requester and response status code. Signup and view all the answers

What adjustment might be made during server tuning for performance optimization?

Modifying the thread count Signup and view all the answers

Study Notes

Web Clients

Web Client: Software accessing web servers via HTTP, including web browsers on various devices.
User Agents: Include traditional browsers and web-crawling software robots.
Traditional Browsers: Text-based or platform-specific, evolving to graphical browsers.
Notable Browsers:
- Mosaic introduced graphical browsing in 1993.
- Netscape Navigator popularized web browsing.
- Internet Explorer (IE) became the dominant browser bundled with Windows.
Browser War: A competition primarily between Netscape and Microsoft, leading to IE's dominance and the emergence of Mozilla as open-source.
Modern Browsers: Include Mozilla/Firefox, Opera, and Safari, alongside IE, with shared basic features supporting HTTP communication.

Basic Browser Functions

Browser Window Layout: Comprised of client area, title bar, menu bar, navigation toolbar, and status bar.
Key Browser Tasks:
- Convert URLs into HTTP requests.
- Resolve host names to IP addresses using DNS.
- Establish and manage TCP connections with web servers.
- Send HTTP requests and receive responses.
- Render and display documents, including positioning of text and graphics.

HTTP URLs

URL Components:
- Authority: Domain name following "http://".
- Path: File path on the server after the authority.
- Query String: Parameters following a question mark.
- Fragment: Portion after a number sign, used for specific sections in HTML documents.

User-Controllable Features

Save Web Pages: Users can preserve pages locally.
Find in Page: Allows searching for text within a page, with a "find as you type" feature in Mozilla.
Automatic Form Filling: Browsers can save form info for future use.
Document Meta-Information: Access details like MIME type, encoding, and size via Mozilla settings.
Themes: Users can customize browser appearance, including navigation bar styles.
History and Bookmarks: Browsers maintain recently visited pages and allow saving of URLs for later access.
Preferences Customization: Users can adjust language, encoding, and other settings.

Web Servers

Primary Function: Accept HTTP requests from clients and return resources in response.
Key Steps in Operation:
- Listening for connection requests on specific ports.
- Handling connections by assigning subtasks.
- Establishing TCP connections for client-server communication.
- Determining virtual hosts based on Host header in requests.
- Mapping request URIs to server resources.
- Returning file resources or executing programs as requested.
- Logging request and response details, including IP addresses and statuses.

Server History

Apache Server: Originated from updates from httpsd users, released in April 1995, and became widely used.
Microsoft IIS: Developed as a competitor, limited to Windows systems.
Programming Language Preferences:
- IIS often uses VBScript; Apache commonly uses Perl or PHP.
- Both servers can run Java programs through servlet containers like Tomcat.

Server Configuration and Tuning

External Communication Settings:
- IP Addresses & TCP Ports: Define client connection points.
- Thread Management: Maximum allowed simultaneous connections.
- Connection Timeout: Duration before closing inactive connections.
Internal Processing Settings:
- Client Access Controls, Logging Configurations, Request-URI Mapping, Password Protection, and Caching options.
Server Tuning: Adjusting parameters for optimized performance.
Tomcat Configuration: Web interface accessible at http://localhost:8080, including key components managing HTTP communications.

Virtual Host Configuration (Tomcat Example)

Virtual Host Definition: Hosts identified by fully qualified domain names; localhost for local testing.
Adding New Virtual Hosts: Specific hosts handle designated requests, default host manages all others.
Web Application Contexts: Define URL paths mapping to server directories, with predefined contexts available.
Application Base: Specifies directory locations for web applications relative to server installation paths.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the fundamentals of web clients and their role in accessing web servers via HTTP. It discusses different types of web clients, including web browsers and user agents. Strengthen your understanding of communication between clients and servers.