Sherif Magdy ElGazzar’s Post

Deciphering the Journey from Browser to Server: The Web Request Adventure Introduction Ever pondered what happens between pressing Enter after typing a URL in your browser and seeing your desired webpage? This intricate procedure unfolds through a series of carefully coordinated steps, tasked with fetching and presenting the webpage. Let's dissect the stages involved in this digital odyssey from the initial DNS query to the webpage's ultimate display. 1. Initiating the Quest with DNS The adventure kicks off with the input of a URL, like https://www.google.com, into your browser. The critical first step is conducting a DNS (Domain Name System) look-up. This entails your browser requesting a DNS server to pinpoint the IP address linked to “www.google.com.” Upon retrieving the correct IP address from the DNS server, your browser advances to the subsequent phase. 2. Establishing a TCP/IP Connection Armed with the IP address, your browser sets out to create a TCP (Transmission Control Protocol) connection to the server, specifying the IP and a port number (port 443 for HTTPS websites). TCP plays a vital role, ensuring a dependable channel between your browser and the server, segmenting the data into packets, and confirming their orderly receipt. 3. The Firewall Gateway Before establishing a TCP connection, the data packets may encounter a firewall. This serves as a cybersecurity sentinel for your system, inspecting packets against established security norms before they proceed to the server. 4. Securing with HTTPS/SSL Upon a successful TCP connection—and for sites employing HTTPS—the browser and server engage in securing the connection via SSL/TLS (Secure Sockets Layer/Transport Layer Security) protocols. This step is pivotal for encrypting the data exchange, safeguarding it from external threats. 5. The Role of Load-Balancers Major websites, such as Google, utilize multiple servers to handle requests. Here, a load-balancer elegantly distributes incoming requests among various servers. This ensures balanced performance and availability, avoiding server overloads. 6. The Application Server Interface Occasionally, a web server communicates with an application server to fulfill the request. Application servers are responsible for executing application logic, managing database queries, and generating dynamic content. Notable examples include Tomcat for Java applications and Django for Python platforms. 7. Database Interaction Should the request necessitate data stored in a database, the application server queries the database to retrieve essential information. Database servers like MySQL, PostgreSQL, or MongoDB supply the requested data to the application server, facilitating continuous request processing. In conclusion, a mere click or tap to view a webpage initiates an elaborate and intriguing process from your browser to the server. This journey incorporates DNS lookups, secure connections, and load balancing to deliver the final webpage.

𝐖𝐡𝐚𝐭 𝐇𝐚𝐩𝐩𝐞𝐧𝐬 𝐖𝐡𝐞𝐧 𝐘𝐨𝐮 𝐓𝐲𝐩𝐞 𝐡𝐭𝐭𝐩𝐬://𝐰𝐰𝐰.𝐠𝐨𝐨𝐠𝐥𝐞.𝐜𝐨𝐦 𝐢𝐧 𝐘𝐨𝐮𝐫 𝐁𝐫𝐨𝐰𝐬𝐞𝐫 𝐚𝐧𝐝 𝐏𝐫𝐞𝐬𝐬 𝐄𝐧𝐭𝐞𝐫 Typing a URL into your browser triggers a series of processes, including DNS requests, TCP/IP connections, and data handling, to retrieve and display the webpage. 1. 𝐃𝐍𝐒 𝐑𝐞𝐪𝐮𝐞𝐬𝐭 The browser initiates a DNS request, translating the domain name (www.google.com) into an IP address. It checks its cache first, then the OS cache, and finally queries a recursive DNS resolver if needed. The resolver contacts root DNS servers, which refer to TLD servers (.com), then authoritative DNS servers for google.com, which return the IP address. 2. 𝐓𝐂𝐏/𝐈𝐏 With the IP address, the browser uses TCP/IP to connect to the server. The connection is established through a three-way handshake: the browser sends a SYN packet, the server replies with SYN-ACK, and the browser responds with ACK, completing the connection. 3. 𝐅𝐢𝐫𝐞𝐰𝐚𝐥𝐥 Firewalls monitor and control network traffic to protect servers from unauthorized access, ensuring safe and legitimate traffic during TCP connections. 4. 𝐇𝐓𝐓𝐏𝐒/𝐒𝐒𝐋 Google uses HTTPS with SSL/TLS to encrypt data, involving a handshake where the browser requests a secure connection, the server provides an SSL certificate, the browser verifies it and encrypts a session key, and the server decrypts it to establish a secure session. 5. 𝐋𝐨𝐚𝐝 𝐁𝐚𝐥𝐚𝐧𝐜𝐞𝐫 Large sites like Google use load balancers to distribute traffic for reliability, employing methods such as Round Robin, Least Connections, and IP Hash. 6. 𝐖𝐞𝐛 𝐒𝐞𝐫𝐯𝐞𝐫 The load balancer sends the request to a web server, which handles HTTP(S) requests and serves static content like HTML, CSS, JavaScript, and images. Common web servers include Apache, Nginx, and IIS. 7. 𝐀𝐩𝐩𝐥𝐢𝐜𝐚𝐭𝐢𝐨𝐧 𝐒𝐞𝐫𝐯𝐞𝐫 For dynamic content, the web server forwards the request to an application server, which processes backend logic, runs code, and interacts with databases to generate responses. Technologies include Node.js, Django, Ruby on Rails, and Spring Boot. 8. 𝐃𝐚𝐭𝐚𝐛𝐚𝐬𝐞 If the request involves data storage or retrieval, the application server queries the database. Databases store and manage data, providing the necessary information to fulfill the request. 9. 𝐑𝐞𝐬𝐩𝐨𝐧𝐬𝐞 After processing the request, the application server sends the response back through the web server to the load balancer, which routes it to the browser. The browser then receives the data and renders the webpage for the user. 𝐂𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧 Understanding the journey from typing a URL to rendering a webpage reveals the complex processes of web interactions, including DNS resolution, encryption, load balancing, and server communication. Mastering these concepts enhances your technical skills and distinguishes you in the field of software engineering.

#RevolutionizeYourServerManagement with #OpenPanel ! 🌐✨ OpenPanel is a free opens source robust administration platform designed specifically for server administrators. It offers new features that make it an ideal solution for hosts and companies who wish to provide their clients with secure, dependable web hosting services: 𝗦𝗲𝗿𝘃𝗲𝗿 𝗠𝗮𝗻𝗮𝗴𝗲𝗺𝗲𝗻𝘁 𝗙𝗲𝗮𝘁𝘂𝗿𝗲𝘀: ☑️ Monitors services and automatically restarts when needed. ☑️ Suspend or delete user accounts for immediate access denial and site shutdowns. ☑️ DNS Zone Editor enables editing of DNS zone files for domains, allowing the addition of various records such as A, AAAA, CNAME, MX, TXT, etc. 𝗥𝗲𝘀𝗼𝘂𝗿𝗰𝗲 𝗠𝗼𝗻𝗶𝘁𝗼𝗿𝗶𝗻𝗴: ☑️ Monitors CPU and memory usage in real-time with trend analysis and server adjustments as needed. 𝗪𝗲𝗯 𝗦𝗲𝗿𝘃𝗲𝗿𝘀: ☑️ Nginx Web Server: You can configure cache exceptions, cache purging, URL overrides, and utilize FastCGI caching at the domain level. ☑️ Apache Web Server: Supports .htaccess files, allowing users to customize and override global settings. 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 𝗙𝗲𝗮𝘁𝘂𝗿𝗲𝘀: ☑️ Containerization isolates each user account within a Docker container, preventing access to other users' or server data. ☑️ SSL/TLS: Automatically obtain Let's Encrypt certificates, generate new ones, and instantons HTTPS redirection for all requests. ☑️ Managing firewall rules (UFW) through the administrator interface, limiting user-accessible ports. 𝗨𝘀𝗲𝗿 𝗠𝗮𝗻𝗮𝗴𝗲𝗺𝗲𝗻𝘁: ☑️ Limits resources by setting quotas on connection speed, disk space usage, number of sites, MySQL databases, and domains. ☑️ Update and downgrade package versions to match those listed in your packages list. ☑️ Impersonate users to log in as them for testing purposes. ☑️ REST API provides a convenient way to manage services remotely via HTTP requests. 𝗔𝗱𝘃𝗮𝗻𝗰𝗲𝗱 𝗙𝗲𝗮𝘁𝘂𝗿𝗲𝘀: ☑️ Supports NodeJS and Python applications, allowing users to create and manage their own apps without hassle. ☑️ OpenCLI is an intuitive command-line interface with over 100 commands. ☑️ WordPress Automatic Installer (WP Manager). ☑️ MySQL and phpMyAdmin: Create and manage MySQL databases. ☑️ Implement caching using separate Redis and Memcached instances. ☑️ SSH and web-based terminals provide remote SSH or automatic login to a web-based terminal interface. 𝗦𝗲𝗿𝘃𝗲𝗿 𝗦𝗲𝘁𝘁𝗶𝗻𝗴𝘀: ☑️ Control your server with ease: manage settings, install/restart services, configure systems, and more. 𝗙𝗶𝗹𝗲 𝗠𝗮𝗻𝗮𝗴𝗲𝗿: ☑️Upload multiple files at once without size restrictions, modify, set permissions, copy, move, and manage with ease. 𝗨𝘀𝗲𝗿 𝗜𝗻𝘁𝗲𝗿𝗳𝗮𝗰𝗲: ☑️ Custom Branding with Logo, Color Scheme, and Font Selection. ☑️ Interface Optimization for Desktop, Tablet & Mobile Devices. Start working with OpenPanel on VPS/VDS servers at HOSTKEY with the "1 click" installation! 👉 https://lnkd.in/ebJ93RXj What hosting control panel do you prefer? #HostingControlPanels #WebHosting

A real alternative to cPanel with open-source code and a familiar interface. What hosting control panel do you prefer to use?

Nginx (pronounced "engine-x") is a high-performance web server and reverse proxy server known for its speed, stability, and low resource consumption. It was created by Igor Sysoev in 2004 to address the C10k problem, which involves handling 10,000 concurrent client connections. Over time, Nginx has grown in popularity, becoming a critical component in many modern web architectures. ## Key Features of Nginx 1. **Reverse Proxy and Load Balancing**: Nginx excels at distributing incoming traffic across multiple backend servers, improving performance and redundancy. Its load balancing capabilities include round-robin, least connections, and IP hash methods. 2. **High Performance**: Unlike traditional web servers that create a new process or thread for each connection, Nginx uses an asynchronous, event-driven architecture. This design enables it to handle many simultaneous connections efficiently, making it suitable for high-traffic websites. 3. **Low Resource Usage**: Nginx is optimized to use minimal memory and CPU, allowing it to serve content quickly and handle a large number of connections without straining system resources. 4. **Static and Dynamic Content**: While Nginx is renowned for serving static content (like HTML, CSS, and images) quickly, it can also act as a reverse proxy for dynamic content generated by application servers like PHP-FPM, Node.js, or Python WSGI. 5. **TLS/SSL Termination**: Nginx can manage SSL/TLS encryption, offloading this task from backend servers and ensuring secure communication between clients and the server. 6. **HTTP/2 and gRPC Support**: Nginx supports modern web protocols like HTTP/2 and gRPC, enhancing performance and enabling better client-server communication. 7. **Caching**: Nginx includes a built-in caching mechanism that stores responses from proxied servers, reducing load and improving response times for frequently requested content. 8. **Security**: Nginx offers robust security features, including access control, rate limiting, and protection against common web attacks like DDoS. ## Use Cases - **Web Server**: Serving static content efficiently and handling SSL termination. - **Reverse Proxy**: Distributing client requests to multiple backend servers to balance the load. - **Load Balancer**: Managing traffic distribution among several servers to optimize performance and reliability. - **API Gateway**: Routing API requests and managing API traffic. ## Conclusion Nginx's versatility and performance make it a cornerstone of modern web infrastructure. Its ability to handle high traffic loads with minimal resource consumption has made it a favorite among developers and system administrators. Whether you're running a small website or a large-scale application, Nginx provides the tools and features needed to deliver content swiftly and securely.

Image of what happens when you enter www.google.com to the web browser Introduction: Greetings! Today, When you type https://www.google.com in your browser and press Enter, a series of complex processes occur to load the webpage. This journey involves several layers of technology and protocols that work together seamlessly. Here’s a breakdown of the steps: 1. DNS Request When you type a URL, the browser first checks its cache, then the operating system's cache, followed by the local router's cache, and finally the ISP's DNS server to resolve the IP address. If the IP address is still not found, the ISP's DNS server performs a recursive search, querying other DNS servers in a hierarchy until the IP address is located. This process is managed by the Domain Name System (DNS). 2. TCP/IP After obtaining the IP address for www.google.com, the browser begins a connection using the Transmission Control Protocol (TCP). This involves a three-way handshake to ensure a reliable connection: the client first sends a SYN (synchronize) packet to the server, the server replies with a SYN-ACK (synchronize-acknowledge) packet, and finally, the client responds with an ACK (acknowledge) packet. 3. Firewall Firewalls are security systems that monitor and control incoming and outgoing network traffic. Both the client and server firewalls check the packets to ensure they meet security criteria. 4. HTTPS/SSL Since the URL uses HTTPS, an encrypted connection is established using SSL/TLS (Secure Sockets Layer/Transport Layer Security). SSL Handshake: This involves the following steps: ClientHello, ServerHello, Certificate Exchange 5. Load Balancer Large-scale websites like Google use load balancers to distribute incoming traffic across multiple servers. Load Balancing Mechanism: The load balancer uses algorithms (e.g., round-robin, least connections) to determine which server should handle the request. 6. Web Server The load balancer forwards the request to a web server. The web server handles HTTP requests, serving static content like HTML, CSS, and JavaScript files. 7. Application Server For dynamic content, the web server forwards the request to an application server. Dynamic Processing: The application server executes server-side code, generates dynamic content, and handles business logic. Technologies involved could include server-side scripting languages like Python, Ruby, or Node.js. 8. Database If the request requires data storage or retrieval, the application server interacts with a database. Database Query: The application server sends a query to the database to store data. Response Handling: The database processes the query and sends back the results to the application server. 9. Rendering the Page Finally, the application server sends the processed data back to the web server, which then sends it to the client’s browser. The browser processes the HTML, CSS, and JavaScript to render the page for the user to see.

Do you know in a Containerized Application there will be a trade-off in network performance ? depending on what network driver/type, some of them make the "abstraction" that adds more complexity layer in it's network side, so choosing the right one based on your needs/priority is critical. I want to share with you my experience in choosing  "host" network in eliminating request bottlenecks that were found during load testing sessions and then will be used in Production. For the context: - Temporary ownership. we just utilize and enhance the “existing stack” that will be transferred back to its owner. So introducing more complex things to them (eg: Kubernetes, etc) is not in the radar at that moment. - NGINX container used as load balancer to distribute traffic to App container, there are also some rules for certain HTTP path will be served by specific upstreams/container. - Direct Container to container communication only happens in “local” LB to the apps, for the heavy tasks are run as background jobs that are executed on a dedicated VM (also as container). - The app cannot run by itself, so it needs to run with an additional package (a.k.a web server) for production use (you know what i mean). The challenges in using "host" network are: - Basically no network isolation between host and each container that ran inside it, which means the listening port in application or server in container must be unique. - Not all container images come with the option to set the listen port, since the author might expect it will use the default network driver. - You cannot monitor network usage/utilization per container anymore (eg: using cAdvisor). These are some points to answer them: - I created a Python script that will generate docker compose file (without additional libs), to manage the port allocation per container that will be listened to and also register them as NGINX upstream lists. And yes there is a feature to set “replica count” per container app type. - Create and put the custom container entrypoint script in read the special environment var injected, that will tell which should be listen to and adjust to web server configuration. - The monitoring is done at VM level and the main load balancer which faces the user directly. As the results in the picture below, some of network related metrics in the main load balancer show a huge difference in before (using driver “bridge”) and after the implementation with the same load test parameters and container count. Which shown the apps across all of VM can serving more request Some notes and takeaway: - There is no silver bullet in optimization, you must emphasize the pros and cost first. yes the sentence “It depends” can be the right answer since it's relative to the priority that you want to achieve. - Without direct mention, you might know the answer to the question “why my containerized apps have higher latency and/or lower throughput in Kubernetes compared to running without it ?”.

Kickstart Your Secure Node.js Server in Just a Few Steps 🚀 Are you ready to level up your Node.js skills? Let’s walk through how to set up a secure server using Express, body-parser, and HTTPS. Whether you’re building a simple API or a full-fledged web app, securing your server from the get-go is crucial. Step 1: Initialize Your Project First things first, let’s create a new Node.js project. Run the following command in your terminal: ```bash npm init -y ``` This will quickly set up a `package.json` file with default settings, giving your project structure. Step 2: Install Essential Dependencies Next, install the key packages that will power your server: ```bash npm install express body-parser https ``` - Express: A fast, minimal framework for building web applications. - body-parser: Middleware to handle JSON and URL-encoded data. - https: Module to add a layer of security with SSL/TLS encryption. Step 3: Create Your Secure Server Now, it’s time to build the server! Here’s a simple `app.js` script: ```javascript const express = require('express'); const bodyParser = require('body-parser'); const https = require('https'); // Your SSL/TLS certificates const privateKey = `YOUR_PRIVATE_KEY_HERE`; const certificate = `YOUR_CERTIFICATE_HERE`; const app = express(); app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended: true })); app.get('/', (req, res) => { res.send('Hello, World!'); }); const options = { key: privateKey, cert: certificate }; https.createServer(options, app).listen(3000, () => { console.log(`Secure server is running at https://localhost:3000`); }); ``` Why This Setup Matters By using HTTPS, you ensure that the data exchanged between your server and clients is encrypted, protecting it from potential eavesdroppers. The body-parser middleware simplifies handling incoming data, allowing you to focus on what really matters—building great features. Ready to Get Started? This setup is perfect for both beginners and seasoned developers who want to ensure their applications are secure right from the start. What will you build next with this secure foundation? Share your thoughts and projects in the comments—I’d love to see what you’re working on! #NodeJS #WebDevelopment #JavaScript #HTTPS #Coding #Security Let’s connect if you’re interested in more tips on secure coding and web development best practices!

A RESTful API (Representational State Transfer) is a web service interface that follows a set of principles and constraints designed to ensure scalability, simplicity, and performance. Below are some of critical aspects of RESTful API's API Methods: GET - Retrieves data from the server. It is used to request a specific resource or collection of resources. POST - Submits data to the server to create a new resource. This method is often used for form submissions or when uploading files. PUT - Updates an existing resource on the server with new data. If the resource does not exist, it can create it in some cases. PATCH - Partially updates an existing resource with the provided data. Unlike PUT, PATCH only changes the fields specified in the request. DELETE - Removes a specified resource from the server. HEAD - Similar to GET, but it only retrieves the headers of the resource, not the actual content. It’s useful for checking if a resource exists or if it has been modified. OPTIONS - Describes the communication options for the target resource. It’s used to determine the available methods and other capabilities supported by the server. CONNECT - Establishes a tunnel to the server, typically used for HTTPS connections through a proxy. TRACE - Echoes back the received request, used mainly for diagnostic purposes to see what changes or modifications are made to the request by intermediate servers. Key API Response Codes: 200 OK - The request was successful, and the content has been delivered. 201 Created - A new resource has been successfully created. 204 No Content - The request succeeded, but there is no content to return. 400 Bad Request - The request is invalid due to a client-side error. 401 Unauthorized - Authentication credentials are missing or incorrect. 403 Forbidden - The server refuses to fulfill the request due to failed authorization. 404 Not Found - The requested resource could not be found. 405 Method Not Allowed - The HTTP method used is not allowed for this resource. 409 Conflict - The request conflicts with the current state of the resource. 500 Internal Server Error - A generic error occurred on the server side. 502 Bad Gateway - The server received an invalid response from another server. 503 Service Unavailable - The server is currently unavailable, often due to overload. 504 Gateway Timeout - The server didn't receive a timely response from an upstream server. 301 Moved Permanently - The resource has been permanently moved to a new URL. 307 Temporary Redirect - The resource is temporarily redirected to another URL. #EnterpriseIntegrations #Integrations #IntegrationArchitecture #RESTFulAPI #APIStatusCode #APIMethods

Excellent Illustration on how the web works: