Code Chronicles

 REST API ගැන ඉගෙන ගන්න පටන් ගන්නකොට නිතරම අහන්නට ලැබෙන වචනයක් තමයි stateless කියන එක. 🔁 ඇහෙන්නේ සරලයි වගේ, නමුත් ඇත්තටම මේක තමයි නවීන වෙබ් තාක්ෂණයේ පදනම් වූ වැදගත්ම architectural තීරණයක්. ඉතින් සරලවම මේක තේරුම් ගමු. 👇 🤔 "Stateless" කියන්නේ ඇත්තටම මොකක්ද? Stateless පද්ධතියක සර්වර් 🖥️ එක client ගේ පෙර requests ගැන කිසිම දෙයක් මතක තියාගන්නේ නැහැ . Client කෙනෙකුගෙන් server එකට එන හැම request එකකම, ඒ request එක තේරුම් ගන්නත් process කරන්නත් අවශ්‍ය සම්පූර්ණ තොරතුරු 📦 තිබෙන්නම ඕන — server එකට "කලින් මතක තියෙන" කිසිම දෙයක් නැහැ. මේක fast-food කවුන්ටරයක ආහාර order කරනවා වගේ දෙයක්. 🍔 හැම වතාවෙම ඔබ ගිහින් ඔබේ සම්පූර්ණ order එක නැවත කියන්න ඕන — "බර්ගර් එකක්, ළූණු නෑ, චීස් වැඩිය, මධ්‍යම ප්‍රමාණයේ ෆ්‍රයිස්, කෝලා එකක්" කියලා 🍟🥤. කැෂියර්ට මතක නැහැ ඔබ පසුගිය සතියේ order කළේ මොකක්ද, මිනිත්තු පහකට කලින් වුනත් සරි. හැම order එකක්ම එකිනෙකට වෙන් වෙලා තියෙනවා. ✅ 🏗️ REST APIs වල මේක වැඩ කරන්නේ කොහොමද? Stateless REST API එකක: 🔑 Client එක authentication ...

In the era of big data, organizations are constantly seeking efficient ways to manage, process, and analyze large volumes of structured and unstructured data. Enter Apache Hadoop , an open-source framework that provides scalable, reliable, and distributed computing solutions. With its rich ecosystem of tools, Hadoop has become a cornerstone for big data projects. Let’s explore the various components and layers of the Hadoop ecosystem and how they work together to deliver insights. Data Processing Layer 🛠️🔍 The heart of Hadoop lies in its data processing capabilities, powered by several essential tools: Apache Pig 🐷 : Allows Hadoop users to write complex MapReduce transformations using a scripting language called Pig Latin , which translates to MapReduce and executes efficiently on large datasets. Apache Hive 🐝 : Provides a SQL-like query language called HiveQL for summarizing, querying, and analyzing data stored in Hadoop’s HDFS or compatible systems like Amazon S3. It makes inter...

 In today’s digital world, cloud computing has revolutionized the way businesses and individuals store, access, and manage data and applications. From reducing the burden of software management to providing scalable platforms for app development, the cloud offers a wide range of services tailored to different needs. Let’s dive into the most common cloud services: SaaS, PaaS, IaaS, and DaaS . 1. SaaS – Software as a Service 🖥️✨ SaaS is the most recognizable form of cloud service for everyday consumers. It takes care of managing software and its deployment, making life easier for businesses by removing the need for technical teams to handle installations, updates, and licensing. 🔑 Key Benefits : Cost Reduction : No need for a dedicated IT team or expensive licensing fees. Ease of Use : Access software directly through the internet without complex setup. 🛠️ Popular SaaS Applications : Salesforce : A leading CRM platform that helps businesses manage customer relationships. Google ...

  Graph databases are designed to manage and navigate complex relationships between data points. Instead of using tables and rows like a relational database, graph databases use nodes and edges to represent data entities and the relationships between them. Here's how they work: Nodes : These are the data entities (e.g., people, places, or objects). Edges : These represent relationships between the nodes (e.g., friendships, ownership, or transactions). Properties : Both nodes and edges can have properties, or additional information attached to them. Key Features of Graph Databases : Relationships are stored as first-class citizens, making data retrieval extremely efficient. The database schema resembles a topographical map , where you can easily query relationships between nodes. The query language used allows for efficient traversal of the graph to find specific data points or relationships. Example Use Cases : Social Networks : Finding "friends of friends" or connectio...

  Shell scripting in Unix/Linux opens the door to a world of automation, efficiency, and convenience. Today, we’re exploring how to use the read command for user input and dive into handling command-line parameters and special variables. Understanding these concepts will help you create more dynamic and powerful scripts! The read Command: Capturing User Input 📥 The read command in shell scripting allows you to capture user input and store it in variables. Here’s the basic syntax: read [option] Var Var… Option : You can use -p to display a prompt message for the user. Example 1: Prompting for a Name Here’s a simple script that asks for the user’s name and prints it: #!/bin/bash # # Using the read command to prompt the user for a name # echo echo -e "Enter your name: \c" # Prompt the user read name # Read input and store it in the 'name' variable echo -e "Your name is $name " # Output the user's name echo Improved Version with -p O...

    Creating and running scripts in Unix/Linux can simplify repetitive tasks, automate processes, and make your workflow more efficient. Whether you're checking logged-in users, displaying the date, or showcasing your current working directory, shell scripting can help you do it all with just a few lines of code. Let’s walk through the basics of creating and running a simple shell script, exploring built-in commands, and enhancing our script with special characters in echo statements. Writing Your First Script ✍️ Imagine you want to create a script that shows the current date and all users currently logged in. To start, open your favorite text editor (like nano or vim ) and type the following commands: date echo "Users currently logged in:" who After typing, save this file with a name like check_users.sh . This script uses: date to display the current date. echo to print a message. who to list all currently logged-in users. Making the Script Executable 🚀 Before you...

  The Unix/Linux shell offers a variety of commands and utilities that make interacting with the system smooth and powerful. Among them, the echo command is a classic, letting you display text on the screen, while built-in commands allow you to manipulate the environment and processes directly. Let’s dive into these essential shell utilities, covering echo , command chaining, and grouping commands for maximum efficiency. The Echo Command 🗣️ The echo command is a simple but valuable tool for displaying text and variables in the terminal. By default, it outputs whatever text you pass to it, followed by a newline. Examples: % echo 'hello there' hello there % echo "hello there" hello there % echo hello there hello there These examples show how you can use single quotes ( ' ), double quotes ( " ), or no quotes to display text with echo . All forms output the text as-is. Equivalent to using echo , you can also use the printf command for more control over f...