Introduction In today's data-driven world, the ability to quickly and efficiently analyze massive datasets is more critical than ever. Enter AWS Redshift, Amazon Web Services' answer to the growing need for comprehensive data warehousing solutions. But what is AWS Redshift, and why is it becoming a staple in the arsenal of data analysts and businesses alike? At its most basic, AWS Redshift is a cloud-based service that allows users to store, query, and analyze large volumes of data. It's designed to handle petabytes of data across a cluster of servers, providing the horsepower needed for complex analytics without the need for infrastructure management typically associated with such tasks. For those who are new to the concept, you might wonder how it differs from traditional databases. Unlike conventional databases that are optimized for transaction processing, AWS Redshift is built specifically for high-speed analysis and reporting of large datasets. This focus on analytics allows Redshift to deliver insights from data at speeds much faster than traditional database systems. One of the key benefits of AWS Redshift is its scalability. You can start with just a few hundred gigabytes of data and scale up to a petabyte or more, paying only for the storage and computing power you use. This makes Redshift a cost-effective solution for companies of all sizes, from startups to global enterprises. Furthermore, AWS Redshift integrates seamlessly with other AWS services, such as S3 for data storage, Data Pipeline for data movement, and QuickSight for visualization, creating a robust ecosystem for data warehousing and analytics. This integration simplifies the process of setting up and managing your data workflows, allowing you to focus more on deriving insights and less on the underlying infrastructure. In essence, AWS Redshift democratizes data warehousing, making it accessible not just to large corporations with deep pockets but to anyone with data to analyze. Whether you're a seasoned data scientist or a business analyst looking to harness the power of your data, AWS Redshift offers a powerful, scalable, and cost-effective platform to bring your data to life. Understanding AWS Redshift and its components can help you to make decisions if you are interested to use this powerful tool, for next sections we are going to dive into Redshift and its components. Is AWS Redshift a Database? While AWS Redshift shares some characteristics with traditional databases, it's more accurately described as a data warehousing service. This distinction is crucial for understanding its primary function and capabilities. Traditional databases are designed primarily for online transaction processing (OLTP), focusing on efficiently handling a large number of short, atomic transactions. These databases excel in operations such as insert, update, delete, and query by a single row, making them ideal for applications that require real-time access to data, like e-commerce websites or banking systems. On the other hand, AWS Redshift is optimized for online analytical processing (OLAP). It's engineered to perform complex queries across large datasets, making it suitable for business intelligence, data analysis, and reporting tasks. Redshift achieves high query performance on large datasets by using columnar storage, data compression, and parallel query execution, among other techniques. So, is AWS Redshift a database? Not in the traditional sense of managing day-to-day transactions. Instead, it's a specialized data warehousing service designed to aggregate, store, and analyze vast amounts of data from multiple sources. Its strength lies in enabling users to gain insights and make informed decisions based on historical data analysis rather than handling real-time transaction processing. In summary, while Redshift has database-like functionalities, especially in data storage and query execution, its role as a data warehousing service sets it apart from conventional database systems. It's this distinction that empowers businesses to harness the full potential of their data for analytics and decision-making processes. Advantages of AWS Redshift Performance Efficiency: AWS Redshift utilizes columnar storage and data compression techniques, which significantly improve query performance by reducing the amount of I/O needed for data retrieval. This makes it exceptionally efficient for data warehousing operations. Scalability: Redshift allows you to scale your data warehouse up or down quickly to meet your computing and storage needs without downtime, ensuring that your data analysis does not get interrupted as your data volume grows. Cost-Effectiveness: With its pay-as-you-go pricing model, AWS Redshift provides a cost-effective solution for data warehousing. You only pay for the resources you use, which helps in managing costs more effectively compared to traditional data warehousing solutions. Easy to Set Up and Manage: AWS provides a straightforward setup process for Redshift, including provisioning resources and configuring your data warehouse without the need for extensive database administration expertise. Security: Redshift offers robust security features, including encryption of data in transit and at rest, network isolation using Amazon VPC, and granular permissions with AWS Identity and Access Management (IAM). Integration with AWS Ecosystem: Redshift seamlessly integrates with other AWS services, such as S3, Glue and QuickSight, enabling a comprehensive cloud solution for data processing, storage, and analysis. Massive Parallel Processing (MPP): Redshift's architecture is designed to distribute and parallelize queries across all nodes in a cluster, allowing for rapid execution of complex data analyses over large datasets. High Availability: AWS Redshift is designed for high availability and fault tolerance, with data replication across different nodes and automatic replacement of failed nodes, ensuring that your data warehouse remains operational. Disadvantages of AWS Redshift Complexity in Management: Despite AWS's efforts to simplify, managing a Redshift cluster can still be complex, especially when it comes to fine-tuning performance and managing resources efficiently. Cost at Scale: While Redshift is cost-effective for many scenarios, costs can escalate quickly with increased data volume and query complexity, especially if not optimized properly. Learning Curve: New users may find there's a significant learning curve to effectively utilize Redshift, especially those unfamiliar with data warehousing principles and SQL. Limited Concurrency: In some cases, Redshift can struggle with high concurrency scenarios where many queries are executed simultaneously, impacting performance. Maintenance Overhead: Regular maintenance tasks, such as vacuuming to reclaim space and analyze to update statistics, are necessary for optimal performance but can be cumbersome to manage. Data Load Performance: Loading large volumes of data into Redshift can be time-consuming, especially without careful management of load operations and optimizations. Cold Start Time: Starting up a new Redshift cluster or resizing an existing one can take significant time, leading to delays in data processing and analysis. AWS Redshift Architecture and Its components The architecture of AWS Redshift is a marvel of modern engineering, designed to deliver high performance and reliability. We'll explore its core components and how they interact to process and store data efficiently. Looking to the image above you can note some components since when client interact until how the data is processed through the components itself. The following we will describe each component and its importance for the functioning of Redshift: Leader Node Function: The leader node is responsible for coordinating query execution. It parses and develops execution plans for SQL queries, distributing the workload among the compute nodes. Communication: It also aggregates the results returned by the compute nodes and finalizes the query results to be returned to the client. Compute Nodes Function: These nodes are where the actual data storage and query execution take place. Each compute node contains one or more slices, which are partitions of the total dataset. Storage: Compute nodes store data in columnar format, which is optimal for analytical queries as it allows for efficient compression and fast data retrieval. Processing: They perform the operations instructed by the leader node, such as filtering, aggregating, and joining data. Node Slices Function: Slices are subdivisions of a compute node's memory and disk space, allowing the node's resources to be used more efficiently. Parallel Processing: Each slice processes its portion of the workload in parallel, which significantly speeds up query execution times. AWS Redshift Architecture and its features Redshift contains some features that helps to provide performance to data processing and compression, below we bring some of these features: Massively Parallel Processing (MPP) Architecture Function: Redshift utilizes an MPP architecture, which enables it to distribute data and query execution across all available nodes and slices. Benefit: This architecture allows Redshift to handle large volumes of data and complex analytical queries with ease, providing fast query performance. Columnar Storage Function: Data in Redshift is stored in columns rather than rows, which is ideal for data warehousing and analytics because it allows for highly efficient data compression and reduces the amount of data that needs to be read from disk for queries. Benefit: This storage format is particularly advantageous for queries that involve a subset of a table's columns, as it minimizes disk I/O requirements and speeds up query execution. Data Compression Function: Redshift automatically applies compression techniques to data stored in its columns, significantly reducing the storage space required and increasing query performance. Customization: Users can select from various compression algorithms, depending on the nature of their data, to optimize storage and performance further. Redshift Spectrum Function: An extension of Redshift's capabilities, Spectrum allows users to run queries against exabytes of data stored in Amazon S3, directly from within Redshift, without needing to load or transform the data. Benefit: This provides a seamless integration between Redshift and the broader data ecosystem in AWS, enabling complex queries across a data warehouse and data lake. Integrations with AWS Redshift Redshift's ability to integrate with various AWS services and third-party applications expands its utility and flexibility. This section highlights key integrations that enhance Redshift's data warehousing capabilities. Amazon S3 (Simple Storage Service) Amazon S3 is an object storage service offering scalability, data availability, security, and performance. Redshift can directly query and join data stored in S3, using Redshift Spectrum, without needing to load the data into Redshift tables. Users can create external tables that reference data stored in S3, allowing Redshift to access data for querying purposes. AWS Glue AWS Glue can automate the ETL process for Redshift, transforming data from various sources and loading it into Redshift tables efficiently. It can also manage the data schema in the Glue Data Catalog, which Redshift can use. As benefits, this integration simplifies data preparation, automates ETL tasks, and maintains a centralized schema catalog, resulting in reduced operational burden and faster time to insights. AWS Lambda You can use Lambda to pre-process data before loading it into Redshift or to trigger workflows based on query outputs. This integration automates data transformation and loading processes, enhancing data workflows and reducing the time spent on data preparation. Amazon DynamoDB Redshift can directly query DynamoDB tables using the Redshift Spectrum feature, enabling complex queries across your DynamoDB and Redshift data. This provides a powerful combination of real-time transactional data processing in DynamoDB with complex analytics and batch processing in Redshift, offering a more comprehensive data analysis solution. Amazon Kinesis Redshift integrates with Kinesis Data Firehose, which can load streaming data directly into Redshift tables. This integration enables real-time data analytics capabilities, allowing businesses to make quicker, informed decisions based on the latest data. Conclusion AWS Redshift exemplifies a powerful, scalable solution tailored for efficient data warehousing and complex analytics. Its integration with the broader AWS ecosystem, including S3, AWS Glue, Lambda, DynamoDB, and Amazon Kinesis, underscores its versatility and capability to streamline data workflows from ingestion to insight. Redshift's architecture, leveraging columnar storage and massively parallel processing, ensures high-speed data analysis and storage efficiency. This enables organizations to handle vast amounts of data effectively, facilitating real-time analytics and decision-making. In essence, AWS Redshift stands as a cornerstone for data-driven organizations, offering a comprehensive, future-ready platform that not only meets current analytical demands but is also poised to evolve with the advancing data landscape.

The Evolution of Data Engineering Data engineering has witnessed a transformative journey, evolving from simple data collection and storage to sophisticated processing and analysis. A historical overview reveals its roots in traditional database management, progressing through the advent of big data, to today's focus on real-time analytics and cloud computing. Recent advances have been catalyzed by the integration of artificial intelligence (AI) and machine learning (ML), pushing the boundaries of what's possible in data-driven decision-making. Core Skills for Data Engineers in 2024 What Data Engineers Need to Know in 2024? To thrive in 2024, data engineers must master a blend of foundational and cutting-edge skills: Programming Languages: Proficiency in languages like Python, Scala, and SQL is non-negotiable, enabling efficient data manipulation and analysis. Database Management: Understanding relational and NoSQL databases, alongside data warehousing solutions, forms the backbone of effective data storage strategies. Cloud Computing Platforms: Expertise in AWS, Google Cloud Platform, and Azure is crucial, as cloud services become central to data engineering projects. Data Modeling & ETL Processes: Developing robust data models and streamlining ETL (Extract, Transform, Load) processes are key to ensuring data quality and accessibility. Emerging Technologies and Their Impact Emerging technologies such as AI and ML, big data frameworks, and automation tools are redefining the landscape: Artificial Intelligence & Machine Learning: These technologies are vital for predictive modeling and advanced data analysis, offering unprecedented insights. Big Data Technologies: Hadoop, Spark, and Flink facilitate the handling of vast datasets, enabling scalable and efficient data processing. Automation and Orchestration Tools: Tools like Apache Airflow and Kubernetes enhance efficiency, automating workflows and data pipeline management. The Importance of Data Governance and Security With increasing data breaches and privacy concerns, data governance and security have become paramount: Regulatory Compliance: Familiarity with GDPR, CCPA, and other regulations is essential for legal compliance. Data Privacy Techniques: Implementing encryption, anonymization, and secure access controls protects sensitive information from unauthorized access. Data Engineering in the Cloud Era The shift towards cloud computing necessitates a deep understanding of cloud services and technologies: Cloud Service Providers: Navigating the offerings of major providers ensures optimal use of cloud resources. Cloud-native Technologies: Knowledge of containerization, microservices, and serverless computing is crucial for modern data engineering practices. Real-time Data Processing The ability to process and analyze data in real-time is becoming increasingly important: Streaming Data Technologies: Tools like Apache Kafka and Amazon Kinesis support high-throughput, low-latency data streams. Real-time Analytics: Techniques for real-time data analysis enable immediate insights, enhancing decision-making processes. Advanced Analytics and Business Intelligence Advanced analytics and BI tools are essential for converting data into actionable insights: Predictive Analytics: Using statistical models and machine learning to predict future trends and behaviors. Visualization Tools: Tools like Tableau and Power BI help in making complex data understandable through interactive visualizations. Career Pathways and Growth Opportunities Exploring certifications, training, and staying informed about industry demand prepares data engineers for career advancement: Certification and Training: Pursuing certifications in specific technologies or methodologies can bolster expertise and credibility. Industry Demand: Understanding the evolving market demand ensures data engineers can align their skills with future opportunities. Preparing for the Future Continuous learning and community engagement are key to staying relevant in the fast-paced field of data engineering: Continuous Learning: Embracing a mindset of lifelong learning ensures data engineers can adapt to new technologies and methodologies. Networking and Community Engagement: Participating in forums, attending conferences, and contributing to open-source projects fosters professional growth and innovation. Conclusion As data becomes increasingly, the role of data engineers in shaping the future of technology cannot be overstated. By mastering core skills, staying informed about emerging technologies, and emphasizing data governance and security, data engineers can lead the charge in leveraging data for strategic advantage in 2024 and beyond.

In the ever-evolving landscape of technology, programming languages stand as the foundational tools empowering innovation, driving progress, and shaping the digital world we inhabit. As we venture into 2024, the significance of understanding and leveraging these languages has never been more pronounced. From powering artificial intelligence to enabling seamless web development, programming languages play a pivotal role in defining the trajectory of tech trends and driving transformative change across industries. In this era of rapid technological advancement, staying abreast of the latest programming languages is not merely advantageous—it's imperative. Developers, engineers, and tech enthusiasts alike must recognize the profound impact that mastering these languages can have on their ability to navigate and thrive in the dynamic tech landscape of 2024. Programming languages serve as the building blocks of innovation, providing developers with the means to translate ideas into tangible solutions. In 2024, familiarity with cutting-edge languages equips individuals with the tools needed to push the boundaries of what's possible, whether through developing AI-driven applications, crafting immersive virtual experiences, or architecting resilient software systems. With every technological advancement comes a myriad of opportunities waiting to be seized. Whether it's capitalizing on the burgeoning fields of data science, blockchain technology, or quantum computing, proficiency in the right programming languages positions individuals to harness these opportunities and carve out their niche in the digital landscape of 2024. In an increasingly competitive job market, proficiency in in-demand programming languages can be a game-changer for career advancement. Employers across industries are seeking skilled professionals capable of leveraging the latest tools and technologies to drive business success. By staying ahead of the curve and mastering emerging languages, individuals can enhance their employability and unlock a wealth of career opportunities. For this post, I decided to write about the programming languages trends for 2024 and I hope this can be useful to you and taking the best decisions and which directions you want to follow this year in this large field. Python Python continues to maintain its position as one of the most popular and versatile programming languages. With its simplicity, readability, and extensive ecosystem of libraries and frameworks, Python is widely used in fields such as data science, artificial intelligence, web development, and automation. In 2024, Python's relevance is further amplified by its adoption in emerging technologies like machine learning, quantum computing, and the metaverse. Rust Rust has been gaining traction as a systems programming language known for its performance, safety, and concurrency features. In 2024, Rust is increasingly used in critical systems development, including operating systems, game engines, and web browsers. Its emphasis on memory safety and zero-cost abstractions makes it particularly suitable for building secure and reliable software, making it a favored choice for projects demanding high performance and robustness. TypeScript TypeScript, a superset of JavaScript with static typing, continues to see widespread adoption in web development. Its ability to catch errors at compile time, improve code maintainability, and enhance developer productivity has made it a preferred choice for building large-scale web applications. In 2024, TypeScript's popularity remains strong, driven by its integration with popular frameworks like Angular, React, and Vue.js, as well as its support for modern JavaScript features. Julia Julia, a high-level programming language designed for numerical and scientific computing, is gaining prominence in fields such as data science, computational biology, and finance. Known for its speed and ease of use, Julia combines the flexibility of dynamic languages with the performance of compiled languages, making it well-suited for tasks involving mathematical computations and large-scale data analysis. In 2024, Julia continues to attract researchers, engineers, and data scientists seeking efficient and expressive tools for scientific computing. Kotlin Kotlin, a statically-typed programming language for the Java Virtual Machine (JVM), has emerged as a popular choice for Android app development. Offering modern features, interoperability with Java, and seamless integration with popular development tools, Kotlin enables developers to build robust and efficient Android applications. In 2024, Kotlin's adoption in the Android ecosystem remains strong, driven by its developer-friendly syntax, strong tooling support, and endorsement by Google as a preferred language for Android development. Golang (Go) Go, often referred to as Golang, continues to gain traction as a language for building scalable and efficient software systems. Known for its simplicity, performance, and built-in concurrency support, Go is well-suited for developing cloud-native applications, microservices, and distributed systems. In 2024, Go's popularity is fueled by its role in enabling the development of resilient and high-performance software architectures, particularly in cloud computing, DevOps, and container orchestration. What programming languages ​​do big tech use? Below we have an overview about programming languages that the main big techs companies are using in their stacks, so if you want to work in a Big Tech get ready to learn these languages. Conclusion In 2024, the programming landscape is characterized by a diverse set of languages, each catering to specific use cases and development requirements. From Python's versatility to Rust's performance, TypeScript's productivity to Julia's scientific computing capabilities, Kotlin's Android development to Go's system-level programming, developers have a rich array of tools at their disposal to tackle the challenges and opportunities presented by emerging technologies and industry trends. Whether building AI-powered applications, crafting scalable web services, or optimizing system performance, the choice of programming language plays a crucial role in shaping the success and impact of software projects in the dynamic tech landscape of 2024.

Introduction to Virtual Threads in Java 21 Concurrency has always been a cornerstone of Java programming, empowering developers to build responsive and scalable applications. However, managing threads efficiently while ensuring high performance and low resource consumption has been a perennial challenge. With the release of Java 21, a groundbreaking feature called Virtual Threads emerges as a game-changer in the world of concurrent programming. Concurrency challenges in Java and the problem with traditional threads Concurrency in Java presents developers with both immense opportunities for performance optimization and formidable challenges in ensuring thread safety and managing shared resources effectively. As applications scale and become more complex, navigating these challenges becomes increasingly crucial. Managing Shared Resources: One of the fundamental challenges in concurrent programming is managing shared resources among multiple threads. Without proper synchronization mechanisms, concurrent access to shared data can lead to data corruption and inconsistencies. Avoiding Deadlocks: Deadlocks occur when two or more threads are blocked indefinitely, waiting for each other to release resources. Identifying and preventing deadlocks is crucial for maintaining the responsiveness and stability of concurrent applications. Performance Bottlenecks: While concurrency can improve performance by leveraging multiple threads, it can also introduce overhead and contention, leading to performance bottlenecks. It's essential to carefully design concurrent algorithms and use appropriate synchronization mechanisms to minimize contention and maximize throughput. High Memory Overhead: Traditional threads in Java are implemented as native threads managed by the operating system. Each native thread consumes a significant amount of memory, typically in the range of several megabytes. This overhead becomes problematic when an application needs to create a large number of threads, as it can quickly deplete system resources. Limited Scalability: The one-to-one mapping between Java threads and native threads imposes a limit on scalability. As the number of threads increases, so does the memory overhead and the scheduling complexity. This limits the number of concurrent tasks an application can handle efficiently, hindering its scalability and responsiveness. Difficulty in Debugging and Profiling: Debugging and profiling concurrent applications built with traditional threads can be challenging due to the non-deterministic nature of thread execution and the potential for subtle timing-related bugs. Identifying and diagnosing issues such as race conditions and thread contention requires specialized tools and expertise. What are Virtual Threads? Virtual Threads represent a paradigm shift in how Java handles concurrency. Traditionally, Java applications rely on OS-level threads, which are heavyweight entities managed by the operating system. Each thread consumes significant memory resources, limiting scalability and imposing overhead on the system. Virtual Threads, on the other hand, are lightweight and managed by the Java Virtual Machine (JVM) itself. They are designed to be highly efficient, allowing thousands or even millions of virtual threads to be created without exhausting system resources. Virtual Threads offer a more scalable and responsive concurrency model compared to traditional threads. Benefits of Virtual Threads Virtual Threads come with a host of features and benefits that make them an attractive choice for modern Java applications: Lightweight: Virtual Threads have minimal memory overhead, allowing for the creation of large numbers of threads without exhausting system resources. This lightweight nature makes them ideal for highly concurrent applications. Structured Concurrency: Virtual Threads promote structured concurrency, which helps developers write more reliable and maintainable concurrent code. By enforcing clear boundaries and lifecycles for concurrent tasks, structured concurrency simplifies error handling and resource management. Improved Scalability: With Virtual Threads, developers can achieve higher scalability and throughput compared to traditional threads. The JVM's scheduler efficiently manages virtual threads, ensuring optimal utilization of system resources. Integration with CompletableFuture: Java 21 introduces seamless integration between Virtual Threads and CompletableFuture, simplifying asynchronous programming. CompletableFuture provides a fluent API for composing and chaining asynchronous tasks, making it easier to write non-blocking, responsive applications. Examples of Virtual Threads Creating and Running a Virtual Thread This example demonstrates the creation and execution of a virtual thread. We use the Thread.startVirtualThread() method to start a new virtual thread with the specified task, which prints a message indicating its execution. We then call join() on the virtual thread to wait for its completion before proceeding. CompletableFuture with Virtual Threads This example showcases the usage of virtual threads with CompletableFuture. We chain asynchronous tasks using supplyAsync(), thenApplyAsync(), and thenAcceptAsync() methods. These tasks execute in virtual threads, allowing for efficient asynchronous processing. Virtual Thread Pool Example In this example, we create a virtual thread pool using Executors.newVirtualThreadExecutor(). We then submit tasks to this pool using submit() method. Each task executes in a virtual thread, demonstrating efficient concurrency management. Using ThreadFactory with Virtual Threads Here, we demonstrate the use of a ThreadFactory with virtual threads. We create a virtual thread factory using Thread.builder().virtual().factory(), and then use it to create a fixed-size thread pool with Executors.newFixedThreadPool(). Tasks submitted to this pool execute in virtual threads created by the virtual thread factory. Virtual Thread Group Example In this final example, we demonstrate how to organize virtual threads into a thread group. We obtain a virtual thread group using Thread.builder().virtual().getThreadGroup() and then create a virtual thread within this group. The task executed by the virtual thread prints a message indicating its execution. Conclusion In conclusion, Virtual Threads introduced in Java 21 mark a significant milestone in the evolution of Java's concurrency model. By providing lightweight, scalable concurrency within the JVM, Virtual Threads address many of the limitations associated with traditional threads, offering developers a more efficient and flexible approach to concurrent programming. With Virtual Threads, developers can create and manage thousands or even millions of threads with minimal overhead, leading to improved scalability and responsiveness in Java applications. The structured concurrency model enforced by Virtual Threads simplifies error handling and resource management, making it easier to write reliable and maintainable concurrent code. Furthermore, the integration of Virtual Threads with CompletableFuture and other asynchronous programming constructs enables developers to leverage the full power of Java's concurrency framework while benefiting from the performance advantages of Virtual Threads. Overall, Virtual Threads in Java 21 represent a significant advancement that empowers developers to build highly concurrent and responsive applications with greater efficiency and scalability. As developers continue to explore and adopt Virtual Threads, we can expect to see further optimizations and enhancements that will further elevate Java's capabilities in concurrent programming.

Introduction In the realm of asynchronous and concurrent programming in Java, Future and CompletableFuture serve as essential tools for managing and executing asynchronous tasks. Both constructs offer ways to represent the result of an asynchronous computation, but they differ significantly in terms of functionality, flexibility, and ease of use. Understanding the distinctions between Future and CompletableFuture is crucial for Java developers aiming to design robust and efficient asynchronous systems. At its core, a Future represents the result of an asynchronous computation that may or may not be complete. It allows developers to submit tasks for asynchronous execution and obtain a handle to retrieve the result at a later point. While Future provides a basic mechanism for asynchronous programming, its capabilities are somewhat limited in terms of composability, exception handling, and asynchronous workflow management. On the other hand, CompletableFuture introduces a more advanced and versatile approach to asynchronous programming in Java. It extends the capabilities of Future by offering a fluent API for composing, combining, and handling asynchronous tasks with greater flexibility and control. CompletableFuture empowers developers to construct complex asynchronous workflows, handle exceptions gracefully, and coordinate the execution of multiple tasks seamlessly. In this article, we will dive deeper into the differences between Future and CompletableFuture, exploring their respective features, use cases, and best practices. By understanding the distinct advantages and trade-offs of each construct, developers can make informed decisions when designing asynchronous systems and leveraging concurrency in Java applications. Let's embark on a journey to explore the nuances of Future and CompletableFuture in the Java ecosystem. Use Cases for Future Parallel Processing: Use Future to parallelize independent tasks across multiple threads and gather results asynchronously. For example, processing multiple files concurrently. Asynchronous IO: When performing IO operations that are blocking, such as reading from a file or making network requests, you can use Future to perform these operations in separate threads and continue with other tasks while waiting for IO completion. Task Execution and Coordination: Use Future to execute tasks asynchronously and coordinate their completion. For example, in a web server, handle multiple requests concurrently using futures for each request processing. Timeout Handling: You can set timeouts for Future tasks to avoid waiting indefinitely for completion. This is useful when dealing with resources with unpredictable response times. Use Cases for CompletableFuture Async/Await Pattern: CompletableFuture supports a fluent API for chaining asynchronous operations, allowing you to express complex asynchronous workflows in a clear and concise manner, similar to the async/await pattern in other programming languages. Combining Results: Use CompletableFuture to combine the results of multiple asynchronous tasks, either by waiting for all tasks to complete (allOf) or by combining the results of two tasks (thenCombine, thenCompose). Exception Handling: CompletableFuture provides robust exception handling mechanisms, allowing you to handle exceptions thrown during asynchronous computations gracefully using methods like exceptionally or handle. Dependency Graphs: You can build complex dependency graphs of asynchronous tasks using CompletableFuture, where the completion of one task triggers the execution of another, allowing for fine-grained control over the execution flow. Non-blocking Callbacks: CompletableFuture allows you to attach callbacks that are executed upon completion of the future, enabling non-blocking handling of results or errors. Completing Future Manually: Unlike Future, you can complete a CompletableFuture manually using methods like complete, completeExceptionally, or cancel. This feature can be useful in scenarios where you want to provide a result or handle exceptional cases explicitly. Examples Creation and Completion Future code example of creation and completion. ExecutorService executor = Executors.newSingleThreadExecutor(); Future future = executor.submit(() -> { Thread.sleep(2000); return 10; }); CompletableFuture code example of creation and completion. CompletableFuture completableFuture = CompletableFuture.supplyAsync(() -> { try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } return 10; }); In CompletableFuture, supplyAsync method allows for asynchronous execution without the need for an external executor service an shown in the first example. Chaining Actions Example below in how to chain actions using Future. Future future = executor.submit(() -> 10); Future result = future.thenApply(i -> "Result: " + i); Now, an example using CompletableFuture in how to chain actions. CompletableFuture completableFuture = CompletableFuture.supplyAsync(() -> 10); CompletableFuture result = completableFuture.thenApply(i -> "Result: " + i); CompletableFuture offers a fluent API (thenApply, thenCompose, etc.) to chain actions, making it easier to express asynchronous workflows. Exception Handling Handling exception using Future Future future = executor.submit(() -> { throw new RuntimeException("Exception occurred"); }); Handling exception using CompletableFuture CompletableFuture completableFuture = CompletableFuture.supplyAsync(() -> { throw new RuntimeException("Exception occurred"); }); CompletableFuture allows for more flexible exception handling using methods like exceptionally or handle. Waiting for Completion // Future Integer result = future.get(); // CompletableFuture Integer result = completableFuture.get(); Both Future and CompletableFuture provide the get() method to wait for the completion of the computation and retrieve the result. Combining Multiple CompletableFutures CompletableFuture future1 = CompletableFuture.supplyAsync(() -> 10); CompletableFuture future2 = CompletableFuture.supplyAsync(() -> 20); CompletableFuture combinedFuture = future1.thenCombine(future2, (x, y) -> x + y); CompletableFuture provides methods like thenCombine, thenCompose, and allOf to perform combinations or compositions of multiple asynchronous tasks. Conclusion In the dynamic landscape of asynchronous and concurrent programming in Java, both Future and CompletableFuture stand as indispensable tools, offering distinct advantages and use cases. While Future provides a basic mechanism for representing the result of asynchronous computations, its capabilities are somewhat limited when it comes to composability, exception handling, and asynchronous workflow management. On the other hand, CompletableFuture emerges as a powerful and flexible alternative, extending the functionalities of Future with a fluent API for composing, combining, and handling asynchronous tasks with greater control and elegance. The choice between Future and CompletableFuture hinges on the specific requirements and complexities of the task at hand. For simple asynchronous operations or when working within the confines of existing codebases, Future may suffice. However, in scenarios that demand more sophisticated asynchronous workflows, exception handling, or task coordination, CompletableFuture offers a compelling solution with its rich feature set and intuitive API.

Introduction In today's data-driven world, the ability to efficiently process and analyze vast amounts of data in real-time has become a game-changer for businesses and organizations of all sizes. From e-commerce platforms and social media to financial institutions and IoT devices, the demand for handling data streams at scale is ever-increasing. This is where Apache Kafka steps in as a pivotal tool in the world of event-driven architecture. Imagine a technology that can seamlessly connect, process, and deliver data between countless systems and applications in real-time. Apache Kafka, often referred to as a distributed streaming platform, is precisely that technology. It's the unsung hero behind the scenes, enabling real-time data flow and providing a foundation for a multitude of modern data-driven applications. In this quick guide about Apache Kafka, we'll take a deep dive into Apache Kafka, unraveling its core concepts, architecture, and use cases. Whether you're new to Kafka or looking to deepen your understanding, this guide will serve as your compass on a journey through the exciting world of real-time data streaming. We'll explore the fundamental principles of Kafka, share real-world examples of its applications, and provide practical insights for setting up your own Kafka environment. So, let's embark on this adventure and discover how Apache Kafka is revolutionizing the way we handle data in the 21st century. Key Concepts of Kafka 1. Topics What Are Kafka Topics? In Kafka, a topic is a logical channel or category for data. It acts as a named conduit for records, allowing producers to write data to specific topics and consumers to read from them. Think of topics as a way to categorize and segregate data streams. For example, in an e-commerce platform, you might have topics like "OrderUpdates," "InventoryChanges," and "CustomerFeedback," each dedicated to a specific type of data. Partitioning within Topics One of the powerful features of Kafka topics is partitioning. When a topic is divided into partitions, it enhances Kafka's ability to handle large volumes of data and distribute the load across multiple brokers. Partitions are the unit of parallelism in Kafka, and they provide fault tolerance, scalability, and parallel processing capabilities. Each partition is ordered and immutable, and records within a partition are assigned a unique offset, which is a numeric identifier representing the position of a record within the partition. This offset is used by consumers to keep track of the data they have consumed, allowing them to resume from where they left off in case of failure or when processing real-time data. Data organization Topics provide a structured way to organize data. They are particularly useful when dealing with multiple data sources and data types. Topics works as a storage within Kafka context where data sent by producers is organized into topics and partitions. Publish-Subscribe Model Kafka topics implement a publish-subscribe model, where producers publish data to a topic, and consumers subscribe to topics of interest to receive the data. An analogy that we can do is when we subscribe to a newsletter to receive some news or articles. When some news is posted, you as a subscriber will receive it. Scalability Topics can be split into partitions, allowing Kafka to distribute data across multiple brokers for scalability and parallel processing. Data Retention Each topic can have its own data retention policy, defining how long data remains in the topic. This makes easier to manage the data volume wheter or not frees up space. 2. Producers In Kafka, a producer is a crucial component responsible for sending data to Kafka topics. Think of producers as information originators—applications or systems that generate and publish records to specific topics within the Kafka cluster. These records could represent anything from user events on a website to system logs or financial transactions. Producers are the source of truth for data in Kafka. They generate records and push them to designated topics for further processing. Also decide which Topic the message will be send based on the nature of the data. This ensures that data is appropriately categorized within the Kafka ecosystem. Data Type Usually producers send messages based on JSON format that makes easier the data transferring into the storage. Acknowledgment Handling Producers can handle acknowledgments from the Kafka broker, ensuring that data is successfully received and persisted. This acknowledgment mechanism contributes to data reliability. Sending data to specific partitions Producers can send messages directly to a specific partition within a Topic. 3. Consumers Consumers are important components in the Kafka context, they are responsible for consuming and providing data from the source. Basically, consumers subscribe to Kafa Topics and any data produced there will be received by consumers representing the pub/sub approach. Subscribing to Topics Consumers actively subscribe to Kafka topics, indicating their interest in specific streams of data. This subscription model enables consumers to receive relevant information aligned with their use case. Data Processing Consumers will always receive new data from topics, each consumer is responsible for processing this data according to their needs. A microservice that works as a consumer for example, it can consume data from a topic responsible for storing application logs and performing any processing before delivering it to the user or to other third-party applications. Integration between apps As mentioned previously, Kafka enables applications to easily integrate their services across varied topics and consumers. One of the most common use cases is integration between applications. In the past, applications needed to connect to different databases to access data from other applications, this created vulnerabilities and violated principles of responsibilities between applications. Technologies like Kafka make it possible to integrate different services using the pub/sub pattern where different consumers represented by applications can access the same topics and process this data in real time without the need to access third-party databases or any other data source, avoiding any security risk and added agility to the data delivery process. 4. Brokers Brokers are fundamental pieces in Kafka's architecture, they are responsible for mediating and managing the exchange of messages between producers and consumers. Brokers manage the storage of data produced by producers and guarantee reliable transmission of data within a Kafka cluster. In practice, Brokers have a transparent role within a Kafka cluster, but below I will highlight some of their responsibilities that make all the difference to the functioning of Kafka. Data reception Brokers are responsible for receiving the data, they function as an entry-point or proxy for the data produced and then manage all storage so that it can be consumed by any consumer. Fault tolerance Like all data architecture, we need to think about fault tolerance. In the context of Kafka, Brokers are responsible for ensuring that even in the event of failures, data is durable and maintains high availability. Brokers are responsible for managing the partitions within the topics capable of replicating the data, predicting any failure and reducing the possibility of data loss. Data replication As mentioned in the previous item, data replication is a way to reduce data loss in cases of failure. Data replication is done from multiple replicas of partitions stored in different Brokers, this allows that even if one Broker fails, there is data replicated in several others. Responsible for managing partitions We mentioned a recent article about partitions within topics but we did not mention who manages them. Partitions are managed by a Broker that works by coordinating reading and writing to that partition and also distributing data loading across the cluster. In short, Brokers perform orchestration work within a Kafka cluster, managing the reading and writing done by producers and consumers, ensuring that message exchanges are carried out and that there will be no loss of data in the event of failures in some of its components through data replication also managed by them. Conclusion Apache Kafka stands as a versatile and powerful solution, addressing the complex demands of modern data-driven environments. Its scalable, fault-tolerant, and real-time capabilities make it an integral part of architectures handling large-scale, dynamic data streams. Kafka has been adopted by different companies and business sectors such as Linkedin, where Kafka was developed by the way, Netflix, Uber, Airbnb, Wallmart, Goldman Sachs, Twitter and more.

Intro Airflow provides different ways of working with automated flows and one of the ways is the possibility of accessing external APIs using HTTP operators and extracting the necessary data. hands-on In this tutorial we will create a DAG which will access an external API and extract the data directly to a local file. If this is your first time using Airflow, I recommend accessing this link to understand more about Airflow and how to set up an environment. Creating the DAG For this tutorial, we will create a DAG that will trigger every 1 hour (schedule_interval="0 * * * *") and access an external API by extracting some data directly to a local JSON file. In this scenario we will use the SimpleHttpOperator operator which provides an API capable of executing requests to external APIs. Note that we use two operators within the same DAG. The SimpleHttpOperator operator that provides ways of accessing external APIs that through the method field we define HTTPs methods (GET, POST, PUT, DELETE). The endpoint field allows specifying the endpoint of the API, which in this case is products and finally, the http_conn_id parameter, where it's necessary to pass the identifier of the connection that will be defined next through the Airflow UI. As shown below, access the menu Admin > Connections Fill in the data as shown in the image below and then save. About the PythonOperator operator, we are only using it to execute a Python function called _write_response using XComs where through the task_id of the write_response task, it is possible to retrieve the result of the response and use it in any part of the code. In this scenario we are using the result retrieved from the API to write to the file. XCom is a communication mechanism between different tasks that makes Airflow very flexible. Tasks can often be executed on different machines and with the use of XComs, communication and information exchange between Tasks is possible. Finally, we define the execution of the tasks and their dependencies, see that we use the >> operator, which is basically to define the order of execution between the tasks. In our case, API access and extraction must be performed before writing to the file extract_data >> write_response. After executing the DAG, it is possible to access the file that was generated with the result of the extraction, just access one of the workers via the terminal, which in this case will only have one. Run the following command below to list the containers: docker ps A listing similar to the one below will be displayed. Notice that one of the lines in the NAMES column refers to the worker, in this case coffee_and_tips_airflow-worker_1. Continuing in the terminal, type the following command to access the Airflow directory where the extract_data.json file is located. docker exec -it coffee_and_tips_airflow-worker_1 /bin/bash It's done, now just open the file and check the content. Conclusion Once again we saw the power of Airflow for automated processes that require easy access and integration of external APIs with few lines of code. In this example, we explore the use of XComs, which aims to make the exchange of messages between tasks that can be executed on different machines in a distributed environment more flexible. Hope you enjoyed!

Intro Java Future is one of several ways to work with the language asynchronously, providing a multi-thread context in which it is possible to execute tasks in parallel without blocking the process. In the example below, we will simulate sending a fictitious email in which, even during sending, the process will not be blocked, that is, it will not be necessary to wait for the sending to finish for the other functionalities or mechanisms to operate again. EmailService class Understanding the EmailService class The class above represents the sending emails in a fictitious way, the idea of ​​using the loop is to simulate the sending is precisely to delay the process itself. Finally, at the end of sending, the method sendEmailBatch(int numberOfEmailsToBeSent) returns a String containing a message referring to the end of the process. EmailServiceAsync class Understanding the EmailServiceAsync class The EmailServiceAsync class represents the asynchronous mechanism itself, in it we have the method sendEmailBatchAsync(int numberOfEmailsToBeSent) which will be responsible for making the process of sending dummy e-mails asynchronous. The asynchronous process is managed by using the ExecutorService instance which facilitates the management of tasks asynchronously which are assigned to a pool of threads. In this case, the call to the sendEmailBatch(int numberOfEmailsToBeSent) method boils down to a task (task) which will be assigned to a Thread defined in Executors.newFixedThreadPool(1). Finally, the method returns a Future that is literally a promise that task will be completed at some point, representing an asynchronous process. EmailServiceAsyncRun class Understanding the EmailServiceAsyncRun class It is in this class where we will test the asynchronous process using Future. Let's recap, in the EmailService class, we've created a method called sendEmailBatch(int numberOfEmailsToBeSent) in which we're simulating through the for the sending of dummy email and printing a sending message that we'll use to test the concurrency. In the EmailServiceAsync class, the sendEmailBatchAsync(int numberOfEmailsToBeSent) method creates an ExecutorService instance that will manage the tasks together with the thread pool, which in this case, we are creating just one Thread defined in Executors.newFixedThreadPool(1) and will return a Future. Now in the EmailServiceAsyncRun class, this is where we actually test the process, let's understand by parts: We instantiate an object of type EmailServiceAsync We create an object of type Future and assign it to the return of the emailAsync.sendEmailBatchAsync(500) method. The idea of ​​argument 500 is just to control the iteration of the For, delaying the process to be finished. We could even use Thread.sleep() as an alternative and set a delay time which would also work fine. Note that we are using the futureReturn.isDone() method to control the while iteration control, that is, this method allows the process not to be blocked while the email flow is executed. In this case, any process that you want to implement to compete while sending is done, can be created inside the while, such as a flow of updating customer tables or any other process. On line 20, using the futureReturn.get() method, we're printing the result of sending the emails. And finally, we finish the executorService and its tasks through the executorService.shutdown() method. Running the process Notice clearly that there are two distinct processes running, the process of sending email "Sending email Nº 498.." and the process of updating a customer table. Finally the process is finished when the message "A total of 500 emails has been sent" is printed. Working with blocking processes The use of Future is widely used for use cases where we need to block a proces. The current Thread will be blocked until the process being executed by Future ends. To do so, simply invoke the futureReturn.get() method directly without using any iteration control as used in the previous example. An important point is that this type of approach can cause resources to be wasted due to the blocking of the current Thread. Conclusion The use of Future is very promising when we need to add asynchronous processes to our code in the simplest way or even use it to block processes. It's a lean API with a certain resource limitation but that works well for some scenarios. Hope you enjoyed!

Intro Airflow has been one of the main orchestration tools on the market and much talked about in the Modern Data Stack world, as it is a tool capable of orchestrating data workloads through ETLs or ELTs. But in fact, Airflow is not just about that, it can be applied in several cases of day-to-day use of a Data or Software Engineer. In this Apache Airflow for Beginners Tutorial, we will introduce Airflow in the simplest way, without the need to know or create ETLs. But what is Airflow actually? Apache Airflow is a widely used workflow orchestration platform for scheduling, monitoring, and managing data pipelines. It has several components that work together to provide its functionalities. Airflow components DAG The DAG (Directed Acyclic Graph) is the main component and workflow representation in Airflow. It is composed of tasks (tasks) and dependencies between them. Tasks are defined as operators (operators), such as PythonOperator, BashOperator, SQLOperator and others. The DAG defines the task execution order and dependency relationships. Webserver The Webserver component provides a web interface for interacting with Airflow. It allows you to view, manage and monitor your workflows, tasks, DAGs and logs. The Webserver also allows user authentication and role-based access control. Scheduler The Scheduler is responsible for scheduling the execution of tasks according to the DAG definition. It periodically checks for pending tasks to run and allocates available resources to perform the tasks at the appropriate time. The Scheduler also handles crash recovery and scheduling task retries. Executor The Executor is responsible for executing the tasks defined in the DAGs. There are different types of executors available in Airflow such as LocalExecutor, CeleryExecutor, KubernetesExecutor and etc. Each executor has its own settings and execution behaviors. Metadatabase Metadatabase is a database where Airflow stores metadata about tasks, DAGs, executions, schedules, among others. It is used to track the status of tasks, record execution history, and provide information for workflow monitoring and visualization. It is possible to use several other databases to record the history such as MySQL, Postgres and among others. Workers Workers are the execution nodes in a distributed environment. They receive tasks assigned by the Scheduler and execute them. Workers can be scaled horizontally to handle larger data pipelines or to spread the workload across multiple resources. Plugins Plugins are Airflow extensions that allow you to add new features and functionality to the system. They can include new operators, hooks, sensors, connections to external systems, and more. Plugins provide a way to customize and extend Airflow's capabilities to meet the specific needs of a workflow. Operators Operators are basically the composition of a DAG. Understand an operator as a block of code with its own responsibility. Because Airflow is an orchestrator and executes a workflow, we can have different tasks to be performed, such as accessing an API, sending an email, accessing a table in a database and performing an operation, executing a Python code or even a Bash command. For each of the above tasks, we must use an operator. Next, we will discuss some of the main operators: BashOperator BashOperator allows you to run Bash commands or scripts directly on the operating system where Airflow is running. It is useful for tasks that involve running shell scripts, utilities, or any action that can be performed in the terminal. In short, when we need to open our system's terminal and execute some command to manipulate files or something related to the system itself, but within a DAG, this is the operator to be used. PythonOperator The PythonOperator allows you to run Python functions as tasks in Airflow. You can write your own custom Python functions and use the PythonOperator to call those functions as part of your workflow. DummyOperator The DummyOperator is a "dummy" task that takes no action. It is useful for creating complex dependencies and workflows without having to perform any real action. Sensor Sensors are used to wait for some external event to occur before continuing the workflow, it can work as a listener. For example, the HttpSensor, which is a type of Sensor, can validate if an external API is active, if so, the flow continues to run. It's not an HTTP operator that should return something, but a type of listener. HttpOperator Unlike a Sensor, the HttpOperator is used to perform HTTP requests such as GET, POST, PUT, DELETE end etc. In this case, it allows you to interact more fully with internal or external APIs. SqlOperator SqlOperator is the operator responsible for performing DML and DDL operations in a database, that is, from data manipulations such as SELECTS, INSERTS, UPDATES and so on. Executors Executors are responsible for executing the tasks defined in a workflow (DAG). They manage the allocation and execution of tasks at runtime, ensuring that each task runs efficiently and reliably. Airflow offers different types of executors, each with different characteristics and functionalities, allowing you to choose the most suitable one for your specific needs. Below, we’ll cover some of the top performers: LocalExecutor LocalExecutor is the default executor in Apache Airflow. It is designed to be used in development and test environments where scalability isn't a concern. LocalExecutor runs tasks on separate threads within the same Airflow process. This approach is simple and efficient for smaller pipelines or single-node runs. CeleryExecutor If you need an executor for distributed and high-scale environments, CeleryExecutor is an excellent choice. It uses Celery, a queued task library, to distribute tasks across separate execution nodes. This approach makes Airflow well-suited for running pipelines on clusters of servers, allowing you to scale horizontally on demand. KubernetesExecutor For environments that use Kubernetes as their container orchestration platform, KubernetesExecutor is a natural choice. It leverages Kubernetes' orchestration capability to run tasks in separate pods, which can result in better resource isolation and easier task execution in containers. DaskExecutor If your workflow requires parallel and distributed processing, DaskExecutor might be the right choice. It uses the Dask library to perform parallel computing on a cluster of resources. This approach is ideal for tasks that can be divided into independent sub-tasks, allowing better use of available resources. Programming language Airflow supports Python as programming language. To be honest, it's not a limiter for those who don't know the language well. In practice, the process of creating DAGs is standard, which can change according to your needs, it will deal with different types of operators, whether or not you can use Python. Hands-on Setting up the environment For this tutorial we will use Docker that will help us provision our environment without the need to install Airflow. If you don't have Docker installed, I recommend following the recommendations in this link and after installing it, come back to follow the tutorial. Downloading project To make it easier, clone the project from the following repository and follow the steps to deploy Airflow. Steps to deploy With docker installed and after downloading the project according to the previous item, access the directory where the project is located and open the terminal, run the following docker command: docker-compose up The above command will start the docker containers where the services of Airflow itself, postgres and more. If you're curious about how these services are mapped, open the project's docker-compose.yaml file and there you'll find more details. Anyway, after executing the above command and the containers already started, access the following address via browser http://localhost:8080/ A screen like below will open, just type airflow for the username and password and access the Airflow UI. Creating a DAG Creating a simple Hello World For this tutorial, we will create a simple DAG where the classic "Hello World" will be printed. In the project you downloaded, go to the /dags folder and create the following python file called hello_world.py. The code above is a simple example of a DAG written in Python. We noticed that we started import some functions, including the DAG itself, functions related to the datetime and the Python operator. Next, we create a Python function that will print to the console "Hello World" called by print_hello function. This function will be called by the DAG later on. The declaration of a DAG starts using the following syntax with DAG(..) passing some arguments like: dag_id: DAG identifier in Airflow context start_date: The defined date is only a point of reference and not necessarily the date of the beginning of the execution nor of the creation of the DAG. Usually the executions are carried out at a later date than the one defined in this parameter, and it is important when we need to calculate executions between the beginning and the one defined in the schedule_interval parameter. schedule_interval: In this parameter we define the periodicity in which the DAG will be executed. It is possible to define different forms of executions through CRON expressions or through Strings already defined as @daily, @hourly, @once, @weekly and etc. In the case of the example, the flow will run only once. catchup: This parameter controls retroactive executions, that is, if set to True, Airflow will execute the retroactive period from the date defined in start_date until the current date. In the previous example we defined it as False because there is no need for retroactive execution. After filling in the arguments, we create the hello_task within the DAG itself using the PythonOperator operator, which provides ways to execute python functions within a DAG. Note that we declared an identifier through the task_id and in the python_callable argument, which is native to the PythonOperator operator, we passed the python print_hello function created earlier. Finally, invoke the hello_task. This way, the DAG will understand that this will be the task to be performed. If you have already deployed it, the DAG will appear in Airflow in a short time to be executed as shown in the image below: After the DAG is created, activate and execute it by clicking on Trigger DAG as shown in the image above. Click on the hello_operator task (center) and then a window will open as shown in the image below: Click the Log button to see more execution details: Note how is simple it to create a DAG, just think about the different possibilities and applicability scenarios. For the next tutorials, we'll do more examples that are a bit more complex by exploring several other scenarios. Conclusion Based on the simple example shown, Airflow presented a flexible and simple approach to controlling automated flows, from creating DAGs to navigating your web component. As I mentioned at the beginning, its use is not limited only to the orchestration of ETLs, but also to the possibility of its use in tasks that require any need to control flows that have dependencies between their components within a context. scalable or not. GitHub Repository Hope you enjoyed!

Introduction Java Reflection is a powerful API that allows a Java program to examine and manipulate information about its own classes at runtime. With Reflection, you can get information about a class's fields, methods, and constructors, and access and modify those elements even if they're private. In this post we're going to write some Java codes exploring some of the facilities of using Reflection and when to apply it in your projects. Bank Class We'll create a simple class called Bank, where we'll create some fields, methods and constructors to be explored using Reflection. Accessing the fields of the Bank class With the Bank class created, let's explore via Reflection the listing of all fields of the class through the getDeclaredFields method of the Class class. Note that through the static method Class.forName, we pass a string with the name of the class we want to explore via Reflection as a parameter. Output Field name: code Field type: class java.lang.Integer ************ Field name: nameOfBank Field type: class java.lang.String ************ Field name: amountOfDepositedMoney Field type: class java.lang.Double ************ Field name: totalOfCustomers Field type: class java.lang.Integer ************ Accessing the methods of the Bank class Through the getDeclaredMethods method, we can retrieve all methods of the Bank class. Output Method name: doDeposit Method type: class java.lang.String ************ Method name: doWithDraw Method type: class java.lang.String ************ Method name: getReceipt Method type: class java.lang.String ************ Creating objects With the use of Reflection to create objects, it is necessary to create them through a constructor. In this case, we must first invoke a constructor to create the object. The detail is that to retrieve this constructor, we must pay attention to the types of parameters that make up the constructor and the order in which they are declared. This makes it flexible to retrieve different constructors with different parameter numbers and type in a class. Notice below that it was necessary to create an array of type Class assigning different types according to the composition of the constructor that we will use to create our object. In this scenario, it will be necessary to invoke the method class.getConstructor(argType) passing the previously created array as an argument. This way, we will have a constructor object that will be used in the creation of our object. Finally, we create a new array of type Object assigning the values ​​that will compose our object following the order defined in the constructor and then just invoke the method constructor.newInstance(argumentsValue) passing the array as a parameter returning the object we want to create. Output Bank{code=1, nameOfBank='Bank of America', amountOfDepositedMoney=1.5, totalOfCustomers=2500} Invoking methods To invoke a method through Reflection is quite simple as shown in the code below. Note that it is necessary to pass as a parameter in the method cls.getMethod("doDeposit", argumentsType) the explicit name of the method, in this case "doDeposit" and in the second parameter, an array representing the type of data used in the parameter of the method doDeposit( double amount), in this case a parameter of type double. Finally, invoke the method method.invoke passing at the first parameter the object referencing the class, in this case an object of type Bank. And as the second parameter, the value that will be executed in the method. Output 145.85 of money has been deposited Conclusion Using Reflection is a good strategy when you need flexibility in exploring different classes and their methods without the need to instantiate objects. Normally, Reflection is used in specific components of an architecture, but it does not prevent it from being used in different scenarios. From the examples shown above, you can see infinite scenarios of its application and the advantages of its use. Hope you enjoyed!

Introduction Released in Java 14 as a preview, more specifically in JEP 395, Record Class is an alternative to working with Classes in Java. Record Class was a very interesting approach designed to eliminate the verbosity when you need to create a class and its components, such as: Canonical constructors Public access methods Implement the equals and hashCode methods Implement the toString method Using Record Classes it is no longer necessary to declare the items above, helping the developer to be more focused on other tasks. Let's understand better in practice. Let's create a Java class called User and add some fields and methods. Note that for a simple class with 4 fields, we create a constructor, public access methods, implement the equals and hashCode methods and finally, the toString method. It works well, but we could avoid the complexity and create less verbose code. In that case, we can use Record Classes instead User class above. User Record Class The difference between Record and a traditional Java Class is remarkable. Note that it wasn't necessary to declare the fields, create the access methods or implement any other method. In a Record Class when created, implicitly the public access methods are created, the implementations of the equals, hashCode and toString methods are also created automatically and it is not necessary to implement them explicitly. And finally, the reference fields or components are created as private final with the same names. Output Disadvantages Record Class behaves like a common Java class, but the difference is that you can't work with inheritance. You can't extends another class, only implement one or more interfaces. Another point is that it's not possible to create non-static instance variables. Final conclusion Record Classes is a great approach for anyone looking for less verbose code or who needs agility in implementing models. Despite the limitation of not being able to extends other Record Classes, it's a limitation that doesn't affect its use in general. Hope you enjoyed!

What is the Change Data Feed? Change Data Feed is a Delta Lake feature as of version 2.0.0 that allows tracking at row levels in Delta tables, changes such as DML operations (Merge, Delete or Update), data versions and the timestamp of when the change happened. The process maps Merge, Delete and Update operations, maintaining the history of changes at line level, that is, each event suffered in a record, Delta through the Change Data Feed manages to register as a kind of audit . Of course it is possible to use it for different use cases, the possibilities are extensive. How it works in practice Applying Change Data Feed for Delta tables is an interesting way to handle with row level records and for this post we will show how it works. We will perform some operations to explore more about the power of the Change Data Feed. We will work with the following Dataset: Creating the Spark Session and configuring some Delta parameters From now on, we'll create the code in chunks for easy understanding. In the code below we are creating the method responsible for maintaining the Spark session and configuring some parameters for Delta to work. Loading the Dataset Let's load the Dataset and create a temporary view to be used in our pipeline later. Creating the Delta Table Now we will create the Delta table already configuring Change Data Feed in the table properties and all the metadata will be based on the previously presented Dataset. Note that we're using the following parameter in the property delta.enableChangeDataFeed = true for activating the Change Data Feed. Performing a Data Merge Now we'll perform a simple Merge operation so that the Change Data Feed can register it as a change in our table. See what Merge uses in our previously created global_temp.raw_product view to upsert the data. Auditing the table Now that the Merge has been executed, let's perform a read on our table to understand what happened and how the Change Data Feed works. Notice that we're passing the following parameters: 1. readChangeFeed where required for using the Change Data Feed. 2. startingVersion is the parameter responsible for restricting which version we want it to be displayed from. Result after execution: See that in addition to the columns defined when creating the table, we have 3 new columns managed by the Change Data Feed. 1. _change_type: Column containing values according to each operation performed as insert, update_preimage , update_postimage, delete 2. _commit_version: Change version 3. _commit_timestamp: Timestamp representing the change date In the above result, the result of the upsert was a simple insert, as it didn't contain all the possible conditions of an update. Deleting a record In this step we will do a simple delete in a table record, just to validate how the Change Data Feed will behave. Auditing the table (again) Note below that after deleting record with id 6, we now have a new record created as delete in the table and its version incremented to 2. Another point is that the original record was maintained, but with the old version. Updating a record Now as a last test, we will update a record to understand again the behavior of the Change Data Feed. Auditing the table (last time) Now as a last test, we run a simple update on a record to understand how it will behave. Notice that 2 new values have been added/updated in the _change_type column. The update_postimage value is the value after the update was performed and this time, for the old record, the same version of the new one was kept in the column _commit_version, because this same record was updated according to column _change_type to update_preimage, that is, value before change. Conclusion The Change Data Feed is a great resource to understand the behavior of your data pipeline and also a way to audit records in order to better understand the operations performed there. According to the Delta team itself, it is a feature that, if maintained, does not generate any significant overhead. It's a feature that can be fully adopted in your data strategy as it has several benefits as shown in this post. Repository GitHub Hope you enjoyed!