Posts Tagged ‘RedHat’
[KotlinConf2025] LangChain4j with Quarkus
In a collaboration between Red Hat and Twilio, Max Rydahl Andersen and Konstantin Pavlov presented an illuminating session on the powerful combination of LangChain4j and Quarkus for building AI-driven applications with Kotlin. The talk addressed the burgeoning demand for integrating artificial intelligence into modern software and the common difficulties developers encounter, such as complex setups and performance bottlenecks. By merging Kotlin’s expressive power, Quarkus’s rapid runtime, and LangChain4j’s AI capabilities, the presenters demonstrated a streamlined and effective solution for creating cutting-edge applications.
A Synergistic Approach to AI Integration
The core of the session focused on the seamless synergy between the three technologies. Andersen and Pavlov detailed how Kotlin’s idiomatic features simplify the development of AI workflows. They presented a compelling case for using LangChain4j, a versatile framework for building language model-based applications, within the Quarkus ecosystem. Quarkus, with its fast startup times and low memory footprint, proved to be an ideal runtime for these resource-intensive applications. The presenters walked through practical code samples, illustrating how to set up the environment, manage dependencies, and orchestrate AI tools efficiently. They emphasized that this integrated approach significantly reduces the friction typically associated with AI development, allowing engineers to focus on business logic rather than infrastructural challenges.
Enhancing Performance and Productivity
The talk also addressed the critical aspect of performance. The presenters demonstrated how the combination of LangChain4j and Quarkus enables the creation of high-performing, AI-powered applications. They discussed the importance of leveraging Quarkus’s native compilation capabilities, which can lead to dramatic improvements in startup time and resource utilization. Additionally, they touched on the ongoing work to optimize the Kotlin compiler’s interaction with the Quarkus build system. Andersen noted that while the current process is efficient, there are continuous efforts to further reduce build times and enhance developer productivity. This commitment to performance underscores the value of this tech stack for developers who need to build scalable and responsive AI solutions.
The Path Forward
Looking ahead, Andersen and Pavlov outlined the future roadmap for LangChain4j and its integration with Quarkus. They highlighted upcoming features, such as the native asynchronous API, which will provide enhanced support for Kotlin coroutines. While acknowledging the importance of coroutines for certain use cases, they also reminded the audience that traditional blocking and virtual threads remain perfectly viable and often preferred for a majority of applications. They also extended an open invitation to the community to contribute to the project, emphasizing that the development of these tools is a collaborative effort. The session concluded with a powerful message: this technology stack is not just about building applications; it’s about empowering developers to confidently tackle the next generation of AI-driven projects.
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[SpringIO2019] Zero Downtime Migrations with Spring Boot by Alex Soto
Deploying software updates without disrupting users is a cornerstone of modern DevOps practices. At Spring I/O 2019 in Barcelona, Alex Soto, a prominent figure at Red Hat, delivered a comprehensive session on achieving zero downtime migrations in Spring Boot applications, particularly within microservices architectures. With a focus on advanced deployment techniques and state management, Alex provided actionable insights for developers navigating the complexities of production environments. This post delves into his strategies, enriched with practical demonstrations and real-world applications.
The Evolution from Monoliths to Microservices
The shift from monolithic to microservices architectures has transformed deployment practices. Alex began by contrasting the simplicity of monolithic deployments—where a single application could be updated during off-hours with minimal disruption—with the complexity of microservices. In a microservices ecosystem, services are interconnected in a graph-like structure, often with independent databases and multiple entry points. This distributed nature amplifies the impact of downtime, as a single service failure can cascade across the system.
To address this, Alex emphasized the distinction between deployment (placing a service in production) and release (routing traffic to it). This separation is critical for zero downtime, allowing teams to test new versions without affecting users. By leveraging service meshes like Istio, developers can manage traffic routing dynamically, ensuring seamless transitions between service versions.
Blue-Green and Canary Deployments
Alex explored two foundational techniques for zero downtime: blue-green and canary deployments. In blue-green deployments, a new version (green) is deployed alongside the existing one (blue), with traffic switched to the green version once validated. This approach minimizes disruption but risks affecting all users if the green version fails. Canary deployments mitigate this by gradually routing a small percentage of traffic to the new version, allowing teams to monitor performance before a full rollout.
Both techniques rely on robust monitoring, such as Prometheus, to detect issues early. Alex demonstrated a blue-green deployment using a movie store application, where a shopping cart’s state was preserved across versions using an in-memory data grid like Redis. This ensured users experienced no loss of data, even during version switches, highlighting the power of stateless and ephemeral state management in microservices.
Managing Persistent State
Persistent state, such as database schemas, poses a significant challenge in zero downtime migrations. Alex illustrated this with a scenario involving renaming a database column from “name” to “full_name.” A naive approach risks breaking compatibility, as some users may access the old schema while others hit the new one. To address this, he proposed a three-step migration process:
- Dual-Write Phase: The application writes to both the old and new columns, ensuring data consistency across versions.
- Data Migration: Historical data is copied from the old column to the new one, often using tools like Spring Batch to avoid locking the database.
- Final Transition: The application reads and writes exclusively to the new column, with the old column retained for rollback compatibility.
This methodical approach, demonstrated with a Kubernetes-based cluster, ensures backward compatibility and uninterrupted service. Alex’s demo showed how Istio’s traffic management capabilities, such as routing rules and mirroring, facilitate these migrations by directing traffic to specific versions without user impact.
Leveraging Istio for Traffic Management
Istio, a service mesh, plays a pivotal role in Alex’s strategy. By abstracting cross-cutting concerns like service discovery, circuit breaking, and security, Istio simplifies zero downtime deployments. Alex showcased how Istio’s sidecar containers handle traffic routing, enabling techniques like traffic mirroring for dark launches. In a dark launch, requests are sent to both old and new service versions, but only the old version’s response is returned to users, allowing teams to test new versions in production without risk.
Istio also supports chaos engineering, simulating delays or timeouts to test resilience. Alex cautioned, however, that such practices require careful communication to avoid unexpected disruptions, as illustrated by anecdotes of misaligned testing efforts. By integrating Istio with Spring Boot, developers can achieve robust, scalable deployments with minimal overhead.
Handling Stateful Services
Stateful services, particularly those with databases, require special attention. Alex addressed the challenge of maintaining ephemeral state, like shopping carts, using in-memory data grids. For persistent state, he recommended strategies like synthetic transactions or throwaway database clusters to handle mirrored traffic during testing. These approaches prevent unintended database writes, ensuring data integrity during migrations.
In his demo, Alex applied these principles to a movie store application, showing how a shopping cart persisted across blue-green deployments. By using Redis to replicate state across a cluster, he ensured users retained their cart contents, even as services switched versions. This practical example underscored the importance of aligning infrastructure with business needs.
Lessons for Modern DevOps
Alex’s presentation offers a roadmap for achieving zero downtime in microservices. By combining advanced deployment techniques, service meshes, and careful state management, developers can deliver reliable, user-focused applications. His emphasis on tools like Istio and Redis, coupled with a disciplined migration process, provides a blueprint for tackling real-world challenges. For teams like those at Red Hat, these strategies enable faster, safer releases, aligning technical excellence with business continuity.
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[DevoxxUS2017] Eclipse Che by Tyler Jewell
At DevoxxUS2017, Tyler Jewell, CEO of Codenvy and project lead for Eclipse Che, delivered a compelling session on the shift from localhost to cloud-based development. Highlighting Eclipse Che as a next-generation IDE and workspace server, Tyler discussed how it streamlines team collaboration and agile workflows. With contributions from industry leaders like Red Hat and Microsoft, Che has rapidly gained traction. This post explores the key themes of Tyler’s presentation, focusing on the future of cloud development.
The Rise of Cloud Development
Tyler Jewell began by outlining market forces driving the adoption of cloud development, such as the need for rapid onboarding and consistent environments. He contrasted traditional localhost setups with cloud-based workflows, emphasizing how Eclipse Che enables one-click environment creation. Tyler’s insights, drawn from his role at Codenvy, highlighted Che’s ability to reduce setup time, allowing teams to focus on coding rather than configuration.
Eclipse Che’s Workspace Innovation
Delving into technical details, Tyler showcased Che’s workspace server, which supports reproducible environments through containerized runtimes. Unlike Vagrant VMs, Che workspaces offer lightweight, scalable solutions, integrating seamlessly with Docker. He demonstrated how Che’s architecture supports distributed teams, enabling collaboration across geographies. Tyler’s live demo illustrated creating and managing workspaces, underscoring Che’s role in modernizing development pipelines.
Community Contributions and Roadmap
Tyler emphasized the vibrant Eclipse Che community, with nearly 100 contributors from companies like IBM and Samsung. He discussed ongoing efforts to enhance language server integration, citing the Language Server Protocol’s potential for dynamic tool installation. Tyler shared Che’s roadmap, focusing on distributed workspaces and team-centric features, inviting developers to contribute to its open-source ecosystem.
Balancing IT Control and Developer Freedom
Concluding, Tyler addressed the tension between IT control and developer autonomy, noting how Che balances root access with governance. He highlighted its integration with agile methodologies, enabling faster iterations and improved collaboration. Tyler’s vision for Che, rooted in his experience at Toba Capital, positioned it as a transformative platform for cloud-native development, encouraging attendees to explore its capabilities.
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[DevoxxUS2017] The Hardest Part of Microservices: Your Data by Christian Posta
At DevoxxUS2017, Christian Posta, a Principal Middleware Specialist at Red Hat, delivered an insightful presentation on the complexities of managing data in microservices architectures. Drawing from his extensive experience with distributed systems and open-source projects like Apache Kafka and Apache Camel, Christian explored how Domain-Driven Design (DDD) helps address data challenges. His talk, inspired by his blog post on ceposta Technology Blog, emphasized the importance of defining clear boundaries and leveraging event-driven technologies to achieve scalable, autonomous systems. This post delves into the key themes of Christian’s session, offering a comprehensive look at navigating data in microservices.
Understanding the Domain with DDD
Christian Posta began by addressing the critical need to understand the business domain when building microservices. He highlighted how DDD provides a framework for modeling complex domains by defining bounded contexts, entities, and aggregates. Using the example of a “book,” Christian illustrated how context shapes data definitions, such as distinguishing between a book as a single title versus multiple copies in a bookstore. This clarity, he argued, is essential for enterprises, where domains like insurance or finance are far more intricate than those of internet giants like Netflix. By grounding microservices in DDD, developers can create explicit boundaries that align with business needs, reducing ambiguity and fostering autonomy.
Defining Transactional Boundaries
Transitioning to transactional boundaries, Christian emphasized minimizing the scope of atomic operations to enhance scalability. He critiqued the traditional reliance on single, ACID-compliant databases, which often leads to brittle systems when applied to distributed architectures. Instead, he advocated for identifying the smallest units of business invariants, such as a single booking in a travel system, and managing them within bounded contexts. Christian’s insights, drawn from real-world projects, underscored the pitfalls of synchronous communication and the need for explicit boundaries to avoid coordination challenges like two-phase commits across services.
Event-Driven Communication with Apache Kafka
A core focus of Christian’s talk was the role of event-driven architectures in decoupling microservices. He introduced Apache Kafka as a backbone for streaming immutable events, enabling services to communicate without tight coupling. Christian explained how Kafka’s publish-subscribe model supports scalability and fault tolerance, allowing services to process events at their own pace. He highlighted practical applications, such as using Kafka to propagate changes across bounded contexts, ensuring eventual consistency while maintaining service autonomy. His demo showcased Kafka’s integration with microservices, illustrating its power in handling distributed data.
Leveraging Debezium for Data Synchronization
Christian also explored Debezium, an open-source platform for change data capture, to address historical data synchronization. He described how Debezium’s MySQL connector captures consistent snapshots and streams binlog changes to Kafka, enabling services to access past and present data. This approach, he noted, supports use cases where services need to synchronize from a specific point, such as “data from Monday.” Christian’s practical example demonstrated Debezium’s role in maintaining data integrity across distributed systems, reinforcing its value in microservices architectures.
Integrating Apache Camel for Robust Connectivity
Delving into connectivity, Christian showcased Apache Camel as a versatile integration framework for microservices. He explained how Camel facilitates communication between services by providing routing and transformation capabilities, complementing Kafka’s event streaming. Christian’s live demo illustrated Camel’s role in orchestrating data flows, ensuring seamless integration across heterogeneous systems. His experience as a committer on Camel underscored its reliability in building resilient microservices, particularly for enterprises transitioning from monolithic architectures.
Practical Implementation and Lessons Learned
Concluding, Christian presented a working example that tied together DDD, Kafka, Camel, and Debezium, demonstrating a cohesive microservices system. He emphasized the importance of explicit identity management, such as handling foreign keys across services, to maintain data integrity. Christian’s lessons, drawn from his work at Red Hat, highlighted the need for collaboration between developers and business stakeholders to refine domain models. His call to action encouraged attendees to explore these technologies and contribute to their open-source communities, fostering innovation in distributed systems.
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[DevoxxUS2017] JavaScript: The New Parts by Joshua Wilson
At DevoxxUS2017, Joshua Wilson, a lead UI developer at Red Hat, delivered an illuminating session on ECMAScript 2015 (ES6) and its transformative features for JavaScript development. With a background transitioning from Java to front-end engineering, Joshua guided attendees through ES6’s modern syntax, including arrow functions, modules, and classes. His presentation offered practical insights for developers seeking to enhance their web development skills. This post explores the core themes of Joshua’s talk, focusing on ES6’s impact on coding elegance and productivity.
Embracing ES6 Features
Joshua Wilson began by introducing key ES6 features, such as arrow functions, which simplify syntax for function expressions, and let and const for block-scoped variables, enhancing code clarity. He demonstrated transforming legacy JavaScript into concise ES6 code, emphasizing improved readability. Drawing from his work at Red Hat, Joshua highlighted how these features streamline UI development, making JavaScript more approachable for developers accustomed to Java’s structure.
Modules and Classes for Modern Development
Delving deeper, Joshua explored ES6 modules, which enable better code organization and dependency management, contrasting them with older CommonJS approaches. He showcased ES6 classes, offering a familiar syntax for Java developers to create object-oriented structures. Joshua addressed challenges like handling null and undefined, noting ES6’s limited improvements but suggesting tools like TypeScript for stricter type safety, aligning with his focus on robust front-end solutions.
Practical Applications and Tooling
Joshua emphasized practical applications, demonstrating how ES6 integrates with build tools like Webpack for seamless module handling. He highlighted ES7’s Array.includes method for improved array searching, addressing edge cases like NaN. His insights, grounded in real-world UI projects at Red Hat, encouraged developers to adopt modern JavaScript practices, leveraging transpilers to ensure compatibility while embracing ES6’s expressive power.
Navigating the JavaScript Ecosystem
Concluding, Joshua encouraged developers to explore the evolving JavaScript ecosystem, recommending resources like Mozilla Developer Network (MDN) for learning ES6. His passion for front-end development inspired attendees to experiment with new syntax, enhancing their ability to craft dynamic, user-friendly interfaces with confidence.
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[DevoxxBE2013] Part 1: Java EE 7: What’s New in the Java EE Platform
Antonio Goncalves and Arun Gupta, luminaries in Java EE advocacy, deliver a comprehensive exploration of Java EE 7’s advancements, blending simplification with expanded capabilities. Antonio, a senior architect and author of Beginning Java EE 6 Platform with GlassFish 3, collaborates with Arun, Red Hat’s Director of Developer Advocacy and former Java EE pioneer at Sun Microsystems, to unveil WebSocket, JSON processing, and enhanced CDI and JTA features. Their session, rich with demos, highlights how these innovations bolster HTML5 support and streamline enterprise development.
Java EE 7, they assert, refines container services while embracing modern web paradigms. From WebSocket’s real-time communication to CDI’s unified bean management, they showcase practical integrations, ensuring developers can craft scalable, responsive applications.
WebSocket for Real-Time Communication
Antonio introduces WebSocket, a cornerstone for HTML5’s bidirectional connectivity. He demonstrates @ServerEndpoint-annotated classes, crafting a chat application where messages flow instantly, bypassing HTTP’s overhead.
Arun details encoders/decoders, transforming POJOs to wire-ready text or binary frames, streamlining data exchange for real-time apps like live dashboards.
JSON Processing and JAX-RS Enhancements
Arun explores JSON-P (JSR 353), parsing and generating JSON with a fluid API. He demos building JSON objects from POJOs, integrating with JAX-RS’s HTTP client for seamless RESTful interactions.
This synergy, Antonio notes, equips developers to handle data-driven web applications, aligning with HTML5’s data-centric demands.
CDI and Managed Bean Alignment
Antonio unveils CDI’s evolution, unifying managed beans with injectable interceptors. He showcases constructor injection and method-level validation, simplifying dependency management across EJBs and servlets.
Arun highlights JTA’s declarative transactions, enabling @Transactional annotations to streamline database operations, reducing boilerplate.
Simplified JMS and Batch Processing
Arun introduces JMS 2.0’s simplified APIs, demonstrating streamlined message publishing. The new Batch API (JSR 352), Antonio adds, orchestrates chunk-based processing for large datasets, with demos showcasing job definitions.
These enhancements, they conclude, enhance usability, pruning legacy APIs while empowering enterprise scalability.
Resource Definitions and Community Engagement
Antonio details expanded resource definitions, configuring data sources via annotations. Arun encourages JCP involvement, noting Java EE 8’s community-driven roadmap.
Their demos—leveraging GlassFish—illustrate practical adoption, inviting developers to shape future specifications.
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[DevoxxBE2013] OpenShift Primer: Get Your Applications into the Cloud
Eric D. Schabell, JBoss technology evangelist at Red Hat, demystifies OpenShift, a PaaS revolutionizing cloud deployment for Java EE, PHP, Ruby, and beyond. Author of the OpenShift Primer e-book, Eric—drawing from his integration and BPM expertise—guides attendees through rapid app migration, showcasing portability without code rewrites. His action-packed session deploys a Java project in minutes, contrasting OpenShift’s ease with cumbersome VMs.
OpenShift’s open-source ethos, Eric argues, delivers developer freedom: Git-based workflows, auto-scaling gears, and cartridge-based runtimes. From free tiers to enterprise scalability, it transforms cloud adoption, with European data centers addressing latency and privacy concerns.
Demystifying PaaS and OpenShift Fundamentals
Eric contrasts IaaS’s VM drudgery with PaaS’s streamlined abstraction. OpenShift, atop Red Hat Enterprise Linux, provisions environments via cartridges—pre-configured stacks for languages like Java.
He demos creating an app: rhc app create, Git push, and instant deployment, emphasizing no vendor lock-in.
Rapid Deployment and Portability
Portability reigns: Eric deploys a legacy Java EE app unchanged, leveraging JBoss EAP cartridges. PHP/Ruby examples follow, highlighting multi-language support.
This agnosticism, Eric notes, preserves investments, scaling from localhost to cloud seamlessly.
Scaling, Monitoring, and Security
Auto-scaling gears adjust to loads, Eric illustrates, with hot-deploy for zero-downtime updates. Monitoring via console tracks metrics; security integrates LDAP and SSL.
For Europe, Irish data centers mitigate latency, with GDPR-compliant options addressing data sovereignty.
Why OpenShift? Open-Source Advantages
Eric’s pitch: unmatched ease, no code changes, and open-source values. Free tiers on AWS East Coast suit demos, with paid plans offering local regions like Ireland.
He invites booth chats, contrasting OpenShift’s speed with competitors’ rigidity.
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[DevoxxBE2013] Introducing Vert.x 2.0: Taking Polyglot Application Development to the Next Level
Tim Fox, the visionary project lead for Vert.x at Red Hat, charts the course of this lightweight, high-performance application platform for the JVM. With a storied tenure at JBoss and VMware—where he spearheaded HornetQ messaging and RabbitMQ integrations—Tim unveils Vert.x 2.0’s maturation into an independent powerhouse. His session delves into the revamped module system, Maven/Bintray reusability, and enhanced build tool/IDE synergy, alongside previews of Scala, Clojure support, and Node.js compatibility.
Vert.x 2.0 empowers polyglot, reactive applications, blending asynchronous eventing with synchronous legacy APIs via worker verticles. Tim’s live demos illustrate deploying modules dynamically, underscoring Vert.x’s ecosystem for mobile, web, and enterprise scalability.
Core API Refinements and Asynchronous Foundations
Tim highlights Vert.x’s event-driven core, refined in 2.0 with intuitive APIs for non-JVM languages. He demonstrates verticles—lightweight actors—for handling requests asynchronously, avoiding blocking calls.
This reactive model, Tim explains, scales to thousands of connections, ideal for real-time web apps, contrasting traditional thread-per-request pitfalls.
Module System and Ecosystem Expansion
The new module system, Tim showcases, leverages Maven repositories for seamless dependency management. He deploys a web server via module names, pulling artifacts from Bintray—eliminating manual installations.
This reusability fosters a vibrant ecosystem, with core modules for HTTP, MySQL (via reversed-engineered async drivers), and more, enabling rapid composition.
Build Tool and IDE Integration
Vert.x 2.0’s Maven/Gradle plugins streamline development, as Tim demos: configure a pom.xml, run mvn vertx:run, and launch a cluster. IDE support, via plugins, offers hot-reloading and debugging.
These integrations, Tim notes, lower barriers, allowing developers to iterate swiftly without Vert.x-specific tooling.
Polyglot Horizons: Scala, Clojure, and Node.js
Tim previews Scala/Clojure bindings, enabling functional paradigms on Vert.x’s event bus. Node.js compatibility, via drop-in modules, bridges JavaScript ecosystems, allowing polyglot teams to collaborate seamlessly.
This inclusivity, Tim asserts, broadens Vert.x’s appeal, supporting diverse languages without sacrificing performance.
Worker Verticles for Legacy Compatibility
For synchronous APIs like JDBC, Tim introduces worker verticles—executing on thread pools to prevent blocking. He contrasts with pure async MySQL drivers, offering flexibility for hybrid applications.
This pragmatic bridge, Tim emphasizes, integrates existing Java libraries effortlessly.
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[DevoxxFR2013] Invokedynamic in 45 Minutes: Unlocking Dynamic Language Performance on the JVM
Lecturer
Charles Nutter has spent over a decade as a Java developer and more than six years leading the JRuby project at Red Hat. Co-lead of JRuby, he works to fuse Ruby’s elegance with the JVM’s power while contributing to other JVM languages and educating the community on advanced virtual machine capabilities. A proponent of open standards, he aims to keep the JVM the premier managed runtime through innovations like invokedynamic.
Abstract
Charles Nutter demystifies invokedynamic, the JVM bytecode instruction introduced in Java 7 to optimize dynamic language implementation. He explains its mechanics—bootstrap methods, call sites, and method handles—through progressive examples, culminating in a toy language interpreter. The presentation contrasts invokedynamic with traditional invokevirtual and invokeinterface, benchmarks performance, and illustrates how it enables JRuby and other languages to approach native Java speeds, paving the way for polyglot JVM ecosystems.
The Problem with Traditional Invocation: Static Assumptions in a Dynamic World
Nutter begins with the JVM’s historical bias toward statically-typed languages. The four classic invocation instructions—invokevirtual, invokeinterface, invokestatic, and invokespecial—assume method resolution at class loading or compile time. For dynamic languages like Ruby, Python, or JavaScript, method existence and signatures are determined at runtime, forcing expensive runtime checks or megamorphic call sites.
JRuby, prior to invokedynamic, relied on reflection or generated bytecodes per call, incurring significant overhead. Even interface-based dispatch suffered from inline cache pollution when multiple implementations competed.
Invokedynamic Mechanics: Bootstrap, Call Sites, and Method Handles
Introduced via JSR-292, invokedynamic defers method linking to a user-defined bootstrap method (BSM). The JVM invokes the BSM once per call site, passing a CallSite object, method name, and type. The BSM returns a MethodHandle—a typed, direct reference to a method—installed into the call site.
Nutter demonstrates a simple BSM:
public static CallSite bootstrap(MethodHandles.Lookup lookup, String name, MethodType type) {
MethodHandle mh = lookup.findStatic(MyClass.class, "target", type);
return new ConstantCallSite(mh);
}
The resulting invokedynamic instruction executes the linked handle directly, bypassing vtable lookups.
Call Site Types and Guarded Invocations
Call sites come in three flavors: ConstantCallSite for immutable linkages, MutableCallSite for dynamic retargeting, and VolatileCallSite for atomic updates. Guarded invocations combine a test (guard) with a target handle:
MethodHandle guard = lookup.findStatic(Guards.class, "isString", MethodType.methodType(boolean.class, Object.class));
MethodHandle target = lookup.findStatic(Handlers.class, "handleString", type);
MethodHandle fallback = lookup.findStatic(Handlers.class, "handleOther", type);
MethodHandle guarded = MethodHandles.guardWithTest(guard, target, fallback);
The JVM inlines the guard, falling back only on failure, enabling polymorphic inline caches.
Building a Toy Language: From Parser to Execution
Nutter constructs a minimal scripting language with arithmetic and print statements. The parser generates invokedynamic instructions with a shared BSM. The BSM resolves operators (+, -, *) to overloaded Java methods based on argument types, caching results per call site.
Execution flows through method handles, achieving near-Java performance. He extends the example to support runtime method missing, emulating Ruby’s method_missing.
Performance Analysis: Benchmarking Invocation Strategies
Nutter presents JMH benchmarks comparing invocation types. invokestatic serves as baseline; invokevirtual adds vtable dispatch; invokeinterface incurs interface check. invokedynamic with ConstantCallSite matches invokestatic, while MutableCallSite aligns with invokevirtual.
Key insight: the JVM’s optimizer treats stable invokedynamic sites as monomorphic, inlining aggressively. JRuby leverages this for core methods, reducing dispatch overhead by 10-100x.
Implications for JVM Languages and Future Evolution
Invokedynamic enables true polyglot JVMs. Nashorn (JavaScript), Dynalink, and Truffle frameworks build upon it. Future enhancements include value types and specialized generics, further reducing boxing.
Nutter concludes that invokedynamic fulfills John Rose’s vision: dynamic dispatch no slower than static, ensuring the JVM’s longevity as a universal runtime.
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[DevoxxBE2013] Java EE 7’s Java API for WebSocket
Arun Gupta, Director of Developer Advocacy at Red Hat, unveils the transformative capabilities of the Java API for WebSocket in Java EE 7. A veteran of Sun Microsystems and Oracle, Arun has championed Java technologies globally, authoring extensive blogs and a best-selling book. His session explores WebSocket’s role in enabling efficient, bidirectional communication, eliminating the need for long polling or AJAX. Through live demonstrations, he illustrates server-side endpoints and client-side integrations, showcasing how this API empowers developers to craft responsive web and rich client applications.
WebSocket, a cornerstone of HTML5, facilitates real-time data exchange over a single TCP connection. Arun highlights its scalability, with GlassFish handling thousands of connections, and introduces tools like Autobahn for compliance testing. This API positions Java developers to build dynamic, scalable systems that complement RESTful architectures.
WebSocket Fundamentals and API Design
Arun introduces WebSocket’s departure from HTTP’s request-response model, leveraging a single, persistent connection. Using annotations like @ServerEndpoint, he demonstrates creating a chat application where messages flow instantly. The client API, accessible from browsers or Java applications, enables seamless integration.
This simplicity, Arun notes, reduces latency, making WebSocket ideal for real-time applications like live updates or collaborative tools.
Server-Side Scalability and Performance
Scalability is a key strength, Arun explains, with WebSocket supporting millions of file descriptors on Linux. He recounts Oracle’s GlassFish tests, achieving robust performance with thousands of connections. The Autobahn test suite, he suggests, validates compliance and load capacity.
Forthcoming WildFly tests, Arun adds, will further benchmark performance, ensuring reliability in production environments.
Complementing REST with WebSocket
Arun clarifies that WebSocket complements JAX-RS, not replaces it. He illustrates a hybrid design: REST for stateless queries, WebSocket for real-time updates. A stock ticker demo shows prices pushed to clients, blending both paradigms.
This synergy, Arun argues, enhances application flexibility, with Java EE 8 discussions exploring further integrations.
Community Engagement and Future Directions
Arun encourages joining Java EE expert groups, noting their transparent processes. Recent community gatherings, he mentions, discussed enhancing WebSocket’s role. He advocates contributing to shape Java EE 8, ensuring it meets developer needs.
This collaborative approach, Arun emphasizes, drives innovation, aligning WebSocket with evolving web standards.