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SymmetricDS is web-enabled, database independent, data synchronization/replication software. It uses web and database technologies to replicate tables between relational databases in near real time. The software was designed to scale for a large number of databases, work across low-bandwidth connections, and withstand periods of network outage. By using database triggers, SymmetricDS guarantees that data changes are captured and atomicity is preserved. Support for database vendors is provided through a Database Dialect layer, with implementations for MySQL, Oracle, SQL Server, PostgreSQL, DB2, Firebird, HSQLDB, H2, and Apache Derby included. Synchronization can be configured to push data (trickle-back) or pull data (trickle-poll) at an interval. SymmetricDS allows for synchronization between two or more tiers of nodes, such as the following: A farm of web server nodes fronting an enterprise-class general office database A handful of regional servers for synchronizing from the general office to remote geographical areas 1000(s) of store server nodes using a departmental class database to sync with a regional node 10(s) of Point of Sale (POS) register nodes using an embedded database to sync with a store server Deployment options include the following: Web application archive (WAR) deployed to an application server such as Tomcat, Jetty, or JBoss Standalone service Embedded in an application SymmetricDS is written in Java and licensed as open source software under the GNU Lesser General Public License (LGPL).

There are many approaches available to scale PostgreSQL beyond running on a single server. An outline of the terminology and basic technologies involved is at High Availability and Load Balancing. There is a presentation covering some of these solutions. There is no one-size fits all replication software. You have to understand your requirements and how various approaches fit into that. For example, here are two extremes in the replication problem space: You have a few servers connected to a local network you want to always keep current for failover and load-balancing purposes. Here you would be considering solutions that are synchronous, eager, and therefore conflict-free. Your users take a local copy of the database with them on laptops when they leave the office, make changes while they are away, and need to merge those with the main database when they return. Here you'd want an asynchronous, lazy replication approach, and will be forced to consider how to handle conflicts in cases where the same record has been modified both on the master server and on a local copy. These are both database replication problems, but the best way to solve them is very different. And as you can see from these examples, replication has a lot of specific terminology that you'll have to understand to figure out what class of solution makes sense for your requirements. A great source for this background is in the Postgres-R Terms and Definitions for Database Replication. The main theoretical topic it doesn't mention is how to resolve conflict resolution in lazy replication cases like the laptop situation, which involves voting and similar schemes.

"ModelDriven.org is a community of government, commercial and university members who use, develop and integrate open source and commercial capabilities to enable agile business solutions based on model driven methods and technologies. ModelDriven.org is standards based, leveraging Model Driven Architecture® as defined by the OMG and the Semantic Web as defined by W3C. This community has both a user membership and a provider membership. The user community drives the agenda - ..Read More >>"

Akka is the platform for the next generation event-driven, scalable and fault-tolerant architectures on the JVM We believe that writing correct concurrent, fault-tolerant and scalable applications is too hard. Most of the time it's because we are using the wrong tools and the wrong level of abstraction. Akka is here to change that. Using the Actor Model together with Software Transactional Memory we raise the abstraction level and provide a better platform to build correct concurrent and scalable applications. For fault-tolerance we adopt the "Let it crash" / "Embrace failure" model which have been used with great success in the telecom industry to build applications that self-heal, systems that never stop. Actors also provides the abstraction for transparent distribution and the basis for truly scalable and fault-tolerant applications. Akka is Open Source and available under the Apache 2 License.

" The UnboundID LDAP SDK for Java is a fast, powerful, user-friendly, and completely free Java API for communicating with LDAP directory servers. It offers better performance, better ease of use, and more features than other Java-based LDAP APIs, and it's the only one that's being actively developed and enhanced. The UnboundID LDAP SDK for Java is free to use and redistribute in open source or proprietary applications under the GPLv2, LGPLv2.1 and the UnboundID Free Use License. It doesn't have any third-party dependencies and commercial support is available from UnboundID. Get quick answers and all the details you need from our LDAP SDK Documentation »"

"Libra is an open source project under the Eclipse Web Tools Platform Container Project. It provides standard tools for OSGi Enterprise application development and in particular tools that integrate the existing WTP and PDE tooling so that OSGi Enterprise applications can be developed with both tooling at the same time. Libra also will enable users to work with tools for better experience in the Server-Side Equinox scenario. The goals of the project are: Providing tools for creation of deployable artifacts for application servers implementing the OSGi Enterprise specification, e.g. wizard for creating new Web Application Bundle projects. Providing tools for converting existing Java EE deployable artifacts to OSGi Enterprise deployable artifacts, e.g. wizard for converting Dynamic Web projects to a Web Application Bundle projects. Contributing tools for editing and validation of the metadata of OSGi Enterprise artifacts, e.g. extension of the PDE Manifest Editor for editing manifest headers that are specific to Web Application Bundles. Developing OSGi server adapter, providing basic implementation of configuring an OSGi-based application server, starting it and deploying OSGi enterprise artifacts. This server adapter should be customizable and extensible by adopters. Delivering tools that improve the experience of developing Server-Side Equinox applications. Extending the tools in scope, so adopters can apply them depending on their own application model."

"Scalaz is a library written in the Scala Programming Language. The intention of Scalaz is to include general functions that are not currently available in the core Scala API. The scalaz-core module depends only on the core Scala API and the core Java 2 Standard Edition API. Scalaz is released under a BSD open source licence making it compatible with the licence of the Scala project. Scalaz 6.0.1 was released in June 2011, targeting Scala 2.8.1 and 2.9.0.1. "

"Jsvc is a set of libraries and applications for making Java applications run on UNIX more easily. Jsvc allows the application (e.g. Tomcat) to perform some privileged operations as root (e.g. bind to a port < 1024), and then switch identity to a non-privileged user. It can run on Win32 via the Cygwin emulation layer (see Cygwin for more information), however Win32 users may prefer to use procrun instead, which allows the application to run as a Windows Service. The sources are located in the src/native/unix subdirectory. In the future APR may be used to provide more portable platform support. "

"Short screencasts that outlines features of applause, a domain-specific language (DSL) and code generator to produce native apps for iPhone, Android and BlackBerry. You can find this open-source project at code.google.com/​p/​applause"

"The RHQ project is a systems management suite that provides extensible and integrated systems management for multiple products and platforms across a set of core features such as monitoring and graphing of values alerting on error conditions remote configuration of managed resources remote operation execution The project is designed with layered modules that provide a flexible architecture for deployment. It delivers a core user interface that provides audited and historical management across an entire enterprise. A Server/Agent architecture provides remote management and plugins implement all specific support for managed products. RHQ is an open source project licensed under the GPL, with some pieces individually licensed under a dual GPL/LGPL license to facilitate the integration with extended packages such as Jopr (now included in RHQ) and Embedded Jopr."

This page contains the latest compiled builds of Pentaho Data Integration (Kettle) community edition.  The builds are based on source code downloaded daily from SVN. Why download these snapshot builds? You want the latest version - to get the latest features in PDI. You want a more stable version - PDI point releases (e.g. 4.0.1) can include important bug fixes - see the PDI JIRA system for a full list of known issues. You need a bug fixed - You're struggling with a critical bug which has been fixed in a more recent version. To save time - You haven't got the time and/or inclination to learn about how to download PDI from SVN and build your own version.

"The Open Data Protocol (OData) is a Web protocol for querying and updating data that provides a way to unlock this data and free it from silos that exist in applications today. OData does this by applying and building upon Web technologies such as HTTP, Atom Publishing Protocol (AtomPub) and JSON to provide access to information from a variety of applications, services, and stores. Project Info odata4j is a new open-source toolkit for building first-class OData producers and first-class OData consumers in Java. "

" Apache SlingTM is an innovative web framework that is intended to bring back the fun to web development. Discussions about Sling happen on our mailing lists, see the Project Information page for more info. Apache Sling in five bullets points REST based web framework Content-driven, using a JCR content repository Powered by OSGi Scripting inside, multiple languages (JSP, server-side javascript, Scala, etc.) Apache Open Source project"

JDBC realm has a lot of attention in recent months. This blog summarizes the evolution of the JDBC realm implementation in GlassFish and explains how the latest implementation works. I would like to thank Jean-Baptiste, and Richter for their contributions and comments. The participation from the open source community definitely helps everyone. I encourage all of you to give feedback, participate, and help evolve this feature further. GlassFish always had the capability for anyone to plug-in a realm. Implementing a custom realm in the Sun Java System Application Server EE 8.0 is described in the article Authentication Using Custom Realms in Sun Java System Application Server. In S1AS 7.x, there is a JDBC Realm bundled in sample. Jean-Baptiste formally filed an enhancement and provided a clear text version of JDBCRealm for GlassFish. Richter wrote another implementation because the GlassFish JDBCRealm at that time not compatible with Tomcat.

It is an open-source testing framework for java programmers. The java programmer can create test cases and test his/her own code. It is one of the unit testing framework. Current version is junit4. To perform unit testing, we need to create test cases.

Last weekend while pondering the question "Is Scala ready for the enterprise?" I decided to write a simple Java EE 6 app entirely in Scala, without using any Java. I had three main reasons for doing this: one was just to see how easy/difficult it would be to write everything in Scala (it was easy).  Another was to document the process for others journeying down the same road (the entire project is on github).  Finally, I wanted to identify advantages of using Scala instead of Java that are specific to Java EE apps (I found several). Background The specific app I created was an adaptation of the Books example from Chapter 10 of Beginning Java™ EE 6 Platform with GlassFish™ 3. It's a simple web app that displays a list of books in a database and lets you add new books. Although it's a pretty trivial app, it does touch on several important Java EE 6 technologies: JPA 2.0, EJB 3.1 and JSF 2.0.

"Neo4j is a graph database. It is an embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables. A graph (mathematical lingo for a network) is a flexible data structure that allows a more agile and rapid style of development."

"A hub for integrating your enterprise with the rich information available on the Web, the WSO2 Mashup Server leverages popular Web 2.0 formats and protocols into your service platform. Combining simple yet rich mashups with reusability, security, reliability, and governance, the WSO2 Mashup Server includes features for connecting Web Services to humans through Web pages, gadgets, feeds, instant messages, email and more. The WSO2 Mashup Server offers: Go Cloud-Native WSO2 Mashups as a Service gives you instant self-service provisioning, multi-tenancy and has built-in monitoring and metering capabilities. Increase productivity Reduce cost Gain more control Avoid vendor lock-in The ideal platform for defining composite services for user interfaces and mobile applications. A simple way to deploy services developed in JavaScript. Access to REST and WS-* web services, feeds, and scraped web pages with data scripted together quickly using common Web developer skills, the result being a new service, or a web page, gadget, email or instant message. The ability to secure hosted Mashups. Support for both recurring and longer-running tasks and service lifecycles. Monitoring, configuration of security and quality of service settings such as throttling. With no up-front license agreements or subscription fees, getting started with the WSO2 Mashup Server requires less developer effort, ensuring faster ROI."