It is time for one of my inbox-clearing blog posts once again. Here’s a bunch of cool stuff that you might like:
Benjamin Kudria just wrapped up an internship at the New York Times. He wrote a detailed recap of his experience and noted that he had the…
Cloud Services focuses on creating innovative solutions by enabling technologies we believe in to work in the cloud environments. Today we would like to present OSGi – the dynamic module system for Java™.
The article by Peter Kriens, Director of Technology for OSGi Alliance, is addressing many questions a newcomer might have on the benefits of developing with OSGi:
Well, these problems are not intrinsic and OSGi technology solves many of them. This article tries to explain why OSGi technology is relevant and why software developers, as well as strategic people, should pay attention. Some people say OSGi technology is the best kept secret of the computing industry. Let us try to change this.
So, what benefits does OSGi’s component system provide you? Well, quite a list:
• Reduced Complexity – Developing with OSGi technology means developing bundles: the OSGi components. Bundles are modules. They hide their internals from other bundles and communicate through well defined services. Hiding internals means more freedom to change later. This not only reduces the number of bugs, it also makes bundles simpler to develop because correctly sized bundles implement a piece of functionality through well defined interfaces. There is an interesting blog that describes what OSGi technology did for their development process.
• Reuse – The OSGi component model makes it very easy to use many third party components in an application. An increasing number of open source projects provide their JARs ready made for OSGi. However, commercial libraries are also becoming available as ready made bundles.
• Real World – The OSGi framework is dynamic. It can update bundles on the fly and services can come and go. Developers used to more traditional Java see this as a very problematic feature and fail to see the advantage. However, it turns out that the real world is highly dynamic and having dynamic services that can come and go makes the services a perfect match for many real world scenarios. For example, a service could model a device in the network. If the device is detected, the service is registered. If the device goes away, the service is unregistered. There are a surprising number of real world scenarios that match this dynamic service model. Applications can therefore reuse the powerful primitives of the service registry (register, get, list with an expressive filter language, and waiting for services to appear and disappear) in their own domain. This not only saves writing code, it also provides global visibility, debugging tools, and more functionality than would have implemented for a dedicated solution. Writing code in such a dynamic environment sounds like a nightmare, but fortunately, there are support classes and frameworks that take most, if not all, of the pain out of it.
We strongly encourage you to read the entire article and see how this technology might benefit you. If you would like a more detailed introduction to OSGi, this is where you could start:
– Getting Started with OSGi by Neil Bartlett.
Cloud Services makes it possible to deploy server side OSGi applications in Amazon EC2 instances. With several mouse clicks exported bundles can be uploaded to remote storage (S3) and added to profile (Launch Configuration). That is all it takes to start virtual servers (EC2 instances) containing OSGi framework provisioned with selected bundles.
El nuevo paso en los web services de Amazon se llama «Elastic Block Store» y consiste en que añaden persistencia a su EC2, el servicio con el que ofrecen capacidad de procesamiento «en la nube». Si unimos este paso al resto de su oferta, con SimpleDb y S3, tenemos una solución cada vez más completa para externalizar el data center de la empresa en su plataforma.
Con este «Elastic Block Store» cada vez hay menos diferencia entre lo que ofrece un hosting «normal» y soluciones como la de los web services de Amazon. En la competencia dentro de su sector, Google App Engine queda muy atrás en la competencia de las plataformas como servicio.
Claro que hablar hoy del fin de de los data centers es adelantarse mucho a la tendencia (Dion Hinchcliffe), además de obviar los problemas que acarrean las «soluciones en la nube», tanto legales como técnicas. La mayor preocupación viene dada por la dependencia de una empresa externa a la hora de mantener el servicio, pero las ventajas por otro lado son numerosas: escalabilidad y costes son las dos que más fuerza van a tener a la hora de que las empresas se planteen la externalización de su data center. Respecto a la disponibilidad, cierto que hay caídas, pero también cabe preguntarse si, como empresa, seríamos capaces de conseguir la estabilidad que ofrece Amazon.
Hay un montón de buenos artículos que pueden ayudar a valorar el paso que ha dado Amazon y que viene a fortalecer su excelente estrategia como plataforma:
- Amazon Web Services Blog.
- Una muy buena explicación en blog.rightscale.com.
- All Things Distributed.
- Dion Hinchcliffe, del que tomo el provocador título del post.
- El sitio oficial, Amazon.com.
Now that Amazon’s Elastic Block Store is live I thought it’d be helpful to explain all the ins and outs as well as how to use them. The official information about EBS is found on the AWS site, I’ve written about the significance of EBS before and…
This is a companion post to my earlier post — Amazon EBS (Elastic Block Store) – Bring Us Your Data. In the other post you can read about the features of EBS. This post goes into more detail on the tool and library support that has been built by our c…