Wednesday, December 27, 2017

Remote Services without OSGi bundles

Remote Services provides a dynamic, transport-independent, simple, modular way to expose micro services.   ECF has created a spec-compliant implementation along with a large and growing number of open and extensible distribution providers.   

Remote services are frequently useful for fog/edge use cases, where the communication transports (e.g. MQTT) may be different than those typically used in the cloud (e.g. http/https, jaxrs, enterprise messaging, etc).   

Typically, remote services are run on OSGi-based frameworks and apps such as Equinox, Felix, Karaf, Eclipse, and others, and indeed ECF's RSA implementation works very well in any of these environments.   

Perhaps less well known, however, is that remote services can be used in other inter-process environments...for example between Java and Python.  

It's also possible to use ECF remote services without an OSGi framework, i.e. running only as Java applications.   This repository has an example of using ECF remote services without an OSGi framework.   The projects are Java applications (no OSGi framework assumed), on both the remote service provider side, as well as the remote service consumer side.   The examples may be run within Eclipse by using the launch configs in the example projects.

Most of the benefits of OSGi Remote Services are still available...for example the ability to use multiple distribution providers for a service, the ability to remotely discover services and dynamically respond to network failure, and the ability to use the OSGi service registry for service dynamics, and service injection.   Also, the service definition, implementation, registration and lookup are exactly the same whether via an OSGi bundle or a Java application.   This allows services to be defined consistently across runtime environments in addition to cross-distribution mechanisms.

Please clone the ServiceRegistry github repository and give things a try!

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Wednesday, December 13, 2017

Remote Services between Python and Java

ECF's implementation of OSGi Remote Services allows multiple distribution providers, which are responsible for the actual rpc communication required by remote services.   Here is a list of ECF distribution providers we've created.

Using Py4j and Google Protocol Buffers, we've recently enhanced an ECF distribution provider that allows the use of remote services (and Remote Service Admin) between OSGi and Python.   Service impls can be in either Java or Python, and consumers can be either Java or Python.     Protocol Buffers can be used to efficiently serialize arguments and return values.

The only dependencies are on OSGi, Py4j, and Google Protocol buffers, so this distribution provider can be used in Eclipse or other OSGi environments like Karaf.

Get the most recent release, with examples and source code at this github repository.

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Monday, December 04, 2017

ECF 3.13.8 and etcd discovery for remote services

ECF 3.13.8 has been available since September, but there are some new things available:

ECF 3.13.8 changes have distributed to maven central

There is a new release (1.3.0) of the etcd discovery provider.    This provider uses an ectd cluster to publish and discover remote services allow complete integration with systems like Kubernetes, which also use etcd for service discovery.

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