Restlet and OSGI remote services - Part 2
In a previous posting, I described some of the advantages of integrating the Restlet framework with ECF's implementation of OSGi remote services admin (RSA).
In this posting, I'll describe a couple of the advantages of doing this for the service host side of things (the server that exports and implements the remote service).
Advantages for Remote Service Host
Modular re-use of Restlet Framework. The Restlet framework can be used to easily define remote services that are exposed via http access methods (e.g. GET, POST, PUT, DELETE). Restlet has become popular as a way to create and expose remote services, and all existing uses of Restlet can immediately and modularly be reused.
Use of standardized meta-data format. One of the most valuable things about the Remote Service Admin specification, I believe, is the standardization of the meta-data for a remote service. This is accomplished by standardizing the EndpointDescription format for remote services. Among other advantages, standardization of this meta-data allows the easy creation of tooling for reading/parsing, as well as writing these meta-data.
Modular re-use of network discovery. Since EndpointDescriptions are standardized, they can be easily published and discovered via various discovery protocols. ECF's discovery API is a transport-independent API for advertising and discovering services, and this API is used by the ECF RSA implementation. This allows discovery providers to be substituted...without any required changes in the export or import of a remote service. So not only can any of the existing ECF discovery providers be used interchangeably for EndpointDescription discovery (Apache Zookeeper, Zeroconf/Bonjour, Service Locator Protocol, DNSSD, xml-file-based discovery), it's also easy to create your own discovery provider, using proprietary or open protocols for remote service discovery...to meet enterprise requirements for security, integration, and customization.
The conclusion, I believe, is that standardization provided by the OSGi RS/RSA specs, along with ECF's modular, provider-based implementation (enabled by OSGi modularity and OSGi services) makes it easy to develop, deploy, manage, and maintain standardized remote services, without giving up flexibility...to determine how those remote services are discovered, accessed and managed in SOA-based systems.
Summary: Modularity and Standardization are complimentary for reuse, flexibility, and interoperability of remote services.