Thursday, March 10, 2016

WSO2 Governance Registry 5.x.x FAQs

The WSO2 Governance Registry (G-Reg) has gone through some major transformations, starting from G-Reg 5.0.0 (the current version as of this writing is 5.1.0). In addition to the new and enhanced registry and repository features, G-Reg now comes with multiple views for different roles, i.e. publishers, consumers/subscribers and administrators. This is a significant change from the previous versions which just included one view for all the users. Before understanding the nuts and bolts of G-Reg let's first understand what a registry is and its purpose. What does it do? Why use one?

If your business is SOA-enabled, you need to keep track of your services and who consumes them. Furthermore, as businesses undergo change, including mergers and acquisitions, the number of platforms, consumers, services, and exposed APIs can increase rapidly. SOA Governance is needed to provide full visibility into existing assets; without it, businesses lack the tools to govern and manage assets consistently.It's all about ensuring and validating that assets and artifacts within the architecture are acting as expected and maintaining a certain level of quality. This is where the registry comes into the picture to facilitate SOA governance. The registry can act as a central database that includes artifacts for all services planned for development, in use and retired. Essentially, it's a catalog of services which are searchable by service consumers and providers. The WSO2 Governance Registry is more than just a SOA registry, because in addition to providing end-to-end SOA governance, it can also store and manage any kind of enterprise asset including but not limited to: services, APIs, policies, projects, applications, people. 

Now that we understand what a registry is, here is a compilation of some FAQs and answers related to WSO2 G-Reg to understand what it offers and how it behaves. 

What is the WSO2 Governance Registry ?

The WSO2 Governance Registry (G-Reg) is a SOA-integrated registry-repository for storing and managing data or metadata related to service artifacts and other artifacts. It provides a rich set of features including SOA governance, lifecycle management, and a strong framework for governing anything. For more information on the features and functionality of WSO2 Governance Registry, go to WSO2 Governance Registry.

WSO2 Governance Registry’s main functionality falls under the following two categories.
Content repository
Governance framework

WSO2 Governance Registry provides three main web based user interfaces to facilitate the features and functionality as follows. 

G-Reg Publisher - an end-user, collaborative web interface  for governance artifacts providers to publish artifacts, manage them, show their dependencies, and gather feedback on quality and usage of them. 

G-Reg Publisher

G-Reg Store - an end-user, collaborative Web interface for consumers to self-register, discover governance artifact functionality, subscribe to artifacts, evaluate them and interact with artifact publishers.

G-Reg Store

G-Reg Management Console - a Web interface for administrators to perform admin tasks. 

Management Console

How does a service consumer use the solution to find a service and implement a service client?

The service consumers can use the G-Reg Store to self-register, discover and search for SOAP/REST services. G-Reg offers configuration options such as tags, categories, comments, properties, ratings and descriptions for a resource. It is important to plan the use of these configurations, to facilitate discovering services and enabling correct SOA Governance. Resources for service discovering tremendously help in service reuse. In fact, it's one of the major functions of a registry-repository product. G-Reg provides enhanced search capabilities to facilitate search based on tags and other advanced criteria.

How does a service provider register a new service?

G-Reg allows service providers to register services through the G-Reg Publisher. Users can choose either to enter service details manually  or to import service information using a WSDL/WADL url. The G-Reg Publisher facilitates artifact providers/creators to publish artifacts, manage them, show their dependencies, and gather feedback on quality and usage of them.

How does a service provider use the solution when making a change to a service specification or endpoint ?

A service provider can use the G-Reg publisher to perform changes such as editing or versioning an existing service.  G-Reg provides tools for asset comparison, dependency management and visualizing service descriptions. It also supports WS-Eventing-based subscriptions and notifications that can be used to govern changes made to individual resources as well as to the lifecycle to which it belongs.

How does the solution facilitate service governance?

Service reuse is the heart of SOA. Before implementing a new service, a service provider can search in the registry for existing implementations. This helps the provider to use an existing service either as it is or by developing a new service associating the existing service. Furthermore, registry-repositories help discover associations among services. This helps to get a better idea of any impacts when changing a particular service. And services in a registry undergoes lifecycle states of create, test, deploy and deprecate.

G-Reg can perform the following functions:

  • Enforce policies during transitions of the states of create, test, deploy and deprecate.
  • Define "who can access what?" of services. Access to certain services may differ depending on the user, user group or state of the service lifecycle.
  • Send notifications to relevant users once a change to a service artifact has been made.

As more and more services are introduced and reused, it is necessary to keep track of dependencies of each service in an organization. G-Reg makes life easier by keeping inter-service dependency information as relationships among service information artifacts. For example, such relationships can be Contains, Implements, Uses, Depends, etc.

Service artifacts evolve over time due to reasons such as fulfilling new requirements and yielding to different versions of the same service. G-Reg provides versioning capabilities that can enable automatic version control of artifacts stored. Additionally. G-Reg keeps older versions of artifacts to allow users to migrate smoothly from one version to another.

In summary, G-Reg provides the following capabilities to facilitate SOA Governance:

  • Record information on services
  • Add service/API information manually or import WSDLs/WADLs
  • Discover services using scheduled tasks and discovery agents
  • Search for an existing service for reuse
  • Search using tags/categories. Supported via SOLR.
  • Discover associations and dependencies of a service
  • Service lifecycle management
  • Lifecycle-based asset management
  • In-built and custom lifecycle executors
  • User access control
  • Automatic version control
  • Notification support (email, UI etc.)
  • An SDK for registry-repository extensibility

How is the solution used at design time vs. runtime?

G-Reg can be used during design-time to record service information and govern the service lifecycle .
If needed, using lifecycle executors, services can be deployed/undeployed in relevant servers based on the lifecycle state transition. For example, a Jenkins job can be triggered during a state transition by a custom lifecycle executor - the executor will invoke a remote API of Jenkins which will, for example, build and and deploy service(s) in production environment when promoted from testing to production.

Run-time policy enforcement can be done when associating a WS-Policy with a SOAP service. G-Reg can apply these policies using Handlers (Handlers provide the basis for extending the WSO2 Governance Registry functionality). This is an extension feature as G-Reg only creates an association out-of-the-box.

How does the solution manage multiple endpoints for a service (e.g. Dev, QA, Production)?

Endpoints can be added manually to a service via G-Reg Publisher.  When importing WSDLs, only one endpoint will be added; however, more endpoints (QA, Prod) can be added manually.

How does the solution manage multiple versions of a service?

G-Reg provides support to version existing services, view all versions of a service and restore to a previous version. It is possible to compare different versions of governance artifacts via the Publisher, provided that the comparison is between versions of the same artifact type. If required, resources can be automatically versioned when they are added or updated. But this feature is disabled by default.

How does the solution manage service deprecation and discontinuation?

Currently, G-Reg only changes the state of the service to Deprecated in the default service lifecycle and can be configured to notify subscribers of that service  However, if any actions need to take place as a result of the lifecycle state being changed to Deprecated, a lifecycle executor can be configured to implement such tasks.


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