Dev/omar/design/serverPlugin

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Contents

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Registry Plugin Feature


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Original Motivation and Use Cases

Enable interception and of registry protocol requests by a Java Plugin to enable following use cases:

  • Allow an AdhocQueryRequest to be modified to add additional predicates to do Role Based filtering
    • Fixes problem where currently a request may match

thousands of objects but after access control checks only a few of the thousands would actually be returned to client. This is a performance issue because the db has to return thousands of objects that are not needed.

  • Allow a publish request to enfrce access control checks that span multiple objects in publish request.
    • Currently this is not possible because omar and ebRR specs only support access control on a per object basis.
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Feature Design

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Interface RegistryPlugin

  • Implemented by all registry plugins
  • Configured by RegistratyAdmin as slots on singleton Registry instance.
    • A separate multi-valued slot for each typoe of plugin
    • For each such Slot each slot value is the fully qualified classname for the plugin class
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Interface RequestInterceptor

  • Administrators could configure a Java class (or classes) as plugin for Request Validation
  • Each plugin would be specific to a specified Role (defined by Subject Role scheme).
  • Each plugin could modify the request as it sees fit or to throw a RegistryException such as an AuthorizationExcpetion.
    • In query scenario it culd add additional predicates to the query to filter down to the tens of objects.
    • In publish scenario it could do a single complex access control check spanning all objects in entire request as well as objects in registry.
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Server Modifications

  • Define constants in BindingUtility for slotName for special slotNames for each type of plugin (use on Registry singleton instance)
  • Refactor code from AuthorizatioNServiceImpl to BindingUtility.getACtionFromRequest(..) to convert a RegistryRequestType to a string defined by ebRIM as supported Actions.
  • Refactor Actiion constants from AuthorizatioNServiceImpl to CanonicalConstants
  • Modified spi.NotificationListener interface to no longer be JAXR based but instead use JAXB Bindings.
    • Makes spi.NotificationListener consistent with spi.RequestInterceptor
    • All plugins would now be based on server interfaces rather than JAXR
  • Fixed PluginNotifier to send JAXB NotificationType instead of JAXR Notification to NotificationListener plugin
  • Added new interface spi.RegistryPlugin
    • This interface defines standard methods for server to learn about the plugin
    • Avoids relying on messy RegistryObjects/Slots based configuration to get information about a plugin to server!
  • Modified spi.RequestInterceptor to extend RegistryPlugin
  • Added a new server.cache package
    • AbsttractCache: base class for all Cache classes
    • ObjectCache: Caches individual objects (implemented but not tested extensively. Seems to work.)
    • RoleCache: Caches User/Roles mappings (implemented and tested even less than ObjectCache)
    • QueryCache: Caches common queries and their results (not implemented yet)
  • Modified server.QueryManagerImpl to make use of ObjectCache
  • Modified EventManager to notify caches of events directly. Decided not to use SUbscription / Notification as it is more complex, unnecessary and inefficient.
  • Added server/plugin package where teh plugin framework classes are added
    • PluginManager: Manages all instances of a particular type of plugin and is responsible for invoking them
      • Currently has no methods.
    • AbstractPluginManager: Common base class for all PluginManagers.
      • Provides factory method for creating plugin instances
    • RequestInterceptorManager: Manager for RequestInterceptor plugins


  • Some minor bug fixes to ServerRequestContext and to invoke RequestInterceptorManager at the right places.
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Testing the Feature

  • No unit tests created yet
  • Using Java UI, manually add appropriate slot to Registry SIngleton instance and then use existing server.LifeCycleManagerImplTest in debugger
    • slot name: urn:freebxml:registry:Registry:interceptors
    • slotType: urn:oasis:names:tc:ebxml-regrep:DataType:String
    • slotValue: ca.on.gov.mgs.gateway.policy.ServiceAdminPolicyPlugin (plugin specific class)
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Design Issues

Diego, please comment on these. Thanks.

  • TBD
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