DDR-RI User Manual 1.1

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Contents 1 Previous Documentation 2 Download 3 New Features Version 1.1 3.1 New REST Service 3.2 Configuration 3.2.1 Required properties 3.2.2 Optional properties 3.2.3 Cache 3.3 How to use 4 Feedback

Previous Documentation

• DDR-RI User Manual 1.0

Download

• Binaries:
  • You can download this release from here
• Source:
  • https://svn.forge.morfeo-project.org/svn/ddr-ri/tags/devinfo_ve_1.1/

New Features Version 1.1

New REST Service

This implementation provides two Services:

• org.morfeo.devinfo.simple.ServiceImpl (the same as Version 1.0)

This service implements a DDR service which knows all the data sources where to retrive values given a vocabulary, aspect and property (the sources are sorted by priority). If a data source can not continue with the request or doesn't know the value of the property, the following data source will be query according to the priority

• org.morfeo.devinfo.simple.connector.RESTService (new Service)

This service is simply a connector to a remote DDR which is based on ServiceImpl and uses a cache for caching the property values indexed by Evidences

Configuration

This implementation uses different properties to configure the REST Service

Required properties

• Property org.morfeo.devinfo.simple.data (the same as Version 1.0)
  • It's the path to resources as device clustering files and ehcache configuration
  • E.g. /apps/DevInfo-Simple-1.1/resources

• Property org.morfeo.devinfo.simple.rest.url
  • URI to DDR Rest Service
  • E.g. http://195.235.93.83:8081/DDRService (MORFEO Service)
  • Install your own DDR REST Service

Optional properties

• Property org.morfeo.devinfo.simple.rest.cache
  • URI or absolute path to the cache configuration file
  • If this property is not defined the path will be the previous data property value + /devinfo/devInfo-cache.xml
  • E.g. /apps/resources/other/devInfo-cache.xml

Cache

• The REST Service uses a cache for caching the property values indexed by Evidences
• The configuration file is described below (we would advise this configuration by default):

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

	<diskStore path="java.io.tmpdir" />

	<defaultCache maxElementsInMemory="10000" eternal="false"
		timeToIdleSeconds="120" timeToLiveSeconds="120" overflowToDisk="true"
		diskSpoolBufferSizeMB="30" maxElementsOnDisk="10000000"
		diskPersistent="false" diskExpiryThreadIntervalSeconds="120"
		memoryStoreEvictionPolicy="LRU" />

	<!-- Holds PropertyValue's for each Evidence -->

	<cache name="devInfo" maxElementsInMemory="500" eternal="false"
		timeToIdleSeconds="3600" memoryStoreEvictionPolicy="LFU">
		<cacheEventListenerFactory
			class="org.morfeo.devinfo.simple.connector.ListenerFactory" />
	</cache>

</ehcache>

• defaultCache is provided by ehcache (by default)
• The cache that holds property values is called devInfo and its definition is mandatory
  • maxElementsInMemory: maximum number of objects that will be created in memory (one object for each evidence)
  • eternal: if eternal, timeouts are ignored and the element is never expired.
  • memoryStoreEvictionPolicy: policy would be enforced upon reaching the maxElementsInMemory limit
  • timeToIdleSeconds:time to idle for an element before it expires
    • org.morfeo.devinfo.simple.connector.ListenerFactory removes expired elements

For more information about the configuration view http://ehcache.sourceforge.net/documentation/configuration.html

How to use

• View previous version

Feedback

Should you have any comment or feedback, please contact us at:

• ddr-ri-develop@lists.morfeo-project.org