Storage Servers

The Storage Servers API provides limited management capabilities for 3rd party triple stores that support the concept of creating and managing several independent triple store instances via the same management endpoint. It is represented by the IStorageServer and IAsyncStorageServer interfaces. These interfaces provide limited abilities to create, delete, get and list stores provided on a server i.e. the ability to manage and access multiple IStorageProvider instances.

Implementations

The following implementations are currently provided:

Implementation	Description
AllegroGraphServer	Manages a catalog of an AllegroGraph server, see the Allegro Graph documentation
SesameServer	Manages a Sesame HTTP Protocol compliant server, see the Sesame documentation
StardogServer	Manages a Stardog server, see the Stardog documentation

Basic Usage

Properties

These interfaces provide a single IOBehaviour property which reports IOBehaviour that describes the capabilities of an implementation i.e. which operations are supported.

Methods

These interfaces provide several methods for carrying out the varying management tasks supported, here we demonstrate each with an example.

ListStores()

The ListStores() method lists the stores available on a server.

using System;
using VDS.RDF;
using VDS.RDF.Storage.Management;

public class ListStoresExample
{
  public static void Main(String[] args)
  {
     //Connect to a server, we use Stardog for this example
     StardogServer server = new StardogServer("http://localhost:5822", "username", "password");

     //Get the list of stores
     foreach (String store : server.ListStores())
     {
       Console.WriteLine(store);
     }
  }
}

GetStore()

The GetStore() method gets a connection to a specific store assuming it is available on the server.

using System;
using VDS.RDF;
using VDS.RDF.Storage;
using VDS.RDF.Storage.Management;

public class ListStoresExample
{
  public static void Main(String[] args)
  {
     //Connect to a server, we use Stardog for this example
     StardogServer server = new StardogServer("http://localhost:5822", "username", "password");

     //Get a specific store
     IStorageProvider store = server.GetStore("example");
  }
}

DeleteStore()

The DeleteStore() method is used to delete a store from the server, this is typically non-reversible and should be used with extreme care.

using System;
using VDS.RDF;
using VDS.RDF.Storage.Management;

public class ListStoresExample
{
  public static void Main(String[] args)
  {
     //Connect to a server, we use Stardog for this example
     StardogServer server = new StardogServer("http://localhost:5822", "username", "password");

     //Delete a specific store
     server.DeleteStore("example");
  }
}

Creating a Store

Creating a store is the most complex operation is done with a combination of the CreateStore() and either the GetDefaultTemplate() or GetAvailableTemplates() method. Creating a store requires that you provide a IStoreTemplate instance which indicates to the server what kind of store to create.

Templates

The GetDefaultTemplate() method returns a template that can be modified in order to create whatever the server considers its default store type. If the server supports multiple store types the GetAvailableTemplates() method will return all available templates.

A template has at the minimum a ID property which specifies the ID for the store to be created, it also has a TemplateName and TemplateDescription properties which describe the type of store the template may be used to create. Templates also provide a Validate() method which can be used to ensure that templates are valid before use, any server will call this on templates passed to the CreateStore() method before actually attempting to create the store.

Since servers may have many implementation specific features typically there will be some number of additional properties that are available on a template that will allow you to customize your template. See documentation for the various supported implementations to see what templates are supported. Template implementations are annotated using System.ComponentModel annotations so can be explored via reflection if you so desire.

CreateStore()

Once you have an appropriate template you can pass it to the CreateStore() method to get the store created. This method will return true if the creation succeeds and false (or an exception) otherwise.

using System;
using VDS.RDF;
using VDS.RDF.Storage.Management;
using VDS.RDF.Storage.Management.Provisioning;

public class ListStoresExample
{
  public static void Main(String[] args)
  {
     //Connect to a server, we use Sesame for this example
     IStorageServer server = new SesameServer("http://localhost:8080/openrdf-sesame/");

     //Create a new store using the default template
     IStoreTemplate template = server.GetDefaultTemplate("example");
     if (server.CreateStore(template))
     {
       Console.WriteLine("Store Created OK");
     }
     else
     {
       Console.WriteLine("Store Creation Failed");
     }
  }
}