XPO – 11.1 Sneak Peek – Data caching improvements

Introduction

First, we would like to refresh your memory and return to the distant past and our old posts about data caching in XPO:

·        XPO is good for distributed applications

·        XPO Beta feature: SQLDependency support

Today is 2011, and we are excited to announce that in v2011 vol1, we greatly improved data caching support in XPO, and added additional functionality to it, allowing this feature to leave the “beta” state.

Want data caching via WCF Services? – Now, it’s easy!

In the previous blog, we already demonstrated how easy it is in 11.1 to create and use WCF Services for IDataStore. If you want to take advantages of XPO data caching using this solution, then the only difference is in using the ICachedDataStore interface and a respective base service class that implements this interface – CachedDataStoreService.

Let’s demonstrate it in action (the exact steps on how to add a data store service can be taken from the previous blog):

  1: using DevExpress.Xpo;
  2: using DevExpress.Xpo.DB;
  3: …
  4: public class Service1 : CachedDataStoreService {
  5:     public static ICachedDataStore MainDataStore;
  6:     static Service1() {
  7:         string connectionString = MSSqlConnectionProvider.GetConnectionString("localhost", "ServiceDB");
  8:         IDataStore dataStore = XpoDefault.GetConnectionProvider(connectionString, AutoCreateOption.DatabaseAndSchema);
  9:         MainDataStore = new DataCacheRoot(dataStore);
 10:     }
 11:     public Service1()
 12:         : base(MainDataStore) {
 13:     }
 14: }

Of course, some modifications of the service binding in the web.config file are necessary as well:

  1: <system.serviceModel>
  2:  <services>
  3:    <service name="WcfService1.Service1" behaviorConfiguration="WcfService1.Service1Behavior">
  4:      <!-- Service Endpoints -->
  5:      <endpoint address="" binding="basicHttpBinding" contract="DevExpress.Xpo.DB.ICachedDataStoreService">
  6:        <identity>
  7:          <dns value="localhost"/>
  8:        </identity>
  9:      </endpoint>
 10:    </service>
 11:  </services>
 12:  <behaviors>
 13:    <serviceBehaviors>
 14:      <behavior name="WcfService1.Service1Behavior">
 15:        <serviceMetadata httpGetEnabled="true"/>
 16:        <serviceDebug includeExceptionDetailInFaults="false"/>
 17:      </behavior>
 18:    </serviceBehaviors>
 19:  </behaviors>
 20: </system.serviceModel>
 21: 

Fortunately, the client part does not need to be modified, because in our example, the service’s name did not change, and in addition, the “data caching domain” of our service is automatically detected by XPO.

Data caching configuration

After looking at how easy it is to implement, you may naturally ask how flexible it really is. Of course we did not forget about flexibility!

For example, it is possible for you to configure which tables need to be cached and which ones don’t. This option can be useful for tables, which are frequently changed – if they are changed a lot, it makes no sense to cache them. The code below demonstrates how the service above can be modified to configure the DataCacheRoot, to cache only the “Customer” table:

  1: using DevExpress.Xpo;
  2: using DevExpress.Xpo.DB;
  3: using DevExpress.Xpo.DB.Helpers;
  4: …
  5: public class Service1 : CachedDataStoreService {
  6:     public static ICachedDataStore MainDataStore;
  7:     static Service1() {
  8:         string connectionString = MSSqlConnectionProvider.GetConnectionString("localhost", "ServiceDB");
  9:         IDataStore dataStore = XpoDefault.GetConnectionProvider(connectionString, AutoCreateOption.DatabaseAndSchema);
 10:         DataCacheRoot dataCacheRoot = new DataCacheRoot(dataStore);
 11:         dataCacheRoot.Configure(
 12:             new DataCacheConfiguration(DataCacheConfigurationCaching.InList, "Customer")
 13:         );
 14:         MainDataStore = dataCacheRoot;
 15:     }
 16:     public Service1()
 17:         : base(MainDataStore) {
 18:     }
 19: }
 20: 

Leveraging SQLDependency

Another configuration option for data caching we would like to tell you about is using SqlDependency feature of MS SQL Server (see here for the background on that). Again, a modified service class demonstrates how this can be done:

  1: using DevExpress.Xpo;
  2: using DevExpress.Xpo.DB;
  3: using DevExpress.Xpo.DB.Helpers;
  4: …
  5: public class Service1 : CachedDataStoreService {
  6:     public static ICachedDataStore MainDataStore;
  7:     static Service1() {
  8:         string connectionString = MSSqlConnectionProvider.GetConnectionString("localhost", "ServiceDB");
  9:         MSSqlConnectionProvider dataStore = (MSSqlConnectionProvider)XpoDefault.GetConnectionProvider(
 10:             connectionString,
 11:             AutoCreateOption.DatabaseAndSchema
 12:         );
 13:         MainDataStore = (ICachedDataStore)MSSql2005SqlDependencyCacheRoot.CreateSqlDependencyCacheRoot(
 14:             dataStore,
 15:             new DataCacheConfiguration(DataCacheConfigurationCaching.InList, "Customer"),
 16:             out objectsToDispose
 17:         );
 18:     }
 19:     public Service1()
 20:         : base(MainDataStore) {
 21:     }
 22: }

That’s it for this blog. Do you like what you see? Please let us know with your comments!

And happy XPOing, as always!;-)

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