Syncing SQL Server 2008 Databases over HTTP using WCF & Sync Framework

Question

Has anyone here worked with Sync Framework and syncing through WCF endpoints? Please share code samples or sample projects. I am specifically looking for offline scenarios where client comes online only to fetch updates from the Server.

Answer 1

I did the following to get Sync Framework working using WCF with SQL Server 2008

• Enabled Change Tracking in SQL Server 2008
• Enabled change tracking for tables participating in the Sync
• Added a metadata table named anchor
• Added a table to track client Ids named "guid"
• Used SqlExpressClientSyncProvider available from MSF's codeplex project site as Client Sync Provider

• Used SqlSyncAdapterBuilder to build adapters for tables participating in the Sync

  foreach (var item in anchorTables)
  {
      // Use adapter builder to generate T-SQL for querying change tracking data and CRUD
      SqlSyncAdapterBuilder builder = new SqlSyncAdapterBuilder();
      builder.Connection = new SqlConnection(this.connectionStringFactory.ConnectionString);
      builder.ChangeTrackingType = ChangeTrackingType.SqlServerChangeTracking;
      builder.SyncDirection = SyncDirection.Bidirectional;
      builder.TableName = item.TableName;
      // Get sync adapters from builder
      SyncAdapter clientAdapter = builder.ToSyncAdapter();
      clientAdapter.TableName = item.TableName;
      this.clientSyncProvider.SyncAdapters.Add(clientAdapter);
  }
  

• Added anchor commands

  SqlCommand anchroCommand =
     new SqlCommand { CommandText = "SELECT @" 
        + SyncSession.SyncNewReceivedAnchor 
        + " = change_tracking_current_version()" };
  
  anchroCommand.Parameters.Add("@" 
        + SyncSession.SyncNewReceivedAnchor, SqlDbType.BigInt)
        .Direction = ParameterDirection.Output;
  
  this.clientSyncProvider.SelectNewAnchorCommand = anchroCommand;
  

• Implemented a WCF Service using a instance of DbServerSyncProvider functioning as Server sync provider. You will have generate sync adapters and set anchor command as shown in previous step for Server provider too.

  [ServiceContract]
  public interface ISyncService
  {
      [OperationContract]
      SyncContext ApplyChanges(SyncGroupMetadata groupMetadata, DataSet dataSet, SyncSession syncSession);
      [OperationContract]
      SyncContext GetChanges(SyncGroupMetadata groupMetadata, SyncSession syncSession);
      [OperationContract]
      SyncSchema GetSchema(Collection<string> tableNames, SyncSession syncSession);
      [OperationContract]
      SyncServerInfo GetServerInfo(SyncSession syncSession);
  }
  

• Created a proxy class implementing ServerSyncProvider to access WCF service

  public class DbServerSyncProviderProxy : ServerSyncProvider
  {
      SyncServiceProxy.SyncServiceClient serviceProxy = new SyncServiceProxy.SyncServiceClient();
      public override SyncContext ApplyChanges(SyncGroupMetadata groupMetadata, DataSet dataSet, SyncSession syncSession)
      {
          return serviceProxy.ApplyChanges(groupMetadata, dataSet, syncSession);
      }
  }
  

• Created an instance of SyncAgent and set RemoteProvider with an instance of proxy class which is used to access WCF service. LocalProvider is set with instance of SqlExpressClientSyncProvider
• Added tables and sync groups to SyncAgent configuration
• SyncAgent.Synchronize()