ODE: Distributing a Replica Set for Indirect Synchronization

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Indirect synchronization using Microsoft Replication Manager is the best synchronization method if you are not always connected to the network; you can specify a network location where message files containing information to be exchanged are deposited for later processing. When you use indirect synchronization, two synchronizers establish a link to each other and exchange messages containing the changes to the data. This method of synchronization is safer and more efficient when using slower WAN and modem connections, because you don't open the remote replica over the connection.

Microsoft Replication Manager must be installed and configured on each computer that uses indirect synchronization.

Follow these steps to configure Microsoft Replication Manager for indirect synchronization and for distributing a replica set that uses indirect synchronization.

Configuring Microsoft Replication Manager

1. Create a shared folder on each computer to serve as a Dropbox. This folder should have its permissions set to give all users at least Read, Write, and Create rights; if you are using Microsoft Windows NT, this folder should have at least Change rights.
2. Run Replication Manager. If you are running Replication Manager for the first time, the Configuration Wizard starts automatically. If you have previously used Replication Manager, start the Configuration Wizard by clicking Configure Microsoft Replication Manager on the Tools menu.
3. On the first page of the wizard, click Next.
4. Click to select the Support Indirect Synchronization check box and then click Next twice.
5. In the list of Shared Folders On This Computer, click the folder that you created in step 1 so that the folder appears in the Dropbox Folder box; you can also type the path to this folder in the Dropbox Folder box. Then click Next.
6. On the screen that asks, Is This Computer an Internet Server? click No and then click Next.
7. Accept the default path to the log file by clicking Next.
8. Type a name for the Synchronizer and then click Next. The default name of the Synchronizer is the name of the computer.
9. Click Finish to complete configuration of Replication Manager.

Distributing a Replica Set for Indirect Synchronization

It is not recommended that you use the Design Master as the hub for synchronization of a replica set. In the following steps, the first replica that you create is the hub replica from which you create all of the other replicas.

1. Complete the steps in the section "Configuring Microsoft Replication Manager" on every computer that is to host a member of the replica set.
2. Create a replica set from an existing database on your primary computer. You can do this by opening the database in Microsoft Access. On the Tools menu, point to Replication, and then click Create Replica. Follow the instructions to create both a Design Master and a replica.
   
   NOTE: You can also use Microsoft Replication Manager to convert a database to a Design Master by clicking Convert Database To Design Master on the Tools menu. The Convert Database To Design Master Wizard allows you to specify different characteristics of the replica set, such as which objects are available to the replica set and whether replicas are read/write or read/only. Unlike the Microsoft Access user interface, however, the wizard does not create the first replica. When the Convert Database To Design Master Wizard asks whether you want to manage the Design Master with this Synchronizer, click No and then click Finish. Then, on the File menu, click New Replica and follow the instructions provided by the New Replica Wizard to create the first replica.
3. Open Microsoft Replication Manager on the primary computer.
4. On the File menu, click Managed Replicas. In the Managed Replicas dialog box, click Manage New.
5. In the Start Managing Replica dialog box, locate the replica that you created in step 2 and click Open; do not manage the Design Master. In the Managed Replicas dialog box, click Close.
6. Start Windows Explorer. Locate the folder containing the managed replica and make a copy of that replica.
7. Move the copy of the replica to the secondary computer.
   
   NOTE: It is important to move the replica rather than copy it to the secondary computer. A copy of the replica should not remain on the primary computer.
8. On the secondary computer, open Microsoft Replication Manager and manage the replica that you moved to this computer in step 7.

When you connect the secondary computer to the network, a line connecting the two transporters appears in the Synchronization window. You can right- click this line to synchronize the replicas. Synchronization is indirect if the primary computer has no network access to the folder containing the replica on the secondary computer and the secondary computer has no network access to the folder containing the replica on the primary computer. There is no way to prevent Microsoft Synchronizer from using direct synchronization if it is running on a computer that has direct network access to the folder containing the target replica. If one replica has direct network access to the other replica, the only way to guarantee indirect synchronization is to use internet synchronization.