In part 1 of this post, I discussed about using the Disconnected Service Agent application block for data synchronization. This entry discusses the second method, which is web synchronization using merge replication.

Web Synchronization over Sql Server Merge Replication

This approach makes use of the merge replication features provided by Sql Server 2005 and Sql Server Mobile, extending it over http using IIS.

Some concepts related to merge replication:

Publisher

The Publisher is a database instance that makes data available to other locations through replication.

Distributor

The Distributor is a database instance that acts as a store for replication specific data associated with one or more Publishers. Each Publisher is associated with a single database (known as a distribution database) at the Distributor.

Subscribers

A Subscriber is a database instance that receives replicated data. A Subscriber can receive data from multiple Publishers and publications.

Publication

A publication is a collection of one or more articles from one database.

Subscription

A subscription is a request for a copy of a publication to be delivered to a Subscriber. The subscription defines what publication will be received, where, and when.

Web synchronization for merge replication provides the ability to replicate data using the HTTPS protocol and is well suited to the following scenarios:

• Synchronizing data from mobile users over the Internet.

• Synchronizing data between Microsoft SQL Server databases across a corporate firewall.

Web synchronization is designed for synchronizing data with laptops, handheld devices, and other clients. It is not intended for high volume server to server applications.

To use Web synchronization for replication, you must perform the following steps.

1. Configure a publication to use Web synchronization.

2. Configure the Microsoft Internet Information Services (IIS) server used to synchronize subscriptions. IIS versions 5.0 and 6.0 are supported.

3. Configure the publication and subscription to use Web synchronization.

Thus we can see that we can use the web synchronization feature of Sql Server when we need to synchronize between a sql server 2005 mobile and sql server 2005. For a more platform–neutral approach, we can use the disconnected web services approach using the Disconnected Services Agent.