## Synchronization

### Purpose

A master database instance and one or more client database instances synchronize their data.

A database instance does not have to be connected to the network on a continuous basis. If you reconnect a database instance to the network, you have to start the synchronization service for that database instance. The synchronization service then updates all the data in the database instance and sends any data changes to the other database instances.

### Prerequisites

· You have completed the configuration.

· You have started the message server.

### Process Flow

...

1. Start the synchronization service

2. You can now change data in one or more of the database instances.

The synchronization services of the respective database instances send the changes in their database instances to the message server and retrieve the changes from the other database instances from the message server. The synchronization service resolves collisions.