# General Replication

## Introduction

| The General Replication Module (DDM) manages the transfer of data between several distributed sites of a company with the aid of the File Replication (DFM) and the Data Exchange (EER) Modules. Data created in a central location is sent to and stored at distributed locations whenever the need arises. Depending on the task at hand, General Replication (DDM) uses either the File Replication Module (DFM) or the Data Exchange Module (EER) for the transfer of data. File Replication (DFM) is used for the transfer of document files, while the Data Exchange Module (EER) can be used for a variety of file types. The General Replication Module (DDM) manages data according to their usage information (file type, creating system, etc.) as well as the sites involved in the exchange. Using the General Replication Module (DDM), new sites, vaults for those sites, and file types for the exchange can be created and configured. This data is then in turn transferred by the File Replication Module (DFM) and the Data Exchange Module (EER). Depending on the actual module used for the transfer process the application may vary: In the File Replication Module (DFM), the replication process can be initiated automatically as part of the check-out procedure either using a batch process or through user an interactive process if requested files are not stored in the local vault or if a current version is not available from the local vault. The use of batch processing for data replication should be preferred since file transfers are initiated at specific times and in regular intervals. If data is required at a specific site, the system will try to locate this data in the local vault. If the requested files are not available or not current at the local vault, a file transfer from the database of the original location can be initiated. Once the data has been transferred to the local vault, it will be available at both sites (->data redundancy). The FileServer provides the files and also controls the check-in process and the distribution of data. If the Data Exchange Module (EER) is used, all import and export processes must be initiated by the user through interactive processes. This module can provide a confirmation message (which is sent back to the sender) stating that files have been received and stored in the remote location. The files are provided, check- or checked out by the FileServer. However, the FileServer does not control the actual data exchange.
| File Replication (DFM)
| Data Exchange (EER)