How the Server Accessory Works

The DATABridge Server Accessory is installed automatically on the host when you install the DATABridge software. On the Unisys MCP server, it interacts with DBEngine. On a remote system, the Server Accessory interacts with the DATABridge Client. It supports communications over TCP/IP, BNA, or HLCN and can support up to 100 simultaneous connections to the DATABridge Client. The Server Accessory is required for all DATABridge Clients (including the DMSII Client and DATABridge Twin). It is not required for DATABridge Accessories such as Span or Snapshot.

The following describes how the Server Accessory works with other DATABridge components in the replication and update process:

  1. The Client calls Server Accessory to retrieve information for a DMSII database.
  2. The Server Accessory calls the Engine, and the Engine accesses the DMSII database via DMSII access routines.
  3. The Server Accessory receives the records from the Engine, calls the filter and format in the Support library, and then sends the records to the Client.
  4. The Server Accessory then calls the Engine to retrieve updates that occurred during the extraction.
  5. The Engine reads the audit trail and sends the information to the Server Accessory, which calls the filter and format in the Support library.
  6. The Server Accessory sends the changed information from the audit file to the Client.

Automatically Closing Audit Files

As with all DATABridge Accessories, the Server Accessory relies on closed audit files to get updated DMSII data. The except is if you are running DATABridge Plus or the Engine parameter Read Active Audit is set to true, in which case the Server Accessory can access information in the current audit file. For information on controlling when audit files are closed for a particular DMSII database, see AuditTimer Utility. To close an audit file manually, see Audit Close Utility.

Using Filtered Audit Files

You can have the Server Accessory read audit files that only contain the DMSII data specific for a DATABridge Client. These audit files are “pre-filtered” by the Tanker Accessory. To use the Tanker Accessory to pre-filter audit files for the Server Accessory, see Tanker Accessory.

DATABridge Client Access

Server Accessory must be running for a DATABridge Client to connect to it. If it is not running, the DATABridge Client tries to connect until it eventually times out.