A basic Sybase Data Federation domain can contain just a grid domain controller (GDC). You can add servers for advanced capabilities or to increase capacity, as required. A machine that participates in a Data Federation domain generally hosts one server.
Grid domain controller (GDC): the grid server on which a Data Federation domain initially starts. The GDC has all the functionality of a grid server. A Data Federation domain must have at least one GDC.
In a Data Federation domain that is configured for failover, there are two GDCs: a primary and a secondary. The secondary GDC is a hot standby that handles requests when the primary GDC is unreachable.
Grid server: hosts the data catalog, provides authorization services for clients requesting data access, serves files shared from the local file system, caches data to improve performance, and runs data services, database operations, and queries.
This figure shows a sample deployment that uses all server types, including primary and secondary GDCs, grid servers, share servers, a proxy server and a DGAS. Users (lower right within the grid) and applications (far right) can access relational data and Web services via Data Federation services configured on the grid servers. They can access files via the DGAS using NFS or CIFS (Windows) clients. Developers can use WorkSpace Data Federation (upper left) to set up data services that integrate data from multiple sources and deliver it to users or applications on demand.
File access for NFS and Windows clients is provided by the data grid access server (DGAS). DGASes provide high-performance caching and make specified data catalog directories available to NFS (UNIX) and CIFS (Windows) clients in a secure fashion.
Extended file sharing is provided using a share server, which makes selected data stored in local file systems visible in the data catalog. Share servers are responsible for file I/O.
You can connect two Data Federation domains using proxy servers. A proxy server allows domains on opposite sides of a firewall to communicate securely with one another so that users of one domain can access data in the other.
For more information on Data Federation servers and how to deploy them, see the Data Federation Administration Guide, part of the DI Suite documentation set, which is available on the Sybase Product Manuals Web site at http://sybooks.sybase.com.
For product-related issues, contact Sybase Technical Support at 1-800-8SYBASE. Send your feedback on this help topic directly to Sybase Technical Publications: pubs@sybase.com