General Communication Facility

The General Communication Facility (GCF) manages communication among all components of Ingres. GCF has five elements:

• Name Server
• Communications Server
• Data Access Server
• Bridge Server
• General Communications Architecture

Name Server

The Name Server keeps track of all DBMS, Data Access, JDBC, Communications, Bridge, Star, Internet Communications, and Enterprise Access servers in an installation and provides user processes with the information they require to connect to local or remote installations.

How the Name Server Works

The Name Server provides information to user processes that enables a connection to a local DBMS Server. When a process wants to connect to a remote DBMS Server:

• The Name Server provides information that allows the process to first connect to a Communications Server.
• The Communications Server establishes communication with the remote DBMS Server.
• The Name Server checks regularly (the default is every five minutes) to ensure that all DBMS Servers on its list are functioning. If a server has shut down, the Name Server automatically deletes its registration.

Name Server Maintenance Utility

The Name Server Maintenance Utility (iinamu) is a part of the General Communication Facility provided by Ingres. This utility allows the system administrator to manually add servers to or delete servers from the list maintained by the Name Server, or to stop and restart the Name Server.

For more information about this utility, see the Command Reference Guide.

Communications Server

The Communications Server (iigcc) is a daemon process that provides the network communication element of the Ingres Net product. It monitors outgoing communication from local applications to remote DBMS Servers and incoming communication from remote applications to local DBMS Servers. An installation can have multiple Communications Server processes.

For more information on the Communications Server, see the Connectivity Guide.

Data Access Server

The Data Access Server enables communication between Java applets and applications and Ingres. The Data Access Server is the server component of the JDBC Driver, and also provides DBMS Server access for the Ingres .NET Data Provider. Data Access Server parameters include the maximum number of inbound sessions, client connections, connection pooling, pooling timeouts, network port, listen address, and protocol status. Configuration of the Data Access Server is done at installation and rarely requires reconfiguration.

Bridge Server

The Ingres Bridge extension enables communication between Ingres clients on one network and servers on a different type of network. Reconfiguration of the Bridge Server is rarely required.

For information on the Bridge Server's role in Ingres connectivity, see the Connectivity Guide.

General Communications Architecture

The General Communications Architecture (GCA) is the lowest level General Communications Facility Application Program Interface. The GCA maintains communication connections between processes on the same local Ingres installation. The GCA is a subroutine library that is a part of all Ingres tools, DBMS Servers, Star Servers, and the libraries associated with embedded SQL and EQUEL.