Chapter 20: Setting Up Communications Across the Network

Each instance in a cluster can communicate with other Adaptive Servers, Open Server applications, and client software across a network. Clients can communicate with one or more servers, and servers can communicate with other servers via remote procedure calls.

Directory services contains information about the network locations of servers. Directory services contain entries for all Adaptive Servers, Backup Servers, and other server products on the network.

In the Sybase client/server environment, a client can connect with an instance if it knows where the server resides on the network and if the server supports the client’s language or character set. When a client initiates a connection, it looks in its directory services for the network location of the target server.

Directory services list the name and address of every server, including Backup Server and XP Server. When you are using a client program, and you want to connect with a particular server, the client program looks up the server name in the directory services and connects to that server.

Servers also need network information. When a server starts up, it looks in its interfaces file to determine where to listen for client connection requests. In addition, each instance can take on a client role when it makes remote procedure calls to other instances.