NOTE

Basic Configuration Tasks

Configuring Client/Server Functions

Configuring Client/Server Functions

This section is relevant only if you installed SNAplus2 to run in a client/server environment (with multiple SNAplus2 nodes in the same network).

Many resources, such as ports and LUs, are configured on an individual node. These are known as “node resources.”

Other resources, such as emulator user definitions, are common to all nodes; only one definition for the resource is maintained for the entire domain. Such resources are known as “domain resources.” Domain resource definitions are stored only on the master server for the domain, and are accessible from all the nodes in the domain.

A standalone SNAplus2 system has only one server; that server always acts as the master.

In a client/server environment, a server can be marked as a configuration server; SNAplus2 maintains a list of these configuration servers. The first server listed is the master server, and any other servers listed are backup servers. The servers are listed in order, so that the second server listed (the first backup server) takes over if the master server is unavailable, the third server listed (the second backup server) takes over if neither the master nor the first backup server is available, and so on.

When any of the nodes in the domain are active, the first available configuration server in the domain (the first server that can be contacted and has SNAplus2 software running) becomes the master server. If the current master becomes unavailable (because it cannot be contacted, perhaps due to a network failure, or because the SNA software running on it is stopped), the next available configuration server in the list becomes the new master.

SNAplus2 can run without a master. This happens if none of the servers in the configuration server list can be contacted. If this happens, you can view and configure node resources only on the servers that can be contacted.

Chapter 4

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