HP-UX SNAplus2 R7 Administration Guide

Basic Configuration Tasks
Configuring Client/Server Functions
4 Basic Configuration Tasks
This chapter provides an overview of configuration tasks and explains how to configure the SNAplus2 node. It also
explains how to configure master and backup servers when SNAplus2 is used in a client/server environment.
4.1 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.
Note
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.
Note
You cannot directly indicate which node acts as the master server; the master server is
selected based on the order in which nodes are added to the configuration server list. If
you wish to move a server to the top of the list, remove all other nodes from the list and
then add them again.
IYou can also use the following administration commands to query, add, and delete configuration servers:
query_sna_net
Lists the servers in the file.
add_backup
Adds a new server to the end of the list.
delete_backup
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