Target nodes for a command

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Resource monitoring and control (RMC) is a daemon that runs on individual systems or on each node of a cluster. It provides a single management and monitoring infrastructure for individual nodes, peer domains, and management domains.

You can execute RMC and resource manager commands on a single node, on all the nodes of a peer domain, or on all the nodes of a management domain. Some commands refine this selection of nodes even further such that you can specify a subset of nodes in the peer domain or management domain. When you work in a cluster, you can also issue commands from a local node to be executed on another node.

Note: If RSCT 3.1.5.0, or later, is installed on your operating system, the RMC subsystem is not recycled on nodes when the node is brought online or taken offline from a peer domain. If the local or management scope is specified, RMC and the execution of resource manager commands are not interrupted by the peer domain transition.

The following environment variables, along with various command flags, determine the nodes that are affected by the RMC and resource manager commands that you enter.

Table 1. Environment variables that determine target nodes for a command
Environment variable	Description
CT_CONTACT	Determines the system where the session with the RMC daemon occurs. When set to a host name or IP address, the command contacts the RMC daemon on the specified host. If not set, the command contacts the RMC daemon on the local system where the command is being run.
CT_MANAGEMENT_SCOPE	Identifies the management scope. The management scope determines the set of possible target nodes for the command. The default is local scope. The valid values follow: 0 The local scope. It is either the local node or the node indicated by the CT_CONTACT environment variable. 1 The local scope. It is either the local node or the node indicated by the CT_CONTACT environment variable. 2 The peer domain scope. It is either the peer domain in which the local node is online, or the peer domain in which the node indicated by the CT_CONTACT environment variable is online. 3 The management domain scope.

Not all of the RMC and resource manager commands use these environment variables, but the ones that do might have command-line flags that you can use to override the environment variable setting or otherwise determine how the command uses the specified values.

When the scope is set to management domain scope (either through the CT_MANAGEMENT_SCOPE environment variable or through command-line options), RMC commands that are issued from the management server return information for managed nodes. Some of these nodes might also be in peer domains within the management domain.

Certain RMC class operations return information about a node's peer domain. When you perform these operations in a management domain scope, some nodes might not be in a peer domain. In these cases, the peer domain field provides only the local host name. When a local host name is provided instead of a peer domain name, the name appears in angle brackets (for example, <local_host_name>).

The Technical Reference: RSCT for AIX® and Technical Reference: RSCT for Multiplatforms guides contain complete reference information for all of the RSCT commands. The reference information contains details on how each command uses these environment variables. The same reference information can be found for any command by viewing its online man page.

Targeting nodes:: When this documentation refers a command, it focuses on the command's basic functions (such as listing a condition, starting monitoring, viewing an audit log) and does not cover targeting nodes in the body of the discussion. However, many commands can target the local node, a remote node, a group of nodes in a peer domain, an entire peer domain, a node in a management domain, and so on. Where appropriate, any information on how the particular command handles the targeting of nodes is covered in a separate Targeting Nodes note.