Every external automation or process under the control of a process agent must have a specified host. The host is defined either in the process agent configuration file, as part of a process definition, or in the external automation in the ObjectServer.
The default process agent configuration file is $NCHOME/omnibus/etc/nco_pa.conf.
The process agent can handle host names and addresses that are specified in different formats. This is necessary because the host details are often extracted from data elements in an event or alert. Depending on the source of the alert, a host might be specified as an IP address or a host name, or in some other format.
At startup, the process agent builds an internal list of all the local host's network interfaces, resolving the name of each network interface that it finds. This list enables the process agent to map a given host to any number of valid local interface host names. For example, the default host name on a machine might be "testbox" but a request might be sent to the process agent asking for a process to be run on "testbox.company.com", or the request might specify the IPv4 or IPv6 address of the host. In each case, the process agent must recognize that the host referred to is the host that the process is running on.
If host name resolution (using DNS or Active Directory, for example) is slow or is not available, the process agent might be slow to start because it must wait for a timeout to occur on all the host names that cannot be resolved. Also, any later process request that uses an unknown host name will not be run. Where a process is configured to start as a Windows service, and problems with DNS resolution cause it to start slowly, the service can timeout on startup. All such failures are logged. System administrators can use this information to fix any network configuration issues on affected hosts.