DNS Lookup Bypass for Host Groups

New Features › CA Process Automation Service Pack 04.1.01 › DNS Lookup Bypass for Host Groups

DNS Lookup Bypass for Host Groups

To improve performance of identifying an operator target that is expressed as a host name or IP address, the following property has been added to the Properties tab for Domain and Environments.

Lookup DNS when matching target in Host Groups?

Formerly, the processing behavior was as if this option was enabled. Now that the option is surfaced in the UI, you can disable the option and bypass DNS lookups.

By default, this field is set to “Enabled” for the Domain, and “Inherit from Domain” for each Environment. "Inherit from Domain" means that the Domain setting is used when resolving Host Groups in any environment. These settings match the behavior implemented in earlier versions of CA Process Automation.

While setting this option to Enabled allows users to freely mix the use of IP addresses and host names, the resulting processing can incur significant overhead. Compare the required processing summarized on the following table:

	Target is host name	Target is IP address
Enabled	Performs a DNS lookup for the hostname and retrieves all associated IP addresses. Attempts to match the host name to a Host Group’s list of host name patterns. Attempts to match each of its IP addresses to a Host Group’s list of IP address ranges. If a match is found, runs the operator on the target.	Performs a DNS lookup for the IP address and retrieves the hostname. Attempts to match the IP address to a Host Group’s list of IP address ranges. Attempts to match each of its host names to a Host Group’s list of host name patterns. If a match is found, runs the operator on the target.
Disabled	Attempts to match the host name to a Host Group's list of host name patterns. If a match is found, runs the operator on the target.	Attempts to match the IP address to a Host Group's list of IP address ranges. If a match is found, runs the operator on the target.

Note that the "Disabled" setting incurs the risk of not finding a match if the target is expressed as an IP address but the Host Group identifies this same host with a host name pattern. Similarly, CA Process Automation would not find a target expressed as a host name if the Host Group list identifies this host within a specified subnet.