Glossary
3-DNS® Administrator Guide Glossary-7
pool ratio
A pool ratio is a ratio weight applied to pools in a wide IP. If the Pool LB
mode is set to Ratio, the 3-DNS Controller uses each pool for load balancing
in proportion to the weight defined for the pool.
preferred method
The preferred method specifies the first load balancing mode that the 3-DNS
Controller uses to load balance a resolution request. See also alternate
method, fallback method.
principal 3-DNS
A 3-DNS that initiates metrics collection by the big3d agents and distributes
the metrics to other members of a sync group. See also receiver 3-DNS.
probe protocol
The probe protocol is the specific protocol used to probe a given path and
collect metrics information for the path. The probe protocols available on
the 3-DNS Controller are: ICMP, DNS_REV, DNS_DOT, UDP, and TCP.
The probe protocols that are available change based on the data center
server type.
prober
A prober is a specific thread of the big3d agent that is used for path probing
of a given set of paths.
prober factory
A prober factory is a utility that collects metrics data, such as round trip time
and packet rate, for a given path between a requesting LDNS and a data
center server. Prober factories are managed by the big3d agent, which
reports the path probing metrics to the 3-DNS Controller. Prober factories
can run on BIG-IP systems, EDGE-FX Caches, and GLOBAL-SITE
Controllers.
production rule
A production rule, on the 3-DNS Controller, can change system behavior
under specific operating conditions. For example, a production rule can
switch load balancing modes or can reroute network traffic to a specific set
of servers. Production rules are based on triggers such as time of day or
current network traffic load.
QOS equation
The QOS equation is the equation on which the Quality of Service load
balancing mode is based. The equation calculates a score for a given path
between a data center server and a local DNS server. The Quality of Service
mode distributes connections based on the best path score for an available
data center server. You can apply weights to the factors in the equation, such
as round trip time and completion rate.