func newClient(timeout time.Duration) exchanger.Exchanger {
clients := make([]exchanger.Exchanger, 2)
for i, proto := range [...]string{"udp", "tcp"} { // See RFC5966
clients[i] = &dns.Client{
Net: proto,
DialTimeout: timeout,
ReadTimeout: timeout,
WriteTimeout: timeout,
}
}
return exchanger.Decorate(
exchanger.While(truncated, clients...),
exchanger.Recursion(3, exchanger.Recurse),
exchanger.ErrorLogging(logging.Error),
exchanger.Instrumentation(logging.CurLog.NonMesosRecursed),
)
}
func exchangers(timeout time.Duration, protos ...string) map[string]exchanger.Exchanger {
exs := make(map[string]exchanger.Exchanger, len(protos))
for _, proto := range protos {
exs[proto] = exchanger.Decorate(
&dns.Client{
Net: proto,
DialTimeout: timeout,
ReadTimeout: timeout,
WriteTimeout: timeout,
},
exchanger.ErrorLogging(logging.Error),
exchanger.Instrumentation(
logging.CurLog.NonMesosForwarded,
logging.CurLog.NonMesosSuccess,
logging.CurLog.NonMesosFailed,
),
)
}
return exs
}