[Twisted-Python] Bring multi service up gradually

[David Pratt]

Hi. I have got a number of services that am bringing together at 
startup. In the past, I have added them to a parent and started them up 
all at one time.  But now I am incorporating a service (the main 
service) that may be available from more than one address and I want to 
connect with one of these addresses first before starting the other 
services.

What I am seeking is some general advice on this since I want the 
startup to be as efficient as possible. I was thinking that quickly 
testing the addresses first, before starting any twisted service might 
help increase the odds of a quick startup. But if this fails, I will 
still need to iterate with a backoff through each address to connect the 
main service, then add the other services when the main service is 
running. Many thanks.

Regards,
David