[avahi] limit on dbus client objects

[Brian Gerkey]

I'm developing an application that can in some cases register a large  
number of services, in the 10s or even 100s.  Because I want this  
application to run on Linux, OS X, and Windows, I'm using the Bonjour  
API.  On Linux, I use Avahi via its Bonjour compatibility layer, and  
on OS X and Windows I use mDNSResponder directly.

Using the Avahi-Bonjour layer on Linux, I quickly get errors during  
service registration that I eventually tracked down to the  
"max_connections_per_user" limit in /etc/dbus-1/system.d/avahi- 
dbus.conf (this is an Ubuntu Dapper box).  This limit defaults to 20,  
and it seems that every time I initialize a new DNSServiceRef (e.g.,  
by registering a service), it uses one of these connections.  Clearly  
I can raise this limit, but that's not a great solution because all  
of my users would have to do the same.

I don't have this problem running the exact same code under OS X with  
mDNSResponder.

Three questions:

- Is there a way to avoid this problem while still using the Bonjour  
API?  E.g., can I get the Avahi-Bonjour layer to reuse its dbus  
client connection somehow?

- If I move to the native Avahi API, will I have a similar problem  
with a single process that registers many services?

- Independent of the Zeroconf implementation that's being used, are  
there drawbacks in general to registering and browsing large numbers  
of services?

	thanks,
	brian.