nginx upstream for broadcasting update messages ?

[Ashish S]

Hi,

I have 2 memcache boxes behind nginx.  For reads, the upstream module
lets me round-robin between the backend memcache boxes. I want the
updates to go to all 2 memcache boxes. My question is, what is the
best way to broadcast the updates to the backend?  Is there a
reference implementation of some module which does similar stuff
(broadcast)?

Thanks
Ashish