Ujwal S. Setlur wrote:

>Hi,
>
>My application needs to figure out which node is
>currently the master, i.e. writable. Is there an easy
>check for that? My app's interface to the db is C
>through libpq.
>  
>
Nodes are just nodes; they have no inherent "master" or "slave" role.

You can check to see which node is the origin for a given replication
set; that would involve looking in _clusterschema.sl_set where set_id =
some set you care about.