On Tue, Sep 27, 2011 at 11:40 AM, Dominic Tarr wrote: > is it okay to register a huge number of listeners to the changes feed? > It will open one socket / feed. So it depends on your os limits mostly. You will have to tune the backlog & fd limit for a start. > I notice that you can use a filter function, which gets passed the request > parameters, > does this mean that the filter function will be called for each doc, for > each listener on the changes feed? Yes > or are the results of each filter call cached so that it is possible to > efficiently register many listeners using the same filter function? It isn't cached in couch, but you can cache it on your applications. - benoît