As I am also using a JS filter and fear the performance and load consequences, how does one go about writing an erlang filter?
-SIvan On Fri, Aug 6, 2010 at 11:55 PM, J Chris Anderson <[email protected]> wrote: > > On Aug 6, 2010, at 1:38 PM, Talib Sharif wrote: > >> Hey All, >> >> Do people have experience with the scalability and performance of the >> _changes api in general, and especially when using with filters? >> >> How many connections can be kept open? >> > > If you use a JavaScript filter, you will have more limited concurrency that > with an Erlang filter, as the JS filters run in their own OS process. CouchDB > tries to be reasonably efficient with these, but they are still much more > heavyweight than the Erlang ones. > >> And is the changes api function of size/updates/total_no_documents? >> > > I think the _changes API should have no scalability issues, as the wall you > will hit long before running an (Erlang) changes filter will be the insert / > update rate of the database itself. > > If you were to say, make thousands of concurrent changes requests, with > varying since=Seq params, that would be the worst case, so you can test that > work load if you want to find boundaries conditions. (Bottleneck here would > be for disk IO reads I think). > > Chris > >> Thanks, >> Talib > >
