On Fri, Apr 4, 2014 at 3:32 AM, Robert Coli <rc...@eventbrite.com> wrote:
> On Thu, Apr 3, 2014 at 12:20 AM, Apoorva Gaurav <apoorva.gau...@myntra.com > > wrote: > >> At the client side we are getting a latency of ~350ms, we are using >> datastax driver 2.0.0 and have kept the fetch size as 500. And these are >> coming while reading rows having ~200 columns. >> > > And you're sure that the 300ms between what cassandra reports and what > your app reports are not just network/serialization time? > We are using the datastax 2.0.0 driver. This latency is for the execute command. We already have the prepared statement cached in app layer before calling execute. > > What do you believe the latency "should" be? > If we store the same data as a json using text data type i.e (studentID int, subjectMarksJson text) we are getting a latency of ~10ms from the same client for even bigger. I understand that json is not the preferred storage for cassandra and will loose various flexibility which a proper tabular approach provides. But such a huge jump in read latency is killer. I'm pastebin-ing the histogram for json storage as well http://pastebin.com/RiW6hMb2. > > =Rob > > -- Thanks & Regards, Apoorva
