Perhaps the best strategy is to have the datastax java-driver do this and I just wait or each result individually. This will give me parallel dispatch.
On Fri, Jul 25, 2014 at 11:40 AM, Graham Sanderson <gra...@vast.com> wrote: > Of course the driver in question is allowed to be smarter and can do so if > use use a ? parameter for a list or even individual elements > > I'm not sure which if any drivers currently do this but we plan to combine > this with token aware routing in our scala driver in the future > > Sent from my iPhone > > On Jul 25, 2014, at 1:14 PM, DuyHai Doan <doanduy...@gmail.com> wrote: > > Nope. Select ... IN() sends one request to a coordinator. This coordinator > dispatch the request to 50 nodes as in your example and waits for 50 > responses before sending back the final result. As you can guess this > approach is not optimal since the global request latency is bound to the > slowest latency among 50 nodes. > > On the other hand if you use async feature from the native protocol, you > client will issue 50 requests in parallel and the answers arrive as soon as > they are fetched from different nodes. > > Clearly the only advantage of using IN() clause is ease of query. I would > advise to use IN() only when you have a "few" values, not 50. > > > On Fri, Jul 25, 2014 at 8:08 PM, Kevin Burton <bur...@spinn3r.com> wrote: > >> Say I have about 50 primary keys I need to fetch. >> >> I'd like to use parallel dispatch. So that if I have 50 hosts, and each >> has record, I can read from all 50 at once. >> >> I assume cassandra does the right thing here ? I believe it does… at >> least from reading the docs but it's still a bit unclear. >> >> Kevin >> >> -- >> >> Founder/CEO Spinn3r.com >> Location: *San Francisco, CA* >> blog: http://burtonator.wordpress.com >> … or check out my Google+ profile >> <https://plus.google.com/102718274791889610666/posts> >> <http://spinn3r.com> >> >> > -- Founder/CEO Spinn3r.com Location: *San Francisco, CA* blog: http://burtonator.wordpress.com … or check out my Google+ profile <https://plus.google.com/102718274791889610666/posts> <http://spinn3r.com>
