Hey Jonathan, Could you give me an example ? I guess my peanut size brain is not able to comprehend it. The idea is If I have an object lets say
<tweet_id , tweet_value > Initially placed in EastCoast DC and replicated to WestCoast DC.(since RF = 2) Now, I observe that the read request for the same <tweet_id> is increasing in Ireland. The data should be automatically be replicated to Ireland DC and the next closes DC(s) (in this case it could be just the WestCoast DC) depending on the RF value. It will be awesome , if I could configure cassandra in a way to achieve the same effect. That ll subvert burden of coding the replication strategy. if not, I will probably need to code it. In that case, it will be of great help, if you could point out which methods I need to reimplement and methods I need to be very cautious while implementing it. Hopefully, I have not confused you enough. ./Rahul On Sun, Apr 13, 2014 at 10:36 PM, Jonathan Ellis <jbel...@gmail.com> wrote: > Replica placement must be determined only by the key, otherwise you > won't know where to look at read time. If your scheme is doable with > that restriction then you should be able to make it work. > > On Sun, Apr 13, 2014 at 9:20 PM, Rahul R <rahul8...@gmail.com> wrote: > > I am trying to develop a custom replication algorithm which replicates > the > > object based on its access patterns. That means, the remote replica which > > is decided by the NetworkTopologyAware Strategy will need to be > > > > 1. Dynamic in Nature (afaik, the objects are statically allocated to a > > particular node in the DHT and replica is placed to a node in a > subsequent > > node in the ring which will be mostly a node in some other DC ) . I > intend > > to change this at run time by changing the object location without > > compromising the consistency guarantees. > > > > The main motive is to place the objects closer to user. With my limited > > knowledge on cassandra, I am not sure how to achieve the same. thus, I > was > > wondering on how to implement the same by overriding > > NetworkTopologyAware< > https://github.com/QwertyManiac/cassandra-cdh4/blob/master/src/java/org/apache/cassandra/locator/NetworkTopologyStrategy.java > > > > class > > file in java, > > > > Any suggestion ? I want to know how ridiculous this idea is ? how > feasible > > is it , is there any other alternative to achieve the same ? > > > > Looking for criticisms. > > > > > > ./Rahul > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder, http://www.datastax.com > @spyced >
