Thanks a lot for you suggestions, I will check the virtual keyspace solution - btw, currently I am using Thrift client with Pycassa, I am not familiar with Hector - does it mean we'll need to move to Hector client?
I thought of using keyspaces for each tenant, but I dont understand how to define the whole cluster. Meaning, assuming the tenants are distributed (replicated) across hundreds of DCs each consists of tens of racks and servers, so can I define a single cassandra cluster for all the servers? it does not seem to be reasonable , this is the reason I thought of sepearating the clusters. Please let me know how would you solve it? Thanks, Miriam On Thu, Feb 17, 2011 at 10:30 PM, Nate McCall <n...@datastax.com> wrote: > Hector's virtual keyspaces would work well for what you describe. Ed > Anuff, who added this feature to Hector, showed me a working > multi-tennancy based app the other day and it worked quite well. > > On Thu, Feb 17, 2011 at 1:44 PM, Norman Maurer <nor...@apache.org> wrote: > > Maybe you could make use of "Virtual Keyspaces". > > > > See this wiki for the idea: > > https://github.com/rantav/hector/wiki/Virtual-Keyspaces > > > > Bye, > > Norman > > > > 2011/2/17 Frank LoVecchio <fr...@isidorey.com>: > >> Why not just create some sort of ACL on the client side and use one > >> Keyspace? It's a lot less management. > >> > >> On Thu, Feb 17, 2011 at 12:34 PM, Mimi Aluminium < > mimi.alumin...@gmail.com> > >> wrote: > >>> > >>> Hi, > >>> I really need your help in this matter. > >>> I will try to simplify my problem and ask specific questions > >>> > >>> I am thinking of solving the multi-tenancy problem by providing a > separate > >>> cluster per each tenant. Does it sound reasonable? > >>> I can end-up with one node belongs to several clusters. > >>> Does Cassandra support several clusters per node? Does it mean several > >>> Cassandra daemons on each node? Do you recommend doing that ? what is > the > >>> overhead? is there any link that explain how to do that? > >>> > >>> Thanks a lot, > >>> Mimi > >>> > >>> > >>> On Wed, Feb 16, 2011 at 6:43 PM, Mimi Aluminium < > mimi.alumin...@gmail.com> > >>> wrote: > >>>> > >>>> Hi, > >>>> We are interested in a multi-tenancy environment, that may consist of > up > >>>> to hundreds of data centers. The current design requires cross rack > and > >>>> cross DC replication. Specifically, the per-tenant CFs will be > replicated 6 > >>>> times: in three racks, with 2 copies inside a rack, the racks will be > >>>> located in at least two different DCs. In the future other replication > >>>> policies will be considered. The application will decide where (which > racks > >>>> and DC) to place each tenant's replicas. and it might be that one > rack can > >>>> hold more than one tenant. > >>>> > >>>> Separating each tenant in a different keyspace, as was suggested > >>>> in previous mail thread in this subject, seems to be a good approach > >>>> (assuming the memtable problem will be solved somehow). > >>>> But then we had concern with regard to the cluster size. > >>>> and here are my questions: > >>>> 1) Given the above, should I define one Cassandra cluster that hold > all > >>>> the DCs? sounds not reasonable given hundreds DCs tens of servers in > each > >>>> DC etc. Where is the bottleneck here? keep-alive messages, the gossip, > >>>> request routing? what is the largest number of servers a cluster can > bear? > >>>> 2) Now assuming that I can create the per-tenant keyspace only for > the > >>>> servers that in the three racks where the replicas are held, does > such > >>>> definition reduces the messaging transfer among the other servers. > Does > >>>> Cassandra optimizes the message transfer in such case? > >>>> 3) Additional possible solution was to create a separate clusters per > >>>> each tenant. But it can cause a situation where one server has to run > two or > >>>> more Cassandra's clusters. Can we run more than one cluster in > parallel, > >>>> does it means two cassandra daemons / instances on one server? what > will be > >>>> the overhead? do you have a link that explains how to deal with it? > >>>> > >>>> Please can you help me to decide which of these solution can work or > you > >>>> are welcome to suggest something else. > >>>> Thanks a lot, > >>>> Mimi > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >> > >> > >> > >> -- > >> Frank LoVecchio > >> Senior Software Engineer | Isidorey, LLC > >> Google Voice +1.720.295.9179 > >> isidorey.com | facebook.com/franklovecchio | franklovecchio.com > >> > > >
