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
