Hi, Thanks for the quick reply. Sorry if my question was not clear. I tried to provide more info.
________________________________ > Date: Tue, 22 Nov 2011 20:43:33 -0500 > Subject: Re: DataCenters each with their own local data source > From: md.jahangi...@gmail.com > To: user@cassandra.apache.org > > Distributing writes to all D.C.s? or reads? Writes should be distributed within the local D.C. Reads could be D.C. specific, or could ask a question to all D.C. instances. > > If each D.C. has data specific to that particular geo, why do you have > to read from remote D.C. ? Users want to aggregate information from different D.C. > > You can easily incorporate logic to re-direct operation(either > write/read) to appropriate(local) D.C. In the middle tier, or does Cassandra have explicit support for that? > > Still wondering why you want to do so?. Am assuming you want to store > data as per I.P. (geo location data) ..Anyways, it was not very clear > from your question what you are trying to do. Each data center has a local data source that we can't afford to replicate across data centers. Users may be interested in querying multiple data centers. > > Thanks, > Jahangir Mohammed. > > On Tue, Nov 22, 2011 at 7:57 PM, Mathieu Lalonde > <mrlalo...@live.ca<mailto:mrlalo...@live.ca>> wrote: > > > Hi, > > I am wondering if Cassandra's features and datacenter awareness can > help me with my scalability problems. > > Suppose that I have a 10-20 Data centers, each with their own local > (massive) source of time series data. I would like: > - to avoid replication across data centers (this seems doable based on: > http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Different-KeySpaces-for-different-nodes-in-the-same-ring-td5096393.html#a5096568 > > ) > - writes for local data to be done on the local data center (not sure > about that one) > - reads from a master data center to any remote data centers (not sure > about that one either) > > It sounds like I am trying to use Cassandra in a very different way > that it was intended to be used. > Should I simply have a middle-tier that takes care of distributing > reads to multiple data centers and treat each data center as its own > autonomous cluster? > > Thanks! > Matt > > >
