Hi guys, Thanks for your reply. It's very helpful. I agree with Plotnik on the scaling part.
For the business logic, it sounds obvious that "it make sense to divide, i.e. metadata and really BIG data into different clusters, of course." as you mentioned. But after I think about it a bit more, what is the real reason for that if the cluster can be scaled horizontally? Each node still has the same amount of data, what is the benefit of having a separate cluster? For analytics application, it has to be on a separate cluster as Paulo pointed out. But if all of use cases are for web application (as of now) what are the drawbacks to put everything into one big cluster? Thanks. -Wei On Monday, October 14, 2013 4:15 AM, Paulo Motta <pauloricard...@gmail.com> wrote: By clusters do you mean data centers? If so, I think it depends on your use case and application requirements. For instance, if you have a web application and and analytics application (hadoop), you would want to separate your cluster in 2 different data centers (even if they're located in the same physical zone). If it's just one application then you can start with one data center and add more data centers later if needed. 2013/10/14 Plotnik, Alexey <aplot...@rhonda.ru> If you are talking about scaling: Cassandra scaling is absolutely horizontal without namenodes or other Mongo-bulshit-like intermediate daemons. And that’s why one big cluster has the same throughput as many smaller clusters. >What will you do when your small clusters will exceed it’s capacity? Cassandra >is designed for very large data so feel free to utilize it’s capabilities. > >If you are talking in terms of business logic: it make sense to divide, i.e. >metadata and really BIG data into different clusters, of course. > >From:Wz1975 [mailto:wz1...@yahoo.com] >Sent: 14 октября 2013 г. 7:20 >To: user@cassandra.apache.org > >Subject: Re: one big cluster vs multiple smaller clusters >Importance: Low > >we have choices of making one big cluster vs a few small clusters. I am trying >to get pros and cons for both options in genera. > > >Thanks. >-Wei > >Sent from my Samsung smartphone on AT&T > > >-------- Original message -------- >Subject: Re: one big cluster vs multiple smaller clusters >From: Jon Haddad <j...@jonhaddad.com> >To: user@cassandra.apache.org >CC: > > >This is a pretty vague question. What are you trying to achieve? > >On Oct 12, 2013, at 9:05 PM, Wei Zhu <wz1...@yahoo.com> wrote: > > > >Hi, >As we bring more use cases to Cassandra, we have been thinking about the best >way to host it. Let's say we will have 15 physical machines available, we can >use all of them to form a big cluster or divide them into 3 clusters with 5 >nodes each. As we will deploy to 1.2, it becomes easier to expand the cluster >with vnodes. I really don't see any good reasons to make 3 smaller clusters. >Did I miss anything obvious? > >Thanks. >-Wei > -- Paulo Ricardo -- European Master in Distributed Computing Royal Institute of Technology - KTH Instituto Superior Técnico - IST http://paulormg.com
