*1. If you only have 3 production servers, Cassandra may not do much for you. You will probably only care if you have lots more servers. 3 servers is a reasonable minimum for a test / dev environment* At How many servers does cassandra start really performing? or how many servers is an ideal setup say for a game 10? On Tue, Jul 14, 2009 at 3:00 AM, Mark Robson <[email protected]> wrote:
> > > 2009/7/14 <[email protected]> > >> I have 3 productions servers, is it better to >> >> A. start the cassandra in one node and add other seeds later >> or >> B. Start cassandra in all the 3 nodes >> >> if i do A, when i later add 2 nodes ,will cassandra pick up the other two >> nodes and start distributing the loads fairly > > > My guess would be: > > 1. If you only have 3 production servers, Cassandra may not do much for > you. You will probably only care if you have lots more servers. 3 servers is > a reasonable minimum for a test / dev environment. > > 2. All of your servers should have static IPs. You should make sure that at > least 2-3 of them are unlikely to go away, and put those in as seeds, the > other servers can come and go and change IP address etc. > > I would set up 2-3 servers which I expected to be unlikely to go away (i.e. > they won't be taken out any time soon), and code their IPs into the seeds. > The other servers can use those to find each other. > > Also your ops team should then be aware, that if they get rid of those > "seed" servers, at some point new boxes should be deployed to take over > those IPs so there are always at least two actively running Cassandra, that > way your other nodes can find one another. > > Having only one seed server would place a single point of failure, which > you don't want. > > If you have a segmented network (e.g. routed, different racks, different > datacentres with VPN between them etc), you could put two seeds in each > segment, which would make discovery tolerant of a partition. > > But having said that, it's relatively inconvenient to have a large number > of seeds as you'd need to keep deploying new config files to all your nodes. > > Mark > -- Bidegg worlds best auction site http://bidegg.com
