So I stripped out the number of clients experiment path information. It is unclear if I can only show horizontal scaling by also spawning many client requests all working at once. So that is why I stripped that information out to distill what our original attempt was at how to show horizontal scaling.
I did tests comparing 1, 2, 10, 20, 50, 100 clients spawned all querying. Performance on 2 nodes starts to degrade from 10 clients on. I saw similar behavior on 4 nodes but haven't done the official runs on that yet. When I tried to grab the list of tokens assigned and populate it in the cassandra.yaml I never got it right. I basically did the command and it was outputting 256 tokens on each node and comma separated. So I tried taking that string and setting that as the value to initial_token but the node wouldn't start up. Not sure if I maybe had a carriage return in there and that was the problem. And if I do that do I need to do more than comment out num_tokens? Thanks, Diane On Thu, Jul 17, 2014 at 6:58 PM, Robert Coli <rc...@eventbrite.com> wrote: > On Thu, Jul 17, 2014 at 3:21 PM, Diane Griffith <dfgriff...@gmail.com> > wrote: > >> So do partitions equate to tokens/vnodes? >> > > A partition is what used to be called a "row". > > Each individual token in the token ring can contain a partition, which you > request using the token as the key. > > A "token range" is the space between two tokens. > > >> If so we had configured all cluster nodes/vms with num_tokens: 256 >> instead of setting init_token and assigning ranges. I am still not getting >> why in Cassandra 2.0, I would assign my own ranges via init_token and this >> was based on the documentation and even this blog item >> <http://www.datastax.com/dev/blog/virtual-nodes-in-cassandra-1-2> that >> made it seem right for us to always configure our cluster vms with >> num_tokens: 256 in the cassandra.yaml file. >> > > If you are using vnodes and don't want to try to figure out what ideally > random token ranges for them are, you should, generally : > > 1) start the node with num_tokens set to a value greater than 1 > 2) once succesffully bootstrapped, dump all node tokens with : > > nodetool info -T | grep Token | awk '{print $3}' | paste -s -d, > > 3) put list from 2) in initial_token list in cassandra.yaml > 4) (optional) restart and verify that your node has the tokens you expect > > So given that I was assuming the partitions were such that it wasn't a >> problem. Is that an incorrect assumption and something to dig into more? >> > > How many client threads do you have? Your OP suggested a low number, which > will not have good results in terms of throughput? > > =Rob > >
