I have tried to retrieve the token range and slice in 4, but the response i get for the following code is different on each node:
TokenRange[] tokenRanges = unwrapTokenRanges(metadata.getTokenRanges(keyspaceName, localHost)).toArray(new TokenRange[0]); On each node, the 1024 token ranges are different, so Im not sure how to do the split. e.g. from node 1 Token ranges - start:-5144720537407094184 end:-5129226025397315327 This token range isn't returned by node 2, 3 or 4. Thanks again Frank On 19 January 2017 at 12:19, Benjamin Roth <benjamin.r...@jaumo.com> wrote: > If you have 4 Nodes with RF 4 then all data is on every node. So you can > just slice the whole token range into 4 pieces and let each node process 1 > slice. > Determining local ranges also only helps if you read with CL_ONE. > > 2017-01-19 13:05 GMT+01:00 Frank Hughes <frankhughes...@gmail.com>: > >> Hello there, >> >> I'm running a 4 node cluster of Cassandra 3.9 with a replication factor >> of 4. >> >> I want to be able to run a java process on each node only selecting a 25% >> of the data on each node, >> so i can process all of the data in parallel on each node. >> >> What is the best way to do this with the java driver ? >> >> I was assuming I could retrieve the token ranges for each node and page >> through the data using these ranges, but this includes the replicated data. >> I was hoping there was away of only selecting the data that a node is >> responsible for and avoiding the replicated data. >> >> Many thanks for any help and guidance, >> >> Frank Hughes >> > > > > -- > Benjamin Roth > Prokurist > > Jaumo GmbH · www.jaumo.com > Wehrstraße 46 · 73035 Göppingen · Germany > Phone +49 7161 304880-6 <+49%207161%203048806> · Fax +49 7161 304880-1 > <+49%207161%203048801> > AG Ulm · HRB 731058 · Managing Director: Jens Kammerer >
