It will work for correctness, but give you a very inaccurate view of performance,.
-Tupshin On Apr 16, 2014 6:05 AM, "Vivek Mishra" <mishra.v...@gmail.com> wrote: > Thanks Mark and Tuphsin. > > So on single node, if i set consistency level to SERIAL and create a > keyspace with RF=1? Would that work? > > > -Vivek > > > On Wed, Apr 16, 2014 at 6:32 PM, Mark Reddy <mark.re...@boxever.com>wrote: > >> The Paxos protocol used for CAS operations will always use at least a >> consistency level effectively equivalent to QUORUM (called SERIAL) when >> writing, even if you explicitly specify a lower level, e.g. ANY or ONE. >> Setting consistency level to ALL will make the write execute on all >> replicas if the condition is met, but the comparison itself is executed >> against a QUORUM number of nodes. As a result, a write operation with ALL >> consistency level that fails to meet the specified check may not throw an >> Exception, even if some replica nodes are not accessible. >> >> >> >> On Wed, Apr 16, 2014 at 2:00 PM, Tupshin Harper <tups...@tupshin.com>wrote: >> >>> No, but you do need a quorum of nodes. >>> >>> >>> http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_config_consistency_c.html >>> >>> SERIAL >>> A write must be written conditionally to the commit log and memory table >>> on a quorum of replica nodes. >>> >>> Used to achievelinearizable >>> consistency<http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_tunable_consistency_c.html#concept_ds_f4h_hwx_zj>for >>> lightweight transactions by preventing unconditional updates. >>> On Apr 16, 2014 5:56 AM, "Vivek Mishra" <mishra.v...@gmail.com> wrote: >>> >>>> Thanks Mark. does this mean with RF=3, all 3 nodes must be up and >>>> running for CAS updates? >>>> >>>> -Vivek >>>> >>>> >>>> On Wed, Apr 16, 2014 at 6:22 PM, Mark Reddy <mark.re...@boxever.com>wrote: >>>> >>>>> create keyspace twitter with replication = {'class':'SimpleStrategy', >>>>>> 'replication_factor' : 3} >>>>> >>>>> >>>>> Your replication factor is your issue here, you have a single node and >>>>> a RF=3. For a single node setup your RF should be 1. You can find more >>>>> info >>>>> about replication here: >>>>> http://www.datastax.com/documentation/cassandra/2.0/cassandra/architecture/architectureDataDistributeReplication_c.html >>>>> >>>>> >>>>> On Wed, Apr 16, 2014 at 1:44 PM, Vivek Mishra >>>>> <mishra.v...@gmail.com>wrote: >>>>> >>>>>> Hi, >>>>>> Mine is a simple case. Running on single node only. Keyspace is: >>>>>> >>>>>> create keyspace twitter with replication = {'class':'SimpleStrategy', >>>>>> 'replication_factor' : 3} >>>>>> >>>>>> -Vivek >>>>>> >>>>>> >>>>>> On Wed, Apr 16, 2014 at 1:27 AM, Tupshin Harper >>>>>> <tups...@tupshin.com>wrote: >>>>>> >>>>>>> Please provide your keyspace definition, and the output of >>>>>>> "nodetool ring" >>>>>>> >>>>>>> -Tupshin >>>>>>> On Apr 15, 2014 3:52 PM, "Vivek Mishra" <mishra.v...@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi, >>>>>>>> I am trying Cassandra light weight transaction support with >>>>>>>> Cassandra 2.0.4 >>>>>>>> >>>>>>>> cqlsh:twitter> create table user(user_id text primary key, namef >>>>>>>> text); >>>>>>>> cqlsh:twitter> insert into user(user_id,namef) values('v','ff') if >>>>>>>> not exists; >>>>>>>> >>>>>>>> *Unable to complete request: one or more nodes were unavailable.* >>>>>>>> >>>>>>>> Any suggestions? >>>>>>>> >>>>>>>> -Vivek >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >> >
