Thanks, i think got the point.CAS doesn't make much sense on single node. -Vivek
On Wed, Apr 16, 2014 at 6:37 PM, Tupshin Harper <tups...@tupshin.com> wrote: > 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 >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>> >>
