Hi Aleksey, Thanks for the response. I read through several JIRAs ( CASSANDRA-1072, CASSANDRA-2495, CASSANDRA-4775, CASSANDRA-6504, CASSANDRA-6506). I would appreciate if you can clarify my understanding of the current state of art.
I understand that the earlier design of having local shards, remote shards and logging only deltas for local shards provided good latency but suffered inconsistencies due to replays not being idempotent. Was this primarily lack of internal idempotent updates (replica-replica) or due to lack external idempotent updates (client-coordinator) ? Also, I have an additional question about the state of counters before CASSANDRA-6504 (or Counters 1.0 if you like). Does the client submit CounterUpdate<counter-name, value, timestamp> ? During the retry is the same CounterUpdate<counter-name, value, timestamp> submitted again identically as the original attempt ? When the coordinator (if it is one of the replica) OR the leader does a write propagation to the other replicas does it include the same CounterUpdate<counter-name, value, timestamp> ? Essentially, my question is: Can we identify each counter update from a client uniquely ? and does the retry use the same unique id ? Also post the implementation of CASSANDRA-6504 (or Counters 2.0 design) I understand that local and remote shards have been replaced by global shards and now counters follow a lock-read-write-unlock-replicate model. Does this guarantee that retries from clients are still idempotent ? Also, in Counters 2.0, is the CounterUpdate sent by the client an unique id ? I would appreciate your clarification on this. Thank you ! Regards, Rajath ------------------------ Rajath Subramanyam On Mon, Oct 6, 2014 at 3:38 PM, Aleksey Yeschenko <alek...@apache.org> wrote: > No, there are no unique ids per increment. That was one of the ideas > suggested in https://issues.apache.org/jira/browse/CASSANDRA-4775, but > ultimately declined. > > Read that ticket, and the one linked to it, for details. > > -- > AY > > On October 6, 2014 at 10:20:05 PM, Rajath Subramanyam (rajat...@gmail.com) > wrote: > > Hi Cassandra developers, > > I am working on a project to make counter updates idempotent. I read that > via CASSANDRA-1546 assigns unique marker ids to counter updates in 0.7.1. > Does this unique marker id hold true in the later versions too ? Or at > least in 0.8.1 ? > > Please let me know. > > Thank you ! > > Regards, > Rajath > ------------------------ > Rajath Subramanyam > >
