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Jeremy Hanna edited comment on CASSANDRA-8119 at 2/17/15 7:21 PM: ------------------------------------------------------------------ I think there's a case for LOCAL_QUORUM + ONE in another datacenter or LOCAL_QUORUM + ONE in every other datacenter. Essentially, it would be nice to guarantee that the data is persisted outside the local datacenter in a couple of forms. was (Author: jeromatron): I think there's a case for LOCAL_QUORUM + ONE in another datacenter or LOCAL_QUORUM + ONE in every other datacenter. > More Expressive Consistency Levels > ---------------------------------- > > Key: CASSANDRA-8119 > URL: https://issues.apache.org/jira/browse/CASSANDRA-8119 > Project: Cassandra > Issue Type: New Feature > Components: API > Reporter: Tyler Hobbs > > For some multi-datacenter environments, the current set of consistency levels > are too restrictive. For example, the following consistency requirements > cannot be expressed: > * LOCAL_QUORUM in two specific DCs > * LOCAL_QUORUM in the local DC plus LOCAL_QUORUM in at least one other DC > * LOCAL_QUORUM in the local DC plus N remote replicas in any DC > I propose that we add a new consistency level: CUSTOM. In the v4 (or v5) > protocol, this would be accompanied by an additional map argument. A map of > {DC: CL} or a map of {DC: int} is sufficient to cover the first example. If > we accept a special keys to represent "any datacenter", the second case can > be handled. A similar technique could be used for "any other nodes". > I'm not in love with the special keys, so if anybody has ideas for something > more elegant, feel free to propose them. The main idea is that we want to be > flexible enough to cover any reasonable consistency or durability > requirements. -- This message was sent by Atlassian JIRA (v6.3.4#6332)