A very interesting proposal and patch for enhancing
nodetool to provide cluster latency-consistency analysis. From JIRA:
We’ve implemented Probabilistically Bounded Staleness, a new technique for predicting consistency-latency trade-offs within Cassandra. Our paper will appear in VLDB 2012, and, in it, we’ve used PBS to profile a range of Dynamo-style data store deployments at places like LinkedIn and Yammer in addition to profiling our own Cassandra deployments. In our experience, prediction is both accurate and much more lightweight than profiling and manually testing each possible replication configuration (especially in production!).
This analysis is important for the many users we’ve talked to and heard about who use “partial quorum” operation (e.g., non-QUORUM ConsistencyLevel). Should they use CL=ONE? CL=TWO? It likely depends on their runtime environment and, short of profiling in production, there’s no existing way to answer these questions.
Original title and link: Latency-Consistency Analysis ( ©myNoSQL)