Re: Measure Latency

2011-05-25 Thread aaron morton
I can get down and dirty in the SQL Server world :) Best analogy is that cassandra is doing "high safety mode synchronous mirroring" http://msdn.microsoft.com/en-us/library/ms189852.aspx The replicating is effectively inside the Transaction commit, cassandra does not have transactions but you g

Re: Measure Latency

2011-05-25 Thread Stephan P
Thanks for the reply. I agree about the eventual consistency feature but in "addition" I'm trying to have an oversight if there is a slowness between nodes in a cluster meaning sometimes "some" network slowness won't translate in CA slowness and sometimes it will. I guess I'm looking for a process

Re: Measure Latency

2011-05-24 Thread Aaron Morton
Once the cluster has returned to the client you know the write has been committed to Consistency Level  number of nodes. i.e. If you send an insert using QUORUM consistency to a cluster with Replication Factor 3, and you get a non error response you know the write has occurred on at least 2 nodes (

Measure Latency

2011-05-24 Thread Stephan Pfammatter
What’s the recommended way of measuring latency between nodes in a cluster? By that I’m not referring to read/write latency for a given KS/CF. Basically I want to inject a row in a node A and want to see how long it takes to get to node B (assuming proper RF is set). I have already some network