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From Peter Schuller <peter.schul...@infidyne.com>
Subject Re: Node added, no performance boost -- are the tokens correct?
Date Fri, 01 Apr 2011 17:15:20 GMT
> Now, I moved the tokens. I still observe that read latency deteriorated with
> 3 machines vs original one. Replication factor is 1, Cassandra version 0.7.2
> (didn't have time to upgrade as I need results by this weekend).

Read *latency* is fully expected to increase if you just add a node.
*Throughput* should increase, unless you have a workload that manages
to be more expensive on RPC than actual reads/writes.

Latency would only be improved by additional nodes under some significant load.

How are you benchmarking? Are you concurrently submitting requests to
all nodes at the same time? Try using stress.py from the Cassandra
tree as a comparison.

If you're sending one request at a time, there is no expectation at
all of a performance improvement - just a decrease in performance.

-- 
/ Peter Schuller

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