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From Hefeng Yuan <hfy...@rhapsody.com>
Subject Calculate number of nodes required based on data
Date Tue, 06 Sep 2011 19:53:19 GMT
Hi,

Is there any suggested way of calculating number of nodes needed based on data? 

We currently have 6 nodes (each has 8G memory) with RF5 (because we want to be able to survive
loss of 2 nodes).
The flush of memtable happens around every 30 min (while not doing compaction), with ~9m serialized
bytes.

The problem is that we see more than 3 nodes doing compaction at the same time, which slows
down the application.
(tried to increase/decrease compaction_throughput_mb_per_sec, not helping much)

So I'm thinking probably we should add more nodes, but not sure how many more to add. 
Based on the data rate, is there any suggested way of calculating number of nodes required?

Thanks,
Hefeng
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