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From Michael Shuler <>
Subject Re: Load balancing issue with virtual nodes
Date Thu, 24 Apr 2014 14:37:42 GMT
On 04/24/2014 09:14 AM, DuyHai Doan wrote:
>   My customer has a cluster with 2 nodes only. I've set virtual nodes so
> future addition of new nodes will be easy.

with RF=?

>   Now, after some benching tests with massive data insert, I can see
> with "htop" that one node has its CPU occupation up to 60% and the other
> only around 10%

This would make sense if the keyspace is RF=1 and the client is 
connecting to one node. This also makes sense if the KS is RF=2 and the 
client is connecting to one node.

>   The massive insertion workload consist of random data and random
> string (20 chars) as partition key so in theory, the Murmur3 partitioner
> should dispatch then evenly between both nodes...
>   Is there any existing JIRA related to load balancing issue with vnodes ?

vnode != node

Clients connect to nodes - real servers with a network connection. 
Vnodes are internal to how C* distributes data in the cluster and have 
nothing to do with network connections of the nodes. Load balancing 
client connections is at the node/network level and how the 
client/driver is configured to distribute network connections - has 
nothing to do with vnodes.


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