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From Ryan Svihla>
Subject Re: Network transfer to one node twice as others
Date Wed, 22 Apr 2015 14:26:07 GMT
Totally depends on the load balancing policy of your driver, your data model, consistently
level and you’re replication factor. The default token aware policy for the DataStax java
driver up to 2.1.4 and 2.0.9 would largely behave this way if you combined it with a hot partition,
and all other languages of the DataStax driver to my knowledge behave the same way today.

If you’re using the DataStax driver go ahead and change the load balancing policy to something
like DCAwareRoundRobin only and see if the result is different. 

Honestly this is probably not a question for the dev mailing list, or even the Cassandra user
mailing list but likely for whatever driver you’re using.

- Ryan

> On Apr 22, 2015, at 9:16 AM, Anishek Agarwal <> wrote:
> Nope not using thrift
> On 22-Apr-2015 7:24 pm, "Benedict Elliott Smith" <>
> wrote:
>> If you're connecting via thrift, all your traffic is most likely being
>> routed to just one node, which then communicates with the other nodes for
>> you.
>> On Wed, Apr 22, 2015 at 6:11 AM, Anishek Agarwal <>
>> wrote:
>>> Forwarding it here, someone with Cassandra internals knowledge can help
>> may
>>> be....
>>> Additionally, i observe the same behavior for reads too where Network
>> read
>>> from one node is twice than other two..
>>> ---------- Forwarded message ----------
>>> From: Anishek Agarwal <>
>>> Date: Tue, Apr 21, 2015 at 5:15 PM
>>> Subject: Network transfer to one node twice as others
>>> To: "" <>
>>> Hello,
>>> We are using cassandra 2.0.14 and have a cluster of 3 nodes. I have a
>>> writer test (written in java) that runs 50 threads to populate data to a
>>> single table in a single keyspace.
>>> when i look at the "iftop"  I see that the amount of network transfer
>>> happening on two nodes is same but on one of the nodes its almost 2ice as
>>> the other two, Any reason that would be the case ?
>>> Thanks
>>> Anishek

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