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Date: Wed, 5 Feb 2014 15:45:20 -0500
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Subject: Question about how DataStax python driver chooses a coordinator
From: Sameer Farooqui <sameer@blueplastic.com>
To: user@cassandra.apache.org
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Does the new DataStax Python Driver 1.0.0 intelligently choose a
coordinator that is also likely to be a replica partner for that row-key
when using vnodes in C* 2.0? If so, how does it do it... just hash the
row-key and see which partition range it falls in and which node owns that
range?

Here is all the DataStax blog post says on this topic:

"When a query is executed, a list of nodes to attempt the query against is
generated. If the query fails against the first node in the list, the
second node may be used, and so on. When sending a query to a node, the
driver selects the least-utilized connection from that node's connection
pool and issues the query."

How is that list of nodes generated?


Also, does the current version of the DS Java driver also intelligently
choose a coordinator that is likely to already hold a replica of the row
key?

- SF

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<div dir=3D"ltr"><div>Does the new&nbsp;DataStax Python Driver 1.0.0 intell=
igently choose a coordinator that is also likely to be a replica partner fo=
r that row-key when using vnodes in C* 2.0? If so, how does it do it... jus=
t hash the row-key and see which partition range it falls in and which node=
 owns that range?</div>
<div><br></div><div>Here is all the DataStax blog post says on this topic:<=
/div><div><br></div>&quot;When a query is executed, a list of nodes to atte=
mpt the query against is generated. If the query fails against the first no=
de in the list, the second node may be used, and so on. When sending a quer=
y to a node, the driver selects the least-utilized connection from that nod=
e&rsquo;s connection pool and issues the query.&quot;<div>
<br></div><div>How is that list of nodes generated?</div><div><br></div><di=
v><br></div><div>Also, does the current version of the DS Java driver also =
intelligently choose a coordinator that is likely to already hold a replica=
 of the row key?</div>
<div><br></div><div>- SF</div></div>

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