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From Tupshin Harper <tups...@tupshin.com>
Subject Re: Any way to get a list of per-node token ranges using the DataStax Java driver?
Date Sat, 01 Mar 2014 00:48:48 GMT
For the first question, try "select * from system.peers"

http://www.datastax.com/documentation/cql/cql_using/use_query_system_c.html?pagename=docs&version=1.2&file=cql_cli/using/query_system_tables

For the second, there is a JMX and nodetool command, but I'm not aware of
any way to get it directly through CQL.

http://www.datastax.com/documentation/cassandra/2.0/cassandra/tools/toolsGetEndPoints.html

-Tupshin


On Fri, Feb 28, 2014 at 1:27 PM, Clint Kelly <clint.kelly@gmail.com> wrote:

> Hi everyone,
>
> I've been working on a rewrite of the Cassandra InputFormat for Hadoop 2
> using the DataStax Java driver instead of the Thrift API.
>
> I have a prototype working now, but there is one bit of code that I have
> not been able to replace with code for the Java driver.  In the
> InputFormat#getSplits method, the old code has a call like the following:
>
>           map = client.describe_ring(ConfigHelper.getInputKeyspace(conf));
>
> This gets a list of the distinct token ranges for the Cassandra cluster.
>
> The rest of "getSplits" then takes these key ranges, breaks them up into
> subranges (to match the user-specified input split size), and then gets the
> replica nodes for the various token ranges (as the locations for the
> splits).
>
> Does anyone know how I can do the following with the native protocol?
>
>    - Get the distinct token ranges for the C* cluster
>    - Get the set of replica nodes for a given range of tokens?
>
> I tried looking around in Cluster and Metadata, among other places, in the
> API docs, but I didn't see anything that looked like it would do what I
> want.
>
> Thanks!
>
> Best regards,
> Clint
>

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