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
