Structure of Erlang MR Arg

Jeremiah Peschka jeremiah.peschka at
Thu Feb 14 10:58:41 EST 2013

Christian brought up something in the "ListKeys or MapReduce" thread that
deserves a discrete thread.

In the MapReduce Implementation docs [1], it looks like the Arg parameter
of an Erlang MR phase is not a single argument but is, in fact, a proplist
of Erlang terms, am I correct in assuming that this is the case?

And, if this is the case, would the JSON submitted to Riak look something
like this:

                  "reduce_phase_batch_size": 250

As we're mucking around in the lower levels of Corrugated Iron, I want to
make sure we're able to send the appropriate jibber jabber back to Erlang


Jeremiah Peschka - Founder, Brent Ozar Unlimited
MCITP: SQL Server 2008, MVP
Cloudera Certified Developer for Apache Hadoop
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the riak-users mailing list