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Claudio Martella commented on GIRAPH-124: ----------------------------------------- As discussed in mailing-list, there are two possible approaches on how to manage a returned Iterable<M> with more messages than the input set: a warning in the logs or an exception. We should take a decision about it. > Combiner should return Iterable<M> instead of M or null. > -------------------------------------------------------- > > Key: GIRAPH-124 > URL: https://issues.apache.org/jira/browse/GIRAPH-124 > Project: Giraph > Issue Type: Improvement > Components: graph > Affects Versions: 0.1.0 > Reporter: Claudio Martella > > Currently VertexCombiner is expected to return a single message combining the > input messages, or null in case no message should be sent. The new expected > interface should return an Iterable<M>, possibly empty. The number of > elements in the returned Iterable is supposed to be smaller than the number > of input messages, by the initial definition of a Combiner (defined as a > function to reduce I/O by combining multiple messages into 1). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira