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Alejandro Abdelnur commented on MAPREDUCE-2293: ----------------------------------------------- I'm OK if '_' it is not allowed as namedoutput name or multiname name? The reason is that there must be a separator character to avoid filename collisions. If there is not such character, the the following 2 named outputs could be configured for a job: * named-output/multi-name FOO with multi-name BAR produces a file named FOO_BAR-##### * name-output/no-multi-name FOO_BAR produces a file named FOO_BAR-##### And that would mean that data written to 2 logical locations end up mixed in the same physical location. > Enhance MultipleOutputs to allow additional characters in the named output > name > ------------------------------------------------------------------------------- > > Key: MAPREDUCE-2293 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-2293 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Affects Versions: 0.21.0 > Reporter: David Rosenstrauch > Assignee: Harsh J > Priority: Minor > Fix For: 0.23.0 > > Attachments: mapreduce.mo.removecheck.r1.diff, > mapreduce.mo.removecheck.r2.diff > > > Currently you are only allowed to use alpha-numeric characters in a named > output name in the MultipleOutputs class. This is a bit of an onerous > restriction, as it would be extremely convenient to be able to use non > alpha-numerics in the name too. (E.g., a '.' character would be very > helpful, so that you can use the named output name for holding a file > name/extension. Perhaps '-' and a '_' characters as well.) > The restriction seems to be somewhat arbitrary - it appears to be only > enforced in the checkTokenName method. (Though I don't know if there's any > downstream impact by loosening this restriction.) > Would be extremely helpful/useful to have this fixed though! -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira