hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mike Spreitzer <mspre...@us.ibm.com>
Subject Can caller mutate value after calling OutputCollector.collect(key,value) ?
Date Sun, 12 Feb 2012 20:58:43 GMT
I have a question about the contract in the org.apache.hadoop.mapred
.OutputCollector interface.  If it matters, let us say we are talking 
about Hadoop-1.0.0.  In my map or reduce method, after it calls 
output.collect(key,value), is it allowed to mutate (side effect) either 
the key or the value?

If the answer is "it depends on the OutputFormat", then what is the answer 
for the more prominent ones, such as SequenceFileFormat and 
TextOutputFormat?

Thanks,
Mike
Mime
View raw message