Hi, Are we sure that this issue was fixed in 0.17.0(or do we need to patch). I am using this version and I still see the issue?
Thanks, Deepika -----Original Message----- From: Arun C Murthy [mailto:[EMAIL PROTECTED] Sent: Tuesday, August 19, 2008 1:04 PM To: core-user@hadoop.apache.org Subject: Re: Cannot read reducer values into a list On Aug 19, 2008, at 12:17 PM, Stuart Sierra wrote: > Hello list, > Thought I would share this tidbit that frustrated me for a couple of > hours. Beware! Hadoop reuses the Writable objects given to the > reducer. For example: > Yes. http://issues.apache.org/jira/browse/HADOOP-2399 - fixed in 0.17.0. Arun > public void reduce(K key, Iterator<V> values, > OutputCollector<K, V> output, > Reporter reporter) > throws IOException { > > List<V> valueList = new ArrayList<V>(); > while (values.hasNext()) { > valueList.add(values.next()); > } > > // Say there were 10 values. valueList now contains 10 > // pointers to the same object. > } > > I assume this is done for efficiency, but a warning in the Reducer > documentation would be nice. > > -Stuart
