Hi, This question is for hdfs-user not mapreduce-user, as such I have removed them.
Yes HDFS does not allow ramdom writes. I suggest your read this doc: http://hadoop.apache.org/common/docs/current/hdfs_design.html Specifically the "Assumptions and Goals" section. Here are two ways to get around this design assumption: 1) Write updated copies of the record with a new time stamp and then dedup based on a unique key and timestamp. 2) Use HBase Cheers, Brock On Sat, Mar 17, 2012 at 9:09 AM, Hassen Riahi <hassen.ri...@cern.ch> wrote: > Hi, > > We are trying to execute a mapper making a random access during writing > files. It seems that HDFS supports only random seek during read and not > during write (neither the file modification). Is it right? we are using > hadoop-0.20. If it is the case, is there any plan to support it in the > future? > > The limitation described above makes the mapper failing to write files. Is > there any suggestions to bypass this limitation? such as write files in a > temp area and copying them then to HDFS? > > Thanks for the help, > Hassen > -- Apache MRUnit - Unit testing MapReduce - http://incubator.apache.org/mrunit/
