MapReduce - Hadoop: The Definitive Guide - page 92

[ 28 ] For an exposition of the scalability limits of HDFS, see Konstantin V. Shvachko, “HDFS Scalability:
The Limits to Growth” , April 2010.
[ 29 ] In Hadoop 1, the name for this property was fs.default.name . Hadoop 2 introduced many new
property names, and deprecated the old ones (see Which Properties Can I Set? ) . This topic uses the new
property names.
[ 30 ] In Hadoop 2 and later, there is a new filesystem interface called FileContext with better handling of
multiple filesystems (so a single FileContext can resolve multiple filesystem schemes, for example) and
a cleaner, more consistent interface. FileSystem is still more widely used, however.
[ 31 ] The text is from The Quangle Wangle's Hat by Edward Lear.
[ 32 ] At the time of this writing, Hadoop is not suited for running across data centers.
[ 33 ] In Hadoop 1.x, hflush() was called sync() , and hsync() did not exist.
[ 34 ] Even for a single file copy, the distcp variant is preferred for large files since hadoop fs -cp copies
the file via the client running the command.