hadoop definitive guide

the processing into two phases: the map phase and the reduce phase.Each phase has key-value pairs as input and output, the types of which may be chosen by the programmer. The programmer also specifies two functions: the map function and the reduce function.Map function and reduce function input and output key-value pairs2.3 Scaling Out horizontal ScalingData FlowA MapReduce job is a unit of work that the client wants to be saved Med: it consists of the input data, the MapReduce program, and con

Give hadoop authoritative guide -- NCDC1929-2011 data Ftp://ftp.ncdc.noaa.gov/pub/data/gsod/ Command:The data are available:1) www -- http://www.ncdc.noaa.gov/cgi-bin/res40.pl? Pagew.gsod.html2) FTP -- ftp://ftp.ncdc.noaa.gov/pub/data/gsod via browser3) command line ftp:A) Enter: Open ftp.ncdc.noaa.govB) login is: ftpC) password is: your email addressD) To move to the correct subdirectory, enter:CD/pub/d