直接對同機台上另一個帳號下命令
su hdfs -c '~/hdfs/sbin/stop-dfs.sh'
使用hadoop streaming
bin/hadoop jar share/hadoop/tools/lib/hadoop-streaming-2.7.1.jar \
-input /usr/ctfan/input01 \
-output /usr/ctfan/output/folder \
-mapper mapper.py \
-reducer reducer.py \
-file ~/ctfan/pyStreaming/mapper.py \
-file ~/ctfan/pyStreaming/reducer.py
mapper.py
#!/usr/bin/env python
import sys
for line in sys.stdin:
line = line.strip()
words = line.split()
for word in words:
print '%s\t%s' % (word, 1)
reducer.py
#!/usr/bin/env python
from operator import itemgetter
import sys
current_word = None
current_count = 0
word = None
for line in sys.stdin:
line = line.strip()
word, count = line.split('\t', 1)
try:
count = int(count)
except ValueError:
continue
if current_word == word:
current_count += count
else:
if current_word:
print '%s\t%s' % (current_word, current_count)
current_count = count
current_word = word
if current_word == word:
print '%s\t%s' % (current_word, current_count)
單機測試streaming命令
echo 'a b c a b' | ./mapper.py | sort -k1,1 | ./reducer.py
參考網頁
hadoop官方文件Michael G. Noll's Blog
