鲁春利的工作笔记，谁说程序员不能有文艺范？
Flume从指定目录读取数据，通过memory作为channel，然后讲数据写入到hdfs。
Spooling Directory Source（http://flume.apache.org/FlumeUserGuide.html#spooling-directory-source）
Memory Channel（http://flume.apache.org/FlumeUserGuide.html#memory-channel）
HDFS Sink（http://flume.apache.org/FlumeUserGuide.html#hdfs-sink）
Flume配置文件
# vim agent-hdfs.conf
# write data to hdfs
agent.sources = sd-source
agent.channels = mem-channel
agent.sinks = hdfs-sink
# define source
agent.sources.sd-source.type = spooldir
agent.sources.sd-source.spoolDir = /opt/flumeSpool
agent.sources.sd-source.fileHeader = true
# define channel
agent.channels.mem-channel.type = memory
# define sink
agent.sinks.hdfs-sink.type = hdfs
agent.sinks.hdfs-sink.hdfs.path = hdfs://nnode:8020/flume/webdata
# assemble
agent.sources.sd-source.channels = mem-channel
agent.sinks.hdfs-sink.channel = mem-channel
说明：/opt/flumeSpool目录需要提前创建，否则flume检测不到该目录，会有错误提示。
启动Agent
[hadoop@nnode flume1.6.0]$ bin/flume-ng agent --conf conf --name agent --conf-file conf/agent-hdfs.conf -Dflume.root.logger=INFO,console
拷贝数据到/opt/flumeSpool目录下
cp /usr/local/hadoop2.6.0/logs/* /opt/flumeSpool
Flume检测到该目录下数据变化，并会自动写入到HDFS
查看HDFS上flume目录
[hadoop@nnode flume1.6.0]$ hdfs dfs -ls -R /flume/
drwxr-xr-x - hadoop hadoop 0 2015-11-21 16:55 /flume/webdata
-rw-r--r-- 2 hadoop hadoop 2568 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836223
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836224
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836225
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836226
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836227
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836228
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836229
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836230
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836231
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836232
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836233
-rw-r--r-- 2 hadoop hadoop 2163 2015-11-21 16:50 /flume/webdata/FlumeData.1448095836234
查看文件
说明：
通过Flume往hdfs写入数据时，默认格式（hdfs.fileType）为SequenceFile，无法直接查看；若希望保存为文本格式，则可以指定hdfs.fileType为DataStream。
查看flumeSpool目录
[root@nnode flumeSpool]# ll
total 3028
-rw-r--r-- 1 root root 227893 Nov 21 16:50 hadoop-hadoop-journalnode-nnode.log.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-journalnode-nnode.out.1.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-journalnode-nnode.out.2.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-journalnode-nnode.out.COMPLETED
-rw-r--r-- 1 root root 1993109 Nov 21 16:50 hadoop-hadoop-namenode-nnode.log.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-namenode-nnode.out.1.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-namenode-nnode.out.2.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-namenode-nnode.out.COMPLETED
-rw-r--r-- 1 root root 169932 Nov 21 16:50 hadoop-hadoop-zkfc-nnode.log.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-zkfc-nnode.out.1.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-zkfc-nnode.out.2.COMPLETED
-rw-r--r-- 1 root root 718 Nov 21 16:50 hadoop-hadoop-zkfc-nnode.out.COMPLETED
说明：Flume处理万文件后默认是不删除的，但是会标记该文件已经被flume处理过了，如果处理后无需对文件保留可以通过Source指定删除策略：
deletePolicy never When to delete completed files: never or immediate