2、 采集文件内容到HDFS
需求分析：
采集需求：比如业务系统使用log4j生成的日志，日志内容不断增加，需要把追加到日志文件中的数据实时采集到hdfs。
同一个日志文件的内容不断增加，hdfs上该文件对应的文件的内容也要同时增加。
根据需求，首先定义以下3大要素
l 采集源，即source——监控文件内容更新 : exec ‘tail -F file’
l 下沉目标，即sink——HDFS文件系统 : hdfs sink
l Source和sink之间的传递通道——channel，可用file channel 也可以用 内存channel
定义flume的配置文件
node03开发配置文件
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin/conf
vim tail-file.conf
配置文件内容
agent1.sources = source1
agent1.sinks = sink1
agent1.channels = channel1
# Describe/configure tail -F source1
agent1.sources.source1.type = exec
agent1.sources.source1.command = tail -F /export/servers/taillogs/access_log
agent1.sources.source1.channels = channel1
#configure host for source
#agent1.sources.source1.interceptors = i1
#agent1.sources.source1.interceptors.i1.type = host
#agent1.sources.source1.interceptors.i1.hostHeader = hostname
# Describe sink1
agent1.sinks.sink1.type = hdfs
#a1.sinks.k1.channel = c1
agent1.sinks.sink1.hdfs.path = hdfs://node01:8020/weblog/flume-collection/%y-%m-%d/%H-%M
agent1.sinks.sink1.hdfs.filePrefix = access_log
agent1.sinks.sink1.hdfs.maxOpenFiles = 5000
agent1.sinks.sink1.hdfs.batchSize= 100
agent1.sinks.sink1.hdfs.fileType = DataStream
agent1.sinks.sink1.hdfs.writeFormat =Text
agent1.sinks.sink1.hdfs.rollSize = 102400
agent1.sinks.sink1.hdfs.rollCount = 1000000
agent1.sinks.sink1.hdfs.rollInterval = 60
agent1.sinks.sink1.hdfs.round = true
agent1.sinks.sink1.hdfs.roundValue = 10
agent1.sinks.sink1.hdfs.roundUnit = minute
agent1.sinks.sink1.hdfs.useLocalTimeStamp = true
# Use a channel which buffers events in memory
agent1.channels.channel1.type = memory
agent1.channels.channel1.keep-alive = 120
agent1.channels.channel1.capacity = 500000
agent1.channels.channel1.transactionCapacity = 600
# Bind the source and sink to the channel
agent1.sources.source1.channels = channel1
agent1.sinks.sink1.channel = channel1
启动flume
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin
bin/flume-ng agent -c conf -f conf/tail-file.conf -n agent1 -Dflume.root.logger=INFO,console