flume的配置详解

Flume：
=====================
    Flume是一种分布式的、可靠的、可用的服务，可以有效地收集、聚合和移动大量的日志数据。
    它有一个基于流数据的简单而灵活的体系结构。
    它具有健壮性和容错能力，具有可调的可靠性机制和许多故障转移和恢复机制。
    它使用一个简单的可扩展数据模型，允许在线分析应用程序。

    

    source：源    
        对channel而言，相当于生产者，通过接收各种格式数据发送给channel进行传输

    channel：通道
        相当于数据缓冲区，接收source数据发送给sink

    sink：沉槽
        对channel而言，相当于消费者，通过接收channel数据通过指定数据类型发送到指定位置



Event：
===============
    flume传输基本单位：
        head + body
        
    

flume安装：
================
    1、解压
    2、符号链接
    3、配置环境变量并使其生效
    4、修改配置文件
        1)重命名flume-env.ps1.template为flume-env.ps1
        2)重命名flume-env.sh.template为flume-env.sh
        3)修改flume-env.sh，配置jdk目录,添加
            export JAVA_HOME=/soft/jdk

    5、flume 查看版本
         flume-ng version

        

flume使用：
=========================
    //flume可以将配置文件写在zk上

    //flume运行命令
    flume-ng agent -n a1 -f xxx.conf    /flume-ng agent -n xx -f xxx.conf

    agent:    a1
    source:    s1
    channel:c1
    sink:    n1

    使用方法：
        1、编写配置文件r_nc.conf
            # 将agent组件起名
            a1.sources = r1
            a1.sinks = k1
            a1.channels = c1

            # 配置source
            a1.sources.r1.type = netcat
            a1.sources.r1.bind = localhost
            a1.sources.r1.port = 8888

            # 配置sink
            a1.sinks.k1.type = logger

            # 配置channel
            a1.channels.c1.type = memory
            a1.channels.c1.capacity = 1000
            a1.channels.c1.transactionCapacity = 100

            # 绑定channel-source, channel-sink
            a1.sources.r1.channels = c1
            a1.sinks.k1.channel = c1

        2、启动flume，指定配置文件
            flume-ng agent -n a1 -f r_nc.conf

        3、启动另一个会话，进行测试
            nc localhost 8888


    //用户手册
        http://flume.apache.org/FlumeUserGuide.html

后台运行程序：
=============================================

    ctrl + z :将程序放在后台运行 =====> [1]+  Stopped                 flume-ng agent -n a1 -f r_nc.conf

    通过 bg %1 的方式将程序后台运行

    通过jobs查看后台任务

    通过  fg %1 的方式将程序放在前台运行

 

flume:
    海量日志数据的收集、聚合和移动


    flume-ng agent -n a1 -f xxx.conf


    source
        相对于channel是生产者    //netcat
    channel
        类似于缓冲区        //memory
    sink
        相对于channel是消费者    //logger

    
Event: 
    header + body
    k v     data


source:
============================================
    1、序列(seq)源：多用作测试
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = seq
        # 总共发送的事件个数
        a1.sources.r1.totalEvents = 1000    

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1
    
    2、压力(stress)源:多用作负载测试
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = org.apache.flume.source.StressSource
        # 单个事件大小,单位：byte
        a1.sources.r1.size = 10240
        # 事件总数
        a1.sources.r1.maxTotalEvents = 1000000

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    3、滚动目录(Spooldir)源：监听指定目录新文件产生，并将新文件数据作为event发送
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = spooldir
        # 设置监听目录
        a1.sources.r1.spoolDir = /home/centos/spooldir

        # 通过以下配置指定消费完成后文件后缀
        #a1.sources.r1.fileSuffix = .COMPLETED 

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1


    4、exec源    //通过执行linux命令产生新数据
            //典型应用 tail -F (监听一个文件,文件增长的时候，输出追加数据)
            //不能保证数据完整性，很可能丢失数据

        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = exec
        # 配置linux命令
        a1.sources.r1.command = tail -F /home/centos/readme.txt

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    5、Taildir源        //监控目录下文件
                //文件类型可通过正则指定
                //有容灾机制

        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = TAILDIR
        # 设置source组 可设置多个
        a1.sources.r1.filegroups = f1
        # 设置组员的监控目录和监控文件类型,使用正则表示,只能监控文件
        a1.sources.r1.filegroups.f1 = /home/centos/taildir/.*

        # 设置定位文件的位置
        # a1.sources.r1.positionFile     ~/.flume/taildir_position.json

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1


sink：
====================================
    1、fileSink    //多用作数据收集
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888

        # 配置sink
        a1.sinks.k1.type = file_roll
        # 配置目标文件夹
        a1.sinks.k1.sink.directory = /home/centos/file
        # 设置滚动间隔，默认30s，设为0则不滚动，成为单个文件
        a1.sinks.k1.sink.rollInterval = 0

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    2、hdfsSink        //默认以seqFile格式写入
                //k：LongWritable
                //v: BytesWritable
                //
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888
        
        # 配置sink
        a1.sinks.k1.type = hdfs
        # 配置目标文件夹
        a1.sinks.k1.hdfs.path = /flume/events/%y-%m-%d/
        # 配置文件前缀
        a1.sinks.k1.hdfs.filePrefix = events-
        # 滚动间隔，秒
        a1.sinks.k1.hdfs.rollInterval = 0
        # 触发滚动文件大小，byte
        a1.sinks.k1.hdfs.rollSize = 1024
        # 配置使用本地时间戳
        a1.sinks.k1.hdfs.useLocalTimeStamp = true
        # 配置输出文件类型，默认SequenceFile
        # DataStream文本格式,不能设置压缩编解码器
        # CompressedStream压缩文本格式，需要设置编解码器
        a1.sinks.k1.hdfs.fileType = DataStream


        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    3、hiveSink：        //hiveserver帮助：hive --service help
                //1、hive --service metastore 启动hive的metastore服务，metastore地址：thrift://localhost:9083
                //2、将hcatalog的依赖放在/hive/lib下，cp hive-hcatalog* /soft/hive/lib    (位置/soft/hive/hcatalog/share/hcatalog)
                //3、创建hive事务表
                //SET hive.support.concurrency=true;                                  
                  SET hive.enforce.bucketing=true;                                    
                  SET hive.exec.dynamic.partition.mode=nonstrict;                     
                  SET hive.txn.manager=org.apache.hadoop.hive.ql.lockmgr.DbTxnManager;
                  SET hive.compactor.initiator.on=true;                               
                  SET hive.compactor.worker.threads=1;
                  
                //create table myhive.weblogs(id int, name string, age int)
                  clustered by(id) into 2 buckets                                         
                  row format delimited                                                          
                  fields terminated by '\t'                                                     
                  stored as orc                                                                 
                  tblproperties('transactional'='true');                                        


        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888

        # 配置sink
        a1.sinks.k1.type = hive
        a1.sinks.k1.hive.metastore = thrift://127.0.0.1:9083
        a1.sinks.k1.hive.database = myhive
        a1.sinks.k1.hive.table = weblogs
        a1.sinks.k1.useLocalTimeStamp = true
        #输入格式，DELIMITED和json
        #DELIMITED    普通文本
        #json        json文件
        a1.sinks.k1.serializer = DELIMITED
        #输入字段分隔符,双引号
        a1.sinks.k1.serializer.delimiter = ","
        #输出字段分隔符,单引号
        a1.sinks.k1.serializer.serdeSeparator = '\t'
        #字段名称，","分隔，不能有空格
        a1.sinks.k1.serializer.fieldnames =id,name,age

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    4、hbaseSink            //SimpleHbaseEventSerializer将rowKey和col设置了默认值，不能自定义
                    //RegexHbaseEventSerializer可以手动指定rowKey和col字段名称

        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888
        
        # 配置sink
        a1.sinks.k1.type = hbase
        a1.sinks.k1.table = flume_hbase
        a1.sinks.k1.columnFamily = f1
        a1.sinks.k1.serializer = org.apache.flume.sink.hbase.RegexHbaseEventSerializer

        
        # 配置col正则手动指定
        # rowKeyIndex手动指定rowKey，索引以0开头
        a1.sinks.k1.serializer.colNames = ROW_KEY,name,age
        a1.sinks.k1.serializer.regex = (.*),(.*),(.*)
        a1.sinks.k1.serializer.rowKeyIndex=0

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    
    5、asynchbaseSink        //异步hbaseSink
                    //异步机制，写入速度快
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888
        
        # 配置sink
        a1.sinks.k1.type = asynchbase
        a1.sinks.k1.table = flume_hbase
        a1.sinks.k1.columnFamily = f1
        a1.sinks.k1.serializer = org.apache.flume.sink.hbase.SimpleAsyncHbaseEventSerializer

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1
        

channel：缓冲区
=====================================
    1、memorychannel
        a1.channels.c1.type = memory
        # 缓冲区中存留的最大event个数
        a1.channels.c1.capacity = 1000
        # channel从source中每个事务提取的最大event数
        # channel发送给sink每个事务发送的最大event数
        a1.channels.c1.transactionCapacity = 100

    2、fileChannel：    //检查点和数据存储在默认位置时，当多个channel同时开启
                //会导致文件冲突，引发其他channel会崩溃
        
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels = c1
        a1.channels.c1.type = file
        a1.channels.c1.checkpointDir = /home/centos/flume/checkpoint
        a1.channels.c1.dataDirs = /home/centos/flume/data

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1


    memoryChannel：快速，但是当设备断电，数据会丢失
    
    FileChannel：  速度较慢，即使设备断电，数据也不会丢失


Avro 
===============================================
    source
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = avro
        a1.sources.r1.bind = 0.0.0.0
        a1.sources.r1.port = 4444

        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

    ***********************************************************************************************    
    *启动avro客户端，发送数据：                                      *
    *    flume-ng avro-client -H localhost -p 4444 -R ~/avro/header.txt -F ~/avro/user0.txt    *
    *                 指定ip                   指定端口 指定header文件      指定数据文件          *
    ***********************************************************************************************


    sink
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = TAILDIR
        a1.sources.r1.filegroups = f1
        a1.sources.r1.filegroups.f1 = /home/centos/taildir/.*

        # 配置sink
        a1.sinks.k1.type = avro
        a1.sinks.k1.bind = 192.168.23.101
        a1.sinks.k1.port = 4444


        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1
        
        



Flume跃点：
=====================================
    1、将s101的flume发送到其他节点
        xsync.sh /soft/flume
        xsync.sh /soft/apache-flume-1.8.0-bin/

    2、切换到root用户，分发环境变量文件
        su root
        xsync.sh /etc/profile
        exit

    3、配置文件
        1)配置s101    //hop.conf
            设置source:avro
            设置sink： hdfs

            # 将agent组件起名
            a1.sources = r1
            a1.sinks = k1
            a1.channels = c1

            # 配置source
            a1.sources.r1.type = avro
            a1.sources.r1.bind = 0.0.0.0
            a1.sources.r1.port = 4444

            # 配置sink
            a1.sinks.k1.type = hdfs
            a1.sinks.k1.hdfs.path = /flume/hop/%y-%m-%d/
            a1.sinks.k1.hdfs.filePrefix = events-
            a1.sinks.k1.hdfs.rollInterval = 0
            a1.sinks.k1.hdfs.rollSize = 1024
            a1.sinks.k1.hdfs.useLocalTimeStamp = true
            a1.sinks.k1.hdfs.fileType = DataStream

            # 配置channel
            a1.channels.c1.type = memory
            a1.channels.c1.capacity = 1000
            a1.channels.c1.transactionCapacity = 100

            # 绑定channel-source, channel-sink
            a1.sources.r1.channels = c1
            a1.sinks.k1.channel = c1


        2)配置s102-s104        //hop2.conf
            设置source:taildir
            设置sink： avro

            # 将agent组件起名
            a1.sources = r1
            a1.sinks = k1
            a1.channels = c1

            # 配置source
            a1.sources.r1.type = TAILDIR
            a1.sources.r1.filegroups = f1
            a1.sources.r1.filegroups.f1 = /home/centos/taildir/.*

            # 配置sink
            a1.sinks.k1.type = avro
            a1.sinks.k1.hostname = 192.168.23.101
            a1.sinks.k1.port = 4444


            # 配置channel
            a1.channels.c1.type = memory
            a1.channels.c1.capacity = 1000
            a1.channels.c1.transactionCapacity = 100

            # 绑定channel-source, channel-sink
            a1.sources.r1.channels = c1
            a1.sinks.k1.channel = c1

    4、在s102-s104创建~/taildir文件夹
        xcall.sh "mkdir ~/taildir"

    
    5、启动s101的flume
        flume-ng agent -n a1 -f /soft/flume/conf/hop.conf

    6、分别启动s102-s104的flume,并将其放在后台运行
        flume-ng agent -n a1 -f /soft/flume/conf/hop2.conf &

    
    7、进行测试，分别在s102-s104的taildir中创建数据，观察hdfs数据情况
        s102]$ echo 102 > taildir/1.txt 
        s103]$ echo 103 > taildir/1.txt
        s104]$ echo 104 > taildir/1.txt

    
interceptor：拦截器
==================================
    是source端组件：负责修改或删除event
    每个source可以配置多个拦截器    ===> interceptorChain

    

    1、Timestamp Interceptor    //时间戳拦截器    + header

        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888
        # 给拦截器起名
        a1.sources.r1.interceptors = i1
        # 指定拦截器类型
        a1.sources.r1.interceptors.i1.type = timestamp


        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1

        
    2、Static Interceptor    //静态拦截器    + header

    3、Host Interceptor    //主机拦截器    + header

    4、设置拦截器链：
        
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1
        a1.channels = c1

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888

        a1.sources.r1.interceptors = i1 i2 i3
        a1.sources.r1.interceptors.i1.type = timestamp
        a1.sources.r1.interceptors.i2.type = host
        a1.sources.r1.interceptors.i3.type = static
        a1.sources.r1.interceptors.i3.key = location
        a1.sources.r1.interceptors.i3.value = NEW_YORK


        # 配置sink
        a1.sinks.k1.type = logger

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1
        a1.sinks.k1.channel = c1
    


channel selector：通道挑选器
====================================
    是source端组件：负责将event发送到指定的channel，相当于分区
        
    当一个source设置多个channel时，默认以副本形式向每个channel发送一个event拷贝

    
    1、replication副本通道挑选器    //默认挑选器，source将所有channel发送event副本
                    //设置source x 1, channel x 3, sink x 3 
                    //    nc       memory    file
    
        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1 k2 k3
        a1.channels = c1 c2 c3

        # 配置source
        a1.sources.r1.type = netcat
        a1.sources.r1.bind = localhost
        a1.sources.r1.port = 8888
        a1.sources.r1.selector.type = replicating

        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        a1.channels.c2.type = memory
        a1.channels.c2.capacity = 1000
        a1.channels.c2.transactionCapacity = 100

        a1.channels.c3.type = memory
        a1.channels.c3.capacity = 1000
        a1.channels.c3.transactionCapacity = 100

        
        # 配置sink
        a1.sinks.k1.type = file_roll
        a1.sinks.k1.sink.directory = /home/centos/file1
        a1.sinks.k1.sink.rollInterval = 0

        a1.sinks.k2.type = file_roll
        a1.sinks.k2.sink.directory = /home/centos/file2
        a1.sinks.k2.sink.rollInterval = 0

        a1.sinks.k3.type = file_roll
        a1.sinks.k3.sink.directory = /home/centos/file3
        a1.sinks.k3.sink.rollInterval = 0

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1 c2 c3
        a1.sinks.k1.channel = c1
        a1.sinks.k2.channel = c2
        a1.sinks.k3.channel = c3


    
    2、Multiplexing 多路复用通道挑选器    //选择avro源发送文件
                        
                        
                        
                        

        # 将agent组件起名
        a1.sources = r1
        a1.sinks = k1 k2 k3
        a1.channels = c1 c2 c3
        
        # 配置source
        a1.sources.r1.type = avro
        a1.sources.r1.bind = 0.0.0.0
        a1.sources.r1.port = 4444
        # 配置通道挑选器
        a1.sources.r1.selector.type = multiplexing
        a1.sources.r1.selector.header = country
        a1.sources.r1.selector.mapping.CN = c1
        a1.sources.r1.selector.mapping.US = c2
        a1.sources.r1.selector.default = c3
        
        # 配置channel
        a1.channels.c1.type = memory
        a1.channels.c1.capacity = 1000
        a1.channels.c1.transactionCapacity = 100

        a1.channels.c2.type = memory
        a1.channels.c2.capacity = 1000
        a1.channels.c2.transactionCapacity = 100

        a1.channels.c3.type = memory
        a1.channels.c3.capacity = 1000
        a1.channels.c3.transactionCapacity = 100

        
        # 配置sink
        a1.sinks.k1.type = file_roll
        a1.sinks.k1.sink.directory = /home/centos/file1
        a1.sinks.k1.sink.rollInterval = 0

        a1.sinks.k2.type = file_roll
        a1.sinks.k2.sink.directory = /home/centos/file2
        a1.sinks.k2.sink.rollInterval = 0

        a1.sinks.k3.type = file_roll
        a1.sinks.k3.sink.directory = /home/centos/file3
        a1.sinks.k3.sink.rollInterval = 0

        # 绑定channel-source, channel-sink
        a1.sources.r1.channels = c1 c2 c3
        a1.sinks.k1.channel = c1
        a1.sinks.k2.channel = c2
        a1.sinks.k3.channel = c3


        1、创建file1 file2 file3文件夹，家目录
            mkdir file1 file2 file3

        2、创建文件夹country，并放入头文件和数据
            创建头文件CN.txt、US.txt、OTHER.txt 
                CN.txt ===> country CN              
                US.txt ===> country US              
                OTHER.txt ===> country OTHER   
            
            创建数据 1.txt 
                1.txt ====> helloworld

        3、运行flume
            flume-ng agent -n a1 -f /soft/flume/selector_multi.conf

        4、运行Avro客户端
            flume-ng avro-client -H localhost -p 4444 -R ~/country/US.txt -F ~/country/1.txt    ===> 查看file2
            flume-ng avro-client -H localhost -p 4444 -R ~/country/CN.txt -F ~/country/1.txt    ===> 查看file1
            flume-ng avro-client -H localhost -p 4444 -R ~/country/OTHER.txt -F ~/country/1.txt    ===> 查看file3


        
sinkProcessor
=================================
    sink Runner 运行一个 sink Group

    sink Group 是由一个或多个 sink 构成

    sink Runner 告诉 sink Group 处理下一批 event

    sink Group 含有一个 sink Processor , 负责指定一个 sink 来处理这批数据


    2、failover 容灾    //将所有sink设置一个优先级
                //数量越大，优先级越高
                //当数据传入时，优先级最高的sink负责处理
                //当sink挂掉，次高优先级的sink被激活，继续处理数据
                //channel和sink必须一对一

        a1.sources = r1
        a1.sinks = s1 s2 s3
        a1.channels = c1 c2 c3

        # Describe/configure the source
        a1.sources.r1.type = seq

        a1.sinkgroups = g1
        a1.sinkgroups.g1.sinks = s1 s2 s3
        a1.sinkgroups.g1.processor.type = failover
        a1.sinkgroups.g1.processor.priority.s1 = 5
        a1.sinkgroups.g1.processor.priority.s2 = 10
        a1.sinkgroups.g1.processor.priority.s3 = 15
        a1.sinkgroups.g1.processor.maxpenalty = 10000

        # Describe the sink
        a1.sinks.s1.type = file_roll
        a1.sinks.s1.sink.directory = /home/centos/file1
        a1.sinks.s2.type = file_roll
        a1.sinks.s2.sink.directory = /home/centos/file2
        a1.sinks.s3.type = file_roll
        a1.sinks.s3.sink.directory = /home/centos/file3

        # Use a channel which buffers events in memory
        a1.channels.c1.type = memory
        a1.channels.c2.type = memory
        a1.channels.c3.type = memory

        # Bind the source and sink to the channel
        a1.sources.r1.channels = c1 c2 c3
        a1.sinks.s1.channel = c1
        a1.sinks.s2.channel = c2
        a1.sinks.s3.channel = c3




Event事件是由Source端封装输入数据的字节数组得来的
    Event event = EventBuilder.withBody(body);



Sink中的process方法返回两种状态：
    1、READY    //一个或多个event成功分发
    2、BACKOFF    //channel中没有数据提供给sink
        

flume中事务的生命周期：
    
    tx.begin()    //开启事务，之后执行操作
    tx.commit()    //提交事务，操作完成后由此提交
    tx.rollback()    //回滚事务，出现异常可以采取回滚措施
    tx.close()    //关闭事务，最后一定要关闭事务