教你一步搭建Flume分布式日志系统

　　在前篇几十条业务线日志系统如何收集处理？中已经介绍了Flume的众多应用场景，那此篇中先介绍如何搭建单机版日志系统。

环境

　　CentOS7.0

      Java1.8

下载

　　官网下载 http://flume.apache.org/download.html

　　当前最新版  apache-flume-1.7.0-bin.tar.gz

　　下载后上传到CentOS中的/usr/local/ 文件夹中，并解压到当前文件中重命名为flume170    /usr/local/flume170

tar -zxvf apache-flume-1.7.0-bin.tar.gz

安装配置

　　修改 flume-env.sh 配置文件,主要是添加JAVA_HOME变量设置

JAVA_HOME=/usr/lib/jvm/java8

　　设置Flume的全局变量 

　　打开profile

vi /etc/profile

　　添加

export FLUME=/usr/local/flume170
export PATH=$PATH:$FLUME/bin

　　然后使环境变量生效

source /etc/profile

验证是否安装成功

flume-ng version

测试小实例

 参考网上Spool类型的示例

　　　　Spool监测配置的目录下新增的文件，并将文件中的数据读取出来。需要注意两点： 
　　　　1) 拷贝到spool目录下的文件不可以再打开编辑。 
　　　　2) spool目录下不可包含相应的子目录 
　　　　创建agent配置文件

# vi /usr/local/flume170/conf/spool.conf
a1.sources = r1
a1.channels = c1
a1.sinks = k1

# Describe/configure the source
a1.sources.r1.type = spooldir
a1.sources.r1.channels = c1
a1.sources.r1.spoolDir =/usr/local/flume170/logs
a1.sources.r1.fileHeader = true

# Use a channel which buffers events in memory
a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000
a1.channels.c1.transactionCapacity = 100

# Describe the sink
a1.sinks.k1.type = logger
a1.sinks.k1.channel = c1

　　spoolDir:设置监控的文件夹，当有文件进入时会读取文件的内容再通过sink发送，发送完成后会在文件名后加上.complete

　　启动flume agent a1

/usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/spool.conf -n a1 -Dflume.root.logger=INFO,console

　　追加一个文件到/usr/local/flume170/logs目录

# echo "spool test1" > /usr/local/flume170/logs/spool_text.log

　　在控制台，可以看到以下相关信息：

14/08/10 11:37:13 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown.
14/08/10 11:37:13 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown.
14/08/10 11:37:14 INFO avro.ReliableSpoolingFileEventReader: Preparing to move file /usr/local/flume170/logs/spool_text.log to/usr/local/flume170/logs/spool_text.log.COMPLETED 14/08/10 11:37:14 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:14 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:14 INFO sink.LoggerSink: Event: { headers:{file=/usr/local/flume170/logs/spool_text.log} body: 73 70 6F 6F 6C 20 74 65 73 74 31 spool test1 } 14/08/10 11:37:15 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:15 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:16 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:16 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown. 14/08/10 11:37:17 INFO source.SpoolDirectorySource: Spooling Directory Source runner has shutdown.

 　　出现上面的内容就表明已经可以运行了，整个安装过程很简单，主要是配置。

　　 至于分布式的需要设置source和sink。

　　如上图，将每个业务中的Flume产生的日志再用一个Flume来接收汇总，然后将汇总后的日志统一发送给KafKa作统一处理，最后保存到HDFS或HBase中。上图中，每个业务中的Flume可以做负载和主备，由此可以看出有很强的扩展性。