【Flume学习之一】Flume简介

环境

　　apache-flume-1.6.0

Flume是分布式日志收集系统。可以将应用产生的数据存储到任何集中存储器中，比如HDFS,HBase；同类工具：Facebook Scribe，Apache chukwa，淘宝Time Tunnel

应用场景图

一、Flume核心组件
1、Event： 一个数据单元，消息头和消息体组成。（Events可以是日志记录、 avro 对象等。）
Flume的数据流由事件(Event)贯穿始终。事件是Flume的基本数据单位，它携带日志数据(字节数组形式)并且携带有头信息，这些Event由Agent外部的Source生成，当Source捕获事件后会进行特定的格式化，然后Source会把事件推入(单个或多个)Channel中。你可以把Channel看作是一个缓冲区，它将保存事件直到Sink处理完该事件。Sink负责持久化日志或者把事件推向另一个Source。

2、Agent
Flume运行的核心是Agent。Flume以agent为最小的独立运行单位，一个agent就是一个JVM，它是一个完整的数据收集工具，含有三个核心组件，分别是source、 channel、 sink。通过这些组件， Event 可以从一个地方流向另一个地方，如下图所示。

3、Source
Source是数据的收集端，负责将数据捕获后进行特殊的格式化，将数据封装到事件（event） 里，然后将事件推入Channel中。 Flume提供了很多内置的Source， 支持 Avro， log4j， syslog 和 http post(body为json格式)。可以让应用程序同已有的Source直接打交道，如AvroSource，SyslogTcpSource。 如果内置的Source无法满足需要， Flume还支持自定义Source。

4、Channel
Channel是连接Source和Sink的组件，大家可以将它看做一个数据的缓冲区（数据队列），它可以将事件暂存到内存中也可以持久化到本地磁盘上， 直到Sink处理完该事件。介绍两个较为常用的Channel， MemoryChannel和FileChannel。

5、Sink
Sink从Channel中取出事件，然后将数据发到别处，可以向文件系统、数据库、 hadoop、hbase存数据， 也可以是其他agent的Source。在日志数据较少时，可以将数据存储在文件系统中，并且设定一定的时间间隔保存数据。

二、Flume 安装

1、解压 apache-flume-1.6.0-bin.tar.gz

[root@node101 src]# tar -zxvf apache-flume-1.6.-bin.tar.gz -C /usr/local/

2、配置jdk路径

[root@node101 conf]# cd /usr/local/apache-flume-1.6.-bin/conf && mv flume-env.sh.template flume-env.sh
[root@node101 conf]# vi flume-env.sh
export JAVA_HOME=/usr/local/jdk1..0_65

注意：JAVA_OPTS 配置 如果我们传输文件过大 报内存溢出时 需要修改这个配置项

3、配置环境变量

[root@node101 apache-flume-1.6.-bin]# vi /etc/profile

[root@node101 bin]# source /etc/profile

4、验证安装是否成功

[root@node101 bin]# flume-ng version
Flume 1.6.
Source code repository: https://git-wip-us.apache.org/repos/asf/flume.git
Revision: 2561a23240a71ba20bf288c7c2cda88f443c2080
Compiled by hshreedharan on Mon May  :: PDT
From source with checksum b29e416802ce9ece3269d34233baf43f

三、简单测试示例

1、flume agent配置文件

############################################################
# Name the components on this agent
a1.sources = r1
a1.sinks = k1
a1.channels = c1

# Describe/configure the source
a1.sources.r1.type = netcat
a1.sources.r1.bind = localhost
a1.sources.r1.port = 

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

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

# Bind the source and sink to the channel
a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1
############################################################

Memory Chanel 配置:
capacity：默认该通道中最大的可以存储的event数量是100，
trasactionCapacity：每次最大可以source中拿到或者送到sink中的event数量也是100
keep-alive：event添加到通道中或者移出的允许时间
byte**：即event的字节量的限制，只包括eventbody

2、启动flume
flume-ng agent --conf /usr/local/apache-flume-1.6.0-bin/conf --conf-file /usr/local/apache-flume-1.6.0-bin/conf/option1 --name a1 -Dflume.root.logger=INFO,console

注意：参数的数序不要打乱 否则启动失败或卡住
--name  或 -n 指定agent的名字
--conf 或 -c 指定配置目录
--conf-file 或 -f 指定配置文件名字
-Dflume.root.logger 指定flume日志显示的级别和输出到控制台

[root@node101 conf]# flume-ng agent --conf /usr/local/apache-flume-1.6.-bin/conf --conf-file /usr/local/apache-flume-1.6.-bin/conf/option1 --name a1 -Dflume.root.logger=INFO,console
Info: Sourcing environment configuration script /usr/local/apache-flume-1.6.-bin/conf/flume-env.sh
Info: Including Hive libraries found via () for Hive access
+ exec /usr/local/jdk1..0_80/bin/java -Xmx20m -Dflume.root.logger=INFO,console -cp '/usr/local/apache-flume-1.6.0-bin/conf:/usr/local/apache-flume-1.6.0-bin/lib/*:/lib/*' -Djava.library.path= org.apache.flume.node.Application --conf-file /usr/local/apache-flume-1.6.-bin/conf/option1 --name a1
-- ::, (lifecycleSupervisor--) [INFO - org.apache.flume.node.PollingPropertiesFileConfigurationProvider.start(PollingPropertiesFileConfigurationProvider.java:)] Configuration provider starting
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.PollingPropertiesFileConfigurationProvider$FileWatcherRunnable.run(PollingPropertiesFileConfigurationProvider.java:)] Reloading configuration file:/usr/local/apache-flume-1.6.-bin/conf/option1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:)] Added sinks: k1 Agent: a1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:)] Processing:k1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:)] Processing:k1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.conf.FlumeConfiguration.validateConfiguration(FlumeConfiguration.java:)] Post-validation flume configuration contains configuration for agents: [a1]
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.AbstractConfigurationProvider.loadChannels(AbstractConfigurationProvider.java:)] Creating channels
-- ::, (conf-file-poller-) [INFO - org.apache.flume.channel.DefaultChannelFactory.create(DefaultChannelFactory.java:)] Creating instance of channel c1 type memory
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.AbstractConfigurationProvider.loadChannels(AbstractConfigurationProvider.java:)] Created channel c1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.source.DefaultSourceFactory.create(DefaultSourceFactory.java:)] Creating instance of source r1, type netcat
-- ::, (conf-file-poller-) [INFO - org.apache.flume.sink.DefaultSinkFactory.create(DefaultSinkFactory.java:)] Creating instance of sink: k1, type: logger
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.AbstractConfigurationProvider.getConfiguration(AbstractConfigurationProvider.java:)] Channel c1 connected to [r1, k1]
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.Application.startAllComponents(Application.java:)] Starting new configuration:{ sourceRunners:{r1=EventDrivenSourceRunner: { source:org.apache.flume.source.NetcatSource{name:r1,state:IDLE} }} sinkRunners:{k1=SinkRunner: { policy:org.apache.flume.sink.DefaultSinkProcessor@71ae13c0 counterGroup:{ name:null counters:{} } }} channels:{c1=org.apache.flume.channel.MemoryChannel{name: c1}} }
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.Application.startAllComponents(Application.java:)] Starting Channel c1
-- ::, (lifecycleSupervisor--) [INFO - org.apache.flume.instrumentation.MonitoredCounterGroup.register(MonitoredCounterGroup.java:)] Monitored counter group for type: CHANNEL, name: c1: Successfully registered new MBean.
-- ::, (lifecycleSupervisor--) [INFO - org.apache.flume.instrumentation.MonitoredCounterGroup.start(MonitoredCounterGroup.java:)] Component type: CHANNEL, name: c1 started
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.Application.startAllComponents(Application.java:)] Starting Sink k1
-- ::, (conf-file-poller-) [INFO - org.apache.flume.node.Application.startAllComponents(Application.java:)] Starting Source r1
-- ::, (lifecycleSupervisor--) [INFO - org.apache.flume.source.NetcatSource.start(NetcatSource.java:)] Source starting
-- ::, (lifecycleSupervisor--) [INFO - org.apache.flume.source.NetcatSource.start(NetcatSource.java:)] Created serverSocket:sun.nio.ch.ServerSocketChannelImpl[/127.0.0.1:]

3、使用Telnet测试

[root@node101 ~]# telnet localhost
Trying ::...
telnet: connect to address ::: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
hello
OK
wjy
OK
haha
OK
^]
telnet> quit
Connection closed.
[root@node101 ~]# 

flume控制台：

-- ::, (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:)] Event: { headers:{} body:   6C 6C 6F 0D                               hello. }
-- ::, (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:)] Event: { headers:{} body:  6A  0D                                     wjy. }
-- ::, (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:)] Event: { headers:{} body:     0D                                  haha. }

注意：先启动flume 44444 然后再telenet，否则Connection refused

退出: 按组合键 ctrl+]  出现

^]

telnet>

再输入quit即可退出

CentOS6.5安装telnet命令

参考：

Apache Flume使用手册

Flume概念与原理

Flume原理解析
Flume构建日志采集系统