Flume环境部署和配置详解及案例(转)

flume是一个分布式、可靠、和高可用的海量日志采集、聚合和传输的系统。支持在日志系统中定制各类数据发送方，用于收集数据;同时，Flume提供对数据进行简单处理，并写到各种数据接受方(比如文本、HDFS、Hbase等)的能力 。
　　一、什么是Flume?
　　flume 作为 cloudera 开发的实时日志收集系统，受到了业界的认可与广泛应用。Flume 初始的发行版本目前被统称为 Flume OG（original generation），属于 cloudera。但随着 FLume 功能的扩展，Flume OG 代码工程臃肿、核心组件设计不合理、核心配置不标准等缺点暴露出来，尤其是在 Flume OG 的最后一个发行版本 0.94.0 中，日志传输不稳定的现象尤为严重，为了解决这些问题，2011 年 10 月 22 号，cloudera 完成了 Flume-728，对 Flume 进行了里程碑式的改动：重构核心组件、核心配置以及代码架构，重构后的版本统称为 Flume NG（next generation）；改动的另一原因是将 Flume 纳入 apache 旗下，cloudera Flume 改名为 Apache Flume。

flume的特点：
　　flume是一个分布式、可靠、和高可用的海量日志采集、聚合和传输的系统。支持在日志系统中定制各类数据发送方，用于收集数据;同时，Flume提供对数据进行简单处理，并写到各种数据接受方(比如文本、HDFS、Hbase等)的能力 。
　　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。

flume的可靠性
　　当节点出现故障时，日志能够被传送到其他节点上而不会丢失。Flume提供了三种级别的可靠性保障，从强到弱依次分别为：end-to-end（收到数据agent首先将event写到磁盘上，当数据传送成功后，再删除；如果数据发送失败，可以重新发送。），Store on failure（这也是scribe采用的策略，当数据接收方crash时，将数据写到本地，待恢复后，继续发送），Besteffort（数据发送到接收方后，不会进行确认）。

flume的可恢复性：
　　还是靠Channel。推荐使用FileChannel，事件持久化在本地文件系统里(性能较差)。

　　flume的一些核心概念：
Agent使用JVM 运行Flume。每台机器运行一个agent，但是可以在一个agent中包含多个sources和sinks。
Client生产数据，运行在一个独立的线程。
Source从Client收集数据，传递给Channel。
Sink从Channel收集数据，运行在一个独立线程。
Channel连接 sources 和 sinks ，这个有点像一个队列。
Events可以是日志记录、 avro 对象等。

　　Flume以agent为最小的独立运行单位。一个agent就是一个JVM。单agent由Source、Sink和Channel三大组件构成，如下图：

　　值得注意的是，Flume提供了大量内置的Source、Channel和Sink类型。不同类型的Source,Channel和Sink可以自由组合。组合方式基于用户设置的配置文件，非常灵活。比如：Channel可以把事件暂存在内存里，也可以持久化到本地硬盘上。Sink可以把日志写入HDFS, HBase，甚至是另外一个Source等等。Flume支持用户建立多级流，也就是说，多个agent可以协同工作，并且支持Fan-in、Fan-out、Contextual Routing、Backup Routes，这也正是NB之处。如下图所示:

　　二、flume的官方网站在哪里？
　　http://flume.apache.org/
　　三、在哪里下载？
　　http://www.apache.org/dyn/closer.cgi/flume/1.5.0/apache-flume-1.5.0-bin.tar.gz
　　四、如何安装？
　　　　1)将下载的flume包，解压到/home/hadoop目录中，你就已经完成了50%：）简单吧
　　　　2)修改 flume-env.sh 配置文件,主要是JAVA_HOME变量设置
root@m1:/home/hadoop/flume-1.5.0-bin# cp conf/flume-env.sh.template conf/flume-env.sh
root@m1:/home/hadoop/flume-1.5.0-bin# vi conf/flume-env.sh
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# If this file is placed at FLUME_CONF_DIR/flume-env.sh, it will be sourced
# during Flume startup.

# Enviroment variables can be set here.

JAVA_HOME=/usr/lib/jvm/java-7-oracle

# Give Flume more memory and pre-allocate, enable remote monitoring via JMX
#JAVA_OPTS="-Xms100m -Xmx200m -Dcom.sun.management.jmxremote"

# Note that the Flume conf directory is always included in the classpath.
#FLUME_CLASSPATH=""


　　　　3)验证是否安装成功
root@m1:/home/hadoop# /home/hadoop/flume-1.5.0-bin/bin/flume-ng version
Flume 1.5.0
Source code repository: https://git-wip-us.apache.org/repos/asf/flume.git
Revision: 8633220df808c4cd0c13d1cf0320454a94f1ea97
Compiled by hshreedharan on Wed May 7 14:49:18 PDT 2014
From source with checksum a01fe726e4380ba0c9f7a7d222db961f
root@m1:/home/hadoop#
　　　　出现上面的信息，表示安装成功了

五、flume的案例
    案例1：Syslogtcp
　　　　Syslogtcp监听TCP的端口做为数据源
　　　　　　a)创建agent配置文件
root@flume1 flume# vi ./conf/syslog_tcp.conf
a1.sources = r1
a1.sinks = k1
a1.channels = c1
# Describe/configure the source
a1.sources.r1.type = syslogtcp
a1.sources.r1.port = 5140
a1.sources.r1.host = localhost
a1.sources.r1.channels = c1
# 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 = 1000
a1.channels.c1.transactionCapacity = 100
# Bind the source and sink to the channel
a1.sources.r1.channels = c1
a1.sinks.k1.channel = c1
　　　　　　b)启动flume agent a1
root@flume1 flume# ./bin/flume-ng agent --conf conf --conf-file ./conf/syslog_tcp.conf --name a1 -Dflume.root.logger=INFO,console
　　　　　　c)新连接shh,测试产生syslog
root@flume1 flume# echo "hello idoall.org syslog" | nc localhost 5140
　　　　　　d)在1的控制台，可以看到以下信息：
/08/10 11:41:45 INFO node.PollingPropertiesFileConfigurationProvider: Reloading configuration file:/home/hadoop/flume-1.5.0-bin/conf/syslog_tcp.conf
/08/10 11:41:45 INFO conf.FlumeConfiguration: Added sinks: k1 Agent: a1
/08/10 11:41:45 INFO conf.FlumeConfiguration: Processing:k1
/08/10 11:41:45 INFO conf.FlumeConfiguration: Processing:k1
/08/10 11:41:45 INFO conf.FlumeConfiguration: Post-validation flume configuration contains configuration for agents: [a1]
/08/10 11:41:45 INFO node.AbstractConfigurationProvider: Creating channels
/08/10 11:41:45 INFO channel.DefaultChannelFactory: Creating instance of channel c1 type memory
/08/10 11:41:45 INFO node.AbstractConfigurationProvider: Created channel c1
/08/10 11:41:45 INFO source.DefaultSourceFactory: Creating instance of source r1, type syslogtcp
/08/10 11:41:45 INFO sink.DefaultSinkFactory: Creating instance of sink: k1, type: logger
/08/10 11:41:45 INFO node.AbstractConfigurationProvider: Channel c1 connected to [r1, k1]
/08/10 11:41:45 INFO node.Application: Starting new configuration:{ sourceRunners:{r1=EventDrivenSourceRunner: { source:org.apache.flume.source.SyslogTcpSource{name:r1,state:IDLE} }} sinkRunners:{k1=SinkRunner: { policy:org.apache.flume.sink.DefaultSinkProcessor@6538b14 counterGroup:{ name:null counters:{} } }} channels:{c1=org.apache.flume.channel.MemoryChannel{name: c1}} }
/08/10 11:41:45 INFO node.Application: Starting Channel c1
/08/10 11:41:45 INFO instrumentation.MonitoredCounterGroup: Monitored counter group for type: CHANNEL, name: c1: Successfully registered new MBean.
/08/10 11:41:45 INFO instrumentation.MonitoredCounterGroup: Component type: CHANNEL, name: c1 started
/08/10 11:41:45 INFO node.Application: Starting Sink k1
/08/10 11:41:45 INFO node.Application: Starting Source r1
/08/10 11:41:45 INFO source.SyslogTcpSource: Syslog TCP Source starting...
/08/10 11:42:15 WARN source.SyslogUtils: Event created from Invalid Syslog data.
/08/10 11:42:15 INFO sink.LoggerSink: Event: { headers:{Severity=0, flume.syslog.status=Invalid, Facility=0} body: 68 65 6C 6C 6F 20 69 64 6F 61 6C 6C 2E 6F 72 67 hello idoall.org }

案例2：netcat
a)创建agent配置文件
root@flume1 flume# vi ./conf/netcat_example.conf

# example.conf: A single-node Flume configuration


# 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 = 44444


# 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 = 1000
a1.channels.c1.transactionCapacity = 100


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

　　　　　　b)启动flume agent a1
root@flume1 flume# ./bin/flume-ng agent --conf conf --conf-file ./conf/example.conf --name a1 -Dflume.root.logger=INFO,console
　　　　　　c)新连接shh,测试产生syslog
[root@flume1 conf]# curl -X GET http://localhost:44444?w=DDDDDDDDDDDDDDDDDDDD
OK
OK
OK
OK
d)在1的控制台，可以看到以下信息：
2016-02-02 14:59:11,849 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:94)] Event: { headers:{} body: 47 45 54 20 2F 3F 77 3D 44 44 44 44 44 44 44 44 GET /?w=DDDDDDDD }
2016-02-02 14:59:11,849 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:94)] Event: { headers:{} body: 55 73 65 72 2D 41 67 65 6E 74 3A 20 63 75 72 6C User-Agent: curl }
2016-02-02 14:59:11,849 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:94)] Event: { headers:{} body: 48 6F 73 74 3A 20 6C 6F 63 61 6C 68 6F 73 74 3A Host: localhost: }
2016-02-02 14:59:11,849 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:94)] Event: { headers:{} body: 41 63 63 65 70 74 3A 20 2A 2F 2A 0D             Accept: */*. }
2016-02-02 14:59:11,850 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:94)] Event: { headers:{} body: 0D                                              . }