Flume OG:Flume original generation 即Flume 0.9.x版本
Flume NG:Flume next generation ，即Flume 1.x版本。
简单比较一下两者的区别：
OG有三个组件agent、collector、master，agent主要负责收集各个日志服务器上的日志，将日志聚合到collector，可设置多个collector，master主要负责管理agent和collector，最后由collector把收集的日志写的HDFS中，当然也可以写到本地、给storm、给Hbase。
NG最大的改动就是不再有分工角色设置，所有的都是agent，可以彼此之间相连，多个agent连到一个agent，此agent也就相当于collector了，NG也支持负载均衡
集群架构
| 角色 | 主机名 | ip |
|---|---|---|
| agent1 | slave1 | 192.168.255’121 |
| agent2 | slave2 | 192.168.255.122 |
| Collector1 | slave3 | 192.168.255.123 |
| collector2 | slave4 | 192.168.255.124 |
1、agent配置
两台agent上所有配置相同
#agent1 name
agent1.channels = c1
agent1.sources = r1
agent1.sinks = k1 k2
#set gruop
agent1.sinkgroups = g1
#set channel
agent1.channels.c1.type = memory
agent1.channels.c1.capacity = 1000
agent1.channels.c1.transactionCapacity = 100
agent1.sources.r1.channels = c1
agent1.sources.r1.type = exec
agent1.sources.r1.command = tail -F /root/test.log
agent1.sources.r1.interceptors = i1 i2
agent1.sources.r1.interceptors.i1.type = static
agent1.sources.r1.interceptors.i1.key = Type
agent1.sources.r1.interceptors.i1.value = LOGIN
agent1.sources.r1.interceptors.i2.type = timestamp
# set sink1
agent1.sinks.k1.channel = c1
agent1.sinks.k1.type = avro
agent1.sinks.k1.hostname = slave3.hanli.com
agent1.sinks.k1.port = 52020
# set sink2
agent1.sinks.k2.channel = c1
agent1.sinks.k2.type = avro
agent1.sinks.k2.hostname = slave4.hanli.com
agent1.sinks.k2.port = 52020
#set sink group
agent1.sinkgroups.g1.sinks = k1 k2
#set failover
agent1.sinkgroups.g1.processor.type = failover
agent1.sinkgroups.g1.processor.priority.k1 = 10
agent1.sinkgroups.g1.processor.priority.k2 = 1
agent1.sinkgroups.g1.processor.maxpenalty = 10000
2、collector配置
在两台collector上操作，除了修改hostname，其他配置项相同
#set Agent name
a1.sources = r1
a1.channels = c1
a1.sinks = k1
#set channel
a1.channels.c1.type = memory
a1.channels.c1.capacity = 1000
a1.channels.c1.transactionCapacity = 100
# other node,nna to nns
a1.sources.r1.type = avro
a1.sources.r1.bind = slave3.hanli.com #此处修改
a1.sources.r1.port = 52020
a1.sources.r1.interceptors = i1
a1.sources.r1.interceptors.i1.type = static
a1.sources.r1.interceptors.i1.key = Collector
a1.sources.r1.interceptors.i1.value = slave3.hanli.com #此处修改
a1.sources.r1.channels = c1
#set sink to hdfs
a1.sinks.k1.type=logger
a1.sinks.k1.channel=c1
3、先启动所有server，再启动所有client，否则会报错。
[root@slave1] /usr/local/flume/conf$ ../bin/flume-ng agent -n agent1 -c ../conf -f flume-client.conf -Dflume.root.logger=DEBUG,console
[root@slave3] /usr/local/flume/conf$ ../bin/flume-ng agent --conf ../conf --conf-file flume-server.conf --name a1 -Dflume.root.logger=INFO,console
Info: Sourcing environment configuration script /usr/local/flume/conf/flume-env.sh
Info: Including Hadoop libraries found via (/usr/local/hadoop/bin/hadoop) for HDFS access
Info: Including Hive libraries found via () for Hive access
+ exec /usr/local/jdk/bin/java -Xmx20m -Dflume.root.logger=INFO,console -cp '/usr/local/flume/conf:/usr/local/flume/lib/*:/usr/local/hadoop/etc/hadoop:/usr/local/hadoop/share/hadoop/common/lib/*:/usr/local/hadoop/share/hadoop/common/*:/usr/local/hadoop/share/hadoop/hdfs:/usr/local/hadoop/share/hadoop/hdfs/lib/*:/usr/local/hadoop/share/hadoop/hdfs/*:/usr/local/hadoop/share/hadoop/yarn/lib/*:/usr/local/hadoop/share/hadoop/yarn/*:/usr/local/hadoop/share/hadoop/mapreduce/lib/*:/usr/local/hadoop/share/hadoop/mapreduce/*:/usr/local/hadoop/contrib/capacity-scheduler/*.jar:/lib/*' -Djava.library.path=:/usr/local/hadoop/lib/native org.apache.flume.node.Application --conf-file flume-server.conf --name a1
......
2018-11-13 16:32:01,797 (lifecycleSupervisor-1-4) [INFO - org.apache.flume.instrumentation.MonitoredCounterGroup.start(MonitoredCounterGroup.java:95)] Component type: SOURCE, name: r1 started
2018-11-13 16:32:01,813 (lifecycleSupervisor-1-4) [INFO - org.apache.flume.source.AvroSource.start(AvroSource.java:260)] Avro source r1 started.
4、测试高可用功能
（1）、agent1上创建源消息
[root@slave1] ~$ echo "hello failover" >> test.log
（2）、由于collector1的priority高，所以会收到，而collector2不会，查看控制台信息如下
2018-11-13 16:32:31,530 (New I/O server boss #3) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x6d3b610a, /192.168.255.121:51624 => /192.168.255.123:52020] OPEN
2018-11-13 16:32:31,531 (New I/O worker #1) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x6d3b610a, /192.168.255.121:51624 => /192.168.255.123:52020] BOUND: /192.168.255.123:52020
2018-11-13 16:32:31,532 (New I/O worker #1) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x6d3b610a, /192.168.255.121:51624 => /192.168.255.123:52020] CONNECTED: /192.168.255.121:51624
2018-11-13 16:33:11,596 (New I/O server boss #3) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x079e815e, /192.168.255.122:46856 => /192.168.255.123:52020] OPEN
2018-11-13 16:33:11,596 (New I/O worker #2) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x079e815e, /192.168.255.122:46856 => /192.168.255.123:52020] BOUND: /192.168.255.123:52020
2018-11-13 16:33:11,596 (New I/O worker #2) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x079e815e, /192.168.255.122:46856 => /192.168.255.123:52020] CONNECTED: /192.168.255.122:46856
2018-11-13 16:34:55,386 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:95)] Event: { headers:{Collector=slave3.hanli.com, Type=LOGIN, timestamp=1542098088198} body: 68 65 6C 6C 6F 20 66 61 69 6C 6F 76 65 72 hello failover }
（3）、停止collector1，在agent1上创建源消息
[root@slave1] ~$ echo "hello failover1" >> test.log
（4）、查看collector2控制台
2018-11-13 16:32:37,574 (New I/O server boss #3) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0xb58dda6a, /192.168.255.121:35108 => /192.168.255.124:52020] OPEN
2018-11-13 16:32:37,575 (New I/O worker #1) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0xb58dda6a, /192.168.255.121:35108 => /192.168.255.124:52020] BOUND: /192.168.255.124:52020
2018-11-13 16:32:37,575 (New I/O worker #1) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0xb58dda6a, /192.168.255.121:35108 => /192.168.255.124:52020] CONNECTED: /192.168.255.121:35108
2018-11-13 16:33:17,625 (New I/O server boss #3) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x8d8ac1ba, /192.168.255.122:52082 => /192.168.255.124:52020] OPEN
2018-11-13 16:33:17,625 (New I/O worker #2) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x8d8ac1ba, /192.168.255.122:52082 => /192.168.255.124:52020] BOUND: /192.168.255.124:52020
2018-11-13 16:33:17,625 (New I/O worker #2) [INFO - org.apache.avro.ipc.NettyServer$NettyServerAvroHandler.handleUpstream(NettyServer.java:171)] [id: 0x8d8ac1ba, /192.168.255.122:52082 => /192.168.255.124:52020] CONNECTED: /192.168.255.122:52082
2018-11-13 16:41:31,319 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:95)] Event: { headers:{Collector=slave4.hanli.com, Type=LOGIN, timestamp=1542098475939} body: 68 65 6C 6C 6F 20 66 61 69 6C 6F 76 65 72 31 hello failover1 }
参考：
https://www.cnblogs.com/AK47Sonic/p/7435940.html
http://www.cnblogs.com/smartloli/p/4468708.html