常见的几种Flume日志收集场景实战

　　这里主要介绍几种常见的日志的source来源，包括监控文件型，监控文件内容增量，TCP和HTTP。

Spool类型

　　用于监控指定目录内数据变更，若有新文件，则将新文件内数据读取上传

Exec

　　EXEC执行一个给定的命令获得输出的源,如果要使用tail命令，必选使得file足够大才能看到输出内容

创建agent配置文件　　

# vi /usr/local/flume170/conf/exec_tail.conf

a1.sources = r1

a1.channels = c1 c2

a1.sinks = k1 k2

# Describe/configure the source

a1.sources.r1.type = exec

a1.sources.r1.channels = c1 c2

a1.sources.r1.command = tail -F /var/log/haproxy.log

# Use a channel which buffers events in memory

a1.channels.c1.type = memory

a1.channels.c1.capacity = 1000

a1.channels.c1.transactionCapacity = 100

a1.channels.c2.type = file

a1.channels.c2.checkpointDir = /usr/local/flume170/checkpoint

a1.channels.c2.dataDirs = /usr/local/flume170/data

# Describe the sink

a1.sinks.k1.type = logger

a1.sinks.k1.channel =c1

a1.sinks.k2.type = FILE_ROLL

a1.sinks.k2.channel = c2

a1.sinks.k2.sink.directory = /usr/local/flume170/files

a1.sinks.k2.sink.rollInterval = 0

启动flume agent a1

　　# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/exec_tail.conf -n a1 -Dflume.root.logger=INFO,console
　　生成足够多的内容在文件里
　　# for i in {1..100};do echo "exec tail$i" >> /usr/local/flume170/log_exec_tail;echo $i;sleep 0.1;done
　　在H32的控制台，可以看到以下信息：

Http

JSONHandler型

基于HTTP POST或GET方式的数据源，支持JSON、BLOB表示形式

创建agent配置文件

# vi /usr/local/flume170/conf/post_json.conf

a1.sources = r1

a1.channels = c1

a1.sinks = k1

# Describe/configure the source

a1.sources.r1.type = org.apache.flume.source.http.HTTPSource

a1.sources.r1.port = 5142

a1.sources.r1.channels = c1

# 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

启动flume agent a1

# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/post_json.conf -n a1 -Dflume.root.logger=INFO,console
生成JSON 格式的POST request
# curl -X POST -d '[{ "headers" :{"a" : "a1","b" : "b1"},"body" : "idoall.org_body"}]' http://localhost:8888
在H32的控制台，可以看到以下信息：

Tcp

Syslogtcp监听TCP的端口做为数据源

创建agent配置文件

# vi /usr/local/flume170/conf/syslog_tcp.conf

a1.sources = r1

a1.channels = c1

a1.sinks = k1

# Describe/configure the source

a1.sources.r1.type = syslogtcp

a1.sources.r1.port = 5140

a1.sources.r1.host = H32

a1.sources.r1.channels = c1

# 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

启动flume agent a1

# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/syslog_tcp.conf -n a1 -Dflume.root.logger=INFO,console
测试产生syslog
# echo "hello idoall.org syslog" | nc localhost 5140
在H32的控制台，可以看到以下信息：

Flume Sink Processors和Avro类型

　　Avro可以发送一个给定的文件给Flume，Avro 源使用AVRO RPC机制。

　　failover的机器是一直发送给其中一个sink，当这个sink不可用的时候，自动发送到下一个sink。channel的transactionCapacity参数不能小于sink的batchsiz
　　在H32创建Flume_Sink_Processors配置文件
　　# vi /usr/local/flume170/conf/Flume_Sink_Processors.conf

a1.sources = r1

a1.channels = c1 c2

a1.sinks = k1 k2

# Describe/configure the source

a1.sources.r1.type = syslogtcp

a1.sources.r1.port = 5140

a1.sources.r1.channels = c1 c2

a1.sources.r1.selector.type = replicating

# Use a channel which buffers events in memory

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

# Describe the sink

a1.sinks.k1.type = avro

a1.sinks.k1.channel = c1

a1.sinks.k1.hostname = H32

a1.sinks.k1.port = 5141

a1.sinks.k2.type = avro

a1.sinks.k2.channel = c2

a1.sinks.k2.hostname = H33

a1.sinks.k2.port = 5141

# 这个是配置failover的关键，需要有一个sink group

a1.sinkgroups = g1

a1.sinkgroups.g1.sinks = k1 k2

# 处理的类型是failover

a1.sinkgroups.g1.processor.type = failover

# 优先级，数字越大优先级越高，每个sink的优先级必须不相同

a1.sinkgroups.g1.processor.priority.k1 = 5

a1.sinkgroups.g1.processor.priority.k2 = 10

# 设置为10秒，当然可以根据你的实际状况更改成更快或者很慢

a1.sinkgroups.g1.processor.maxpenalty = 10000

　　在H32创建Flume_Sink_Processors_avro配置文件

　　# vi /usr/local/flume170/conf/Flume_Sink_Processors_avro.conf

a1.sources = r1

a1.channels = c1

a1.sinks = k1

# Describe/configure the source

a1.sources.r1.type = avro

a1.sources.r1.channels = c1

a1.sources.r1.bind = 0.0.0.0

a1.sources.r1.port = 5141

# 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

　　将2个配置文件复制到H33上一份

　　/usr/local/flume170# scp -r /usr/local/flume170/conf/Flume_Sink_Processors.conf 　　H33:/usr/local/flume170/conf/Flume_Sink_Processors.conf
　　/usr/local/flume170# scp -r /usr/local/flume170/conf/Flume_Sink_Processors_avro.conf 　　H33:/usr/local/flume170/conf/Flume_Sink_Processors_avro.conf
　　打开4个窗口，在H32和H33上同时启动两个flume agent
　　# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/Flume_Sink_Processors_avro.conf -n a1 -Dflume.root.logger=INFO,console
　　# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/Flume_Sink_Processors.conf -n a1 -Dflume.root.logger=INFO,console
　　然后在H32或H33的任意一台机器上，测试产生log
　　# echo "idoall.org test1 failover" | nc H32 5140

　　因为H33的优先级高，所以在H33的sink窗口，可以看到以下信息，而H32没有：

　　这时我们停止掉H33机器上的sink(ctrl+c)，再次输出测试数据
　　# echo "idoall.org test2 failover" | nc localhost 5140
　　可以在H32的sink窗口，看到读取到了刚才发送的两条测试数据：

　　我们再在H33的sink窗口中，启动sink：
　　# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/Flume_Sink_Processors_avro.conf -n a1 -Dflume.root.logger=INFO,console
　　输入两批测试数据：
　　# echo "idoall.org test3 failover" | nc localhost 5140 && echo "idoall.org test4 failover" | nc localhost 5140
　　在H33的sink窗口，我们可以看到以下信息，因为优先级的关系，log消息会再次落到H33上：

Load balancing Sink Processor

　　load balance type和failover不同的地方是，load balance有两个配置，一个是轮询，一个是随机。两种情况下如果被选择的sink不可用，就会自动尝试发送到下一个可用的sink上面。
　　在H32创建Load_balancing_Sink_Processors配置文件
　　# vi /usr/local/flume170/conf/Load_balancing_Sink_Processors.conf

a1.sources = r1

a1.channels = c1

a1.sinks = k1 k2

# Describe/configure the source

a1.sources.r1.type = syslogtcp

a1.sources.r1.port = 5140

a1.sources.r1.channels = c1

# 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 = avro

a1.sinks.k1.channel = c1

a1.sinks.k1.hostname = H32

a1.sinks.k1.port = 5141

a1.sinks.k2.type = avro

a1.sinks.k2.channel = c1

a1.sinks.k2.hostname = H33

a1.sinks.k2.port = 5141

# 这个是配置failover的关键，需要有一个sink group

a1.sinkgroups = g1

a1.sinkgroups.g1.sinks = k1 k2

# 处理的类型是load_balance

a1.sinkgroups.g1.processor.type = load_balance

a1.sinkgroups.g1.processor.backoff = true

a1.sinkgroups.g1.processor.selector = round_robin

　　在H32创建Load_balancing_Sink_Processors_avro配置文件

　　# vi /usr/local/flume170/conf/Load_balancing_Sink_Processors_avro.conf

a1.sources = r1

a1.channels = c1

a1.sinks = k1

# Describe/configure the source

a1.sources.r1.type = avro

a1.sources.r1.channels = c1

a1.sources.r1.bind = 0.0.0.0

a1.sources.r1.port = 5141

# 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

　　将2个配置文件复制到H33上一份

/usr/local/flume170# scp -r /usr/local/flume170/conf/Load_balancing_Sink_Processors.conf H33:/usr/local/flume170/conf/Load_balancing_Sink_Processors.conf
/usr/local/flume170# scp -r /usr/local/flume170/conf/Load_balancing_Sink_Processors_avro.conf H33:/usr/local/flume170/conf/Load_balancing_Sink_Processors_avro.conf

打开4个窗口，在H32和H33上同时启动两个flume agent
# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/Load_balancing_Sink_Processors_avro.conf -n a1 -Dflume.root.logger=INFO,console
# /usr/local/flume170/bin/flume-ng agent -c . -f /usr/local/flume170/conf/Load_balancing_Sink_Processors.conf -n a1 -Dflume.root.logger=INFO,console

然后在H32或H33的任意一台机器上，测试产生log，一行一行输入，输入太快，容易落到一台机器上
# echo "idoall.org test1" | nc H32 5140
# echo "idoall.org test2" | nc H32 5140
# echo "idoall.org test3" | nc H32 5140
# echo "idoall.org test4" | nc H32 5140

在H32的sink窗口，可以看到以下信息
1. 14/08/10 15:35:29 INFO sink.LoggerSink: Event: { headers:{Severity=0, flume.syslog.status=Invalid, Facility=0} body: 69 64 6F 61 6C 6C 2E 6F 72 67 20 74 65 73 74 32 idoall.org test2 }
2. 14/08/10 15:35:33 INFO sink.LoggerSink: Event: { headers:{Severity=0, flume.syslog.status=Invalid, Facility=0} body: 69 64 6F 61 6C 6C 2E 6F 72 67 20 74 65 73 74 34 idoall.org test4 }

在H33的sink窗口，可以看到以下信息：
1. 14/08/10 15:35:27 INFO sink.LoggerSink: Event: { headers:{Severity=0, flume.syslog.status=Invalid, Facility=0} body: 69 64 6F 61 6C 6C 2E 6F 72 67 20 74 65 73 74 31 idoall.org test1 }
2. 14/08/10 15:35:29 INFO sink.LoggerSink: Event: { headers:{Severity=0, flume.syslog.status=Invalid, Facility=0} body: 69 64 6F 61 6C 6C 2E 6F 72 67 20 74 65 73 74 33 idoall.org test3 }
说明轮询模式起到了作用。

　　以上均是建立在H32和H33能互通，且Flume配置都正确的情况下运行，且都是非常简单的场景应用，值得注意的一点是Flume说是日志收集，其实还可以广泛的认为“日志”可以当作是信息流，不局限于认知的日志。