高可用架構圖
下面我們搭建一個高可用的Flume NG集羣，架構圖如下所示：
圖中，我們可以看出，Flume的存儲可以支持多種，這裏只列舉了HDFS和Kafka（如：存儲最新的一週日誌，並給Storm系統提供實時日誌流）。
角色分配
Flume的Agent和Collector分佈如下表所示：
名稱 HOST 角色
Agent1 node01 Web Server
Collector1 node02 AgentMstr1
Collector2 node03 AgentMstr2
圖中所示，Agent1數據分別流入到Collector1和Collector2，Flume NG本身提供了Failover機制，可以自動切換和恢復。在上圖中，有3個產生日誌服務器分佈在不同的機房，要把所有的日誌都收集到一個集羣中存儲。下面我們開發配置Flume NG集羣
node01安裝配置flume與拷貝文件腳本
將node03機器上面的flume安裝包以及文件生產的兩個目錄拷貝到node01機器上面去
node03機器執行以下命令
cd /export/servers
scp -r apache-flume-1.6.0-cdh5.14.0-bin/ node01:$PWD
scp -r shells/ taillogs/ node01:$PWD
node01機器配置agent的配置文件
cd/export/servers/apache-flume-1.6.0-cdh5.14.0-bin/conf
vim agent.conf
#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 /export/servers/taillogs/access_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 = node02
agent1.sinks.k1.port = 52020
#
## set sink2
agent1.sinks.k2.channel = c1
agent1.sinks.k2.type = avro
agent1.sinks.k2.hostname = node03
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
#
node02與node03配置flumecollection
node02機器修改配置文件
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin/conf
vim collector.conf
#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 = node02
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 = node02
a1.sources.r1.channels = c1
#
##set sink to hdfs
a1.sinks.k1.type=hdfs
a1.sinks.k1.hdfs.path= hdfs://node01:8020/flume/failover/
a1.sinks.k1.hdfs.fileType=DataStream
a1.sinks.k1.hdfs.writeFormat=TEXT
a1.sinks.k1.hdfs.rollInterval=10
a1.sinks.k1.channel=c1
a1.sinks.k1.hdfs.filePrefix=%Y-%m-%d
#
node03機器修改配置文件
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin/conf
vim collector.conf
#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 = node03
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 = node03
a1.sources.r1.channels = c1
#
##set sink to hdfs
a1.sinks.k1.type=hdfs
a1.sinks.k1.hdfs.path= hdfs://node01:8020/flume/failover/
a1.sinks.k1.hdfs.fileType=DataStream
a1.sinks.k1.hdfs.writeFormat=TEXT
a1.sinks.k1.hdfs.rollInterval=10
a1.sinks.k1.channel=c1
a1.sinks.k1.hdfs.filePrefix=%Y-%m-%d
順序啓動命令
node03機器上面啓動flume
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin
bin/flume-ng agent -n a1 -c conf -f conf/collector.conf -Dflume.root.logger=DEBUG,console
node02機器上面啓動flume
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin
bin/flume-ng agent -n a1 -c conf -f conf/collector.conf -Dflume.root.logger=DEBUG,console
node01機器上面啓動flume
```bash
cd /export/servers/apache-flume-1.6.0-cdh5.14.0-bin
bin/flume-ng agent -n agent1 -c conf -f conf/agent.conf -Dflume.root.logger=DEBUG,console
node01機器啓動文件產生腳本
```bash
cd /export/servers/shells
sh tail-file.sh
FAILOVER測試
下面我們來測試下Flume NG集羣的高可用（故障轉移）。場景如下：我們在Agent1節點上傳文件，由於我們配置Collector1的權重比Collector2大，所以 Collector1優先採集並上傳到存儲系統。然後我們kill掉Collector1，此時有Collector2負責日誌的採集上傳工作，之後，我們手動恢復Collector1節點的Flume服務，再次在Agent1上次文件，發現Collector1恢復優先級別的採集工作。具體截圖如下所示：
Collector1優先上傳
Collector1宕機，Collector2獲取優先上傳權限
重啓Collector1服務，Collector1重新獲得優先上傳的權限
總結:
flume的高可用這裏主要配置了failover 即node01中的配置文件:
##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
#