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02. Spark Streaming實時流處理學習——分布式日志收集架構Flume

2. 分布式日志收集架構Flume

2.1 業務現狀分析

如上圖,大量的系統和各種服務的日志資料持續生成。使用者有了很好的商業創意想要充分利用這些系統日志資訊。比如使用者行為分析,軌迹跟蹤等等。

如何将日志上傳到Hadoop叢集上?

對比方案存在什麼問題,以及有什麼優勢?

  • 方案1: 容錯,負載均衡,高延時等問題如何消除?
  • 方案2: Flume架構

2.2 Flume概述

flume官網

http://flume.apache.org

Flume is a distributed, reliable, and available service for efficiently collecting(收集), aggregating(聚合), and moving(移動)large amounts of log data. It has a simple and flexible architecture based on streaming data flows. It is robust and fault tolerant with tunable reliability mechanisms and many failover and recovery mechanisms. It uses a simple extensible data model that allows for online analytic application.

Flume是有Cloudera提供的一個分布式、高可靠、高可用的服務,用于分布式的海量日志的高效收集、聚合、移動的系統

Flume的設計目标

  • 可靠性
  • 擴充性
  • 管理性(agent有效的管理者)

業界同類産品對比

  • Flume(*): Cloudera/Apache Java
  • Scribe: Facebook C/C++ 不再維護
  • Chukwa:Yahoo/Apache Java 不再維護
  • Fluentd:Ruby
  • Logstash(*):ELK(ElasticSearch,Kibana)

Flume發展史

  • Cloudera 0.9.2 Flume-OG
  • flume-728 Flume-NG => Apache
  • 2012.7 1.0
  • 2015.5 1.6 (* +)
  • ~ 1.8

2.3 Flume架構及核心元件

  1. Source(收集)
  2. Channel(聚合)
  3. Sink(輸出)

multi-agent flow

In order to flow the data across multiple agents or hops, the sink of the previous agent and source of the current hop need to be avro type with the sink pointing to the hostname (or IP address) and port of the source.

A very common scenario in log collection is a large number of log producing clients sending data to a few consumer agents that are attached to the storage subsystem. For example, logs collected from hundreds of web servers sent to a dozen of agents that write to HDFS cluster.

This can be achieved in Flume by configuring a number of first tier agents with an avro sink, all pointing to an avro source of single agent (Again you could use the thrift sources/sinks/clients in such a scenario). This source on the second tier agent consolidates the received events into a single channel which is consumed by a sink to its final destination.

Multiplexing the flow

Flume supports multiplexing the event flow to one or more destinations. This is achieved by defining a flow multiplexer that can replicate or selectively route an event to one or more channels.

The above example shows a source from agent “foo” fanning out the flow to three different channels. This fan out can be replicating or multiplexing. In case of replicating flow, each event is sent to all three channels. For the multiplexing case, an event is delivered to a subset of available channels when an event’s attribute matches a preconfigured value. For example, if an event attribute called “txnType” is set to “customer”, then it should go to channel1 and channel3, if it’s “vendor” then it should go to channel2, otherwise channel3. The mapping can be set in the agent’s configuration file.

2.4 Flume環境部署

前置條件

  • Java Runtime Environment - Java 1.8 or later
  • Memory - Sufficient memory for configurations used by sources, channels or sinks
  • Disk Space - Sufficient disk space for configurations used by channels or sinks
  • Directory Permissions - Read/Write permissions for directories used by agent

安裝JDK

  • 下載下傳JDK包
  • 解壓JDK包
tar -zxvf jdk-8u162-linux-x64.tar.gz  [install dir]
* 配置JAVA環境變量:
修改系統配置檔案 /etc/profile  或者  ~/.bash_profile
export JAVA_HOME=[jdk install dir]
export PATH = $JAVA_HOME/bin:$PATH
執行指令 
source /etc/profile  或者 
source ~/.bash_profile 
使得配置生效。
執行指令 
java -version 
檢測環境配置是否生效。           

安裝Flume

  • 下載下傳Flume包
wget http://www.apache.org/dist/flume/1.7.0/apache-flume-1.7.0-bin.tar.gz           
  • 解壓Flume包
tar -zxvf apache-flume-1.7.0-bin.tar.gz -C [install dir]           
  • 配置Flume環境變量
vim /etc/profile  或者
vim ~/.bash_profile
export FLUME_HOME=[flume install dir]
export PATH = $FLUME_HOME/bin:$PATH
執行指令 
source /etc/profile  或者 
source ~/.bash_profile 
使得配置生效。           
  • 修改flume-env.sh腳本檔案
export JAVA_HOME=[jdk install dir]
執行指令
flume-ng version
檢測安裝情況           

2.5 Flume實戰

  • 需求1:從指定的網絡端口采集資料輸出到控制台

使用Flume的關鍵就是寫配置檔案

  1. 配置source
  2. 配置Channel
  3. 配置Sink
  4. 把以上三個元件連結起來

a1: agent名稱

r1: source的名稱

k1: sink的名稱

c1: channel的名稱

單一節點 Flume 配置

# 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           

啟動Flume agent

flume-ng agent \
--name a1 \
--conf  $FLUME_HOME/conf    \
--conf-file  $FLUME_HOME/conf/example.conf \
-Dflume.root.logger=INFO,console
           

使用telnet或者nc進行測試

telnet [hostname]  [port]     或者
nc [hostname]  [port]           

Event = 可選的headers + byte array

Event: { headers:{} body: 74 68 69 73 20 69 73 20 61 20 74 65 73 74 20 70 this is a test p }           
  • 需求2:監控一個檔案實時采集新增的資料輸出到控制台

    技術(Agent)選型:exec source + memory channel + logger sink

# 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 = exec
a1.sources.r1.command = tail -f  /root/data/data.log
a1.sources.r1.shell = /bin/bash -c

# 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           
flume-ng agent \
--name a1 \
--conf  $FLUME_HOME/conf    \
--conf-file  $FLUME_HOME/conf/example.conf \
-Dflume.root.logger=INFO,console
           

修改data.log檔案,監測是否資料是否輸出到控制台

echo hello >> data.log
echo world >> data.log
echo welcome >> data.log           

控制台輸出

2018-09-02 03:55:00,672 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:95)] Event: { headers:{} body: 68 65 6C 6C 6F                                  hello }
2018-09-02 03:55:06,748 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:95)] Event: { headers:{} body: 77 6F 72 6C 64                                  world }
2018-09-02 03:55:22,280 (SinkRunner-PollingRunner-DefaultSinkProcessor) [INFO - org.apache.flume.sink.LoggerSink.process(LoggerSink.java:95)] Event: { headers:{} body: 77 65 6C 63 6F 6D 65                            welcome }           

至此,需求2成功實作。

  • 需求3(*):将A伺服器上的日志實時采集到B伺服器上(重點掌握)

    技術(Agent)選型:

exec source + memory channel + avro sink

avro source + memory channel + logger sink

# exec-memory-avro.conf: A single-node Flume configuration

# Name the components on this agent
exec-memory-avro.sources = exec-source
exec-memory-avro.sinks = avro-sink
exec-memory-avro.channels = memory-channel

# Describe/configure the source
exec-memory-avro.sources.exec-source.type = exec
exec-memory-avro.sources.exec-source.command = tail -f  /root/data/data.log
exec-memory-avro.sources.exec-source.shell = /bin/bash -c

# Describe the sink
exec-memory-avro.sinks.avro-sink.type = avro
exec-memory-avro.sinks.avro-sink.hostname = c7-master
exec-memory-avro.sinks.avro-sink.port = 44444

# Use a channel which buffers events in memory
exec-memory-avro.channels.memory-channel.type = memory
exec-memory-avro.channels.memory-channel.capacity = 1000
exec-memory-avro.channels.memory-channel.transactionCapacity = 100

# Bind the source and sink to the channel
exec-memory-avro.sources.exec-source.channels = memory-channel
exec-memory-avro.sinks.avro-sink.channel = memory-channel           
# avro-memory-logger.conf: A single-node Flume configuration

# Name the components on this agent
avro-memory-logger.sources = avro-source
avro-memory-logger.sinks = logger-sink
avro-memory-logger.channels = memory-channel

# Describe/configure the source
avro-memory-logger.sources.avro-source.type = avro
avro-memory-logger.sources.avro-source.bind = c7-master
avro-memory-logger.sources.avro-source.port = 44444

# Describe the sink
avro-memory-logger.sinks.logger-sink.type = logger

# Use a channel which buffers events in memory
avro-memory-logger.channels.memory-channel.type = memory
avro-memory-logger.channels.memory-channel.capacity = 1000
avro-memory-logger.channels.memory-channel.transactionCapacity = 100

# Bind the source and sink to the channel
avro-memory-logger.sources.avro-source.channels = memory-channel
avro-memory-logger.sinks.logger-sink.channel = memory-channel           

優先啟動 avro-memory-logger agent

flume-ng agent \
--name avro-memory-logger \
--conf  $FLUME_HOME/conf    \
--conf-file  $FLUME_HOME/conf/avro-memory-logger.conf \
-Dflume.root.logger=INFO,console
           

再啟動 exec-memory-avro agent

flume-ng agent \
--name exec-memory-avro \
--conf  $FLUME_HOME/conf    \
--conf-file  $FLUME_HOME/conf/exec-memory-avro.conf \
-Dflume.root.logger=INFO,console
           

日志收集過程:

1)機器A上監控一個檔案,當我們通路主站時會有使用者行為日志記錄到access.log中

2)avro sink把新産生的日志輸出到對應的avro source指定的hostname:port主機上。

3)通過avro source對應的agent将我們的日志輸出到控制台。