如何保证kafka 的消息机制 ack-fail 源码跟踪

发布网友 发布时间：2022-03-29 21:28

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懂视网 时间：2022-03-30 01:49

kafka支持的特性如下：

　　

　　1、消息持久化和缓存。Kafka高度依赖文件系统来存储和缓存消息。一般的人都认为“磁盘是缓慢的”，这使得人们对“持久化结构提供具有竞争性的性能”这样的结论持有怀疑态度。实际上，磁盘比人们预想的快很多也慢很多，这取决于它们如何被使用；一个好的磁盘结构设计可以使之跟网络速度一样快。

　　

　　2、消息读取。Kafka在读方面使用了sendfile这个高级系统函数，也即zero-copy技术，感兴趣的同学可以去阅读IBM的文章。 这项技术通过减少系统拷贝次数，极大地提高了数据传输的效率。

　　

　　3、端到端的批量压缩。在许多场景下，瓶颈实际上不是CPU而是网络。这在需要在多个数据中心之间发送消息的数据流水线的情况下更是如此。当然，用户可以不需要Kafka的支持而发送压缩后的消息，但是这会导致非常差的压缩率。高效的压缩需要将多个消息一块儿压缩而不是对每一个消息进行压缩。理想情况下，这可以在端到端的情况下实现，数据会先被压缩，然后被生产者发送，并且在服务端也是保持压缩状态，只有在最终的消费者端才会被解压缩。

热心网友 时间：2022-03-29 22:57

Kafka is a distributed, partitioned, replicated commit log service. It provides the functionality of a messaging system, but with a unique design.(Kafka布式、区(partitioned)、基于备份(replicated)commit-log存储服务.提供类似于messaging system特性,设计实现完全同)kafka种高吞吐量布式发布订阅消息系统特性：
　　（1）、通O(1)磁盘数据结构提供消息持久化种结构于即使数TB消息存储能够保持间稳定性能
　　（2）、高吞吐量：即使非普通硬件kafka支持每秒数十万消息
　　（3）、支持通kafka服务器消费机集群区消息
　　（4）、支持Hadoop并行数据加载
、用Kafka面自带脚本进行编译
　　载Kafka源码面自带gradlew脚本我利用编译Kafka源码：
1 # wget
2 # tar -zxf kafka-0.8.1.1-src.tgz
3 # cd kafka-0.8.1.1-src
4 # ./gradlew releaseTarGz
运行面命令进行编译现异信息：
01 :core:signArchives FAILED
02
03 FAILURE: Build failed with an exception.
04
05 * What went wrong:
06 Execution failed for task ':core:signArchives'.
07 > Cannot perform signing task ':core:signArchives' because it
08 has no configured signatory
09
10 * Try:
11 Run with --stacktrace option to get the stack trace. Run with
12 --info or --debug option to get more log output.
13
14 BUILD FAILED
bug（）用面命令进行编译
1 ./gradlew releaseTarGzAll -x signArchives
候编译功（编译程现）编译程我指定应Scala版本进行编译：
1 ./gradlew -PscalaVersion=2.10.3 releaseTarGz -x signArchives
编译完core/build/distributions/面kafka_2.10-0.8.1.1.tgz文件网载直接用
二、利用sbt进行编译
　　我同用sbt编译Kafka步骤：
01 # git clone
02 # cd kafka
03 # git checkout -b 0.8 remotes/origin/0.8
04 # ./sbt update
05 [info] [SUCCESSFUL ] org.eclipse.jdt#core;3.1.1!core.jar (2243ms)
06 [info] downloading ...
07 [info] [SUCCESSFUL ] ant#ant;1.6.5!ant.jar (1150ms)
08 [info] Done updating.
09 [info] Resolving org.apache.hadoop#hadoop-core;0.20.2 ...
10 [info] Done updating.
11 [info] Resolving com.yammer.metrics#metrics-annotation;2.2.0 ...
12 [info] Done updating.
13 [info] Resolving com.yammer.metrics#metrics-annotation;2.2.0 ...
14 [info] Done updating.
15 [success] Total time: 168 s, completed Jun 18, 2014 6:51:38 PM
16
17 # ./sbt package
18 [info] Set current project to Kafka (in build file:/export1/spark/kafka/)
19 Getting Scala 2.8.0 ...
20 :: retrieving :: org.scala-sbt#boot-scala
21 confs: [default]
22 3 artifacts copied, 0 already retrieved (14544kB/27ms)
23 [success] Total time: 1 s, completed Jun 18, 2014 6:52:37 PM
于Kafka 0.8及版本需要运行命令：
01 # ./sbt assembly-package-dependency
02 [info] Loading project definition from /export1/spark/kafka/project
03 [warn] Multiple resolvers having different access mechanism configured with
04 same name 'sbt-plugin-releases'. To avoid conflict, Remove plicate project
05 resolvers (`resolvers`) or rename publishing resolver (`publishTo`).
06 [info] Set current project to Kafka (in build file:/export1/spark/kafka/)
07 [warn] Credentials file /home/wyp/.m2/.credentials does not exist
08 [info] Including slf4j-api-1.7.2.jar
09 [info] Including metrics-annotation-2.2.0.jar
10 [info] Including scala-compiler.jar
11 [info] Including scala-library.jar
12 [info] Including slf4j-simple-1.6.4.jar
13 [info] Including metrics-core-2.2.0.jar
14 [info] Including snappy-java-1.0.4.1.jar
15 [info] Including zookeeper-3.3.4.jar
16 [info] Including log4j-1.2.15.jar
17 [info] Including zkclient-0.3.jar
18 [info] Including jopt-simple-3.2.jar
19 [warn] Merging 'META-INF/NOTICE' with strategy 'rename'
20 [warn] Merging 'org/xerial/snappy/native/README' with strategy 'rename'
21 [warn] Merging 'META-INF/maven/org.xerial.snappy/snappy-java/LICENSE'
22 with strategy 'rename'
23 [warn] Merging 'LICENSE.txt' with strategy 'rename'
24 [warn] Merging 'META-INF/LICENSE' with strategy 'rename'
25 [warn] Merging 'META-INF/MANIFEST.MF' with strategy 'discard'
26 [warn] Strategy 'discard' was applied to a file
27 [warn] Strategy 'rename' was applied to 5 files
28 [success] Total time: 3 s, completed Jun 18, 2014 6:53:41 PM
我sbt面指定scala版本：
01 <!--
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10 sbt "++2.10.3 update"
11 sbt "++2.10.3 package"
12 sbt "++2.10.3 assembly-package-dependency"