linux安装Zookeeper

ZooKeeper是一种集中式服务，用于维护配置信息，命名，提供分布式同步和提供组服务。所有这些类型的服务都以分布式应用程序的某种形式使用。每次实施它们都需要做很多工作来修复不可避免的错误和竞争条件。由于难以实现这些类型的服务，应用程序最初通常会吝啬它们，这使得它们在变化的情况下变得脆弱并且难以管理。即使正确完成，这些服务的不同实现也会在部署应用程序时导致管理复杂性。

• 下载
  选择zookeeper版本，手动下载上传至服务器或者yum下载http://mirror.bit.edu.cn/apache/zookeeper
  注意3.5.5要下载bin源码包，否则需要配置maven环境 执行maven clean install

wget http://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.5.5/apache-zookeeper-3.5.5-bin.tar.gz

• 解压

tar -zxvf apache-zookeeper-3.5.5-bin.tar.gz

• 拷贝zoo_samle.cfg为zoo.cfg

#进入到conf目录
cd apache-zookeeper-3.5.5-bin/conf
#拷贝zoo_samle.cfg为zoo.cfg
cp zoo_sample.cfg zoo.cfg

• 编辑zoo.cfg文件

vim /usr/local/apache-zookeeper-3.5.5-bin/conf/zoo.cfg

修改为

# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial 
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between 
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just 
# example sakes.
dataDir=/usr/local/apache-zookeeper-3.5.5-bin/tmp/zookeeper
# the port at which the clients will connect
clientPort=2181
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=60
#
# Be sure to read the maintenance section of the 
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
#
# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

• 设置环境变量

export ZOOKEEPER_HOME=/usr/local/apache-zookeeper-3.5.5-bin
export PATH=$ZOOKEEPER_HOME/bin:$PATH

或者编辑 vim ~/.bashrc 文本，写入以上变量，然后使用 source ~/.bashrc 生效

• 启动

/usr/local/apache-zookeeper-3.5.5-bin/bin/zkServer.sh start

• 查看状态

/usr/local/apache-zookeeper-3.5.5-bin/bin/zkServer.sh status

• 停止

/usr/local/apache-zookeeper-3.5.5-bin/bin/zkServer.sh stop

• 注意
  1.出现 Client port found: 2181. Client address: localhost.
  
  解决方案
  1、不能和Tomcat部署在同一台机器上，因为zookeeper和tomcat同样默认使用的都是8080端口；
  2、修改端口，如果必须部署到一台服务器上，则选择修改tomcat的端口号，将tomcat的8080释放出来；

2.出现Starting zookeeper ... FAILED TO START

因为apache-zookeeper-3.5.5.tar.gz为源码包，未进行编译打包
解决方案
1.配置maven环境 执行maven clean install进行打包
2.直接下载apache-zookeeper-3.5.5-bin.tar.gz使用

• 连接zookeeper

  
  

• 使用案例
  SpringBoot整合Dubbo+zk https://www.jianshu.com/p/1cd4d1c9a4a5