Zookeeper入门——安装、配置解析、节点

怼烎@ 2023-05-28 13:00 18阅读 0赞

# Zookeeper简介 #

Zookeeper是提供高性能、高可用 且具备严格的顺序访问控制能力的分布式协调服务。  
**设计目标**  
简单的数据结构：共享的树形结构，类似文件系统，存储于内存  
可以构建集群：避免单点故障，3-5台机器就可以组成集群，超过半数正常工作就能对外提供服务  
顺序访问：对于每个读请求，zk会分配一个全局唯一的递增编号，利用这个特性可以实现高级协调服务；  
高性能：基于内存操作，服务于非事务请求，适用于读操作为主的业务场景。3台zk集群能达到13w QPS；

**使用场景如下：**  
数据发布订阅，负载均衡，命名服务，Master选举，集群管理，配置管理，分布式队列，分布式锁

**下载安装**

wget  https://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.6.0/apache-zookeeper-3.6.0.tar.gz
    tar -zxvf apache-zookeeper-3.6.0.tar.gz
    ## 进入conf文件夹下，重命名配置文件,因为zookeeper默认找zoo.cfg
    cp  zoo_sample.cfg  zoo.cfg
    #启动 bin目录下
    ./zkServer.sh start

目录结构  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70]

**配置文件解析**  
打开后是这样的(比较乱，直接看解析吧)

s conf]# # The number of ticks that the initial 
    [root@VM_0_4_centos conf]# # synchronization phase can take
    [root@VM_0_4_centos conf]# initLimit=10
    [root@VM_0_4_centos conf]# # The number of ticks that can pass between 
    [root@VM_0_4_centos conf]# # sending a request and getting an acknowledgement
    [root@VM_0_4_centos conf]# syncLimit=5
    [root@VM_0_4_centos conf]# # the directory where the snapshot is stored.
    [root@VM_0_4_centos conf]# # do not use /tmp for storage, /tmp here is just 
    [root@VM_0_4_centos conf]# # example sakes.
    [root@VM_0_4_centos conf]# dataDir=/lisz/data
    [root@VM_0_4_centos conf]# # the port at which the clients will connect
    [root@VM_0_4_centos conf]# clientPort=2181
    [root@VM_0_4_centos conf]# # the maximum number of client connections.
    [root@VM_0_4_centos conf]# # increase this if you need to handle more clients
    [root@VM_0_4_centos conf]# #maxClientCnxns=60
    [root@VM_0_4_centos conf]# #
    [root@VM_0_4_centos conf]# # Be sure to read the maintenance section of the 
    [root@VM_0_4_centos conf]# # administrator guide before turning on autopurge.
    [root@VM_0_4_centos conf]# #
    [root@VM_0_4_centos conf]# # http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
    [root@VM_0_4_centos conf]# #
    [root@VM_0_4_centos conf]# # The number of snapshots to retain in dataDir
    [root@VM_0_4_centos conf]# #autopurge.snapRetainCount=3
    [root@VM_0_4_centos conf]# # Purge task interval in hours
    [root@VM_0_4_centos conf]# # Set to "0" to disable auto purge feature
    [root@VM_0_4_centos conf]# #autopurge.purgeInterval=1
    [root@VM_0_4_centos conf]# snapCount=100000
    [root@VM_0_4_centos conf]# ## Metrics Providers
    [root@VM_0_4_centos conf]# #
    [root@VM_0_4_centos conf]# # https://prometheus.io Metrics Exporter
    [root@VM_0_4_centos conf]# #metricsProvider.className=org.apache.zookeeper.metrics.prometheus.PrometheusMetricsProvider
    [root@VM_0_4_centos conf]# #metricsProvider.httpPort=7000
    [root@VM_0_4_centos conf]# #metricsProvider.exportJvmInfo=true

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 1]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 2]

## Znode节点 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 3]

**四种节点类型**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 4]  
我们可以启动客户端，尝试创建相关节点（节点必须有值）

//conf 下启动客户端脚本
    [root@VM_0_4_centos bin]# ./zkCli.sh
    //进入根目录，创建节点
    [zk: localhost:2181(CONNECTED) 2] ls /
    [zookeeper]
    [zk: localhost:2181(CONNECTED) 3] create /aaaa aaa  //必须指定aaa的值，否则无法创建
    //获取节点
    [zk: localhost:2181(CONNECTED) 10] get /aaaa

创建临时节点  
create -e /aaaa aaa  
获取节点返回的是这样的  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 5]  
每个参数的含义如下  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 6]

启动ZK服务: sh bin/zkServer.sh start   
查看ZK服务状态: sh bin/zkServer.sh status   
停止ZK服务: sh bin/zkServer.sh stop   
重启ZK服务: sh bin/zkServer.sh restart !\[在  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzAwMDMw_size_16_color_FFFFFF_t_70 7]

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