大数据高可用集群之zookeeper3.4.5安装配置

一、安装准备

下载地址：https://www.apache.org/dyn/closer.cgi/zookeeper/

官方文档：https://zookeeper.apache.org/doc/r3.4.5/

二、解压安装

解压文件

cd /usr/local/hadoop
tar zxpf zookeeper-3.4.5.tar.gz

创建软连接

ln -s zookeeper-3.4.5 zookeeper

三、配置zoo.cfg

cd /usr/local/hadoop/zookeeper/conf
vim /usr/local/hadoop/zookeeper/conf/zoo.cfg

给zoo.cfg文件添加一下内容

# 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/hadoop/zookeeper/data
dataLogDir=/usr/local/hadoop/zookeeper/logs
# the port at which the clients will connect
clientPort=2181
#
# 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

server.1=hadoop001:2888:3888
server.2=hadoop002:2888:3888
server.3=hadoop003:2888:3888

配置文件说明

tickTime：心跳时间，默认2000毫秒即2秒
initLimit：初始化时follower和leader之间的最多心跳数
syncLimit：follower和leader之间请求响应的最多心跳数
dataDir：存放myid、版本信息和数据持久化的目录
dataLogDir：zookeeper存放日志的目录
clientPort：zookeeper监听的端口，默认2181
server.N=ip:2888:3888：server节点配置，N表示第N台zk的节点

四、配置myid

zookeeper根据配置文件自动创建dataDir、dataLogDir目录，需要自己手动创建

mkdir /usr/local/hadoop/zookeeper/data
mkdir /usr/local/hadoop/zookeeper/logs

给每台zk节点配置myid，每个节点myid的值和zoo.cfg中的server.N一致

echo "1" > /usr/local/hadoop/zookeeper/data/myid

echo "2" > /usr/local/hadoop/zookeeper/data/myid

echo "3" > /usr/local/hadoop/zookeeper/data/myid

cat /usr/local/hadoop/zookeeper/data/myid

zookeeper的选举机制和myid密切关联，myid值大的相对更容易成为leader，具体这里就不详细讨论了。

如果不配置myid，会在 zookeeper.out 文件中抛出错误

[myid:] - ERROR [main:QuorumPeerMain@85] - Invalid config, exiting abnormally
org.apache.zookeeper.server.quorum.QuorumPeerConfig$ConfigException: Error processing /usr/local/hadoop/zookeeper/bin/../conf/zoo.cfg

五、配置环境变量

编辑 /etc/profile 文件

vim /etc/profile

添加一下内容

export ZOO_HOME=/usr/local/hadoop/zookeeper
export PATH=$PATH:$ZOO_HOME/bin

六、启动zookeeper

zkServer.sh start

zkServer.sh status

jps

这里第二个节点选举成了leader