一、什么是ZooKeeper？

ZooKeeper（动物园管理员），顾名思义，是用来管理Hadoop（大象）、Hive（蜜蜂）、Pig（小猪）的管理员，同时Apache HBase、Apache Solr、LinkedIn Sensei等众多项目中都采用了ZooKeeper。

ZooKeeper是一个集中式服务，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某种形式被分布式应用进程使用。每次它们被实现时，都有大量的工作用于修复不可避免的bug和竞选条件。由于实现这类服务的困难，应用进程最初通常跳过它们，这使得它们在存在更改时变得脆弱，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进程时导致管理复杂性。

二、Zookeeper集群

Kafka使用Zookeeper来存储集群元数据以及消费者元数据。Zookeeper集群被称为群组。Zookeeper使用的是一致性协议，所以建议每个群组里应该包含奇数个节点（比如3个、5个等），因为只有当群组里的大多数节点（也就是法定人数）处于可用状态，Zookeeper才能处理外部的请求。也就是说，如果3个节点的集群，允许1个节点失效。如果5个节点的集群，允许2个节点失效。

三、Docker方式配置ZooKeeper

myid文档：标识要写到快照目录下面myid文档里

采用Docker镜像：wurstmeister/zookeeper，部署一个3节点的集群。

节点一：

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version: '2'
services:
  zookeeper:    image: wurstmeister/zookeeper    volumes:
      - ./zoo.cfg:/opt/zookeeper-3.4.9/conf/zoo.cfg      - ./data:/opt/zookeeper-3.4.9/data      - ./logs:/opt/zookeeper-3.4.9/logs      - ./myid:/opt/zookeeper-3.4.9/data/myid    ports:
      - "2181:2181"
      - "2888:2888"
      - "3888:3888"
    restart: always

myid文档
1

1

zoo.cfg文档

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tickTime=2000# synchronization phase can takeinitLimit=10# The number of ticks that can pass between# sending a request and getting an acknowledgementsyncLimit=5# the directory where the snapshot is stored.# do not use /tmp for storage, /tmp here is just# example sakes.dataDir=/opt/zookeeper-3.4.9/datadataLogDir=/opt/zookeeper-3.4.9/logs# the port at which the clients will connectclientPort=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 dataDirautopurge.snapRetainCount=3
# Purge task interval in hours# Set to "0" to disable auto purge featureautopurge.purgeInterval=1
#kafka01 (10.100.158.245)server.1=0.0.0.0:2888:3888
#kafka02 (10.100.19.15)server.2=10.150.19.15:2888:3888
#kafka03 (10.100.124.217)server.3=10.100.124.217:2888:3888

节点二：

docker-compose.yml

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version: '2'
services:
  zookeeper:    image: wurstmeister/zookeeper    volumes:
      - ./zoo.cfg:/opt/zookeeper-3.4.9/conf/zoo.cfg      - ./data:/opt/zookeeper-3.4.9/data      - ./logs:/opt/zookeeper-3.4.9/logs      - ./myid:/opt/zookeeper-3.4.9/data/myid    ports:
      - "2180:2181"
      - "2888:2888"
      - "3888:3888"
    restart: always

myid文档
1

2

zoo.cfg文档

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# The number of milliseconds of each ticktickTime=2000# The number of ticks that the initial# synchronization phase can takeinitLimit=10# The number of ticks that can pass between# sending a request and getting an acknowledgementsyncLimit=5# the directory where the snapshot is stored.# do not use /tmp for storage, /tmp here is just# example sakes.dataDir=/opt/zookeeper-3.4.9/datadataLogDir=/opt/zookeeper-3.4.9/logs# the port at which the clients will connectclientPort=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 dataDirautopurge.snapRetainCount=3
# Purge task interval in hours# Set to "0" to disable auto purge featureautopurge.purgeInterval=1
#kafka01 (10.100.158.245)server.1=10.100.158.245:2888:3888
#kafka02 (10.100.19.15)server.2=0.0.0.0:2888:3888
#kafka03 (10.100.124.217)server.3=10.100.124.217:2888:3888

节点三：

docker-compose.yml

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version: '2'
services:
  zookeeper:    image: wurstmeister/zookeeper    volumes:
      - ./zoo.cfg:/opt/zookeeper-3.4.9/conf/zoo.cfg      - ./data:/opt/zookeeper-3.4.9/data      - ./logs:/opt/zookeeper-3.4.9/logs      - ./myid:/opt/zookeeper-3.4.9/data/myid    ports:
      - "2179:2181"
      - "2888:2888"
      - "3888:3888"
    restart: always

myid文档
1

3

zoo.cfg文档

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# The number of milliseconds of each ticktickTime=2000# The number of ticks that the initial# synchronization phase can takeinitLimit=10# The number of ticks that can pass between# sending a request and getting an acknowledgementsyncLimit=5# the directory where the snapshot is stored.# do not use /tmp for storage, /tmp here is just# example sakes.dataDir=/opt/zookeeper-3.4.9/datadataLogDir=/opt/zookeeper-3.4.9/logs# the port at which the clients will connectclientPort=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 dataDirautopurge.snapRetainCount=3
# Purge task interval in hours# Set to "0" to disable auto purge featureautopurge.purgeInterval=1
#kafka01 (10.100.158.245)server.1=10.100.158.245:2888:3888
#kafka02 (10.100.19.15)server.2=10.100.19.15:2888:3888
#kafka03 (10.100.124.217)server.3=0.0.0.0:2888:3888

四、查看ZooKeeper状态

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# 服务器1[root@VM_158_24_centos ~]# docker exec -it s1_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: leader   #服务器2 [root@VM_19_15_centos ~]# docker exec -it s2_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: follower   #服务器3 [root@VM_124_27_centos ~]# docker exec -it s3_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: follower

停掉leader，2个follower的状态有变化，如下：

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# 服务器1
 [root@VM_158_245_centos ~]# docker stop s1_zookeeper_1s1_zookeeper_1  # 服务器2
 
2018-10-30 10:54:44,555 [myid:2] - WARN [WorkerSender[myid=2]:QuorumCnxManager@400] - Cannot open channel to 1  election address /10.154.158.245:3888

java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:381) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:354) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:452) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:433) at java.lang.Thread.run(Thread.java:745)
2018-10-30 10:54:44,556 [myid:2] - INFO [WorkerSender[myid=2]:QuorumPeer$QuorumServer@149] - Resolved hostname: 10.154.158.245 to address: /10.154.158.245

2018-10-30 10:54:44,556 [myid:2] - INFO [WorkerReceiver[myid=2]:FastLeaderElection@600] - Notification: 1 (message format version), 3 (n.leader), 0x500000000 (n.zxid), 0xf4 (n.round), LOOKING (n.state), 2 (n.sid), 0x5 (n.peerEpoch) LOOKING (my state)
2018-10-30 10:54:44,759 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:QuorumPeer@844] - FOLLOWING
2018-10-30 10:54:44,759 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:ZooKeeperServer@173] - Created server with tickTime 2000 minSessionTimeout 4000 maxSessionTimeout 40000 datadir /opt/zookeeper-3.4.9/logs/version-2 snapdir /opt/zookeeper-3.4.9/data/version-2

2018-10-30 10:54:44,759 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:Follower@61] - FOLLOWING - LEADER ELECTION TOOK - 215

2018-10-30 10:54:44,760 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:QuorumPeer$QuorumServer@149] - Resolved hostname: 10.105.124.217 to address: /10.105.124.217

2018-10-30 10:54:44,761 [myid:2] - WARN [QuorumPeer[myid=2]/0.0.0.0:2181:Learner@236] - Unexpected exception, tries=0, connecting to /10.105.124.217:2888

java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at org.apache.zookeeper.server.quorum.Learner.connectToLeader(Learner.java:228) at org.apache.zookeeper.server.quorum.Follower.followLeader(Follower.java:69) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:846)
2018-10-30 10:54:45,794 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:Learner@329] - Getting a snapshot from leader
2018-10-30 10:54:45,796 [myid:2] - INFO [QuorumPeer[myid=2]/0.0.0.0:2181:FileTxnSnapLog@240] - Snapshotting: 0x500000000 to /opt/zookeeper-3.4.9/data/version-2/snapshot.500000000
  # 服务器3

2018-10-30 10:54:44,567 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:FastLeaderElection@818] - New election. My id = 3, proposed zxid=0x500000000

2018-10-30 10:54:44,568 [myid:3] - WARN [WorkerSender[myid=3]:QuorumCnxManager@400] - Cannot open channel to 1 at election address /10.154.158.245:3888

java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:381) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:354) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:452) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:433) at java.lang.Thread.run(Thread.java:745)
2018-10-30 10:54:44,569 [myid:3] - INFO [WorkerSender[myid=3]:QuorumPeer$QuorumServer@149] - Resolved hostname: 10.154.158.245 to address: /10.154.158.245

2018-10-30 10:54:44,569 [myid:3] - INFO [WorkerReceiver[myid=3]:FastLeaderElection@600] - Notification: 1 (message format version), 3 (n.leader), 0x500000000 (n.zxid), 0xf4 (n.round), LOOKING (n.state), 3 (n.sid), 0x5 (n.peerEpoch) LOOKING (my state)
2018-10-30 10:54:44,575 [myid:3] - INFO [WorkerReceiver[myid=3]:FastLeaderElection@600] - Notification: 1 (message format version), 3 (n.leader), 0x500000000 (n.zxid), 0xf4 (n.round), LOOKING (n.state), 2 (n.sid), 0x5 (n.peerEpoch) LOOKING (my state)
2018-10-30 10:54:44,776 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:QuorumPeer@856] - LEADING
2018-10-30 10:54:44,779 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:Leader@59] - TCP NoDelay set to: true
2018-10-30 10:54:44,780 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:ZooKeeperServer@173] - Created server with tickTime 2000 minSessionTimeout 4000 maxSessionTimeout 40000 datadir /opt/zookeeper-3.4.9/logs/version-2 snapdir /opt/zookeeper-3.4.9/data/version-2

2018-10-30 10:54:44,780 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:Leader@361] - LEADING - LEADER ELECTION TOOK - 219

2018-10-30 10:54:45,782 [myid:3] - INFO [LearnerHandler-/10.154.19.15:42938:LearnerHandler@329] - Follower sid: 2 : info : org.apache.zookeeper.server.quorum.QuorumPeer$QuorumServer@7f54169
2018-10-30 10:54:45,808 [myid:3] - INFO [LearnerHandler-/10.154.19.15:42938:LearnerHandler@384] - Synchronizing with Follower sid: 2 maxCommittedLog=0x0 minCommittedLog=0x0 peerLastZxid=0x300000000

2018-10-30 10:54:45,809 [myid:3] - INFO [LearnerHandler-/10.154.19.15:42938:LearnerHandler@458] - Sending SNAP
2018-10-30 10:54:45,809 [myid:3] - INFO [LearnerHandler-/10.154.19.15:42938:LearnerHandler@482] - Sending snapshot last zxid of peer is 0x300000000 zxid of leader is 0x600000000sent zxid of db as 0x500000000

2018-10-30 10:54:45,820 [myid:3] - INFO [LearnerHandler-/10.154.19.15:42938:LearnerHandler@518] - Received NEWLEADER-ACK message from 2

2018-10-30 10:54:45,820 [myid:3] - INFO [QuorumPeer[myid=3]/0.0.0.0:2181:Leader@952] - Have quorum of supporters, sids: [ 2,3 ]; starting up and setting last processed zxid: 0x600000000

再次查看status:

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 #服务器2 [root@VM_19_15_centos ~]# docker exec -it s2_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: follower   #服务器3 [root@VM_124_217_centos ~]# docker exec -it s3_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: leader

服务器3变成leader了！

重新启动服务器1，服务器1是follower

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 [root@VM_158_245_centos ~]# docker start s1_zookeeper_1
 s1_zookeeper_1 [root@VM_158_245_centos ~]# docker exec -it s1_zookeeper_1 bin/zkServer.sh status
 ZooKeeper JMX enabled by default
 Using config: /opt/zookeeper-3.4.9/bin/../conf/zoo.cfg Mode: follower

参考

原文:大专栏 kafka集群搭建 - ZooKeeper

来源：https://www.cnblogs.com/petewell/p/11422089.html

标签

kafka集群搭建

zookeeper集群

info

Docker