Create zookeeper cluster in ubuntu,18.04

zookeeper-cluster.adoc

1. Download zookeeper distribution

   wget http://apachemirror.wuchna.com/zookeeper/zookeeper-3.4.14/zookeeper-3.4.14.tar.gz

2. Extract distribution

   tar -xzvf zookeeper-3.4.14.tar.gz

3. Create zookeeper cluster directory

   sudo mkdir /opt/zookeeper-cluster

4. Copy extracted distribution to zookeeper cluster directory

   sudo mv zookeeper-3.4.14 /opt/zookeeper-cluster/zookeeper-1

5. working change directory /opt/zookeeper-cluster

   cd /opt/zookeeper-cluster

6. Make additional two copies of distribution

   sudo cp -R zookeeper-1 zookeeper-2
   sudo cp -R zookeeper-1 zookeeper-3

7. Change ownership

   sudo chown -R <user>:<group> zookeeper-1
   sudo chown -R <user>:<group> zookeeper-2
   sudo chown -R <user>:<group> zookeeper-3

8. Rename zoo_sample.cfg to zoo.cfg

   mv zookeeper-1/conf/zoo_sample.cfg zookeeper-1/conf/zoo.cfg
   mv zookeeper-2/conf/zoo_sample.cfg zookeeper-2/conf/zoo.cfg
   mv zookeeper-3/conf/zoo_sample.cfg zookeeper-3/conf/zoo.cfg

9. Update dataDir

   sed -i 's/dataDir=.*/dataDir=\/opt\/zookeeper-cluster\/zookeeper-1\/data/g' zookeeper-1/conf/zoo.cfg
   sed -i 's/dataDir=.*/dataDir=\/opt\/zookeeper-cluster\/zookeeper-2\/data/g' zookeeper-2/conf/zoo.cfg
   sed -i 's/dataDir=.*/dataDir=\/opt\/zookeeper-cluster\/zookeeper-3\/data/g' zookeeper-3/conf/zoo.cfg

10. Update clientPort

    sed -i 's/clientPort=.*/clientPort=2181/g' zookeeper-1/conf/zoo.cfg
    sed -i 's/clientPort=.*/clientPort=2182/g' zookeeper-2/conf/zoo.cfg
    sed -i 's/clientPort=.*/clientPort=2183/g' zookeeper-3/conf/zoo.cfg

11. Add peer server details

    cat << EOF >> zookeeper-1/conf/zoo.cfg
    server.1=192.168.56.150:2887:3887
    server.2=192.168.56.150:2888:3888
    server.3=192.168.56.150:2889:3889
    EOF
    
    cat << EOF >>  zookeeper-2/conf/zoo.cfg
    server.1=192.168.56.150:2887:3887
    server.2=192.168.56.150:2888:3888
    server.3=192.168.56.150:2889:3889
    EOF
    
    cat << EOF >>  zookeeper-3/conf/zoo.cfg
    server.1=192.168.56.150:2887:3887
    server.2=192.168.56.150:2888:3888
    server.3=192.168.56.150:2889:3889
    EOF

Note	id suffix should match the myid file content

1. Create data dir

   mkdir zookeeper-1/data
   mkdir zookeeper-2/data
   mkdir zookeeper-3/data

2. Create myid file with server id

   echo  "1" > zookeeper-1/data/myid
   echo  "2" > zookeeper-2/data/myid
   echo  "3" > zookeeper-3/data/myid

3. Start the servers

   cd zookeeper-1
   bin/zkServer.sh start
   cd ../zookeeper-2
   bin/zkServer.sh start
   cd ../zookeeper-3
   bin/zkServer.sh start

4. Verify nodes are up and leader and follower are chosen

   echo stat | nc localhost 2181 | grep Mode