原文日期：2018-05-12

The zookeeper is a stronger midware, and it a high-perfomance coordination service for distributed applications.It exposed common service - such as naming, configuration management, synchronization,and group services. You can create the distribute lock, distribute configuration file manage, and the other distribute thing by using it.
I will to install the zookeeper next.

1. Prepare

Machine number: 3 (ip:192.168.0.10,192.168.0.11,192.168.0.12)
Machine exposed port: 2181(client port), 2788(used by machine communication), 3788(used by machine communication)
Operating System: Centos 7
Java: openjdk1.8
zookeeper: 3.4.12

tip: To ensure the communication of the 3 machine and the client can connection zookeeper service of the machine. we must close the firewall on the machine or open the port(above:2181,2788,3788) on the machine.

2. Standalone

download zookeeper

Click the zookeeper url to download.

unzip file

Unzip file to your app path.(eg:/app/zookeeper)

create config file

Go into the conf directory in the zookeeper path ,copy the zoo_sample.cfg file to zoo.cfg file.
For the linux ,you can input the follow:

cp zoo_sample.cfg zoo.cfg

In the file, There is a default client port that value of 2181, you can connection the zookeeper by the port.

start the zookeeper

Go into the bin directory in the zookeeper path, and input the follow:

sh zkServer.sh start

sh zkServer.sh start-foreground

Now, you can connection all of machine.input the follow command. (eg: the ip is 192.168.0.10, the port is 2181)

sh zkCli.sh -server 192.168.0.10:2181

tip: you also add the bin directory in the zookeeper path to the environment variable. looke the follow:

export PATH="$PATH:/app/zookeeper/bin"

3. Master slave

prepare

The First, you must have more the three machine. and the odd number of machine is the best practice, such as three, five, seven.(eg: I use the three machine)

define the unique id by every machine

Define the unique id by every machine.(eg: 1->192.168.0.10, 2->192.168.0.11, 3->192.168.0.12)

update the `config` file by every machine

update content below the follow:

dataDir=/app/zk/data # data directory
dataLogDir=/app/zk/log # log directory

# the machine define 
server.1=192.168.0.10:2788:3788
server.2=192.168.0.11:2788:3788
server.3=192.168.0.12:2788:3788

create `myid` file

Create a myid file in the data directory of zookeeper, and the file must contain the value of the machine id by predefined.
Such as the follow:
The first machine's id value is 1.

echo 1 > myid

The second machine's id value is 2.

echo 2 > myid

The third machine's id value is 3.

echo 3 > myid

Start all of machine

Input the command by every machine:

sh zkServer.sh start

sh zkServer.sh start-foreground

Now, you can connection all of machine by the follow command.

sh zkCli.sh -server 192.168.0.10:2181,192.168.0.11:2181,192.168.0.12:2181

also lookup every machine's mode by the follow command

sh zkServer.sh status

zookeeper install