Amazon Linux System installation Configuration zookeeper cluster

Brief introduction:

Zookeeper is a distributed, open source distributed application Coordination Service that is an open source implementation of Google's chubby and an important component of Hadoop and HBase. It is a software that provides consistent services for distributed applications, including configuration maintenance, domain name services, distributed synchronization, group services, and so on.

The goal of zookeeper is to encapsulate complex and error-prone services that provide users with easy-to-use interfaces and performance-efficient, robust systems.

Zookeeper mode:

Standalone Standalone mode:

There is only one zookeeper service instance that is not guaranteed to be highly reliable and resilient, can be used in test environments, and is not recommended for production environments.

Distributed cluster Mode:

With multiple zookeeper instances running, it is recommended that more than one ZK instance be on a different server. Data is constantly synchronized between different zookeeper instances in the cluster. More than half of the instances remain normal operation, the ZK service will be able to run normally, for example: There are 5 ZK instances, hanging 2, and 3 remaining, still can work normally, if there are 6 ZK instances, 3 are hung, it will not work properly.

Pseudo-Cluster mode:

In simple terms, the cluster pseudo-distribution mode is the zookeeper service that simulates the cluster under a single machine.

This article mainly explains the cluster mode installation deployment

First, installation environment

1. Operating system: Amazon Linux (current version based on CENTOS6 core)

2, jdk-1.7.9

3, zookeeper-3.4.8

Ii. Installation of JDK

Installing zookeeper requires the JDK to be installed first,

Install JDK Reference Site blog http://linuxtech.blog.51cto.com/3670088/1706792

Third, modify the Hosts file

Host name-to-IP address mapping configuration

There are two key roles in the Zookeeper cluster: leader and follower. All nodes in the cluster serve as a whole to the distributed application, and each node in the cluster is connected to each other, so when the zookeeper cluster is configured, the mapping of the host to the IP address of each node should be configured to map information of the other nodes in the cluster.

For example, for the configuration of each node in my zookeeper cluster, take slave-01 as an example, the/etc/hosts content is as follows:

192.168.0.101 slave-1

192.168.0.102 slave-2

192.168.0.103 slave-3

Zookeeper employs an election algorithm called leader election. In the whole cluster running process, there is only one leader, the other is follower, if the zookeeper cluster in the process of leader the problem, the system will use this algorithm to re-select a leader. Therefore, the above mappings must be configured to ensure that each node is connected to each other.

When the zookeeper cluster is started, a leader will be selected first, and in the leader election process, a node that satisfies the election can become leader.

Iv. installation and configuration of zookeeper

To http://zookeeper.apache.org/releases.html to download the zookeeper, it is recommended to choose stable version, that is stable.

Tar zxvf zookeeper-3.4.8.tar.gz-c/export/server/

cd/export/server/

MV Zookeeper-3.4.8/zookeeper

CD zookeeper/

CP Conf/zoo_sample.cfg Conf/zoo.cfg

Mkdir-p/export/data/zookeeper/

Modifying the Zoo.cfg configuration file

Sed-i ' s/datadir=\/tmp\/zookeeper/datadir=\/export\/data\/zookeeper/' conf/zoo.cfg

echo "

> server.1=slave-1:2888:3888

> server.2=slave-2:2888:3888

> server.3=slave-3:2888:3888

> ' >> conf/zoo.cfg

V. Configuring environment Variables for zookeeper

Cat >>/etc/profile <<eof

Export Zookeeper_home=/export/server/zookeeper

Export path= $PATH: $ZOOKEEPER _home/bin

Eof

Make it effective

Source/etc/profile

Six: Remote replication distribution installation files

The above has been configured on a machine slave-01 to complete the zookeeper, you can now remotely copy the configured installation files to each node in the cluster corresponding to the directory:

Seven: Set myID

Under the directory specified by our ZOO.CFG configuration DataDir, create a myID file that contains a number that identifies the current host, conf/ The number of x in the server.x configured in the Zoo.cfg file is entered in the myID file, for example:

[[Email protected]/]echo "1" >/export/data/zookeeper/myid

[[Email protected]/]echo "2" >/export/data/zookeeper/myid

[[Email protected]/]echo "3" >/export/data/zookeeper/myid

Eight, start zookeeper cluster

On each node of the zookeeper cluster, execute the script that starts the Zookeeper service as follows:

chmod +x-r bin/

CD bin/

./zkserver.sh Start

To view the boot log:

TAIL-500F Zookeeper.out

Nine, view status

To see if the zookeeper cluster is started

./zkserver.sh Status

ZooKeeper JMX enabled by default

Using config:/export/server/zookeeper/bin/. /conf/zoo.cfg

Mode:follower

The display of the leader is:

ZooKeeper JMX enabled by default

Using config:/export/server/zookeeper/bin/. /conf/zoo.cfg

Mode:leader

Viewing the startup status of zookeeper

echo Ruok | NC 192.168.0.101 2181

Console output: Imok

Ten, testing

You can connect to one of the servers via the Zkcli.sh-server IP, and then you can control ZK with interactive commands

Finish

This article is from the "Small Five Car God" blog, please be sure to keep this source http://linuxtech.blog.51cto.com/3670088/1775378

Amazon Linux System installation Configuration zookeeper cluster