Hadoop是一个复杂的系统组合，搭建一个用于生产的Hadoop环境是一件非常麻烦的事情。但这个世界上总有一些牛人会帮你解决一些看似痛苦的问题，如果现在没有，那也是早晚的事。CDH是Cloudera旗下的Hadoop套装环境，CDH的相关介绍请各位亲自己查阅www.cloudera.com，我就不再多说了。这里主要是介绍使用CDH5.3安装一个可以用于生产的Hadoop环境。虽然人家Cloudera牛人帮你解决了hadoop安装的问题，但随之而来的是：Cloudera Manager的安装不比hadoop的安装来得简单，而且有很多坑，后面的文章里我们将一一踩过去。

第一篇 环境准备

一、服务器准备：

我们准备一个12台的小集群，所有服务器安装Redhat 6.4 server x64 操作系统。服务器的hostname统一命名为server[1-12].cdhwork.org，内网ip地址为192.168.10.[1-12]，所有服务器都必须设置DNS服务器（可以用202.96.209.5或者8.8.8.8），所有服务器的root密码必须设置成一样的。

以下操作请用root账户在所有服务器上执行相同操作。

1、关闭防火墙

/etc/init.d/iptables stop #关闭防火墙
chkconfig iptables off    #设置启动时关闭防火墙服务

命令行执行:
setenforce 0

vi /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled

3、加快内存释放

执行命令：
sysctl vm.swappiness=0

vi /etc/sysctl.conf

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

vm.swappiness = 0

4、关闭redhat的内存hugepage

执行命令：
echo never > /sys/kernel/mm/redhat_transparent_hugepage/defrag

vi /etc/rc.local

#!/bin/sh
#
# This script will be executed *after* all the other init scripts.
# You can put your own initialization stuff in here if you don't
# want to do the full Sys V style init stuff.
echo never > /sys/kernel/mm/redhat_transparent_hugepage/defrag

touch /var/lock/subsys/local

5、修改hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

# CDH本地镜像
192.168.10.1	archive.cloudera.com

# ClouderaManager
192.168.10.1 	server1.cdhwork.org

# Cloudera Management Service Host Monitor，Cloudera Management Service Service Monitor
192.168.10.2	server2.cdhwork.org

# HDFS NameNode,Hive Gateway,Impala Catalog Server,Cloudera Management Service Alert Publisher,Spark Gateway,ZooKeeper Server
192.168.10.3	server3.cdhwork.org

# HDFS SecondaryNameNode,Hive Gateway,Impala StateStore,Solr Server,Spark Gateway,YARN (MR2 Included) ResourceManager,ZooKeeper Server
192.168.10.4	server4.cdhwork.org

# HDFS Balancer,Hive Gateway,Hue Server,Cloudera Management Service Activity Monitor,Oozie Server,Spark Gateway,Sqoop 2 Server,ZooKeeper Server
192.168.10.5	server5.cdhwork.org

# HBase Master,Hive Gateway,MapReduce JobTracker,Solr Server,Spark Gateway,YARN (MR2 Included) JobHistory Server,ZooKeeper Server,Postgresql-9.2
192.168.10.6	server6.cdhwork.org

# HBase REST Server,HBase Thrift Server,Hive Metastore Server,HiveServer2,Key-Value Store Indexer Lily HBase Indexer,Cloudera Management Service Event Server,Spark History Server
192.168.10.7	server7.cdhwork.org

# HBase RegionServer,HDFS DataNode,Impala Daemon,MapReduce TaskTracker,YARN (MR2 Included) NodeManager
192.168.10.8	server8.cdhwork.org
192.168.10.9	server9.cdhwork.org
192.168.10.10	server10.cdhwork.org
192.168.10.11	server11.cdhwork.org
192.168.10.12	server12.cdhwork.org

6、配置yum源

cd /etc/yum.repos.d/
mv rhel-source.repo rhel-source.repo.bak
vi rhel-source.repo

[base]
name=CentOS-6.6 - Base
baseurl=http://mirrors.163.com/centos/6.6/os/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6
exclude=postgresql*

#released updates
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.163.com/centos/6.6/updates/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6
exclude=postgresql*

#packages used/produced in the build but not released
#[addons]
#name=CentOS-$releasever - Addons
#baseurl=http://mirrors.163.com/centos/6.6/addons/x86_64/
#gpgcheck=1
#gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.163.com/centos/6.6/extras/x86_64/
gpgcheck=1
gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.163.com/centos/6.6/centosplus/x86_64/
gpgcheck=1
enabled=0

保存修改退出。修改yum源是为了让后面的安装速度更快些。当然，有个前提是你所有的服务器都可以访问外网，如果不能，要么安装一个代理服务器，代理访问外网；要么直接自己做一个yum源的镜像来提供服务。建议自建yum镜像，这样既方便又省事，唯一缺陷就是占一点磁盘空间。

自建镜像站点可以用wget -r <target>命令复制目标站点下所有内容，用httpd服务来一共web访问，如果你的复制站点在/usr/site，你可以直接在/var/www/html/下创建一个软连接：

ln -s /usr/site /var/www/html/site

7、更新服务器环境到最新设置

yum update

这样做是为了让后面的Cloudera安装时尽量不出错，因为很多时候Cloudera会莫名其妙的报依赖的rpm资源包不存在，或者版本太旧啥的。才开始一直不知道如何解决，后来一狠心做了一次系统更新，竟然解决了！虽然不知道为啥会这样，但总算解决了问题不是？所以大家辛苦点更新一下吧，如果网络速度够快，花不了多长时间。

CDH5.3集群安装笔记-环境准备（1）