之前写了scrapy-cluster的集群配置，没有写它的基础环境搭建，现在补上zookeeper和kafka的安装配置；先讲讲zookeeper的搭建
安装环境：

[root@shulaibao4 ~]# more /etc/issue
CentOS release 6.2 (Final)
Kernel \r on an \m

安装java
我用的是：jdk-8u121-linux-x64.tar.gz（下载地址）
下载好后解压：tar -zxvf jdk-8u121-linux-x64.tar.gz
然后移动到/usr/java/目录下： mv jdk1.8.0_121 /usr/java
接着去配置环境：vim /etc/profile
在文件中添加以下配置：

export JAVA_HOME=/usr/java/jdk1.8.0_121
export PATH=$PATH:$JAVA_HOME/bin
export CLASSPATH=$CLASSPATH:$JAVA_HOME/lib:.

然后保存并退出，在命令行下输入 source /etc/profile 加载配置
完成后用 java -version 验证 java 是否安装成功，如不成功请检查你的配置。

zookeeper安装和详解
下载：

[root@shulaibao4 ~]# cd /usr/lib
[root@shulaibao4 lib]# wget http://mirror.bit.edu.cn/apache/zookeeper/zookeeper-3.4.10/zookeeper-3.4.10.tar.gz

下载完成后解压并进入文件：

[root@shulaibao4 lib]# tar -zxf zookeeper-3.4.10.tar.gz
[root@shulaibao4 lib]# cd zookeeper-3.4.10
[root@shulaibao4 zookeeper-3.4.10]# cd conf
[root@shulaibao4 conf]# cp zoo_sample.cfg zoo.cfg
[root@shulaibao4 conf]# vim zoo.cfg

zoo.cfg原始内容如下：

# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial 
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between 
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just 
# example sakes.
dataDir=/tmp/zookeeper
# the port at which the clients will connect
clientPort=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 dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

单机模式下zoo.cfg不需要做修改就可以运行

[root@shulaibao4 conf]# cd ..
[root@shulaibao4 zookeeper-3.4.10]# bin/zkServer.sh start 
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
[root@shulaibao4 zookeeper-3.4.10]# bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: standalone
[root@shulaibao4 zookeeper-3.4.10]# bin/zkServer.sh stop
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Stopping zookeeper STOPPED
[root@shulaibao4 zookeeper-3.4.10]# 

接下来讲讲怎么配置参数

tickTime=2000 
# 心跳时间，为了确保client-server连接存在的，以毫秒为单位，最小超时时间为两个心跳时间。

initLimit=10
# 多少个tickTime内，允许其他server连接并初始化数据，如果zooKeeper管理的数据较大，则应相应增大这个值。

syncLimit=5
# 多少个tickTime内，允许follower同步，如果follower落后太多，则会被丢弃

#dataDir=/tmp/zookeeper
dataDir=/home/zookeeper/data
# 用于存放内存数据库快照的文件夹，同时用于集群的myid文件也存在这个文件夹里。

dataLogDir=/home/zookeeper/log
# 用于单独设置transaction log的目录，transaction log分离可以避免和普通log还有快照的竞争。

clientPort=2181
#　客户端监听端口。

#maxClientCnxns=60
#　最大并发客户端数，用于防止DOS的，默认值是10，设置为0是不加限制。

#autopurge.snapRetainCount=3
# 快照保留在dataDir的数量

#autopurge.purgeInterval=1
# 清洗任务间隔时间, 设置为“0”禁用自动清洗功能

server.1=localhost:20881:30881
# 设置集群中的所有要链接的机器, 
# 设置格式为 server.A = B : C : D
# A代表zookeeper.pid的序号，与待会写入数据目录的myid相同，是zookeeper中当前机器的编号，因此A在集群中不可重复。
# B代表zookeeper集群中机器的主机名（ip亦可）
# C代表通信端口
# D代表选举端口

配置完成后保存并退出，再来创建zookeeper的数据目录和日志目录，我的建在/home 目录下，并写入myid

[root@shulaibao4 zookeeper-3.4.10]# mkdir /home/zookeeper
[root@shulaibao4 zookeeper-3.4.10]# mkdir /home/zookeeper/data
[root@shulaibao4 zookeeper-3.4.10]# mkdir /home/zookeeper/log
[root@shulaibao4 zookeeper-3.4.10]# echo 1 > /home/zookeeper/data/myid

接着我们来设置zookeeper在系统中的环境变量vim /etc/profile在其中加入

export PATH=/usr/lib/zookeeper-3.4.10/bin:$PATH

然后source /etc/profile即可
接下来看看我们搭建的集群

[root@shulaibao4 zookeeper-3.4.10]# cd 
[root@shulaibao4 ~]# zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
[root@shulaibao4 ~]# zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: standalone
[root@shulaibao4 ~]# zkCli.sh
Connecting to localhost:2181
2017-05-27 16:45:05,671 [myid:] - INFO  [main:Environment@100] - Client environment:zookeeper.version=3.4.10-39d3a4f269333c922ed3db283be479f9deacaa0f, built on 03/23/2017 10:13 GMT
2017-05-27 16:45:05,678 [myid:] - INFO  [main:Environment@100] - Client environment:host.name=shulaibao4
2017-05-27 16:45:05,678 [myid:] - INFO  [main:Environment@100] - Client environment:java.version=jdk1.8.0_121
2017-05-27 16:45:05,683 [myid:] - INFO  [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2017-05-27 16:45:05,683 [myid:] - INFO  [main:Environment@100] - Client environment:java.home=/usr/java/jdk1.8.0_121/jre
2017-05-27 16:45:05,684 [myid:] - INFO  [main:Environment@100] - Client environment:java.class.path=/usr/lib/zookeeper-3.4.10/bin/../build/classes:/usr/lib/zookeeper-3.4.10/bin/../build/lib/*.jar:/usr/lib/zookeeper-3.4.10/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/lib/zookeeper-3.4.10/bin/../lib/slf4j-api-1.6.1.jar:/usr/lib/zookeeper-3.4.10/bin/../lib/netty-3.10.5.Final.jar:/usr/lib/zookeeper-3.4.10/bin/../lib/log4j-1.2.16.jar:/usr/lib/zookeeper-3.4.10/bin/../lib/jline-0.9.94.jar:/usr/lib/zookeeper-3.4.10/bin/../zookeeper-3.4.10.jar:/usr/lib/zookeeper-3.4.10/bin/../src/java/lib/*.jar:/usr/lib/zookeeper-3.4.10/bin/../conf::/usr/java/jdk1.8.0_121/lib:.:/usr/java/jdk1.8.0_121/lib:.
2017-05-27 16:45:05,684 [myid:] - INFO  [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2017-05-27 16:45:05,684 [myid:] - INFO  [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2017-05-27 16:45:05,684 [myid:] - INFO  [main:Environment@100] - Client environment:java.compiler=<NA>
2017-05-27 16:45:05,685 [myid:] - INFO  [main:Environment@100] - Client environment:os.name=Linux
2017-05-27 16:45:05,685 [myid:] - INFO  [main:Environment@100] - Client environment:os.arch=amd64
2017-05-27 16:45:05,685 [myid:] - INFO  [main:Environment@100] - Client environment:os.version=2.6.32-220.el6.x86_64
2017-05-27 16:45:05,685 [myid:] - INFO  [main:Environment@100] - Client environment:user.name=root
2017-05-27 16:45:05,686 [myid:] - INFO  [main:Environment@100] - Client environment:user.home=/root
2017-05-27 16:45:05,686 [myid:] - INFO  [main:Environment@100] - Client environment:user.dir=/root
2017-05-27 16:45:05,689 [myid:] - INFO  [main:ZooKeeper@438] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@57dbe098
2017-05-27 16:45:05,742 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server localhost/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
Welcome to ZooKeeper!
2017-05-27 16:45:05,761 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@876] - Socket connection established to localhost/127.0.0.1:2181, initiating session
JLine support is enabled
2017-05-27 16:45:05,811 [myid:] - INFO  [main-SendThread(localhost:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server localhost/127.0.0.1:2181, sessionid = 0x15c4911d2d00000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0] ls

这是一台机器的配置，多台机器时只需要修改zoo.cfg文件，在文件中加入所有主机，

server.A = B : C : D

按照规则来配置就行，然后scp 到其他机器上，在其他机器上只要做以下几步：
1， 检查安装java
2， 创建对应的数据目录和日志目录
3， 在数据目录中写入对应的myid的值，
4， 在/etc/profile中加入zookeeper的路径
当这些都做完时，一个完整的集群已搭建完成，可以启动每台机器的zookeeper，看看各自的情况。这里我搭建三台机器，启动集群之后来看看他们各自的状态

机器一：

[root@shulaibao4 ~]# zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: leader
[root@shulaibao4 ~]# 

机器二：

[root@shulaibao3 ~]# zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /usr/lib/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
[root@shulaibao3 ~]#

机器三：

[root@workstation1 ~]# zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /data4/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
[root@workstation1 ~]#

详解 zkCli.sh(zkCli.cmd)
zkCli.sh(zkCli.cmd) 是zookeeper提供的命令行工具，方便我们查看服务器的状态，增加，修改，删除数据，zkCli.sh是linux执行文件，zkCli.cmd是windows执行文件，以下以linux为例。
单机启动直接在命令行下输入zkCli.sh即可，在连接集群时需要指定到集群中的某个主机；

[root@shulaibao4 usr]# zkCli.sh -server shulaibao4:2181
Connecting to shulaibao4:2181
      ……  此处略   ……
WatchedEvent state:SyncConnected type:None path:null
[zk: 172.31.22.13:2181(CONNECTED) 0] 

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