分佈式架構中一致性解決方案——Zookeeper集羣搭建

　　當咱們的項目在不知不覺中作大了以後，各類問題就出來了，真jb頭疼，好比性能，業務系統的並行計算的一致性協調問題，好比分佈式架構的事務問題，

咱們須要多臺機器共同commit事務，經典的案例固然是銀行轉帳，支付寶轉帳這種，若是是一臺機器的話，這個仍是很方便的，windows中自帶了一個事務協

調器mstsc，可是呢，你那種很大很牛逼的項目不可能全是windows服務器，對吧，有些人爲了解決這個問題，會採用2pc，3pc這種算法，或者是paxos的思

想進行分佈式下的一致性處理，固然在這個世界上，真的不須要你本身去開發這種協調性，由於如今已經有了專門解決這種問題的解決方案，好比zookeeper。

 

一：zookeeper集羣搭建

　　有些人應該明白，zookeeper正是google的chubby的開源實現，使用zookeeper以前，咱們先來搭建一個集羣。

1. 下載

   從官網上，咱們能夠看到，zookeeper的最新版本是3.4.8，下載地址是：http://apache.fayea.com/zookeeper/zookeeper-3.4.8/，能夠下載一下：

 

2. 文件夾配置

接下來咱們解壓一下，根目錄爲zkcluster，下面使用clientport（3000，3001，3002）這樣的端口做爲文件夾名稱，裏面就是zookeeper解壓包，以下面這樣：

 

3. 配置zoo.cfg

   如今咱們有三個文件夾，也就是3個zookeeper程序，在3001/conf/下面有一個zoo_sample.cfg文件，如今咱們改爲zoo.cfg，而且修改以下：

# 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=/root/zkcluster/3001/data
dataLogDir=/root/zkcluster/3001/logs
# the port at which the clients will connect
clientPort=3001
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=6
#
# 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

server.1=192.168.161.134:2888:3888
server.2=192.168.161.134:2889:3889
server.3=192.168.161.134:2890:3890

這裏咱們要注意的是，紅色的部分分別就是：指定zookeeper的data和log文件夾，指定clientport訪問的端口和servers的列表。

 

4. 生成pid文件

    咱們在servers列表中，能夠看到有server.1 ,server.2, server.3 三個字符串，生成pid文件的內容就取決如此，好比server.1的地址，

咱們的pid文件裏面就是1，不過要知道的是，pid文件要在data目錄下，好比下面這樣:

 

ok，一樣的道理，3002和3003的文件夾同3001就能夠了，好比他們的zoo.cfg以下：

 

--------  3002 --------------

# 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=/root/zkcluster/3002/data
dataLogDir=/root/zkcluster/3002/logs
# the port at which the clients will connect
clientPort=3002
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=6
#
# 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

server.1=192.168.161.134:2888:3888
server.2=192.168.161.134:2889:3889
server.3=192.168.161.134:2890:3890

 

--------  3003 --------------

# 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=/root/zkcluster/3003/data
dataLogDir=/root/zkcluster/3003/logs
# the port at which the clients will connect
clientPort=3003
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=6
#
# 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

server.1=192.168.161.134:2888:3888
server.2=192.168.161.134:2889:3889
server.3=192.168.161.134:2890:3890

 

5. 啓動各自服務器

    到如今爲止，咱們各個zookeeper程序的配置都結束了，接下來咱們到各自目錄的bin目錄下，經過zkServer.sh來進行啓動，好比下面這樣：

ok，接下來咱們來開始啓動，經過以下命令便可：

./zkServer.sh start-foreground

 

如今咱們都啓動了，接下來咱們能夠用命令看下哪一個server是leader，哪些是follower。。。

[root@localhost bin]# ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /root/zkcluster/3001/bin/../conf/zoo.cfg
Mode: follower
[root@localhost bin]# 


[root@localhost bin]# ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /root/zkcluster/3002/bin/../conf/zoo.cfg
Mode: leader
[root@localhost bin]# 

[root@localhost bin]# ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /root/zkcluster/3003/bin/../conf/zoo.cfg
Mode: follower
[root@localhost bin]# 

到目前爲止，咱們的服務端操做都ok啦，，，是否是好吊。。。

 

二：驅動下載

1.  java的驅動就方便了，直接在源代碼中就提供了，直接copy一下lib文件夾中的jar包就ok了，真是tmd的方便。

 

2. 用C#驅動的也不要太煩，要使用也是不難的，咱們能夠經過nuget下載一下就能夠了，轉換過來的版本也是3.4.8的最新版本，好比下面這樣：

 

好了，大概就說這麼多，但願對你有幫助~~~