zookeeper學習與實戰（二）集羣部署

時間 2019-12-02

標籤 zookeeper 學習實戰集羣部署欄目 Zookeeper 简体版

原文原文鏈接

上一篇介紹了單機版zookeeper安裝，這種狀況通常用於開發測試。若是是生產環境建議用分佈式集羣部署，防止單點故障，增長zookeeper服務的高可用。html

【環境介紹】java

三臺機器：192.168.126.160，192.168.126.161，192.168.126.162mysql

操做系統：centos linuxlinux

以上就是本次集羣的機器狀況。下面進行安裝和配置：web

1、安裝和配置sql

1）解壓文件（先在一臺機器上操做）數據庫

tar -zxvf zookeeper-3.4.6.tar.gz

2）重命名配置文件zoo_sample.cfg並修改其內容以下：apache

mv zoo_sample.cfg zoo.cfg
vim zoo.cn

內容爲：vim

tickTime=2000  
dataDir=/home/mysql/zookeeper-3.4.6/data
clientPort=2181  
initLimit=5  
syncLimit=2  
server.1=192.168.126.160:2888:3888  
server.2=192.168.126.161:2888:3888  
server.3=192.168.126.162:2888:3888

tickTime：該參數用來定義心跳的間隔時間，zookeeper的客戶端和服務端之間也有和web開發裏相似的session的概念，而zookeeper裏最小的session過時時間就是tickTime的兩倍。單位是毫秒centos

dataDir: 存放內存數據庫的快照，用戶恢復數據，若是不指定logdatadir，那麼默認log也會存在這裏。

clientPort：供客戶端程序鏈接的端口，若是在單機部署多臺server，那麼端口須要不一樣。

server.x：用於集羣中發現彼此，這裏的1,2,3須要跟data/myid裏數字對應，後面會有說明。2888表示集羣中互聯的端口，3888用於選主的端口。

initLimit：參數設定了容許全部跟隨者與領導者進行鏈接並同步的時間，若是在設定的時間段內，半數以上的跟隨者未能完成同步，領導者便會宣佈放棄領導地位，進行另外一次的領導選舉。若是zk集羣環境數量確實很大，同步數據的時間會變長，所以這種狀況下能夠適當調大該參數。默認爲10
syncLimit：參數設定了容許一個跟隨者與一個領導者進行同步的時間，若是在設定的時間段內，跟隨者未完成同步，它將會被集羣丟棄。全部關聯到這個跟隨者的客戶端將鏈接到另一個跟隨着。

而後，把修改好的zookeeper安裝文件傳輸到其餘兩臺機器上：

 scp -r zookeeper-3.4.6 192.168.126.161:/home/

3）設置myid

在咱們配置的dataDir指定的目錄下面，建立一個myid文件，裏面內容爲一個數字，用來標識當前主機，conf/zoo.cfg文件中配置的server.X中X爲何數字，則myid文件中就輸入這個數字，例如：

192.168.126.160> cd /zookeeper-3.4.6/data && touch myid && echo "1" >myid
192.168.126.161> cd /zookeeper-3.4.6/data && touch myid && echo "2" >myid
192.168.126.162> cd /zookeeper-3.4.6/data && touch myid && echo "3" >myid

到這裏，整個集羣就配置好了。

2、啓動

192.168.126.160> cd /zookeeper-3.4.6/bin
192.168.126.160 bin> ./zkServer.sh start
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

192.168.126.161> cd /zookeeper-3.4.6/bin
192.168.126.161 bin> ./zkServer.sh start
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

192.168.126.162> cd /zookeeper-3.4.6/bin
192.168.126.162 bin> ./zkServer.sh start
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

安裝正確，以上三臺都啓動了，組成了一個zookeeper集羣，即便其中一臺down機了，其餘兩臺還能夠繼續提供服務。

3、命令

一、查看集羣機器狀態：

192.168.126.160>  ./zkServer.sh status
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Mode: follower

192.168.126.161> ./zkServer.sh status
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Mode: leader

192.168.126.162>  ./zkServer.sh status
JMX enabled by default
Using config: /home/mysql/zookeeper-3.4.6/bin/../conf/zoo.cfg
Mode: follower

126.161機器是leader，其餘都是小弟角色。

二、經過客戶端腳本鏈接到集羣：

如今整個集羣對外是一個總體，鏈接到任意一臺機器上看到的視圖都是同樣的。

192.168.126.162> ./zkCli.sh -server 192.168.126.160:2181
Connecting to 192.168.126.160:2181
2016-11-25 16:40:47,036 [myid:] - INFO  [main:Environment@100] - Client environment:zookeeper.version=3.4.6-1569965, built on 02/20/2014 09:09 GMT
2016-11-25 16:40:47,038 [myid:] - INFO  [main:Environment@100] - Client environment:host.name=darren.org
2016-11-25 16:40:47,038 [myid:] - INFO  [main:Environment@100] - Client environment:java.version=1.7.0_67
2016-11-25 16:40:47,039 [myid:] - INFO  [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:java.home=/usr/java/jdk1.7.0_67-cloudera/jre
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:java.class.path=/home/mysql/zookeeper-3.4.6/bin/../build/classes:/home/mysql/zookeeper-3.4.6/bin/../build/lib/*.jar:/home/mysql/zookeeper-3.4.6/bin/../lib/slf4j-log4j12-1.6.1.jar:/home/mysql/zookeeper-3.4.6/bin/../lib/slf4j-api-1.6.1.jar:/home/mysql/zookeeper-3.4.6/bin/../lib/netty-3.7.0.Final.jar:/home/mysql/zookeeper-3.4.6/bin/../lib/log4j-1.2.16.jar:/home/mysql/zookeeper-3.4.6/bin/../lib/jline-0.9.94.jar:/home/mysql/zookeeper-3.4.6/bin/../zookeeper-3.4.6.jar:/home/mysql/zookeeper-3.4.6/bin/../src/java/lib/*.jar:/home/mysql/zookeeper-3.4.6/bin/../conf:.:/usr/java/jdk1.7.0_67-cloudera/lib/dt.jar:/usr/java/jdk1.7.0_67-cloudera/lib/tools.jar:/usr/java/jdk1.7.0_67-cloudera/jre/lib/rt.jar
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:java.compiler=<NA>
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:os.name=Linux
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:os.arch=amd64
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:os.version=2.6.32-504.23.4.el6.x86_64
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:user.name=root
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:user.home=/root
2016-11-25 16:40:47,040 [myid:] - INFO  [main:Environment@100] - Client environment:user.dir=/home/mysql/zookeeper-3.4.6/bin
2016-11-25 16:40:47,041 [myid:] - INFO  [main:ZooKeeper@438] - Initiating client connection, connectString=192.168.126.160:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@71fdf17c
Welcome to ZooKeeper!
2016-11-25 16:40:47,073 [myid:] - INFO  [main-SendThread(192.168.126.160:2181):ClientCnxn$SendThread@975] - Opening socket connection to server 192.168.126.160/192.168.126.160:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2016-11-25 16:40:47,076 [myid:] - INFO  [main-SendThread(192.168.126.160:2181):ClientCnxn$SendThread@852] - Socket connection established to 192.168.126.160/192.168

.126.160:2181, initiating session [zk: 192.168.126.160:2181(CONNECTING) 0] 2016-11-25 16:40:47,100 [myid:] - INFO [main-SendThread(192.168.126.160:2181):ClientCnxn$SendThread@1235] - Session establishment complete on server 192.168.126.160/192.168.126.160:2181, sessionid = 0x1589a9a25170000, negotiated timeout = 30000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null [zk: 192.168.126.160:2181(CONNECTED) 0]

查看數據：

[zk: 192.168.126.160:2181(CONNECTED) 0] ls /
[zookeeper]

用ls /命令查看目錄狀況，發現只有一個zookeeper目錄。

咱們到安裝目錄的/data文件夾下看看都有什麼文件？

-rw-r--r-- 1 root root        1 Nov 25 16:29 acceptedEpoch
-rw-r--r-- 1 root root        1 Nov 25 16:29 currentEpoch
-rw-r--r-- 1 root root 67108880 Nov 25 16:40 log.100000001
-rw-r--r-- 1 root root      296 Nov 25 16:29 snapshot.0