ZooKeeper 单机模式和集群模式的环境搭建

ZooKeeper环境搭建

下载最新稳定版的 Zookeeper

  使用的是最新稳定版的 zookeeper-3.4.9

Standalone Operation

  1、 将下载的 ZooKeeper 解压，进入 conf 目录，复制一份 zoo_sample.cfg 的配置文件命名为 zoo.cfg，修改如下：

# the basic time unit in milliseconds used by ZooKeeper. It is used to do heartbeats
tickTime=2000
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just 
# example sakes.
dataDir=/var/lib/zookeeper
# the port at which the clients will connect
clientPort=2181

  2、 进入 bin 目录，启动 ZooKeeper：

./zkServer.sh start

  启动运行后会创建相关目录，所以注意相关目录的写权限。启动的日志如下：

ZooKeeper JMX enabled by default
Using config: /usr/local/zookeeper-3.4.9/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED

  3、 Client Connecting to ZooKeeper

  客户端连接到 ZooKeeper：

./zkCli.sh -server 127.0.0.1:2181

  连接成功的日志输出：

Welcome to ZooKeeper!
2016-09-05 09:53:14,485 [myid:] - INFO  [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server 127.0.0.1/127.0.0.1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2016-09-05 09:53:14,625 [myid:] - INFO  [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@876] - Socket connection established to 127.0.0.1/127.0.0.1:2181, initiating session
[zk: 127.0.0.1:2181(CONNECTING) 0] 2016-09-05 09:53:14,800 [myid:] - INFO  [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x156f80a3ea00000, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null

[zk: 127.0.0.1:2181(CONNECTED) 0] 

  4、 基本指令操作

  （1）help 帮助指令，列出可操作的相关指令

ZooKeeper -server host:port cmd args
    stat path [watch]
    set path data [version]
    ls path [watch]
    delquota [-n|-b] path
    ls2 path [watch]
    setAcl path acl
    setquota -n|-b val path
    history 
    redo cmdno
    printwatches on|off
    delete path [version]
    sync path
    listquota path
    rmr path
    get path [watch]
    create [-s] [-e] path data acl
    addauth scheme auth
    quit 
    getAcl path
    close 
    connect host:port

  （2）create /test_znode test_data

[zk: 127.0.0.1:2181(CONNECTED) 2] create /test_znode test_data
Created /test_znode

  （3）ls /

[zk: 127.0.0.1:2181(CONNECTED) 3] ls /
[zookeeper, test_znode]

  （4）get /test_znode

[zk: 127.0.0.1:2181(CONNECTED) 4] get /test_znode
test_data
cZxid = 0x6
ctime = Mon Sep 05 09:59:46 CST 2016
mZxid = 0x6
mtime = Mon Sep 05 09:59:46 CST 2016
pZxid = 0x6
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 9
numChildren = 0

  （5）set /test_znode other_data

[zk: 127.0.0.1:2181(CONNECTED) 5] set /test_znode other_data
cZxid = 0x6
ctime = Mon Sep 05 09:59:46 CST 2016
mZxid = 0x7
mtime = Mon Sep 05 10:02:20 CST 2016
pZxid = 0x6
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 10
numChildren = 0

  （6）delete /test_znode

[zk: 127.0.0.1:2181(CONNECTED) 6] delete /test_znode
[zk: 127.0.0.1:2181(CONNECTED) 7] ls /
[zookeeper]

Clustered (Multi-Server) Setup

  为获取稳定的服务，需要将 ZooKeeper 部署在分布式集群中，由于 ZooKeeper 通过仲裁机制
检测系统是否可以正常对外提供服务，所以集群选择奇数个服务器进行搭建。构建容错集群最小的服务器数是3台服务器。

  1、 每台服务器中，同 Standalone Operation 一样，在 zookeeper 解压目录下的 conf 目录中创建 zoo.cfg 配置文件：

tickTime=2000
initLimit=10
syncLimit=5
dataDir=/var/lib/zookeeper
# the port to listen for client connections; that is, the port that clients attempt to connect to.
clientPort=2181
server.1=192.168.1.111:2888:3888
# Ubuntu_Server_64_1
server.2=192.168.1.133:2888:3888
# Ubuntu_Server_64_2
server.3=192.168.1.135:2888:3888

  其中，server.id=host:port:port的配置说明：

• server.id：在 zoo.cfg 文件中配置的配置的 dataDir 路径下（即：/var/lib/zookeeper）创建myid文件，里面写入 id 值
• host：构建 zookeeper 集群的服务器的 ip 地址
• port：第一个 port 用于连接 leader 服务器；第二个 port 用于 leader election

  2、 每台服务器中，在 zoo.cfg 文件中配置的配置的 dataDir 路径下（即：/var/lib/zookeeper）创建myid文件
  注意 myid 文件中写入该服务器的 id 标识，注意只能有一行，不能包括其他多余的字符；并且 该 id 要与 zoo.cfg 中配置的 server.id 相对应（ip要对应）

  3、 启动 zookeeper 集群
  （1）启动其中一个、zookeeper 服务器

./zkServer.sh start

  （2）尝试连接服务器

telnet 192.168.1.111 2181

  输出信息后输入 stat：

markliu@Linux:/usr/local/zookeeper-3.4.9/bin$ telnet 192.168.1.135 2181
Trying 192.168.1.135...
Connected to 192.168.1.135.
Escape character is '^]'.
stat
This ZooKeeper instance is not currently serving requests
Connection closed by foreign host.

  由于只启动了一个服务器，所以整个 zookeeper 集群不能对外提供服务，zookeeper 集群中正常运行的服务器需要多余未正常运行的服务器。

  （2）启动另外一个 zookeeper 服务器，并 telnet 连接服务器

markliu@Linux:/usr/local/zookeeper-3.4.9/bin$ telnet 192.168.1.135 2181
Trying 192.168.1.135...
Connected to 192.168.1.135.
Escape character is '^]'.
stat
Zookeeper version: 3.4.9-1757313, built on 08/23/2016 06:50 GMT
Clients:
 /192.168.1.111:43624[0](queued=0,recved=1,sent=0)

Latency min/avg/max: 0/0/0
Received: 1
Sent: 0
Connections: 1
Outstanding: 0
Zxid: 0x200000000
Mode: leader
Node count: 4
Connection closed by foreign host.

  （3）客户端连接到 ZooKeeper：

./zkCli.sh -server 192.168.1.135:2181

  输出日志：

markliu@Linux:/usr/local/zookeeper-3.4.9/bin$ ./zkCli.sh -server 192.168.1.135:2181Connecting to 192.168.1.135:2181
2016-09-05 21:30:22,677 [myid:] - INFO  [main:Environment@100] - Client environment:zookeeper.version=3.4.9-1757313, built on 08/23/2016 06:50 GMT
2016-09-05 21:30:22,727 [myid:] - INFO  [main:Environment@100] - Client environment:host.name=localhost
2016-09-05 21:30:22,727 [myid:] - INFO  [main:Environment@100] - Client environment:java.version=1.8.0_91
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.home=/usr/local/jdk1.8.0_91/jre
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.class.path=/usr/local/zookeeper-3.4.9/bin/../build/classes:/usr/local/zookeeper-3.4.9/bin/../build/lib/*.jar:/usr/local/zookeeper-3.4.9/bin/../lib/slf4j-log4j12-1.6.1.jar:/usr/local/zookeeper-3.4.9/bin/../lib/slf4j-api-1.6.1.jar:/usr/local/zookeeper-3.4.9/bin/../lib/netty-3.10.5.Final.jar:/usr/local/zookeeper-3.4.9/bin/../lib/log4j-1.2.16.jar:/usr/local/zookeeper-3.4.9/bin/../lib/jline-0.9.94.jar:/usr/local/zookeeper-3.4.9/bin/../zookeeper-3.4.9.jar:/usr/local/zookeeper-3.4.9/bin/../src/java/lib/*.jar:/usr/local/zookeeper-3.4.9/bin/../conf::.:/usr/local/jdk1.8.0_91/lib:/usr/local/jdk1.8.0_91/jre/lib
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2016-09-05 21:30:22,741 [myid:] - INFO  [main:Environment@100] - Client environment:java.compiler=
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:os.name=Linux
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:os.arch=amd64
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:os.version=3.16.0-30-generic
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:user.name=markliu
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:user.home=/home/markliu
2016-09-05 21:30:22,742 [myid:] - INFO  [main:Environment@100] - Client environment:user.dir=/usr/local/zookeeper-3.4.9/bin
2016-09-05 21:30:22,744 [myid:] - INFO  [main:ZooKeeper@438] - Initiating client connection, connectString=192.168.1.135:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@506c589e
Welcome to ZooKeeper!
2016-09-05 21:30:23,097 [myid:] - INFO  [main-SendThread(192.168.1.135:2181):ClientCnxn$SendThread@1032] - Opening socket connection to server 192.168.1.135/192.168.1.135:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2016-09-05 21:30:23,578 [myid:] - INFO  [main-SendThread(192.168.1.135:2181):ClientCnxn$SendThread@876] - Socket connection established to 192.168.1.135/192.168.1.135:2181, initiating session
2016-09-05 21:30:23,600 [myid:] - INFO  [main-SendThread(192.168.1.135:2181):ClientCnxn$SendThread@1299] - Session establishment complete on server 192.168.1.135/192.168.1.135:2181, sessionid = 0x356fa8189d40002, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null
[zk: 192.168.1.135:2181(CONNECTED) 0]