zookeeper(1）初识zookeeper

一、zookeeper的安装

1、下载zookeeper(当然在安装zookeeper之前得先装好jdk，这里就不说了)，版本自己随便选一个(后面我再说版本的问题)，点击这里下载。

2、然后在usr下创建zookeeper文件夹，把下载的tar包扔进去，再解压缩。

3、之后在解压缩的根目录创建data文件夹，如下:

4、创建好之后进入data文件夹，pwd命令获取到data文件夹的绝对路径。复制data的绝对路径，返回上一级，打开conf文件夹，重命名conf文件夹下的zoo_samle.cfg为zoo.cfg，再打开编辑zoo.cfg，更改dataDir的位置为刚刚复制的data目录的绝对路径:

 

5、到这里就已经全部安装好了，进入解压后的根目录下面的bin目录执行:./zkServer.sh start执行开启zookeeper就可以了。

6、查看当前zookeeper运行状态 ，./zkServer.sh status 

    JMX enabled by default
    Using config: /root/zookeeper-3.4.6/bin/../conf/zoo.cfg
    Mode: standalone

7、连接客户端 sh zkCli.sh     断开连接 ctrl+c

Connecting to localhost:2181
2019-03-11 07:30:32,026 [myid:] - INFO [main:Environment@100] - Client environment:zookeeper.version=3.4.6-1569965, built on 02/20/2014 09:09 GMT
2019-03-11 07:30:32,028 [myid:] - INFO [main:Environment@100] - Client environment:host.name=localhost
2019-03-11 07:30:32,028 [myid:] - INFO [main:Environment@100] - Client environment:java.version=1.7.0_71
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.vendor=Oracle Corporation
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.home=/usr/local/src/java/jdk1.7.0_71/jre
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.class.path=/root/zookeeper-3.4.6/bin/../build/classes:/root/zookeeper-3.4.6/bin/../build/lib/*.jar:/root/zookeeper-3.4.6/bin/../lib/slf4j-log4j12-1.6.1.jar:/root/zookeeper-3.4.6/bin/../lib/slf4j-api-1.6.1.jar:/root/zookeeper-3.4.6/bin/../lib/netty-3.7.0.Final.jar:/root/zookeeper-3.4.6/bin/../lib/log4j-1.2.16.jar:/root/zookeeper-3.4.6/bin/../lib/jline-0.9.94.jar:/root/zookeeper-3.4.6/bin/../zookeeper-3.4.6.jar:/root/zookeeper-3.4.6/bin/../src/java/lib/*.jar:/root/zookeeper-3.4.6/bin/../conf:.:/usr/local/src/java/jdk1.7.0_71/lib.tools.jar
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.library.path=/usr/java/packages/lib/i386:/lib:/usr/lib
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.io.tmpdir=/tmp
2019-03-11 07:30:32,031 [myid:] - INFO [main:Environment@100] - Client environment:java.compiler=<NA>
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:os.name=Linux
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:os.arch=i386
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:os.version=2.6.32-431.el6.i686
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:user.name=root
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:user.home=/root
2019-03-11 07:30:32,033 [myid:] - INFO [main:Environment@100] - Client environment:user.dir=/root/zookeeper-3.4.6/bin
2019-03-11 07:30:32,034 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=localhost:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@d5e4c7
Welcome to ZooKeeper!
2019-03-11 07:30:32,080 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@975] - Opening socket connection to server localhost/0:0:0:0:0:0:0:1:2181. Will not attempt to authenticate using SASL (unknown error)
JLine support is enabled
2019-03-11 07:30:32,102 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@852] - Socket connection established to localhost/0:0:0:0:0:0:0:1:2181, initiating session
2019-03-11 07:30:32,121 [myid:] - INFO [main-SendThread(localhost:2181):ClientCnxn$SendThread@1235] - Session establishment complete on server localhost/0:0:0:0:0:0:0:1:2181, sessionid = 0x167d21b8ff0007a, negotiated timeout = 30000

WATCHER::

WatchedEvent state:SyncConnected type:None path:null

[zk: localhost:2181(CONNECTED) 0] help
ZooKeeper -server host:port cmd args
connect host:port
get path [watch]
ls path [watch]
set path data [version]
rmr path
delquota [-n|-b] path
quit
printwatches on|off
create [-s] [-e] path data acl
stat path [watch]
close
ls2 path [watch]
history
listquota path
setAcl path acl
getAcl path
sync path
redo cmdno
addauth scheme auth
delete path [version]
setquota -n|-b val path
[zk: localhost:2181(CONNECTED) 1]

8.创建一个资源节点并查看当前目录下的资源

[zk: localhost:2181(CONNECTED) 1] create /oldservice 0
Created /oldservice
[zk: localhost:2181(CONNECTED) 2] ls /
[oldservice, dubbo, zookeeper]
[zk: localhost:2181(CONNECTED) 3] create /oldservice/wsdl 1
Created /oldservice/wsdl
[zk: localhost:2181(CONNECTED) 4] ls /
[oldservice, dubbo, zookeeper]
[zk: localhost:2181(CONNECTED) 5] ls /oldservice
[wsdl]
[zk: localhost:2181(CONNECTED) 6]

9.删除节点，必须一层一层对应删除　

[zk: localhost:2181(CONNECTED) 7] delete /oldservice/wsdl
[zk: localhost:2181(CONNECTED) 8] ls /oldservice
[]
[zk: localhost:2181(CONNECTED) 9] delete /oldservice
[zk: localhost:2181(CONNECTED) 10] ls /
[dubbo, zookeeper]
[zk: localhost:2181(CONNECTED) 11]

10.拿到节点信息　--节点特性：（节点唯一，临时节点(不能有子节点  -e)，有序(-s)和无序节点）

[zk: localhost:2181(CONNECTED) 13] get /dubbo
null
cZxid = 0x2
ctime = Fri Dec 21 11:26:37 PST 2018
mZxid = 0x2
mtime = Fri Dec 21 11:26:37 PST 2018
pZxid = 0x8b2
cversion = 11
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 11

获取临时节点信息：（参数解析）

get /temp
0（节点值）
cZxid = 0x400000004（创建事务id）
ctime = Thu Mar 14 04:53:57 PDT 2019
mZxid = 0x400000004(修改、更新事务id)
mtime = Thu Mar 14 04:53:57 PDT 2019
pZxid = 0x400000004(子节点变更以后才会产生pZxid的影响)
cversion = 0（当前节点子节点的版本号）（版本号类似乐观锁的概念，通过版本号去保存数据的变化）
dataVersion = 0（数据内容的版本号）
aclVersion = 0（当前节点acl(权限控制)变化的版本号）ACL CREATE/READ/WRITE/DELETE/ADMIN
ephemeralOwner = 0x3697c0684e80000（绑定当前会话信息，此节点属于当前会话，会话关闭，改临时节点被删除）
dataLength = 1（数据长度）
numChildren = 0（当前节点下子节点个数）

watcher:

get /temp true(设置watcher监听)
0
cZxid = 0x400000004
ctime = Thu Mar 14 04:53:57 PDT 2019
mZxid = 0x400000004
mtime = Thu Mar 14 04:53:57 PDT 2019
pZxid = 0x400000004
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x3697c0684e80000
dataLength = 1
numChildren = 0
[zk: localhost:2181(CONNECTED) 6]

WATCHER::

WatchedEvent state:SyncConnected type:NodeDataChanged path:/temp

另一台机器上：

[zk: localhost:2181(CONNECTED) 11] set /temp test 对节点值进行修改

cZxid = 0x400000004
ctime = Thu Mar 14 04:53:57 PDT 2019
mZxid = 0x400000005
mtime = Thu Mar 14 05:25:04 PDT 2019
pZxid = 0x400000004
cversion = 0
dataVersion = 1
aclVersion = 0
ephemeralOwner = 0x3697c0684e80000
dataLength = 4
numChildren = 0

可以看到上面标黄的watcher通知

集群搭建：

       1、下载ZooKeeper的安装包：

　　2、将下载的zookeeper-3.4.6包放到/opt目录下，目录结构如下图所示：

　   3、在/tmp目录下新建一个zookeeper目录，并在zookeeper目录下新建一个data目录。

　   4、三台linux系统的ip：　　

server.1=192.168.25.129:2888:3888
server.2=192.168.25.130:2888:3888
server.3=192.168.25.131:2888:3888

5、安装jdk8：

　　下载下来后拷贝到/usr/java目录下，然后：tar-zxvf jdk-8u112-linux-i586.tar.gz解压后目录下有一个jdk1.8.0_111文件下。然后通过vi /etc/profile命令来设置环境变量：

　　　　export JAVA_HOME=/usr/java/jdk1.8.0_111
　　　　export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
　　　　export PATH=$PATH:$JAVA_HOME/bin

　　保存后进入cd /etc目录下，输入source profile命令使修改生效，然后java -version命令查看jdk版本信息。

　6.zoo-sample.cfg文件名统一修改为zoo.cfg

# 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/tmp/zookeeper/data
# 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
server.1=192.168.25.129:2888:3888  
server.2=192.168.25.130:2888:3888
server.3=192.168.25.131:2888:3888

　　

其中：

　　　　initLimit=10: 对于从节点最初连接到主节点时的超时时间，单位为tick值的倍数。

　　　　syncLimit=5：对于主节点与从节点进行同步操作时的超时时间，单位为tick值的倍数。

　　　　dataDir=/tmp/zookeeper: 用于配置内存数据库保存的模糊快照的目录。即刚刚创建的data文件夹就是在此目录中。文件信息都存放在data目录下。

　　　　clientPort=2181: 表示客户端所连接的服务器所监听的端口号，默认是2181。即zookeeper对外提供访问的端口号。　　

　　　　　　server.1=192.168.25.129:2888:3888

                     server.2=192.168.25.130:2888:3888

                     server.3=192.168.25.131:2888:3888

7、新建myid文件：

　　　　在三个linux机器上刚刚创建的data目录下新建一个myid文件并打开，vi myid命令。

　　　　在192.168.25.129机器上输入1，保存退出；在192.168.25.130机器上输入2，保存退出；在192.168.25.131机器上输入3，保存退出。这里的1,2,3是与server1,2,3相对应的。

8、配置环境变量：

　　　　vi  etc/profile 在最后添加如下两个。

　　　　export ZOOKEEPER_HOME=/opt/zookeeper-3.4.6
　　　　export PATH=$PATH:$ZOOKEEPER_HOME/bin:$ZOOKEEPER_HOME/conf

　　　　保存后进入cd /etc目录下，输入source profile命令使修改生效。

9、启动zookeeper：

　　　　分别在3台机器上/opt/zookeeper-3.4.6/bin目录下启动；

　　　　[root@zk1 bin]# zkServer.sh start来启动。

　　　　zkServer.sh restart　　(重启)

　　　　zkServer.sh status　　(查看状态)

　　　　zkServer.sh stop　　(关闭)

　　　　zkServer.sh start-foreground　　(以打印日志方式启动)

　　　　当对三台机器同时 zkServer.sh start启动时，发现都启动成功了，但是以zkServer.sh status命令来查看启动状态时，发现总是在报错，查看报错信息

　　　　报这种异常一般有三种情况：

　　　　（1）：zoo.cfg配置文件中，server.x:2888:3888配置出现错误；

　　　　（2）：myid文件内容和server.x不对应，或者myid不在data目录下；

　　　　（3）：系统防火墙是否在启动。（查看防火墙状态/etc/init.d/iptables status）iptables: Firewall is not running.则是关闭的，若未关闭，则systemctl stop firewalld

　　　　

      修改后启动ZooKeeper集群

在ZooKeeper集群的每个结点上，执行启动ZooKeeper服务的脚本，如下所示：

  1. hadoop@slave-01:~/installation/zookeeper-3.3.4$ tail -500f zookeeper.out   
  2. 2012-01-08 06:51:19,117 - INFO  [main:QuorumPeerConfig@90] - Reading configuration from: /home/hadoop/installation/zookeeper-3.3.4/bin/../conf/zoo.cfg  
  3. 2012-01-08 06:51:19,133 - INFO  [main:QuorumPeerConfig@310] - Defaulting to majority quorums  
  4. 2012-01-08 06:51:19,167 - INFO  [main:QuorumPeerMain@119] - Starting quorum peer  
  5. 2012-01-08 06:51:19,227 - INFO  [main:NIOServerCnxn$Factory@143] - binding to port 0.0.0.0/0.0.0.0:2181  
  6. 2012-01-08 06:51:19,277 - INFO  [main:QuorumPeer@819] - tickTime set to 2000  
  7. 2012-01-08 06:51:19,278 - INFO  [main:QuorumPeer@830] - minSessionTimeout set to -1  
  8. 2012-01-08 06:51:19,279 - INFO  [main:QuorumPeer@841] - maxSessionTimeout set to -1  
  9. 2012-01-08 06:51:19,281 - INFO  [main:QuorumPeer@856] - initLimit set to 5  
  10. 2012-01-08 06:51:19,347 - INFO  [Thread-1:QuorumCnxManager$Listener@473] - My election bind port: 3888  
  11. 2012-01-08 06:51:19,393 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@621] - LOOKING  
  12. 2012-01-08 06:51:19,396 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@663] - New election. My id =  1, Proposed zxid = 0  
  13. 2012-01-08 06:51:19,400 - INFO  [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 1 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 1 (n.sid), LOOKING (my state)  
  14. 2012-01-08 06:51:19,416 - WARN  [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888  
  15. java.net.ConnectException: Connection refused  
  16.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  17.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  18.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  19.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  20.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)  
  21.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)  
  22.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)  
  23.         at java.lang.Thread.run(Thread.java:662)  
  24. 2012-01-08 06:51:19,420 - WARN  [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  25. java.net.ConnectException: Connection refused  
  26.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  27.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  28.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  29.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  30.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)  
  31.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)  
  32.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)  
  33.         at java.lang.Thread.run(Thread.java:662)  
  34. 2012-01-08 06:51:19,612 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888  
  35. java.net.ConnectException: Connection refused  
  36.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  37.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  38.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  39.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  40.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  41.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  42.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  43. 2012-01-08 06:51:19,615 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  44. java.net.ConnectException: Connection refused  
  45.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  46.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  47.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  48.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  49.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  50.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  51.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  52. 2012-01-08 06:51:19,616 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 400  
  53. 2012-01-08 06:51:20,019 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888  
  54. java.net.ConnectException: Connection refused  
  55.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  56.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  57.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  58.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  59.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  60.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  61.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  62. 2012-01-08 06:51:20,021 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  63. java.net.ConnectException: Connection refused  
  64.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  65.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  66.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  67.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  68.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  69.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  70.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  71. 2012-01-08 06:51:20,022 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 800  
  72. 2012-01-08 06:51:20,825 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888  
  73. java.net.ConnectException: Connection refused  
  74.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  75.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  76.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  77.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  78.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  79.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  80.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  81. 2012-01-08 06:51:20,827 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  82. java.net.ConnectException: Connection refused  
  83.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  84.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  85.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  86.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  87.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  88.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  89.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  90. 2012-01-08 06:51:20,828 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 1600  
  91. 2012-01-08 06:51:22,435 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888  
  92. java.net.ConnectException: Connection refused  
  93.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  94.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  95.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  96.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  97.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  98.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  99.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  100. 2012-01-08 06:51:22,439 - WARN  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  101. java.net.ConnectException: Connection refused  
  102.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  103.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  104.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  105.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  106.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)  
  107.         at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)  
  108.         at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)  
  109. 2012-01-08 06:51:22,441 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 3200  
  110. 2012-01-08 06:51:22,945 - INFO  [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 2 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 2 (n.sid), LOOKING (my state)  
  111. 2012-01-08 06:51:22,946 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@721] - Updating proposal  
  112. 2012-01-08 06:51:22,949 - WARN  [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888  
  113. java.net.ConnectException: Connection refused  
  114.         at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)  
  115.         at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)  
  116.         at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)  
  117.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)  
  118.         at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)  
  119.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)  
  120.         at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)  
  121.         at java.lang.Thread.run(Thread.java:662)  
  122. 2012-01-08 06:51:22,951 - INFO  [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 2 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 1 (n.sid), LOOKING (my state)  
  123. 2012-01-08 06:51:23,156 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@643] - FOLLOWING  
  124. 2012-01-08 06:51:23,170 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@80] - TCP NoDelay set to: true  
  125. 2012-01-08 06:51:23,206 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:zookeeper.version=3.3.3-1203054, built on 11/17/2011 05:47 GMT  
  126. 2012-01-08 06:51:23,207 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:host.name=slave-01  
  127. 2012-01-08 06:51:23,207 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.version=1.6.0_30  
  128. 2012-01-08 06:51:23,208 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.vendor=Sun Microsystems Inc.  
  129. 2012-01-08 06:51:23,208 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.home=/home/hadoop/installation/jdk1.6.0_30/jre  
  130. 2012-01-08 06:51:23,209 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.class.path=/home/hadoop/installation/zookeeper-3.3.4/bin/../build/classes:/home/hadoop/installation/zookeeper-3.3.4/bin/../build/lib/*.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../zookeeper-3.3.4.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/log4j-1.2.15.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/jline-0.9.94.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-lang-2.4.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-collections-3.2.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-cli-1.1.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/apache-rat-tasks-0.6.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/apache-rat-core-0.6.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../src/java/lib/*.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../conf:/home/hadoop/installation/jdk1.6.0_30/lib/*.jar:/home/hadoop/installation/jdk1.6.0_30/jre/lib/*.jar  
  131. 2012-01-08 06:51:23,210 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.library.path=/home/hadoop/installation/jdk1.6.0_30/jre/lib/i386/client:/home/hadoop/installation/jdk1.6.0_30/jre/lib/i386:/home/hadoop/installation/jdk1.6.0_30/jre/../lib/i386:/usr/java/packages/lib/i386:/lib:/usr/lib  
  132. 2012-01-08 06:51:23,210 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.io.tmpdir=/tmp  
  133. 2012-01-08 06:51:23,212 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.compiler=<NA>  
  134. 2012-01-08 06:51:23,212 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.name=Linux  
  135. 2012-01-08 06:51:23,212 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.arch=i386  
  136. 2012-01-08 06:51:23,213 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.version=3.0.0-14-generic  
  137. 2012-01-08 06:51:23,213 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.name=hadoop  
  138. 2012-01-08 06:51:23,214 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.home=/home/hadoop  
  139. 2012-01-08 06:51:23,214 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.dir=/home/hadoop/installation/zookeeper-3.3.4  
  140. 2012-01-08 06:51:23,223 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:ZooKeeperServer@151] - Created server with tickTime 2000 minSessionTimeout 4000 maxSessionTimeout 40000 datadir /home/hadoop/storage/zookeeper/version-2 snapdir /home/hadoop/storage/zookeeper/version-2  
  141. 2012-01-08 06:51:23,339 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@294] - Getting a snapshot from leader  
  142. 2012-01-08 06:51:23,358 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@325] - Setting leader epoch 1  
  143. 2012-01-08 06:51:23,358 - INFO  [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FileTxnSnapLog@254] - Snapshotting: 0  
  144. 2012-01-08 06:51:25,511 - INFO  [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 3 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 3 (n.sid), FOLLOWING (my state)  
  145. 2012-01-08 06:51:42,584 - INFO  [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 3 (n.leader), 0 (n.zxid), 2 (n.round), LOOKING (n.state), 3 (n.sid), FOLLOWING (my state)  

我启动的顺序是slave-01>slave-02>slave-03，由于ZooKeeper集群启动的时候，每个结点都试图去连接集群中的其它结点，先启动的肯定连不上后面还没启动的，所以上面日志前面部分的异常是可以忽略的。通过后面部分可以看到，集群在选出一个Leader后，最后稳定了。

其他结点可能也出现类似问题，属于正常。

10、连接到ZooKeeper：

　　　　在命令行中输入：zkCli.sh -server 192.168.25.129:2181，即可连接到其中一台ZooKeeper服务器。其他自动实现同步，客户端只需要和一台保持连接即可。

11.创建zNode节点：

　　　　连接成功后，在屏幕上输入： create  /hello  helloworld即可在主节点上创建一个新的zNode节点。zNode节点名称hello  ，数据helloworld，产看其他节点上同步的数据。

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原文地址：https://www.cnblogs.com/flgb/p/10513755.html