zookeeper是一个为分布式应用所设计的分布式的、开源的调度服务，它主要用来解决分布式应用中经常遇到的一些数据管理问题，简化分布式应用，协调及其管理的难度，提高性能的分布式服务。
本章的目的：如何安装zookeeper（在win7环境下），zookeeper下载https://mirrors.cnnic.cn/apache/zookeeper/。这里下载的版本是3.4.8.
zoomkeeper本身是可以单节点模式安装运行，不过一般为了确保zookeeper的稳定性和可用性，都会采用分布式部署，也进而保证了分布式应用的可靠性。它在分布式zookepper集群中，会基于选举算法来实现一个leader，多个follower。
参考文章：http://blog.csdn.net/lovesummerforever/article/details/48975703
单节点安装：
1）下载zookeeper-3.4.8.tar.gz,并解压到目录：D:Workzookeeperzookeeper-3.4.8下
2）进入conf目录下把zoo_sample.cfg文件重名为：zoo.cfg，并修改配置为如下:
# 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=D:\Work\zookeeper\data # log config dataLogDir=D:\Work\zookeeper\log # 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
3）启动zookeeper服务：
进入目录：D:Workzookeeperzookeeper-3.4.8in，执行zkServer.cmd，这样就启动了zookeeper服务了。
--启动打印信息 D:Workzookeeperzookeeper-3.4.8in>zkServer.cmd D:Workzookeeperzookeeper-3.4.8in>call "D:Program FilesJavajdk1.8.0_111"injava "-Dzookeeper.log.dir=D:Workzookeeperzookeeper-3.4.8in.." "-Dzookeeper.root.logger=INFO,CONSOLE" -cp "D:Workzookeeperzookeeper-3.4.8in..uildclasses;D:Workzookeeperzookeeper-3.4.8in..uildlib*;D:Workzookeeperzookeeper-3.4.8in..*;D:Workzookeeperzookeeper-3.4.8in..lib*;D:Workzookeeperzookeeper-3.4.8in..conf" org.apache.zookeeper.server.quorum.QuorumPeerMain "D:Workzookeeperzookeeper-3.4.8in..confzoo.cfg" 2017-09-09 21:02:58,180 [myid:] - INFO [main:QuorumPeerConfig@103] - Reading configuration from: D:Workzookeeperzookeeper-3.4.8in..confzoo.cfg 2017-09-09 21:02:58,204 [myid:] - INFO [main:DatadirCleanupManager@78] - autopurge.snapRetainCount set to 3 2017-09-09 21:02:58,205 [myid:] - INFO [main:DatadirCleanupManager@79] - autopurge.purgeInterval set to 0 2017-09-09 21:02:58,205 [myid:] - INFO [main:DatadirCleanupManager@101] - Purge task is not scheduled. 2017-09-09 21:02:58,211 [myid:] - WARN [main:QuorumPeerMain@113] - Either no config or no quorum defined in config, running in standalone mode 2017-09-09 21:02:58,445 [myid:] - INFO [main:QuorumPeerConfig@103] - Reading configuration from: D:Workzookeeperzookeeper-3.4.8in..confzoo.cfg 2017-09-09 21:02:58,446 [myid:] - INFO [main:ZooKeeperServerMain@95] - Starting server 2017-09-09 21:02:58,769 [myid:] - INFO [main:Environment@100] - Server environment:zookeeper.version=3.4.8--1, built on 02/06/2016 03:18 GMT 2017-09-09 21:02:58,772 [myid:] - INFO [main:Environment@100] - Server environment:host.name=192.168.233.1 2017-09-09 21:02:58,777 [myid:] - INFO [main:Environment@100] - Server environment:java.version=1.8.0_111 2017-09-09 21:02:58,778 [myid:] - INFO [main:Environment@100] - Server environment:java.vendor=Oracle Corporation 2017-09-09 21:02:58,780 [myid:] - INFO [main:Environment@100] - Server environment:java.home=D:Program FilesJavajdk1.8.0_111jre 2017-09-09 21:02:58,782 [myid:] - INFO [main:Environment@100] - Server environment:java.class.path=D:Workzookeeperzookeeper-3.4.8in..uildclasses;D:Workzookeeperzookeeper-3.4.8in..uildlib*;D:Workzookeeperzookeeper-3.4.8in..zookeeper-3.4.8.jar;D:Workzookeeperzookeeper-3.4.8in..libjline-0.9.94.jar;D:Workzookeeperzookeeper-3.4.8in..liblog4j-1.2.16.jar;。。。2017-09-09 21:02:58,784 [myid:] - INFO [main:Environment@100] - Server environment:java.library.path=D:Program FilesJavajdk1.8.0_111in;D:Program FilesJavajdk1.8.0_111in;D:Program FilesJavajdk1.8.0_111jrein; . 2017-09-09 21:02:58,789 [myid:] - INFO [main:Environment@100] - Server environment:java.io.tmpdir=C:UsersADMINI~1AppDataLocalTemp 2017-09-09 21:02:58,791 [myid:] - INFO [main:Environment@100] - Server environment:java.compiler=<NA> 2017-09-09 21:02:58,800 [myid:] - INFO [main:Environment@100] - Server environment:os.name=Windows 7 2017-09-09 21:02:58,801 [myid:] - INFO [main:Environment@100] - Server environment:os.arch=amd64 2017-09-09 21:02:58,804 [myid:] - INFO [main:Environment@100] - Server environment:os.version=6.1 2017-09-09 21:02:58,811 [myid:] - INFO [main:Environment@100] - Server environment:user.name=Administrator 2017-09-09 21:02:58,813 [myid:] - INFO [main:Environment@100] - Server environment:user.home=C:UsersAdministrator 2017-09-09 21:02:58,816 [myid:] - INFO [main:Environment@100] - Server environment:user.dir=D:Workzookeeperzookeeper-3.4.8in 2017-09-09 21:02:58,849 [myid:] - INFO [main:ZooKeeperServer@787] - tickTime set to 2000 2017-09-09 21:02:58,851 [myid:] - INFO [main:ZooKeeperServer@796] - minSessionTimeout set to -1 2017-09-09 21:02:58,852 [myid:] - INFO [main:ZooKeeperServer@805] - maxSessionTimeout set to -1 2017-09-09 21:03:00,548 [myid:] - INFO [main:NIOServerCnxnFactory@89] - binding to port 0.0.0.0/0.0.0.0:2181 --当客户端启动后，就立即打印出来以下信息： 2017-09-09 21:05:23,463 [myid:] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxnFactory@192] - Accepted socket connection from /127.0.0.1:33988 2017-09-09 21:05:23,483 [myid:] - INFO [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:ZooKeeperServer@900] - Client attempting to establish new session at /127.0.0.1:33988 2017-09-09 21:05:23,496 [myid:] - INFO [SyncThread:0:FileTxnLog@199] - Creating new log file: log.1 2017-09-09 21:05:23,542 [myid:] - INFO [SyncThread:0:ZooKeeperServer@645] - Established session 0x15e66bc75ec0000 with negotiated timeout 30000 for client /127.0.0.1:33988
4）启动客户端
进入目录：D:Workzookeeperzookeeper-3.4.8in，执行zkCli.cmd -server 127.0.0.1:2181，这样就启动了zookeeper服务了。
D:Workzookeeperzookeeper-3.4.8in>zkCli.cmd -server 127.0.0.1:2181 Connecting to 127.0.0.1:2181 2017-09-09 21:05:21,934 [myid:] - INFO [main:Environment@100] - Client environment:zookeeper.version=3.4.8--1, built on 02/06/2016 03:18 GMT 2017-09-09 21:05:21,942 [myid:] - INFO [main:Environment@100] - Client environment:host.name=192.168.233.1 2017-09-09 21:05:21,943 [myid:] - INFO [main:Environment@100] - Client environment:java.version=1.8.0_111 2017-09-09 21:05:21,947 [myid:] - INFO [main:Environment@100] - Client environment:java.vendor=Oracle Corporation 2017-09-09 21:05:21,948 [myid:] - INFO [main:Environment@100] - Client environment:java.home=D:Program FilesJavajdk1.8.0_111jre 2017-09-09 21:05:21,949 [myid:] - INFO [main:Environment@100] - Client environment:java.class.path=D:Workzookeeperzookeeper-3.4.8in..uildclasses;D:Workzookeeperzookeeper-3.4.8in..。。。。; . 2017-09-09 21:05:21,960 [myid:] - INFO [main:Environment@100] - Client environment:java.io.tmpdir=C:UsersADMINI~1AppDataLocalTemp 2017-09-09 21:05:21,963 [myid:] - INFO [main:Environment@100] - Client environment:java.compiler=<NA> 2017-09-09 21:05:21,965 [myid:] - INFO [main:Environment@100] - Client environment:os.name=Windows 7 2017-09-09 21:05:21,967 [myid:] - INFO [main:Environment@100] - Client environment:os.arch=amd64 2017-09-09 21:05:21,969 [myid:] - INFO [main:Environment@100] - Client environment:os.version=6.1 2017-09-09 21:05:21,973 [myid:] - INFO [main:Environment@100] - Client environment:user.name=Administrator 2017-09-09 21:05:21,975 [myid:] - INFO [main:Environment@100] - Client environment:user.home=C:UsersAdministrator 2017-09-09 21:05:21,977 [myid:] - INFO [main:Environment@100] - Client environment:user.dir=D:Workzookeeperzookeeper-3.4.8in 2017-09-09 21:05:21,983 [myid:] - INFO [main:ZooKeeper@438] - Initiating client connection, connectString=127.0.0.1:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@7aec35a Welcome to ZooKeeper! 2017-09-09 21:05:23,459 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$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) 2017-09-09 21:05:23,464 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@876] - Socket connection established to 127.0.0.1/127.0.0.1:2181, initiating session JLine support is enabled [zk: 127.0.0.1:2181(CONNECTING) 0] 2017-09-09 21:05:23,548 [myid:] - INFO [main-SendThread(127.0.0.1:2181):ClientCnxn$SendThread@1299] - Session establishmentcomplete on server 127.0.0.1/127.0.0.1:2181, sessionid = 0x15e66bc75ec0000, negotiated timeout = 30000 WATCHER:: WatchedEvent state:SyncConnected type:None path:null
这样就安装完成了单节点zookeeper服务。
伪分布式安装：
伪分布式安装就是在同一台pc上安装，安装时使用同一个zookeeper包，多个配置文件分别配置为不同的端口。
1）将D:Workzookeeperzookeeper-3.4.8conf下的zoo.cfg分别复制出文件zoo1.cfg,zoo2.cfg,zoo3.cfg三个文件，分别修改配置为：
zoo1.cfg
# the directory where the snapshot is stored. # do not use /tmp for storage, /tmp here is just # example sakes. dataDir=D:\Work\zookeeper\data\1 # log config dataLogDir=D:\Work\zookeeper\log\1 # the port at which the clients will connect clientPort=2181 server.1=localhost:2887:3887 server.2=localhost:2888:3888 server.3=localhost:2889:3889
zoo2.cfg
# do not use /tmp for storage, /tmp here is just # example sakes. dataDir=D:\Work\zookeeper\data\2 # log config dataLogDir=D:\Work\zookeeper\log\2 # the port at which the clients will connect clientPort=2182 server.1=localhost:2887:3887 server.2=localhost:2888:3888 server.3=localhost:2889:3889
zoo3.cfg
# the directory where the snapshot is stored. # do not use /tmp for storage, /tmp here is just # example sakes. dataDir=D:\Work\zookeeper\data\3 # log config dataLogDir=D:\Work\zookeeper\log\3 # the port at which the clients will connect clientPort=2183 server.1=localhost:2887:3887 server.2=localhost:2888:3888 server.3=localhost:2889:3889
备注：
假设把配置文件表示为：zoo{num}.cfg, server.{num}=ip/domain:Port1:Port2
其中num：表示数字表示第几号服务器；ip/domain ：是服务器域名或者ip地址。
Port1：表示这个服务器和集群中的Leader服务器交换信息的端口；
Port2：表示万一集群中的Leader服务器挂了，需要一个端口重新进行选举，选出一个新的Leader，这个端口就是用来执行选举时服务器相互通信的端口。
由于我们是伪集群，所以ip或者域名是一样的，所以要分配不同的端口号
2）创建目录D:Workzookeeperdata1,D:Workzookeeperdata2,D:Workzookeeperdata3
分别在三个文件下创建myid文件，文件内容依次为：1，2，3
3）进入D:Workzookeeperzookeeper-3.4.8in下复制文件zkServer.cmd为zkServer-1.cmd,zkServer-2.cmd,zkServer-3.cmd
zkServer-1.cmd内容修改为如下：
setlocal call "%~dp0zkEnv.cmd" set ZOOMAIN=org.apache.zookeeper.server.quorum.QuorumPeerMain set ZOOCFG=D:\Work\zookeeper\zookeeper-3.4.8\conf\zoo1.cfg echo on call %JAVA% "-Dzookeeper.log.dir=%ZOO_LOG_DIR%" "-Dzookeeper.root.logger=%ZOO_LOG4J_PROP%" -cp "%CLASSPATH%" %ZOOMAIN% "%ZOOCFG%" %* endlocal
zkServer-2.cmd内容修改为如下：
setlocal call "%~dp0zkEnv.cmd" set ZOOMAIN=org.apache.zookeeper.server.quorum.QuorumPeerMain set ZOOCFG=D:\Work\zookeeper\zookeeper-3.4.8\conf\zoo2.cfg echo on call %JAVA% "-Dzookeeper.log.dir=%ZOO_LOG_DIR%" "-Dzookeeper.root.logger=%ZOO_LOG4J_PROP%" -cp "%CLASSPATH%" %ZOOMAIN% "%ZOOCFG%" %* endlocal
zkServer-3.cmd内容修改为如下：
setlocal call "%~dp0zkEnv.cmd" set ZOOMAIN=org.apache.zookeeper.server.quorum.QuorumPeerMain set ZOOCFG=D:\Work\zookeeper\zookeeper-3.4.8\conf\zoo3.cfg echo on call %JAVA% "-Dzookeeper.log.dir=%ZOO_LOG_DIR%" "-Dzookeeper.root.logger=%ZOO_LOG4J_PROP%" -cp "%CLASSPATH%" %ZOOMAIN% "%ZOOCFG%" %* endlocal
4）分别启动zkServer-1.cmd,zkServer-2.cmd,zkServer-3.cmd
进入目录：D:Workzookeeperzookeeper-3.4.8in，分布执行zkServer-1.cmd,zkServer-2.cmd,zkServer-3.cmd,启动伪分布式zookeeper集群，启动过程中如果前两个启动的服务户出现异常情况为正常，直到3个zkServer-x.cmd都启动完后就不会出现异常情况。
