ZooKeeper的安裝模式分爲三種,分別爲:單機模式(stand-alone)、集羣模式和集羣僞分佈模式。ZooKeeper 單機模式的安裝相對比較簡單,如果第一次接觸ZooKeeper的話,建議安裝ZooKeeper單機模式或者集羣僞分佈模式。
ZooKeeper Standalone模式
從Apache網站上(zookeeper.apache.org)下載ZooKeeper軟件包,我選擇了3.3.4版本的(zookeeper-3.3.4.tar.gz),在一臺Linux機器上安裝非常容易,只需要解壓縮後,簡單配置一下即可以啓動ZooKeeper服務器進程。
將zookeeper-3.3.4/conf目錄下面的 zoo_sample.cfg修改爲zoo.cfg,配置文件內容如下所示:
- tickTime=2000
- dataDir=/home/hadoop/storage/zookeeper
- clientPort=2181
- initLimit=5
- syncLimit=2
- tickTime —— the basic time unit in milliseconds used by ZooKeeper. It is used to do heartbeats and the minimum session timeout will be twice the tickTime.
- dataDir —— the location to store the in-memory database snapshots and, unless specified otherwise, the transaction log of updates to the database.
- clientPort —— the port to listen for client connections
- cd zookeeper-3.3.4/
- bin/zkServer.sh start
在客戶端連接ZooKeeper服務器,執行如下命令:
- bin/zkCli.sh -server dynamic:2181
- bin/zkCli.sh
- hadoop@master:~/installation/zookeeper-3.3.4$ bin/zkCli.sh -server dynamic:2181
- Connecting to dynamic:2181
- 2012-01-08 21:30:06,178 - INFO [main:Environment@97] - Client environment:zookeeper.version=3.3.3-1203054, built on 11/17/2011 05:47 GMT
- 2012-01-08 21:30:06,188 - INFO [main:Environment@97] - Client environment:host.name=master
- 2012-01-08 21:30:06,191 - INFO [main:Environment@97] - Client environment:java.version=1.6.0_30
- 2012-01-08 21:30:06,194 - INFO [main:Environment@97] - Client environment:java.vendor=Sun Microsystems Inc.
- 2012-01-08 21:30:06,200 - INFO [main:Environment@97] - Client environment:java.home=/home/hadoop/installation/jdk1.6.0_30/jre
- 2012-01-08 21:30:06,203 - INFO [main:Environment@97] - Client 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
- 2012-01-08 21:30:06,206 - INFO [main:Environment@97] - Client 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
- 2012-01-08 21:30:06,213 - INFO [main:Environment@97] - Client environment:java.io.tmpdir=/tmp
- 2012-01-08 21:30:06,216 - INFO [main:Environment@97] - Client environment:java.compiler=<NA>
- 2012-01-08 21:30:06,235 - INFO [main:Environment@97] - Client environment:os.name=Linux
- 2012-01-08 21:30:06,244 - INFO [main:Environment@97] - Client environment:os.arch=i386
- 2012-01-08 21:30:06,246 - INFO [main:Environment@97] - Client environment:os.version=3.0.0-14-generic
- 2012-01-08 21:30:06,251 - INFO [main:Environment@97] - Client environment:user.name=hadoop
- 2012-01-08 21:30:06,254 - INFO [main:Environment@97] - Client environment:user.home=/home/hadoop
- 2012-01-08 21:30:06,255 - INFO [main:Environment@97] - Client environment:user.dir=/home/hadoop/installation/zookeeper-3.3.4
- 2012-01-08 21:30:06,264 - INFO [main:ZooKeeper@379] - Initiating client connection, connectString=dynamic:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@bf32c
- 2012-01-08 21:30:06,339 - INFO [main-SendThread():ClientCnxn$SendThread@1061] - Opening socket connection to server dynamic/192.168.0.107:2181
- Welcome to ZooKeeper!
- 2012-01-08 21:30:06,397 - INFO [main-SendThread(dynamic:2181):ClientCnxn$SendThread@950] - Socket connection established to dynamic/192.168.0.107:2181, initiating session
- JLine support is enabled
- 2012-01-08 21:30:06,492 - INFO [main-SendThread(dynamic:2181):ClientCnxn$SendThread@739] - Session establishment complete on server dynamic/192.168.0.107:2181, sessionid = 0x134b9b714f9000c, negotiated timeout = 30000
- WATCHER::
- WatchedEvent state:SyncConnected type:None path:null
- [zk: dynamic:2181(CONNECTED) 0]
接着,可以使用help查看Zookeeper客戶端可以使用的基本操作命令。
ZooKeeper Distributed模式
ZooKeeper分佈式模式安裝(ZooKeeper集羣)也比較容易,這裏說明一下基本要點。
首先要明確的是,ZooKeeper集羣是一個獨立的分佈式協調服務集羣,“獨立”的含義就是說,如果想使用ZooKeeper實現分佈式應用的協調與管理,簡化協調與管理,任何分佈式應用都可以使用,這就要歸功於Zookeeper的數據模型(Data Model)和層次命名空間(Hierarchical Namespace)結構,詳細可以參考http://zookeeper.apache.org/doc/trunk/zookeeperOver.html。在設計你的分佈式應用協調服務時,首要的就是考慮如何組織層次命名空間。
下面說明分佈式模式的安裝配置,過程如下所示:
第一步:主機名稱到IP地址映射配置
ZooKeeper集羣中具有兩個關鍵的角色:Leader和Follower。集羣中所有的結點作爲一個整體對分佈式應用提供服務,集羣中每個結點之間都互相連接,所以,在配置的ZooKeeper集羣的時候,每一個結點的host到IP地址的映射都要配置上集羣中其它結點的映射信息。
例如,我的ZooKeeper集羣中每個結點的配置,以slave-01爲例,/etc/hosts內容如下所示:
- 192.168.0.179 slave-01
- 192.168.0.178 slave-02
- 192.168.0.177 slave-03
ZooKeeper採用一種稱爲Leader election的選舉算法。在整個集羣運行過程中,只有一個Leader,其他的都是Follower,如果ZooKeeper集羣在運行過程中Leader出了問題,系統會採用該算法重新選出一個Leader。因此,各個結點之間要能夠保證互相連接,必須配置上述映射。
ZooKeeper集羣啓動的時候,會首先選出一個Leader,在Leader election過程中,某一個滿足選舉算的結點就能成爲Leader。整個集羣的架構可以參考http://zookeeper.apache.org/doc/trunk/zookeeperOver.html#sc_designGoals。
第二步:修改ZooKeeper配置文件
在其中一臺機器(slave-01)上,解壓縮zookeeper-3.3.4.tar.gz,修改配置文件conf/zoo.cfg,內容如下所示:
- tickTime=2000
- dataDir=/home/hadoop/storage/zookeeper
- clientPort=2181
- initLimit=5
- syncLimit=2
- server.1=slave-01:2888:3888
- server.2=slave-02:2888:3888
- server.3=slave-03:2888:3888
第三步:遠程複製分發安裝文件
上面已經在一臺機器slave-01上配置完成ZooKeeper,現在可以將該配置好的安裝文件遠程拷貝到集羣中的各個結點對應的目錄下:
- cd /home/hadoop/installation/
- scp -r zookeeper-3.3.4/ hadoop@slave-02:/home/hadoop/installation/
- scp -r zookeeper-3.3.4/ hadoop@slave-03:/home/hadoop/installation/
在我們配置的dataDir指定的目錄下面,創建一個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爲什麼數字,則myid文件中就輸入這個數字,例如:
- hadoop@slave-01:~/installation/zookeeper-3.3.4$ echo "1" > /home/hadoop/storage/zookeeper/myid
- hadoop@slave-02:~/installation/zookeeper-3.3.4$ echo "2" > /home/hadoop/storage/zookeeper/myid
- hadoop@slave-03:~/installation/zookeeper-3.3.4$ echo "3" > /home/hadoop/storage/zookeeper/myid
第五步:啓動ZooKeeper集羣
在ZooKeeper集羣的每個結點上,執行啓動ZooKeeper服務的腳本,如下所示:
- hadoop@slave-01:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start
- hadoop@slave-02:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start
- hadoop@slave-03:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start
- hadoop@slave-01:~/installation/zookeeper-3.3.4$ tail -500f zookeeper.out
- 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
- 2012-01-08 06:51:19,133 - INFO [main:QuorumPeerConfig@310] - Defaulting to majority quorums
- 2012-01-08 06:51:19,167 - INFO [main:QuorumPeerMain@119] - Starting quorum peer
- 2012-01-08 06:51:19,227 - INFO [main:NIOServerCnxn$Factory@143] - binding to port 0.0.0.0/0.0.0.0:2181
- 2012-01-08 06:51:19,277 - INFO [main:QuorumPeer@819] - tickTime set to 2000
- 2012-01-08 06:51:19,278 - INFO [main:QuorumPeer@830] - minSessionTimeout set to -1
- 2012-01-08 06:51:19,279 - INFO [main:QuorumPeer@841] - maxSessionTimeout set to -1
- 2012-01-08 06:51:19,281 - INFO [main:QuorumPeer@856] - initLimit set to 5
- 2012-01-08 06:51:19,347 - INFO [Thread-1:QuorumCnxManager$Listener@473] - My election bind port: 3888
- 2012-01-08 06:51:19,393 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@621] - LOOKING
- 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
- 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)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
- at java.lang.Thread.run(Thread.java:662)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
- at java.lang.Thread.run(Thread.java:662)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 2012-01-08 06:51:19,616 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 400
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 2012-01-08 06:51:20,022 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 800
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 2012-01-08 06:51:20,828 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 1600
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404)
- at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688)
- at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622)
- 2012-01-08 06:51:22,441 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 3200
- 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)
- 2012-01-08 06:51:22,946 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@721] - Updating proposal
- 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
- java.net.ConnectException: Connection refused
- at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
- at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
- at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371)
- at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360)
- at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333)
- at java.lang.Thread.run(Thread.java:662)
- 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)
- 2012-01-08 06:51:23,156 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@643] - FOLLOWING
- 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
- 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
- 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
- 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
- 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.
- 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
- 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
- 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
- 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
- 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>
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 2012-01-08 06:51:23,358 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@325] - Setting leader epoch 1
- 2012-01-08 06:51:23,358 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FileTxnSnapLog@254] - Snapshotting: 0
- 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)
- 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)
其他結點可能也出現類似問題,屬於正常。
第六步:安裝驗證
可以通過ZooKeeper的腳本來查看啓動狀態,包括集羣中各個結點的角色(或是Leader,或是Follower),如下所示,是在ZooKeeper集羣中的每個結點上查詢的結果:
- hadoop@slave-01:~/installation/zookeeper-3.3.4$ bin/zkServer.sh status
- JMX enabled by default
- Using config: /home/hadoop/installation/zookeeper-3.3.4/bin/../conf/zoo.cfg
- Mode: follower
- hadoop@slave-02:~/installation/zookeeper-3.3.4$ bin/zkServer.sh status
- JMX enabled by default
- Using config: /home/hadoop/installation/zookeeper-3.3.4/bin/../conf/zoo.cfg
- Mode: leader
- hadoop@slave-03:~/installation/zookeeper-3.3.4$ bin/zkServer.sh status
- JMX enabled by default
- Using config: /home/hadoop/installation/zookeeper-3.3.4/bin/../conf/zoo.cfg
- Mode: follower
另外,可以通過客戶端腳本,連接到ZooKeeper集羣上。對於客戶端來說,ZooKeeper是一個整體(ensemble),連接到ZooKeeper集羣實際上感覺在獨享整個集羣的服務,所以,你可以在任何一個結點上建立到服務集羣的連接,例如:
- hadoop@slave-03:~/installation/zookeeper-3.3.4$ bin/zkCli.sh -server slave-01:2181
- Connecting to slave-01:2181
- 2012-01-08 07:14:21,068 - INFO [main:Environment@97] - Client environment:zookeeper.version=3.3.3-1203054, built on 11/17/2011 05:47 GMT
- 2012-01-08 07:14:21,080 - INFO [main:Environment@97] - Client environment:host.name=slave-03
- 2012-01-08 07:14:21,085 - INFO [main:Environment@97] - Client environment:java.version=1.6.0_30
- 2012-01-08 07:14:21,089 - INFO [main:Environment@97] - Client environment:java.vendor=Sun Microsystems Inc.
- 2012-01-08 07:14:21,095 - INFO [main:Environment@97] - Client environment:java.home=/home/hadoop/installation/jdk1.6.0_30/jre
- 2012-01-08 07:14:21,104 - INFO [main:Environment@97] - Client 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
- 2012-01-08 07:14:21,111 - INFO [main:Environment@97] - Client 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
- 2012-01-08 07:14:21,116 - INFO [main:Environment@97] - Client environment:java.io.tmpdir=/tmp
- 2012-01-08 07:14:21,124 - INFO [main:Environment@97] - Client environment:java.compiler=<NA>
- 2012-01-08 07:14:21,169 - INFO [main:Environment@97] - Client environment:os.name=Linux
- 2012-01-08 07:14:21,175 - INFO [main:Environment@97] - Client environment:os.arch=i386
- 2012-01-08 07:14:21,177 - INFO [main:Environment@97] - Client environment:os.version=3.0.0-14-generic
- 2012-01-08 07:14:21,185 - INFO [main:Environment@97] - Client environment:user.name=hadoop
- 2012-01-08 07:14:21,188 - INFO [main:Environment@97] - Client environment:user.home=/home/hadoop
- 2012-01-08 07:14:21,190 - INFO [main:Environment@97] - Client environment:user.dir=/home/hadoop/installation/zookeeper-3.3.4
- 2012-01-08 07:14:21,197 - INFO [main:ZooKeeper@379] - Initiating client connection, connectString=slave-01:2181 sessionTimeout=30000 watcher=org.apache.zookeeper.ZooKeeperMain$MyWatcher@bf32c
- 2012-01-08 07:14:21,305 - INFO [main-SendThread():ClientCnxn$SendThread@1061] - Opening socket connection to server slave-01/192.168.0.179:2181
- Welcome to ZooKeeper!
- 2012-01-08 07:14:21,376 - INFO [main-SendThread(slave-01:2181):ClientCnxn$SendThread@950] - Socket connection established to slave-01/192.168.0.179:2181, initiating session
- JLine support is enabled
- [zk: slave-01:2181(CONNECTING) 0] 2012-01-08 07:14:21,872 - INFO [main-SendThread(slave-01:2181):ClientCnxn$SendThread@739] - Session establishment complete on server slave-01/192.168.0.179:2181, sessionid = 0x134bdcd6b730000, negotiated timeout = 30000
- WATCHER::
- WatchedEvent state:SyncConnected type:None path:null
- [zk: slave-01:2181(CONNECTED) 0] ls /
- [zookeeper]
集羣僞分佈模式
簡單來說,集羣僞分佈模式就是在單機下模擬集羣的ZooKeeper服務。
那麼,如何對配置 ZooKeeper 的集羣僞分佈模式呢?其實很簡單,在 zookeeper 配置文檔中, clientPort參數用來設置客戶端連接 zookeeper 的端口。 server.1=IP1:2887:3887 中, IP1 指示的是組成 ZooKeeper 服務的機器 IP 地址, 2887 爲用來進行 leader 選舉的端口, 3887 爲組成 ZooKeeper 服務的機器之間通信的端口。集羣僞分佈模式我們使用每個配置文檔模擬一臺機器,也就是說,需要在單臺機器上運行多個 zookeeper 實例。但是,我們必須要保證各個配置文檔的 clientPort 不能衝突。
下面是我們所配置的集羣僞分佈模式,通過 zoo1.cfg , zoo2.cfg , zoo3.cfg 模擬了三臺機器的 ZooKeeper集羣。詳見代碼清單 C :
代碼清單C : zoo1.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.
dataDir=/root/hadoop-0.20.2/zookeeper-3.3.1/d_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 :
# 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.
dataDir=/root/hadoop-0.20.2/zookeeper-3.3.1/d_2
# the port at which the clients will connect
clientPort=2182
#the location of the log file
dataLogDir=/root/hadoop-0.20.2/zookeeper-3.3.1/logs
server.1=localhost:2887:3887
server.2=localhost:2888:3888
server.3=localhost:2889:3889
zoo3.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.
dataDir=/root/hadoop-0.20.2/zookeeper-3.3.1/d_2
# the port at which the clients will connect
clientPort=2183
#the location of the log file
dataLogDir=/root/hadoop-0.20.2/zookeeper-3.3.1/logs
server.1=localhost:2887:3887
server.2=localhost:2888:3888
server.3=localhost:2889:3889
從上述三個代碼清單中可以看到,除了 clientPort 不同之外, dataDir 也不同。另外,不要忘記在 dataDir 所對應的目錄中創建 myid 文件來指定對應的 zookeeper 服務器實例。
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下面來說明zookeeper結合sheepdog的安裝和使用:
首先下載源碼包:
wget http://mirror.bjtu.edu.cn/apache/zookeeper/zookeeper-3.4.5/zookeeper-3.4.5.tar.gz
然後執行:$ tar -zxvf zookeeper-x.x.x.tar.gz $ cd zookeeper-x.x.x/src/c $ ./configure --prefix=/usr $ make $ make install然後修改配置文件,如下所示:
$ cd zookeeper-x.x.x/conf $ mv zoo_sample.cfg zoo.cfg #Setting this to 0 entirely removes the limit on concurrent connections. $ echo "maxClientCnxns=0" >> zoo.cfg $ mkdir -p /tmp/zookeeper然後啓動:
$ sudo ./bin/zkServer.sh start安裝sheepdog:
$ git clone git://github.com/collie/sheepdog.git $ cd sheepdog/ $ ./configure --enable-zookeeper $ make $ sudo make install使用zookeeper作爲集羣控制器啓動sheepdog:
$ sudo sheep /store -c zookeeper:IP1:2181,IP2:2181,IP3:2181 # use default 30s heartbeat or $ sudo sheep /store -c zookeeper:IP1:2181,IP2:2181,IP3:2181,timeout=10s # use 10s heartbeat for small sized cluster like 30 nodes.做完這些事情後,就可以體驗一下,集羣的感覺了。