初識zookeeper(一)之zookeeper的安裝及配置
1、簡要介紹
zookeeper是一個分布式的應用程序協調服務,是Hadoop和Hbase的重要組件,是一個樹型的目錄服務,支持變更推送。除此還可以用作dubbo服務的注冊中心。
2、安裝
2.1 下載安裝
wget http://mirrors.cnnic.cn/apache/zookeeper/zookeeper-3.4.6/zookeeper-3.4.6.tar.gz tar -zxvf zookeeper-3.4.6.tar.gz cd zookeeper-3.4.6 cp conf/zoo_sample.cfg conf/zoo.cfg
2.2 配置
2.2.1 單點方式
(1)修改zoo.cfg,如果沒有特殊要求,全部默認也可以,主要修改的地方就是dataDir 和 clientPort,如下:
tickTime=2000 initLimit=10 syncLimit=5 dataDir=/app/soft/zookeeper-3.4.6/data (換成真實輸出目錄) clientPort=2181
#tickTime:這個時間是作為 Zookeeper 服務器之間或客戶端與服務器之間維持心跳的時間間隔,也就是每個 tickTime 時間就會發送一個心跳,以毫秒為單位。
#initLimit:LF初始通信時限,集群中的follower服務器(F)與leader服務器(L)之間初始連接時能容忍的最多心跳數(tickTime的數量)
#syncLimit:集群中的follower服務器與leader服務器之間請求和應答之間能容忍的最多心跳數(tickTime的數量)。
#dataDir:顧名思義就是 Zookeeper 保存數據的目錄,默認情況下,Zookeeper 將寫數據的日志文件也保存在這個目錄里。
#clientPort:這個端口就是客戶端連接 Zookeeper 服務器的端口,Zookeeper 會監聽這個端口,接受客戶端的訪問請求。
#dataLogDir:日志文件目錄,Zookeeper保存日志文件的目錄
#服務器名稱與地址:集群信息(服務器編號,服務器地址,LF通信端口,選舉端口),規則如:server.N=yyy:A:B
#其中N表示服務器編號,YYY表示服務器的IP地址,A為LF通信端口,表示該服務器與集群中的leader交換的信息的端口。B為選舉端口,表示選舉新leader時服務器間相互通信的端口(當leader掛掉時,其余服務器會相互通信,選擇出新的leader)。一般來說,集群中每個服務器的A端口都是一樣,每個服務器的B端口也是一樣。但是當所采用的為偽集群時,IP地址都一樣,只能時A端口和B端口不一樣。
(2)啟動:bin/zkServer.sh start
(3)查看是否成功:bin/zkServer.sh status
(4)查看日志:vi zooKeeper.out
2.2.2 集群方式(單IP多節點)
(1)拷貝3份zookeeper-3.4.6.tar.gz,如zookeeper_node1、zookeeper_node2、zookeeper_node3,結構如下:
(2)進入zookeeper_node1--->conf,修改zoo.cfg,如下:
tickTime=2000 initLimit=10 syncLimit=5 dataDir=/app/soft/zookeeper_node1/data (換成真實輸出目錄) clientPort=2181 server.1=127.0.0.1:2888:3888 server.2=127.0.0.1:2889:3889
server.3=127.0.0.1:2890:3890
(3)然后在上面dataDir對應的目錄下創建myid文件,如下:
mkdir data vi myid
myid指明自己的id,對應上面zoo.cfg中"server."后的數字,第一臺的內容為1,第二臺的內容為2,第三臺的內容為3,內容如下:
1
(4)依次類推,調整2、3節點的地址及端口,如下:
節點2:
tickTime=2000 initLimit=10 syncLimit=5 dataDir=/app/soft/zookeeper_node2/data (換成真實輸出目錄) clientPort=2182 server.1=127.0.0.1:2888:3888 server.2=127.0.0.1:2889:3889 server.3=127.0.0.1:2890:3890
節點3:
tickTime=2000 initLimit=10 syncLimit=5 dataDir=/app/soft/zookeeper_node3/data (換成真實輸出目錄) clientPort=2183 server.1=127.0.0.1:2888:3888 server.2=127.0.0.1:2889:3889 server.3=127.0.0.1:2890:389
(5),修改節點2、3的myid;
(6)啟動服務,如下:
[root@localhost soft]# zookeeper_node1/bin/zkServer.sh start JMX enabled by default Using config: /app/soft/zookeeper_node1/bin/../conf/zoo.cfg Starting zookeeper ... STARTED [root@localhost soft]# vi zookeeper.out 2015-06-25 05:43:13,252 [myid:] - INFO [main:QuorumPeerConfig@103] - Reading configuration from: /app/soft/zookeeper_nod 2015-06-25 05:43:13,257 [myid:] - INFO [main:QuorumPeerConfig@340] - Defaulting to majority quorums 2015-06-25 05:43:13,260 [myid:1] - INFO [main:DatadirCleanupManager@78] - autopurge.snapRetainCount set to 3 2015-06-25 05:43:13,260 [myid:1] - INFO [main:DatadirCleanupManager@79] - autopurge.purgeInterval set to 0 2015-06-25 05:43:13,262 [myid:1] - INFO [main:DatadirCleanupManager@101] - Purge task is not scheduled. 2015-06-25 05:43:13,273 [myid:1] - INFO [main:QuorumPeerMain@127] - Starting quorum peer 2015-06-25 05:43:13,285 [myid:1] - INFO [main:NIOServerCnxnFactory@94] - binding to port 0.0.0.0/0.0.0.0:2181 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@959] - tickTime set to 2000 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@979] - minSessionTimeout set to -1 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@990] - maxSessionTimeout set to -1 2015-06-25 05:43:13,315 [myid:1] - INFO [main:QuorumPeer@1005] - initLimit set to 10 2015-06-25 05:43:13,359 [myid:1] - INFO [Thread-1:QuorumCnxManager$Listener@504] - My election bind port: /127.0.0.1:388 2015-06-25 05:43:13,371 [myid:1] - INFO [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:QuorumPeer@714] - LOOKING 2015-06-25 05:43:13,374 [myid:1] - INFO [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:FastLeaderElection@815] - New election. 2015-06-25 05:43:13,252 [myid:] - INFO [main:QuorumPeerConfig@103] - Reading configuration from: /app/soft/zookeeper_node1/bin/../conf/zoo.cfg 2015-06-25 05:43:13,257 [myid:] - INFO [main:QuorumPeerConfig@340] - Defaulting to majority quorums 2015-06-25 05:43:13,260 [myid:1] - INFO [main:DatadirCleanupManager@78] - autopurge.snapRetainCount set to 3 2015-06-25 05:43:13,260 [myid:1] - INFO [main:DatadirCleanupManager@79] - autopurge.purgeInterval set to 0 2015-06-25 05:43:13,262 [myid:1] - INFO [main:DatadirCleanupManager@101] - Purge task is not scheduled. 2015-06-25 05:43:13,273 [myid:1] - INFO [main:QuorumPeerMain@127] - Starting quorum peer 2015-06-25 05:43:13,285 [myid:1] - INFO [main:NIOServerCnxnFactory@94] - binding to port 0.0.0.0/0.0.0.0:2181 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@959] - tickTime set to 2000 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@979] - minSessionTimeout set to -1 2015-06-25 05:43:13,312 [myid:1] - INFO [main:QuorumPeer@990] - maxSessionTimeout set to -1 2015-06-25 05:43:13,315 [myid:1] - INFO [main:QuorumPeer@1005] - initLimit set to 10 2015-06-25 05:43:13,359 [myid:1] - INFO [Thread-1:QuorumCnxManager$Listener@504] - My election bind port: /127.0.0.1:3888 2015-06-25 05:43:13,371 [myid:1] - INFO [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:QuorumPeer@714] - LOOKING 2015-06-25 05:43:13,374 [myid:1] - INFO [QuorumPeer[myid=1]/0:0:0:0:0:0:0:0:2181:FastLeaderElection@815] - New election. My id = 1, proposed zxid=0x2 2015-06-25 05:43:13,376 [myid:1] - INFO [WorkerReceiver[myid=1]:FastLeaderElection@597] - Notification: 1 (message format version), 1 (n.leader), 0x2 (n.zxid), 0x1 (n.round), LOOKING (n.state), 1 (n.sid), 0x1 (n.peerEpoch) LOOKING (my state) 2015-06-25 05:43:13,379 [myid:1] - WARN [WorkerSender[myid=1]:QuorumCnxManager@382] - Cannot open channel to 2 at election address /127.0.0.1:3889 java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:579) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:368) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:341) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:449) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:430) at java.lang.Thread.run(Thread.java:745) 2015-06-25 05:43:13,385 [myid:1] - WARN [WorkerSender[myid=1]:QuorumCnxManager@382] - Cannot open channel to 3 at election address /127.0.0.1:3890 java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
發現報錯,是因為2、3節點服務還未啟動。按照節點1的啟動方式,依次啟動2、3節點,再次查看日志,發現服務正常。
查看日志命令:vi zookeeper.out
(7)查看服務狀態,如下:
[root@localhost soft]# zookeeper_node1/bin/zkServer.sh status JMX enabled by default Using config: /app/soft/zookeeper_node1/bin/../conf/zoo.cfg Mode: follower [root@localhost soft]# zookeeper_node2/bin/zkServer.sh status JMX enabled by default Using config: /app/soft/zookeeper_node2/bin/../conf/zoo.cfg Mode: leader [root@localhost soft]# zookeeper_node3/bin/zkServer.sh status JMX enabled by default Using config: /app/soft/zookeeper_node3/bin/../conf/zoo.cfg Mode: follower
可以看出1是follower,2是leader,3是follower。
Zookeeper部署中的坑
坑之一
Error contacting service. It is probably not running
在配置完zookeeper集群后,三個節點,分別啟動三個節點如下:
[root@master bin]# zkServer.sh start
JMX enabled by default
Using config: /usr/local/zk/bin/../conf/zoo.cfg
Starting zookeeper … STARTED
在查看zookeeper狀態時遇到
[root@master bin]# zkServer.sh status
JMX enabled by default
Using config: /usr/local/zk/bin/../conf/zoo.cfg
Error contacting service. It is probably not running.
而其他兩個節點卻是現實正常;
分析原因并解決:
分析方法:
先stop 掉原zk
zkServer.sh stop
然后以start-foreground方式啟動,會看到啟動日志
zkServer.sh start-foreground
本文地址:http://www.paymoon.com:8001/index.php/2015/06/04/zookeeper-building/
一些常見原因:
原因之一
其原因是在編輯zoo.cfg配置文件時,指定了log的輸出目錄,但是卻未創建。
因此需要按照里面指定的目錄進行創建。
mkdir /tmp/zookeeper/log |
原因之二
最后檢查配置zoo.cfg配置發現是該節點的主機名寫錯了;先停止三個節點zookeeper服務,逐一的修改節點上zoo.cfg配置文件,在逐一的啟動 ,結果顯示正常;
PS: zk類的安裝搭建過程中, 如果報錯, 一定要把status中的錯誤貼出來, 其它的信息不容易找到答案.
原因之三
1
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Caused by: java.lang.IllegalArgumentException: ./zookeeper/myid file is missing
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