Ubuntu16.04安装配置使用Zookeeper集群
集群系统环境
Zookeeper集群可以使用单节点或者多节点进行配置，但节点的数量必须要求为奇数个，这是因为需要符合zookeeper的选举机制。这里使用仍使用三个节点进行配置。前提：各个主机中/etc/hostname和/etc/hosts文件中已经配置好对应主机名称和IP信息。
- heron01: IP
- heron02: IP
- heron03: IP
说明：该文章为Heron高可用集群配置的一部分内容，因此集群环境沿用集群配置中的内容。
下载安装Zookeeper
1. 这里使用了手动下载：下载地址 。这里选择了3.10.4的版本（2017-10-04）
2. 解压安装文件至指定目录，我的这里为：/home/yitian/zookeeper
yitian@ubuntu:~/zookeeper$ tar -zxvf zookeeper-3.4.10.tar.gz配置Zookeeper集群
准备工作：关闭Ubuntu的防火墙：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/conf$ sudo ufw disable
Firewall stopped and disabled on system startup
1. 修改配置文件：在/zookeeper-3.10.4/conf/目录下，复制zoo_sample.cfg文件为zoo.cfg，修改后如下：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/conf$ ll
total 24
...
-rw-rw-r-- 1 yitian yitian 535 Mar 23 2017 configuration.xsl
-rw-rw-r-- 1 yitian yitian 2161 Mar 23 2017 log4j.properties
-rw-rw-r-- 1 yitian yitian 1025 Feb 16 01:40 zoo.cfg
-rw-rw-r-- 1 yitian yitian 922 Mar 23 2017 zoo_sample.cfg
2. 编辑zoo.cfg文件，（1）修改和添加zookeeper中的dataDir和dataLogDir目录（zoo.cfg文件中可以找到默认的配置项）：
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just
# example sakes.
# zookeeper的DATA文件路径，在zookeeper集群环境下，需要在该路径下配置不同的myid文件
dataDir=/home/yitian/zookeeper/data
dataLogDir=/home/yitian/zookeeper/logs
（2）其他配置项保持默认，在配置文件末尾添加需要配置的集群信息;
server.1=heron01:2888:3888 # 这里使用三台主机
server.2=heron02:2888:3888
server.3=heron03:2888:3888
3. 在集群中各个主机的DataDir目录下，配置各自的myid文件。在之前设置的dataDir（/home/yitian/zookeeper/data # zookeeper）中新建myid文件, 写入一个数字, 该数字表示这是第几号server. 该数字必须和zoo.cfg文件中的server.X中的X一一对应.并且同一集群内每个节点的数字是不相同的。
heron01，heron02，heron03中myid文件内容分别如下：
yitian@heron01:~/zookeeper/data$ cat myid
1
yitian@heron02:~/zookeeper/data$ cat myid
2
yitian@heron03:~/zookeeper/data$ cat myid
3
至此，zookeeper集群配置完毕。
启动并查看状态
对集群中的每个节点配置完成如上步骤后，依次启动各个节点的zookeeper（如下命令）：
启动heron01：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Error contacting service. It is probably not running.
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... already running as process 3467.
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: leader启动heron02：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/conf$ ../bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Error contacting service. It is probably not running.
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/conf$ ../bin/zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/conf$ ../bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
启动heron03：
yitian@ubuntu:~$ ./zookeeper/zookeeper-3.4.10/bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Error contacting service. It is probably not running.
yitian@ubuntu:~$ ./zookeeper/zookeeper-3.4.10/bin/zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
yitian@ubuntu:~$ ./zookeeper/zookeeper-3.4.10/bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: follower
可以看到，此时heron01为leader，heron02和heron03为follower。这里zookeeper的选举机制和原理可参考zookeeper的文档这里不再赘述。至此，zookeeper集群安装配置完成。
常见问题和解决方法
1. 在启动heron02中zookeeper之后，3888端口已经监听，但仍启动失败，情况如下：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ netstat -tunlp
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.1.1:53 0.0.0.0:* LISTEN -
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN -
tcp6 0 0 :::35789 :::* LISTEN 3467/java
tcp6 0 0 192.168.201.129:3888 :::* LISTEN 3467/java
tcp6 0 0 :::22 :::* LISTEN -
tcp6 0 0 :::2181 :::* LISTEN 3467/java
udp 0 0 0.0.0.0:5353 0.0.0.0:* -
udp 0 0 0.0.0.0:44346 0.0.0.0:* -
udp 0 0 0.0.0.0:59810 0.0.0.0:* -
udp 0 0 127.0.1.1:53 0.0.0.0:* -
udp 0 0 0.0.0.0:68 0.0.0.0:* -
udp 0 0 0.0.0.0:631 0.0.0.0:* -
udp6 0 0 :::5353 :::* -
udp6 0 0 :::58146 :::*
而且，启动zookeeper时出现如下情况：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Error contacting service. It is probably not running.
问题解决：之前没有关闭防火墙，现在关闭防火墙重启zookeeper命令，防火墙关闭命令见上面，重启后如下：
yitian@ubuntu:~/zookeeper/zookeeper-3.4.10/bin$ ./zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... already running as process 3467. # 启动成功2. 启动heron01主机中zookeeper时，总是mode：standalone模式，防护墙已关闭，但出现情况如下：
yitian@ubuntu:~$ ./zookeeper/zookeeper-3.4.10/bin/zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
yitian@ubuntu:~$ ./zookeeper/zookeeper-3.4.10/bin/zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/yitian/zookeeper/zookeeper-3.4.10/bin/../conf/zoo.cfg
Mode: standalone
查看jps，无QuorumPeerMain进程。且查看日志记录（/home/yitian/zookeeper/zookeeper-3.4.10/bin/zookeeper.out）有如下错误：
java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67)
at org.apache.zookeeper.server.NIOServerCnxnFactory.configure(NIOServerCnxnFactory.java:90)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.runFromConfig(QuorumPeerMain.java:130)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:111)
at org.apache.zookeeper.server.quorum.QuorumPeerMain.main(QuorumPeerMain.java:78)问题原因：2181端口被其他进程占用（停止zkServer.sh没有用）。（1）首先查看端口占用情况：（切换至root用户，可以查看进程PID）：
root@ubuntu:/home/yitian/zookeeper/zookeeper-3.4.10/conf# netstat -nltp | grep 2181
tcp6 0 0 :::2181 :::* LISTEN 1111/java （2）杀死该zookeeper进程，然后重新启动，即可解决该问题：
root@ubuntu:/home/yitian/zookeeper/zookeeper-3.4.10/conf# kill -9 1111
root@ubuntu:/home/yitian/zookeeper/zookeeper-3.4.10/conf# netstat -nltp | grep 2181
参考资料
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Ubuntu16.04安装配置ZooKeeper集群