1.Could not find the main class: org.apache.zookeeper.server.quorum.QuorumPeerMain. Program will exit.
安装包损坏，找不到对应文件。重新安装。
2.
2013-03-28 11:13:32,205 - INFO [main:QuorumPeerConfig@90] - Reading configuration from: /root/zookeeper-3.3.5/bin/../conf/zoo.cfg
2013-03-28 11:13:32,209 - INFO [main:QuorumPeerConfig@310] - Defaulting to majority quorums
2013-03-28 11:13:32,217 - INFO [main:QuorumPeerMain@119] - Starting quorum peer
2013-03-28 11:13:32,231 - INFO [main:NIOServerCnxn$Factory@143] - binding to port 0.0.0.0/0.0.0.0:2181
2013-03-28 11:13:32,241 - INFO [main:QuorumPeer@819] - tickTime set to 2000
2013-03-28 11:13:32,241 - INFO [main:QuorumPeer@830] - minSessionTimeout set to -1
2013-03-28 11:13:32,242 - INFO [main:QuorumPeer@841] - maxSessionTimeout set to -1
2013-03-28 11:13:32,242 - INFO [main:QuorumPeer@856] - initLimit set to 10
2013-03-28 11:13:32,250 - INFO [main:FileSnap@82] - Reading snapshot /usr/zookeeper/version-2/snapshot.0
2013-03-28 11:13:32,259 - INFO [Thread-1:QuorumCnxManager$Listener@473] - My election bind port: 3888
2013-03-28 11:13:32,266 - INFO [QuorumPeer:/0.0.0.0:2181:QuorumPeer@621] - LOOKING
2013-03-28 11:13:32,267 - INFO [QuorumPeer:/0.0.0.0:2181:FastLeaderElection@663] - New election. My id = 2, Proposed zxid = 2
2013-03-28 11:13:32,270 - WARN [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 1 at election address /172.16.217.2:3888
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)
如果tomcat服务器异常终止，下次启动时就有可能出现java.net.BindException: Address already in use （端口号被占用）问题，导致启动失败。使用如下命令查看端口号占用情况：
$netstat -pant | grep 8080 ＃-t参数，显示进程号
可以看到，很明显的端口号还在使用中，这是因为tomcat上次的异常终止，导致部分socket没有关闭，也可能是其他原因，根据个人情况而定。如果等待100s，像上图所示的处于 CLOSE_WAIT状态的连接会自动关闭，如果不想等待，执行如下命令，强制终止进程，从上面可以看出，进程号为 7705
也可以使用如下命令查看占用端口号8080的进程号是什么
$fuser -v -n tcp 8080
3.
检测集群中zookeeper启动状态：
通过在控制台输入命令检查集群zookeeper启动状态。
命令如“echo ruok | nc 192.168.3.131 2181”，
控制台输出“imok”
4.
Jps命令无法使用：
输入：echo $JAVA_HOME，如果输出的java路径不正确，则找不到jps
环境变量未注册，jps的目录位于java目录中