问题描述：在安装cdh元数据myslq高可用时，使用的是myslq主主复制+keepalived实现。期间发现切换时，出现如下异常信息！
花了很长时间寻找问题的原因。因为切换的时候，使用本机命令行是可以连接的，但是夸服务器就无法连接，没有去这方面的尝试，后来使用navicate无法连接后，就推测是mysql高可用切换的问题导致的。
问题分析：如果不重启keepalived，是无法实现切换和连接的。以下问题就是由于这个原因导致的，本质是无法连接mysql，不是jar包的问题。网上很多人的异常是因为mysql驱动问题，错误不太一样 。
解决方案：
1)尝试手工重启services keepalived restart ，后问题解决
2)当mysql切换的时候，自动重启另外一台服务器的keepalived。通过配置脚本的方式来解决。本质原因还是在重启的时候不能执行：
/opt/model/keepalived-2.0.0/shell/sqlCdh2.sh
#!/bin/bash
service keepalived restart
cat /opt/model/keepalived-2.0.0/shell/restartCdh2Keepalived.sh
ssh root@172.17.10.153 nohup /opt/model/keepalived-2.0.0/shell/sqlCdh2.sh >/opt/model/keepalived-2.0.0/shell/result.txt 2>&1 &
调用重启
cat /root/shutdown
/opt/model/keepalived-2.0.0/shell/restartCdh2Keepalived.sh
sleep 10#这句话必须要加上，否则不能重启另外一台服务的keepalived
killall keepalived
cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id mysql-ha
}
vrrp_instance VI_1 {
state BACKUP
interface ens32
virtual_router_id 201
#优先级，高优先级竞选为master
priority 100
advert_int 1
#设置为不抢占 注：这个配置只能设置在backup主机上，而且这个主机优先级要比另外一台高，另一台不要设置这个选项
nopreempt
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
172.17.10.155
}
}
virtual_server 172.17.10.155 3306 {
delay_loop 2
lb_algo rr
lb_kind DR
persistence_timeout 60
protocol TCP
real_server 172.17.10.152 3306 {
weight 1
notify_down /root/shutdown.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 2
delay_before_retry 1
}
}
}
异常信息：
2018-12-18 17:45:21,820 FATAL org.apache.oozie.service.Services: SERVER[cdh3] Runtime Exception during Services Load. Check your list of ‘oozie.services’ or ‘oozie.services.ext’
2018-12-18 17:45:21,825 FATAL org.apache.oozie.service.Services: SERVER[cdh3] E0103: Could not load service classes, Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
org.apache.oozie.service.ServiceException: E0103: Could not load service classes, Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
at org.apache.oozie.service.Services.loadServices(Services.java:309)
at org.apache.oozie.service.Services.init(Services.java:213)
at org.apache.oozie.servlet.ServicesLoader.contextInitialized(ServicesLoader.java:46)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4210)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4709)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:802)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:583)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:944)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:779)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:505)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1322)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:325)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1068)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:822)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1060)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
at org.apache.catalina.core.StandardService.start(StandardService.java:525)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:759)
at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
Caused by: <openjpa-2.2.2-r422266:1468616 fatal general error> org.apache.openjpa.persistence.PersistenceException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
at org.apache.openjpa.jdbc.sql.DBDictionaryFactory.newDBDictionary(DBDictionaryFactory.java:102)
at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.getDBDictionaryInstance(JDBCConfigurationImpl.java:603)
at org.apache.openjpa.jdbc.meta.MappingRepository.endConfiguration(MappingRepository.java:1518)
at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:531)
at org.apache.openjpa.lib.conf.Configurations.configureInstance(Configurations.java:456)
at org.apache.openjpa.lib.conf.PluginValue.instantiate(PluginValue.java:120)
at org.apache.openjpa.conf.MetaDataRepositoryValue.instantiate(MetaDataRepositoryValue.java:68)
at org.apache.openjpa.lib.conf.ObjectValue.instantiate(ObjectValue.java:83)
at org.apache.openjpa.conf.OpenJPAConfigurationImpl.newMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:967)
at org.apache.openjpa.conf.OpenJPAConfigurationImpl.getMetaDataRepositoryInstance(OpenJPAConfigurationImpl.java:958)
at org.apache.openjpa.kernel.AbstractBrokerFactory.makeReadOnly(AbstractBrokerFactory.java:644)
at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:203)
at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:156)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:227)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:154)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:60)
at org.apache.oozie.service.JPAService.getEntityManager(JPAService.java:500)
at org.apache.oozie.service.JPAService.init(JPAService.java:201)
at org.apache.oozie.service.Services.setServiceInternal(Services.java:386)
at org.apache.oozie.service.Services.setService(Services.java:372)
at org.apache.oozie.service.Services.loadServices(Services.java:305)
… 26 more
Caused by: org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)
at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
at org.apache.openjpa.lib.jdbc.DelegatingDataSource.getConnection(DelegatingDataSource.java:110)
at org.apache.openjpa.lib.jdbc.DecoratingDataSource.getConnection(DecoratingDataSource.java:87)
at org.apache.openjpa.jdbc.sql.DBDictionaryFactory.newDBDictionary(DBDictionaryFactory.java:91)
… 46 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1121)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:357)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2482)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2519)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2304)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:834)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:416)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:346)
at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)
at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)
at org.apache.commons.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)
at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)
… 51 more
Caused by: java.net.ConnectException: Connection refused
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at java.net.Socket.<init>(Socket.java:434)
at java.net.Socket.<init>(Socket.java:244)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:259)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:307)
… 67 more
———————
作者：liygcoding
来源：本人博客地址
原文：https://blog.csdn.net/wumiqing1/article/details/85088373
