mysql连接异常解决方法

部分异常信息:

2020-05-26 00:00:14,768 [qtp1919892312-15] ERROR [com.thinkgem.jeesite.modules.api.web.RestforUserController] - org.springframework.dao.RecoverableDataAccessException:
### Error querying database. Cause: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 1 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
### The error may exist in file [/opt/download/jetty/webapps/xxxx/WEB-INF/classes/mappings/modules/sys/OfficeDao.xml]
### The error may involve defaultParameterMap
### The error occurred while setting parameters
### SQL: SELECT a.id, a.parent_id AS "parent.id", a.parent_ids, a.area_id AS "area.id", a.code, a.serviceName, a.name, a.sort, a.type, a.grade, a.address, a.longitude, a.latitude, a.logo, a.zip_code, a.master, a.phone, a.fax, a.email, a.applids, a.remarks, a.create_by AS "createBy.id", a.create_date, a.update_by AS "updateBy.id", a.update_date, a.del_flag FROM xxxx a, ( SELECT o.id, o.parent_id, o.parent_ids FROM xxxxx o WHERE o.id = ( SELECT u.company_id FROM sys_user u WHERE u.id = ? AND u.del_flag = '0' ) ) t WHERE ( a.id = t.id AND t.parent_id = '0' ) OR ( FIND_IN_SET( a.id, t.parent_ids ) AND a.parent_id = '0' )
### Cause: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 1 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
; SQL []; Communications link failure

The last packet successfully received from the server was 1 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.; nested exception is com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 1 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
at org.springframework.jdbc.support.SQLExceptionSubclassTranslator.doTranslate(SQLExceptionSubclassTranslator.java:98)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73)
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81)
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:371)
at com.sun.proxy.$Proxy24.selectOne(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:163)
at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:68)
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:52)
at com.sun.proxy.$Proxy52.getTopCompanyIdByClientID(Unknown Source)
at com.thinkgem.jeesite.modules.api.service.UserService.getServiceNameByClientID(UserService.java:236)
at com.thinkgem.jeesite.modules.api.service.UserService$$FastClassBySpringCGLIB$$8b89335.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)

Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet successfully received from the server was 1 milliseconds ago. The last packet sent successfully to the server was 1 milliseconds ago.
at sun.reflect.GeneratedConstructorAccessor55.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:555)
at com.mysql.cj.protocol.a.NativeProtocol.checkErrorMessage(NativeProtocol.java:725)
at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:664)
at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:979)
at com.mysql.cj.NativeSession.execSQL(NativeSession.java:1153)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:951)
... 144 more

解决方法是修改德鲁伊的配置:

原来的德鲁伊配置:

<!-- 配置获取连接等待超时的时间 -->
<property name="maxWait" value="60000"/>
<!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="1200"/>
<!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="30000"/>
<property name="validationQuery" value="SELECT 'x'"/>
<property name="testWhileIdle" value="true"/>
<property name="testOnBorrow" value="false"/>
<property name="testOnReturn" value="false"/>
<!-- 打开removeAbandoned功能 -->
<property name="removeAbandoned" value="true"/>
<!-- 1800秒，也就是30分钟 -->
<property name="removeAbandonedTimeout" value="300"/>
<!-- 关闭abanded连接时输出错误日志 -->
<property name="logAbandoned" value="true"/>
<!-- 配置监控统计拦截的filters -->
<property name="filters" value="stat"/>


修改后的德鲁伊配置:

<!-- 配置获取连接等待超时的时间 -->
<property name="maxWait" value="60000"/>
<!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="1200"/>
<!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="30000"/>
<property name="validationQuery" value="SELECT 1"/>
<property name="keepAlive" value="true"/>
<property name="testWhileIdle" value="true"/>
<property name="testOnBorrow" value="true"/>
<property name="testOnReturn" value="true"/>
<!-- 打开removeAbandoned功能 -->
<property name="removeAbandoned" value="true"/>
<!-- 1800秒，也就是30分钟 -->
<property name="removeAbandonedTimeout" value="3600"/>
<!-- 关闭abanded连接时输出错误日志 -->
<property name="logAbandoned" value="true"/>
<!-- 配置监控统计拦截的filters -->
<property name="filters" value="stat"/>