为提高效率，提问时请尽量提供详细背景信息，问题描述清晰可优先响应。以下信息点请尽量提供： tidb版本：3.0.3 问题描述：在我运行一段时候后，再连接tidb抛出以下错误： ERROR 2019-11-06 16:59:36 com.taimeitetch.flinketl.facade.impl.ExecuteEngineFacadeImpl.process(85) | org.springframework.dao.RecoverableDataAccessException:
Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 916,696 milliseconds ago. The last packet sent successfully to the server was 916,697 milliseconds ago.
The error may exist in URL [jar:file:/data/flink_process/flinketl-process-1.0.0.jar!/com/taimeitetch/flinketl/service/base/dao/ColumnDescMapper.xml]
The error may involve com.taimeitetch.flinketl.service.base.dao.ColumnDescMapper.selectByTable-Inline
The error occurred while setting parameters
SQL: SHOW COLUMNS FROM edc.edc_subject_item_group_value
Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 916,696 milliseconds ago. The last packet sent successfully to the server was 916,697 milliseconds ago. ; SQL []; Communications link failure
The last packet successfully received from the server was 916,696 milliseconds ago. The last packet sent successfully to the server was 916,697 milliseconds ago.; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 916,696 milliseconds ago. The last packet sent successfully to the server was 916,697 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:74) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:421) at com.sun.proxy.$Proxy17.selectList(Unknown Source) at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:206) at org.apache.ibatis.binding.MapperMethod.executeForMany(MapperMethod.java:114) at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:58) at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:43) at com.sun.proxy.$Proxy20.selectByTable(Unknown Source) at com.taimeitetch.flinketl.service.base.impl.CommonServiceImpl.findTableStructure(CommonServiceImpl.java:152) at com.taimeitetch.flinketl.service.base.impl.CommonServiceImpl.findTableStructureMap(CommonServiceImpl.java:160) at com.taimeitetch.flinketl.service.input.impl.SelectSqlServiceImpl.fetchProcess(SelectSqlServiceImpl.java:83) at com.taimeitetch.flinketl.service.input.impl.SelectSqlServiceImpl.fetchProcess(SelectSqlServiceImpl.java:47) at com.taimeitetch.flinketl.facade.engines.process.impl.OfflineJobProcessImpl.executeByPipeline(OfflineJobProcessImpl.java:165) at com.taimeitetch.flinketl.facade.engines.process.impl.OfflineJobProcessImpl.process(OfflineJobProcessImpl.java:118) at com.taimeitetch.flinketl.facade.engines.impl.FlinkEngineImpl.executeEngin(FlinkEngineImpl.java:37) at com.taimeitetch.flinketl.facade.impl.ExecuteEngineFacadeImpl.process(ExecuteEngineFacadeImpl.java:83) at com.taimeitetch.flinketl.process.FlinkETLProcess.main(FlinkETLProcess.java:58) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.flink.client.program.PackagedProgram.callMainMethod(PackagedProgram.java:529) at org.apache.flink.client.program.PackagedProgram.invokeInteractiveModeForExecution(PackagedProgram.java:421) at org.apache.flink.client.program.ClusterClient.run(ClusterClient.java:423) at org.apache.flink.client.cli.CliFrontend.executeProgram(CliFrontend.java:813) at org.apache.flink.client.cli.CliFrontend.runProgram(CliFrontend.java:287) at org.apache.flink.client.cli.CliFrontend.run(CliFrontend.java:213) at org.apache.flink.client.cli.CliFrontend.parseParameters(CliFrontend.java:1050) at org.apache.flink.client.cli.CliFrontend.lambda$main$11(CliFrontend.java:1126) at org.apache.flink.runtime.security.NoOpSecurityContext.runSecured(NoOpSecurityContext.java:30) at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:1126) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 916,696 milliseconds ago. The last packet sent successfully to the server was 916,697 milliseconds ago. 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:404) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:981) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3652) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2460) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2625) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2551) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1861)
注意：我使用navicat读写该tidb时没有任何问题
以下是我连接池的一些参数： jdbc.maxConnectionsPerPartition=4 jdbc.minConnectionsPerPartition=3 jdbc.partitionCount=3 jdbc.acquireIncrement=5 jdbc.poolAvailabilityThreshold=20
jdbc.idleMaxAgeInMinutes=600 jdbc.connectionTimeoutInMs=600000 jdbc.idleConnectionTestPeriodInMinutes=100 jdbc.maxConnectionAgeInSeconds=36000