Question

我更改了休眠超时设置以及空闲时间，但它无法正常工作我的hibernate属性是

 <property name="hibernate.c3p0.min_size">5</property>
    <property name="hibernate.c3p0.max_size">20</property>
    <property name="hibernate.c3p0.timeout">300000</property>
    <property name="hibernate.c3p0.max_statements">50</property>
    <property name="hibernate.c3p0.idle_test_period">300000</property>

并且，我得到了以下异常：

Exception in thread "main" org.hibernate.exception.JDBCConnectionException: unable to obtain isolated JDBC connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:103)
    at org.hibernate.id.enhanced.TableGenerator$1.getNextValue(TableGenerator.java:530)
    at org.hibernate.id.enhanced.NoopOptimizer.generate(NoopOptimizer.java:40)
    at org.hibernate.id.enhanced.TableGenerator.generate(TableGenerator.java:526)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:105)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:682)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:674)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:669)
    at com.ihealthmantra.upload.com.ihealthmantra.customer.upload.service.SellerUploadImpl.lambda$4(SellerUploadImpl.java:801)
    at java.util.ArrayList.forEach(Unknown Source)
    at com.ihealthmantra.upload.com.ihealthmantra.customer.upload.service.SellerUploadImpl.createTimeSlotUploadedSeller(SellerUploadImpl.java:738)
    at com.ihealthmantra.upload.com.ihealthmantra.customer.upload.service.SellerUploadImpl.populateSlot(SellerUploadImpl.java:1146)
    at com.ihealthmantra.upload.App.main(App.java:81)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 820,677 milliseconds ago.  The last packet sent successfully to the server was 820,679 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990)
    at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3746)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2509)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2480)
    at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4811)
    at com.mchange.v2.c3p0.impl.NewProxyConnection.setAutoCommit(NewProxyConnection.java:912)
    at org.hibernate.c3p0.internal.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:78)
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:386)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:48)
    ... 17 more
Caused by: java.net.SocketException: Connection reset by peer: socket write error

之前工作正常，但随着最近的数据增长，它开始抛出异常。

Answer 1

...服务器是820,679毫秒前。比服务器长配置值为＆＃39; wait_timeout＆＃39; ...

似乎与数据库服务器的连接所花费的时间比为超时设置的值要长。在你的例外中也提到了它。

要解决此问题，您可以增加超时值或使用autoReconnect=true字符串传递JDBC（如您的例外中所述）

要更改MySQL中的wait_timeout值，您可以参考现有帖子。

MySQL wait_timeout Variable - GLOBAL vs SESSION

或

将autoReconnect=true附加到您的JDBC网址字符串

jdbc:mysql://localhost:3306/exodb?autoReconnect=true

如何解决无法获取隔离的JDBC连接？

1 个答案: