Failed to connect to the database after several deployments to the server

Question

Failed to connect to the database after several deployments to the server

I uploaded my war file to my server, it works fine after deployment, but after a while it shows an exception. I use struts2 and hibernate

my hibernate.cfg.xml

 <session-factory> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/dbName</property> <property name="hibernate.connection.username">UserName</property> <property name="hibernate.connection.password">Password</property> <property name="hibernate.connection.zeroDateTimeBehavior">round</property> <property name="autoReconnect">true</property> <property name="show_sql">true</property> <property name="format_sql">true</property> <property name="maxIdleTime">0</property> <property name="use_sql_comments">true</property> <property name="hibernate.connection.pool_size">20</property> <property name="hibernate.current_session_context_class">org.hibernate.context.ThreadLocalSessionContext</property> <property name="current_session_context_class">thread</property> </session-factory>

On the console After executing the request, it displays the following Exception

 263512233 [http-bio-12414-exec-1768] WARN org.hibernate.util.JDBCExceptionReporter - SQL Error: 0, SQLState: 08003 263512233 [http-bio-12414-exec-1768] ERROR org.hibernate.util.JDBCExceptionReporter - No operations allowed after connection closed.Connection was implicitly closed by the driver. org.hibernate.exception.JDBCConnectionException: could not execute query at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:99) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.loader.Loader.doList(Loader.java:2545) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2276) at org.hibernate.loader.Loader.list(Loader.java:2271) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:459) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:365) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1268) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102) at iland.login.LoginBusiness.HbmLogin(LoginBusiness.java:104) at iland.login.LoginAction.doLogin(LoginAction.java:53) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450) at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563) at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.Connection was implicitly closed by the driver. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:407) at com.mysql.jdbc.Util.getInstance(Util.java:382) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927) at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1213) at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1200) at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4203) at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4169) at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:534) at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:452) at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1700) at org.hibernate.loader.Loader.doQuery(Loader.java:801) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:274) at org.hibernate.loader.Loader.doList(Loader.java:2542) ... 77 more Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 102,104,208 milliseconds ago. The last packet sent successfully to the server was 102,104,208 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(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:407) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3348) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1967) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2626) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2111) at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2273) at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208) at org.hibernate.loader.Loader.getResultSet(Loader.java:1953) at org.hibernate.loader.Loader.doQuery(Loader.java:802) ... 79 more Caused by: java.net.SocketException: Broken pipe at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92) at java.net.SocketOutputStream.write(SocketOutputStream.java:136) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65) at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123) at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3329) ... 87 more Hibernate: /* insert iland.hbm.ErrorLog */ insert into xrcwrn_retail_shop.error_log (class, method, line_no, error, add_date) values (?, ?, ?, ?, ?) Aug 19, 2014 5:23:08 AM com.opensymphony.xwork2.util.logging.commons.CommonsLogger error SEVERE: Exception occurred during processing request: null java.lang.NullPointerException at iland.login.LoginBusiness.LoginSessionSave(LoginBusiness.java:123) at iland.login.LoginBusiness.HbmLogin(LoginBusiness.java:116) at iland.login.LoginAction.doLogin(LoginAction.java:53) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450) at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:239) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:161) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563) at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:964) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:515) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:662)

How to solve the problem above. So that he can work normally all the time.

Edit: After several hours of deployment, the problem is higher. On my server, I am using Apache Tomcat 7 and my sql database.

New addition: Added the following data

 <property name="hibernate.c3p0.min_size">5</property> <property name="hibernate.c3p0.max_size">20</property> <property name="hibernate.c3p0.timeout">0</property> <property name="hibernate.c3p0.max_statements">50</property> <property name="hibernate.c3p0.idle_test_period">0</property>

There is still a problem, what kind of modification / addition should I do here

+7

java mysql hibernate c3p0

xrcwrn Aug 19 '14 at 10:31

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4 answers

Roman c · Answer 1 · 2014-08-22T16:54:16+0000

In your configuration properties, you used the c3p0 maxIdleTime property, but the c3p0 properties are configured using the c3p0. prefix c3p0. or hibernate.c3p0. . Note that enabling any of the c3p0 properties automatically enables the corresponding connection provider using the sleep mode heuristic. It is not visible in the log that you are using c3p0. If you have not configured data sources, then Hibernate will use hibernate.connection.provider_class org.hibernate.connection.DriverManagerConnectionProvider . This connection provider has a built-in rudimentary connection pool for which you can set hibernate.connection.pool_size , but it is used only for development purposes. Never use it in a production environment.

You may have an endless discussion of the topic How to fix java.net.SocketException: Broken pipe . After a while, you will realize that you still have open connections in the pool that suddenly close on the other side for the following reasons:

Firewalls or routers can block connection downtime (MySQL client / server protocol is not ping).
The MySQL server can close unoccupied connections that exceed wait_timeout or the interactive_timeout threshold.

You can use the following tips to help resolve these issues:

A recent version of the JDBC driver (5.1.13+) is used.
Make sure wait_timeout and interactive_timeout set high enough. Check if interactiveClient .
Make sure tcpKeepalive turned on.
Make sure that any configurable firewall or router timeout settings allow the maximum expected connection downtime.
Make sure the connections are valid when used in the connection pool. Use a query starting with /* ping */ to do a light ping instead of a full query. Please note: the ping syntax must be exactly as specified here.
Explicitly test the connection before using it if the connection remains inactive for a long period of time.
To minimize the duration of disconnection of the connection object when executing different application logic.

To accomplish some of these options, you are better off using a connection pool that you can use with Hibernate. Hibernate has support for commons-dbcp, c3p0 and proxool. You can also configure the JNDI data source on the web server for use in sleep mode, it has a connection pool. See Chapter 7 Connector Connector Pool / J.

If you like to configure Hibernate with c3p0, you should read this How-To to configure the C3P0 connection pool . To configure the dbcp example, you should check this MySQL, Hibernate, and Broken Pipe Exception message. No matter which connection pool you use, it is up to you.

Amuletxheart · Answer 2 · 2014-08-19T10:38:53+0000

Which server are you using? Do you host a service such as OpenShift on a cloud platform?

Usually for free plans, your site will rotate for a while after idle. When accessing again after a while, the web server spins faster, but the database server spins more slowly, causing a connection error. Usually just refreshing the page several times will wake everything up and go well.

https://www.openshift.com/products/pricing in the Continuous Gear section

Update: if you are working on your own server,

Change this line to the next for quick fix.

 <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/dbName?autoReconnect=true</property>

See this question for a better understanding.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: no action is allowed after closing the connection

John r · Answer 3 · 2014-08-19T14:03:16+0000

The problem arises because the application stops opening connections for too long, and something synchronizes them. One of the three reasons is disconnection:

Firewall between application server and database server
OS database server
Database engine

Are you considering setting maxIdleTime to a non-zero value or setting Hibernate to use a connection pool that can periodically check connections (thereby keeping the TCP connection open) or cancel them after they have been open for a certain period of time ?

Tee_shady · Answer 4 · 2014-08-22T07:27:40+0000

You need to configure downtime and configure connection pool, I recommend c3p0

http://www.mkyong.com/hibernate/how-to-configure-the-c3p0-connection-pool-in-hibernate/

You can also describe here how to configure the parameters and how they work.

What are the required C3P0 settings for sleep mode to avoid blocking.

In some cases, when you "modify" your application from the outside, errors may occur

Failed to connect to the database after several deployments to the server

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