Я получаю эту ошибку (не так часто):

2013-05-08 16:44:35,786  WARN (JDBCExceptionReporter.java:100) [org.hibernate.util.JDBCExceptionReporter, logExceptions] - SQL Error: 0, SQLState: 08S01
2013-05-08 16:44:35,786 ERROR (JDBCExceptionReporter.java:101) [org.hibernate.util.JDBCExceptionReporter, logExceptions] - 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.
2013-05-08 16:44:35,833 ERROR (AdminDaoImpl.java:297) [com.myapp.admin.db.AdminDaoImpl, createFilePackage] - data-upload: Exception while adding new file package
org.hibernate.exception.JDBCConnectionException: Cannot open connection
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:97) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1354) [hibernate-core-3.3.2.GA.jar:3.3.2.GA]
    at com.myapp.admin.db.AdminDaoImpl. createFilePackage(AdminDaoImpl.java:182) [AdminDaoImpl.class:na]
    at com.myapp.admin.ctrl.UploadController.processUploadZip(UploadController.java:217) [UploadController.class:na]
    at sun.reflect.GeneratedMethodAccessor106.invoke(Unknown Source) [na:na]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) [na:1.6.0_35]
    at java.lang.reflect.Method.invoke(Method.java:597) [na:1.6.0_35]
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:212) [spring-web-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:126) [spring-web-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:96) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:617) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:578) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:900) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789) [spring-webmvc-3.1.0.RELEASE.jar:3.1.0.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:647) [servlet-api.jar:na]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728) [servlet-api.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) [catalina.jar:7.0.35]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.35]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) [catalina.jar:7.0.35]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) [catalina.jar:7.0.35]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) [catalina.jar:7.0.35]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [catalina.jar:7.0.35]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) [catalina.jar:7.0.35]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) [catalina.jar:7.0.35]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) [catalina.jar:7.0.35]
    at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:200) [tomcat-coyote.jar:7.0.35]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) [tomcat-coyote.jar:7.0.35]
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310) [tomcat-coyote.jar:7.0.35]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_35]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_35]
    at java.lang.Thread.run(Thread.java:662) [na:1.6.0_35]
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

У меня есть два веб-приложения (Spring mvc + Hibernate + MySQL), размещенных на общем сервере:

1) главное приложение для показа файлов для скачивания (которое вставляется через приложение администратора)

2) приложение администратора с операциями CRUD

Эта ошибка появляется когда-то, когда я использую "админ» приложение для загрузки файлов »главный" Приложение, скажем, может быть после успешной загрузки / обработки около 100-120 файлов / запросов и при каждом обращении к базе данных с 10-20 запросами на вставку / обновление.

Детали хостинга:

Private tomcat hosting
java 1.6.0_35-b10
tomcat 7.0.35
heap size 288MB
MySQL Server 5
commons-dbcp 1.2.2
mysql-connector-java 5.1.9

Свойства базы данных + Hibernate + DBCP:

    
    
    
    

    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    


hibernate.dialect=org.hibernate.dialect.MySQLDialect
hibernate.hbm2ddl.auto=none
hibernate.jdbc.batch_size=100
hibernate.show_sql=false
hibernate.format_sql=false
hibernate.cache.use_second_level_cache=true
hibernate.cache.use_query_cache=false
hibernate.cache.provider_class=org.hibernate.cache.NoCacheProvider
hibernate.current_session_context_class=thread

Заинтересованный кодекс:

public String createFilePackage(FilePackage package) {
    String message = "";

    Session session = getSessionFactory().openSession();
    Transaction tx = null;
    try {
        tx = session.beginTransaction();

        // handling package, around 10-14 DB insert, 10 SELECT and 5 update queries on same session

        tx.commit();

    } catch(Exception e) {
        logger.error("file-upload: Exception while adding new font package", e);
        if(tx != null) { tx.rollback(); }
    } finally {
        session.close();
    }
    return message;
}

любой посоветуете как решить эту проблему?