title: getting "oracle.net.ns.NetException: Socket read timed out" error
body: <p>Getting "Socket read timed out" Exception while Connection to oracle database frequently. On restart server and database it works for sometimes but after sometimes it getting again. What is the root cause of below exception.</p>
  
  <pre><code>Mar 20, 2018 2:37:37 PM org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptions
  ERROR: IO Error: Socket read timed out
  Mar 20, 2018 2:37:37 PM org.apache.catalina.core.StandardWrapperValve invoke
  SEVERE: Servlet.service() for servlet [mvc] in context with path [/bl] threw exception [org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Could not open connection] with root cause
  oracle.net.ns.NetException: Socket read timed out
  at oracle.net.ns.Packet.receive(Packet.java:321)
  at oracle.net.ns.NSProtocol.connect(NSProtocol.java:287)
  at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1054)
  at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:308)
  at oracle.jdbc.driver.PhysicalConnection.&lt;init&gt;(PhysicalConnection.java:536)
  at oracle.jdbc.driver.T4CConnection.&lt;init&gt;(T4CConnection.java:228)
  at  oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
  at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:521)
  at org.apache.commons.dbcp2.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:39)
  at org.apache.commons.dbcp2.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:256)
  at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:861)
  at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:435)
  at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:363)
  at org.apache.commons.dbcp2.PoolingDataSource.getConnection(PoolingDataSource.java:134)
  at org.apache.commons.dbcp2.BasicDataSource.getConnection(BasicDataSource.java:1533)
  at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:139)
  at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:380)
  at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:228)
  at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:171)
  at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:63)
  at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:162)
  at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:186)
  at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:160)
  at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1885)
  at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1862)
  at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1839)
  at org.hibernate.loader.Loader.doQuery(Loader.java:910)
  at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:355)
  at org.hibernate.loader.Loader.doList(Loader.java:2554)
  at org.hibernate.loader.Loader.doList(Loader.java:2540)
  at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2370)
  at org.hibernate.loader.Loader.list(Loader.java:2365)
  at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:497)
  at  org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:387)
  at  org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:236)
  at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1300)
  at org.hibernate.internal.QueryImpl.list(QueryImpl.java:103)
  at org.hibernate.jpa.internal.QueryImpl.list(QueryImpl.java:573)
  at org.hibernate.jpa.internal.QueryImpl.getResultList(QueryImpl.java:449)
  at com.leafletcorp.dao.impl.UserDaoImpl.getUserById(UserDaoImpl.java:87)
  at com.leafletcorp.service.impl.UserServiceImpl.findUser(UserServiceImpl.java:563)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
  at java.lang.reflect.Method.invoke(Unknown Source)
  at  org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
  at  org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
  at  org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
  at  org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
  at  org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
  at  org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
  at  org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
  at   org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
  at  org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
  at  org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
        at com.sun.proxy.$Proxy131.findUser(Unknown Source)
  at com.leafletcorp.web.LoginController.home(LoginController.java:528)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
  at java.lang.reflect.Method.invoke(Unknown Source)
  at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
  at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
  at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
  at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
  at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
  at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
  at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
  at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
  at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at com.leafletcorp.sso.ServiceProviderSSOFilter.doFilter(ServiceProviderSSOFilter.java:220)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at com.leafletcorp.interceptors.LogSessionServletFilter.doFilter(LogSessionServletFilter.java:35)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:178)
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
  at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
  at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
  at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
  at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
  at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
  at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
  at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
  at java.lang.Thread.run(Unknown Source)
  </code></pre>
  
  <p>It works on restart server but after sometime it throws same exception. Can anybody explain root cause of this ?</p>