VelocityServlet: Error processing the template

Cannot open connection
org.hibernate.exception.LockAcquisitionException: Cannot open connection at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:87) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:420) at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144) at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:129) at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57) at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1290) at sun.reflect.GeneratedMethodAccessor35.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:301) at $Proxy0.beginTransaction(Unknown Source) at org.apache.roller.business.hibernate.HibernatePersistenceStrategy.getSession(HibernatePersistenceStrategy.java:91) at org.apache.roller.business.hibernate.HibernatePersistenceStrategy.load(HibernatePersistenceStrategy.java:200) at org.apache.roller.business.hibernate.HibernateUserManagerImpl.getWebsite(HibernateUserManagerImpl.java:531) at org.apache.roller.business.hibernate.HibernateUserManagerImpl.getWebsiteByHandle(HibernateUserManagerImpl.java:553) at org.apache.roller.presentation.velocity.RSDServlet.handleRequest(RSDServlet.java:80) at org.apache.velocity.servlet.VelocityServlet.doRequest(VelocityServlet.java:358) at org.apache.velocity.servlet.VelocityServlet.doGet(VelocityServlet.java:317) at javax.servlet.http.HttpServlet.service(HttpServlet.java:689) at javax.servlet.http.HttpServlet.service(HttpServlet.java:802) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:292) at org.acegisecurity.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:108) at org.acegisecurity.intercept.web.SecurityEnforcementFilter.doFilter(SecurityEnforcementFilter.java:197) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:143) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.wrapper.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:50) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.securechannel.ChannelProcessingFilter.doFilter(ChannelProcessingFilter.java:168) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:154) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:246) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:220) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:303) at org.acegisecurity.util.FilterChainProxy.doFilter(FilterChainProxy.java:173) at org.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:120) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.roller.presentation.filters.SchemeEnforcementFilter.doFilter(SchemeEnforcementFilter.java:121) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.roller.presentation.filters.CharEncodingFilter.doFilter(CharEncodingFilter.java:104) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.apache.catalina.valves.FastCommonAccessLogValve.invoke(FastCommonAccessLogValve.java:481) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:595) Caused by: java.sql.SQLException: ORA-02391: exceeded simultaneous SESSIONS_PER_USER limit at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331) at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:283) at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:278) at oracle.jdbc.driver.T4CTTIoauthenticate.receiveOauth(T4CTTIoauthenticate.java:785) at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:362) at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java:414) at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:165) at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35) at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801) at org.apache.commons.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:82) at org.apache.commons.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:300) at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:816) at org.apache.commons.dbcp.AbandonedObjectPool.borrowObject(AbandonedObjectPool.java:119) at org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:140) at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:518) at org.hibernate.connection.DatasourceConnectionProvider.getConnection(DatasourceConnectionProvider.java:69) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:417) ... 62 more