title: Siddhi Event Tables are not properly working with Apache storm
body: <p>I have tried to use event tables in my execution plan and try to join table with input stream in  WSO2 CEP v4.1.0 in distributed mode with Apache Storm.</p>
  
  <p>Here is my Siddhi query.</p>
  
  <pre><code>@Plan:name('ExecutionPlan')
  
  @Import('InputStream:1.0.0')
  define stream InputStream (id string, param1 int, param2 double, param3 string, param4 string, param5 string, param6 string, param7 string);
  
  @Export('outputStream:1.0.0')
  define stream OutputStream (id string, param3 string);
  
  @From(eventtable = 'rdbms' , datasource.name = 'MYSQL' , table.name = 'cep') 
  define table cepTable (id string, param1 int, param2 double, param3 string, param4 string, param5 string, param6 string, param7 string);
  
  @name('query1') 
  @dist(parallel='2', execGroup='Filtering')
  partition with ( id of InputStream )
  begin
    from InputStream join cepTable 
    on cepTable.id == InputStream.id 
    select InputStream.id as id, InputStream.param3 as param3  
    insert into OutputStream;
  end;
  </code></pre>
  
  <p>But it provide following exceptions </p>
  
  <pre><code>TID: [-1234] [] [2016-05-13 14:19:11,847] ERROR {org.wso2.carbon.event.processor.admin.EventProcessorAdminService} -  Error while initialising the connection, null 
  org.wso2.carbon.event.processor.core.exception.ExecutionPlanConfigurationException: Error while initialising the connection, null
      at org.wso2.carbon.event.processor.core.EventProcessorDeployer.processDeploy(EventProcessorDeployer.java:154)
      at org.wso2.carbon.event.processor.core.EventProcessorDeployer.executeManualDeployment(EventProcessorDeployer.java:178)
      at org.wso2.carbon.event.processor.core.internal.util.EventProcessorConfigurationFilesystemInvoker.save(EventProcessorConfigurationFilesystemInvoker.java:95)
      at org.wso2.carbon.event.processor.core.internal.CarbonEventProcessorService.editInactiveExecutionPlan(CarbonEventProcessorService.java:181)
      at org.wso2.carbon.event.processor.admin.EventProcessorAdminService.editInactiveExecutionPlan(EventProcessorAdminService.java:108)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke(Method.java:606)
      at org.apache.axis2.rpc.receivers.RPCUtil.invokeServiceClass(RPCUtil.java:212)
      at org.apache.axis2.rpc.receivers.RPCMessageReceiver.invokeBusinessLogic(RPCMessageReceiver.java:117)
      at org.apache.axis2.receivers.AbstractInOutMessageReceiver.invokeBusinessLogic(AbstractInOutMessageReceiver.java:40)
      at org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:110)
      at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
      at org.apache.axis2.transport.local.LocalTransportReceiver.processMessage(LocalTransportReceiver.java:169)
      at org.apache.axis2.transport.local.LocalTransportReceiver.processMessage(LocalTransportReceiver.java:82)
      at org.wso2.carbon.core.transports.local.CarbonLocalTransportSender.finalizeSendWithToAddress(CarbonLocalTransportSender.java:45)
      at org.apache.axis2.transport.local.LocalTransportSender.invoke(LocalTransportSender.java:77)
      at org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:442)
      at org.apache.axis2.description.OutInAxisOperationClient.send(OutInAxisOperation.java:430)
      at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:225)
      at org.apache.axis2.client.OperationClient.execute(OperationClient.java:149)
      at org.wso2.carbon.event.processor.stub.EventProcessorAdminServiceStub.editInactiveExecutionPlan(EventProcessorAdminServiceStub.java:2473)
      at org.apache.jsp.eventprocessor.edit_005fexecution_005fplan_005fajaxprocessor_jsp._jspService(edit_005fexecution_005fplan_005fajaxprocessor_jsp.java:84)
      at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
      at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
      at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
      at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
      at org.wso2.carbon.ui.JspServlet.service(JspServlet.java:155)
      at org.wso2.carbon.ui.TilesJspServlet.service(TilesJspServlet.java:80)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
      at org.eclipse.equinox.http.helper.ContextPathServletAdaptor.service(ContextPathServletAdaptor.java:37)
      at org.eclipse.equinox.http.servlet.internal.ServletRegistration.service(ServletRegistration.java:61)
      at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:128)
      at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:68)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
      at org.wso2.carbon.tomcat.ext.servlet.DelegationServlet.service(DelegationServlet.java:68)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
      at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
      at org.wso2.carbon.ui.filters.CSRFPreventionFilter.doFilter(CSRFPreventionFilter.java:88)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
      at org.wso2.carbon.ui.filters.CRLFPreventionFilter.doFilter(CRLFPreventionFilter.java:59)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
      at org.wso2.carbon.tomcat.ext.filter.CharacterSetFilter.doFilter(CharacterSetFilter.java:61)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
      at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
      at org.wso2.carbon.tomcat.ext.valves.CompositeValve.continueInvocation(CompositeValve.java:99)
      at org.wso2.carbon.tomcat.ext.valves.CarbonTomcatValve$1.invoke(CarbonTomcatValve.java:47)
      at org.wso2.carbon.webapp.mgt.TenantLazyLoaderValve.invoke(TenantLazyLoaderValve.java:57)
      at org.wso2.carbon.event.receiver.core.internal.tenantmgt.TenantLazyLoaderValve.invoke(TenantLazyLoaderValve.java:48)
      at org.wso2.carbon.tomcat.ext.valves.TomcatValveContainer.invokeValves(TomcatValveContainer.java:47)
      at org.wso2.carbon.tomcat.ext.valves.CompositeValve.invoke(CompositeValve.java:62)
      at org.wso2.carbon.tomcat.ext.valves.CarbonStuckThreadDetectionValve.invoke(CarbonStuckThreadDetectionValve.java:159)
      at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
      at org.wso2.carbon.tomcat.ext.valves.CarbonContextCreatorValve.invoke(CarbonContextCreatorValve.java:57)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
      at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)
      at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1739)
      at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1698)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
      at java.lang.Thread.run(Thread.java:745)
  Caused by: org.wso2.siddhi.core.exception.ExecutionPlanRuntimeException: Error while initialising the connection, null
      at org.wso2.siddhi.extension.eventtable.rdbms.DBHandler.&lt;init&gt;(DBHandler.java:79)
      at org.wso2.siddhi.extension.eventtable.RDBMSEventTable.init(RDBMSEventTable.java:119)
      at org.wso2.siddhi.core.util.parser.helper.DefinitionParserHelper.addEventTable(DefinitionParserHelper.java:99)
      at org.wso2.siddhi.core.util.ExecutionPlanRuntimeBuilder.defineTable(ExecutionPlanRuntimeBuilder.java:74)
      at org.wso2.siddhi.core.util.parser.ExecutionPlanParser.defineTableDefinitions(ExecutionPlanParser.java:194)
      at org.wso2.siddhi.core.util.parser.ExecutionPlanParser.parse(ExecutionPlanParser.java:140)
      at org.wso2.siddhi.core.SiddhiManager.createExecutionPlanRuntime(SiddhiManager.java:53)
      at org.wso2.siddhi.core.SiddhiManager.createExecutionPlanRuntime(SiddhiManager.java:61)
      at org.wso2.carbon.event.processor.common.storm.component.SiddhiBolt.init(SiddhiBolt.java:104)
      at org.wso2.carbon.event.processor.common.storm.component.SiddhiBolt.&lt;init&gt;(SiddhiBolt.java:86)
      at org.wso2.carbon.event.processor.core.internal.storm.util.StormTopologyConstructor.constructTopologyBuilder(StormTopologyConstructor.java:114)
      at org.wso2.carbon.event.processor.core.internal.storm.StormTopologyManager.submitTopology(StormTopologyManager.java:127)
      at org.wso2.carbon.event.processor.core.internal.CarbonEventProcessorService.addExecutionPlan(CarbonEventProcessorService.java:314)
      at org.wso2.carbon.event.processor.core.EventProcessorDeployer.processDeploy(EventProcessorDeployer.java:124)
      ... 76 more
  Caused by: java.sql.SQLException
      at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:254)
      at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182)
      at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:701)
      at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:635)
      at org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:188)
      at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:127)
      at org.wso2.siddhi.extension.eventtable.rdbms.DBHandler.&lt;init&gt;(DBHandler.java:73)
      ... 89 more
  Caused by: java.lang.NullPointerException
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:278)
      at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:246)
      ... 95 more
  </code></pre>
  
  <p>What is the reason for it?</p>