error in setting up multiple connections mode in h2 database

Question

currently I am using h2 database in single connection mode. Below is my current config:

javax.persistence.jdbc.url=jdbc:h2:file:sql/xacml;MODE=MySQL

I want to support multiple connections for h2 database and i followed the steps mentioned in the link: http://www.h2database.com/html/tutorial.html#using_server

My new configuration looks like:

javax.persistence.jdbc.url=jdbc:h2:tcp://localhost/var/lib/servers/console/bin/sql/xacml;MODE=MySQL

However when I'm trying to access my UI page which initializes the connection I'm getting following exceptions:

[EL Info]: 2015-05-20 10:57:45.533--ServerSession(428804302)--EclipseLink, version: Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd
[EL Severe]: ejb: 2015-05-20 10:57:48.497--ServerSession(428804302)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.ConnectException: Connection refused: localhost" [90067-174]
Error Code: 90067
[EL Info]: 2015-05-20 10:57:48.502--ServerSession(428804302)--EclipseLink, version: Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd
May 20, 2015 10:57:48 AM com.vaadin.server.DefaultErrorHandler doDefault
SEVERE:
javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.ConnectException: Connection refused: localhost" [90067-174]
Error Code: 90067
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:766)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:204)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.createEntityManagerImpl(EntityManagerFactoryDelegate.java:304)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:336)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:302)
        at com.att.research.xacml.admin.XacmlAdminUI.init(XacmlAdminUI.java:278)
        at com.vaadin.ui.UI.doInit(UI.java:646)
        at com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:214)
        at com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74)
        at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
        at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408)
        at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350)
        at com.att.research.xacml.admin.XacmlAdminUI$Servlet.service(XacmlAdminUI.java:235)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
        at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.ConnectException: Connection refused: localhost" [90067-174]
Error Code: 90067
        at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
        at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:326)
        at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:138)
        at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
        at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.setOrDetectDatasource(DatabaseSessionImpl.java:204)
        at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:741)
        at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:239)
        at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:685)
        ... 35 more
Caused by: org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.ConnectException: Connection refused: localhost" [90067-174]
        at org.h2.message.DbException.getJdbcSQLException(DbException.java:332)
        at org.h2.message.DbException.get(DbException.java:161)
        at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:417)
        at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:305)
        at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:105)
        at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:90)
        at org.h2.Driver.connect(Driver.java:73)
        at java.sql.DriverManager.getConnection(DriverManager.java:664)
        at java.sql.DriverManager.getConnection(DriverManager.java:208)
        at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:98)
        ... 40 more
Caused by: java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
        at java.net.Socket.connect(Socket.java:589)
        at org.h2.util.NetUtils.createSocket(NetUtils.java:119)
        at org.h2.util.NetUtils.createSocket(NetUtils.java:100)
        at org.h2.engine.SessionRemote.initTransfer(SessionRemote.java:100)
        at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:413)
        ... 47 more

Can anyone point me on how to get this configuration working?

Answer 1

The error message seems to indicate the H2 server is not started.

When you're using a H2 server url connection, the server must be started before either by your application or through another java process.

So it's up to you to decide where to put the following magic line, starting the H2 server:

org.h2.tools.Server.createTcpServer('-tcpAllowOthers').start();

Please make sure you've created the H2 database prior to that, and remember the path in server url is relative to where the server was started. So if you put for example the H2 database where the java process was started, you just need the following url jdbc:h2:tcp://localhost/mydatabase