JPA-Verbindung zu MySQL löst "ZU VIELEN VERBINDUNGEN" Fehler

Question

Ich versuche, eine Verbindung zu MySQL-Datenbank über den Application-Server Glassfish und JPA.

Mein persistence.xml sieht wie folgt aus:

<?xml version="1.0" encoding="UTF-8"?> 
<persistence version="2.1" 
xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> 
<persistence-unit name="WEBSERVIE-EJB" 
    transaction-type="JTA"> 
    <jta-data-source>AVS_TWO</jta-data-source> 
    <properties> 
     <property name="eclipselink.ddl-generation" value="create-or-extend-tables" />   
    </properties> 
</persistence-unit> 
</persistence> 

Aber wenn ich trie, dass die Konsole von Eclipse gibt mir die folgende Fehlermeldung:

Exception : Connection could not be allocated because: Data source rejected establishment of connection, message from server: "Too many connections"

Exception [EclipseLink-4019] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.DatabaseException Exception Description: Error while obtaining information about the database. Refer to the nested exception for more details. at org.eclipse.persistence.exceptions.DatabaseException.errorRetrieveDbMetadataThroughJDBCConnection(DatabaseException.java:368) at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.setOrDetectDatasource(DatabaseSessionImpl.java:225) at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:734) at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:239) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:681) 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 org.glassfish.persistence.jpa.JPADeployer$2.visitPUD(JPADeployer.java:451) at org.glassfish.persistence.jpa.JPADeployer$PersistenceUnitDescriptorIterator.iteratePUDs(JPADeployer.java:510) at org.glassfish.persistence.jpa.JPADeployer.iterateInitializedPUsAtApplicationPrepare(JPADeployer.java:492) at org.glassfish.persistence.jpa.JPADeployer.event(JPADeployer.java:395) at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:131) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:484) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219) at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:527) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:523) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:360) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:522) at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:546) at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1423) at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1500(CommandRunnerImpl.java:108) at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1762) at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1674) at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534) at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224) at org.glassfish.grizzly.http.server.StaticHttpHandler.service(StaticHttpHandler.java:297) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246) at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191) at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168) at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189) at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206) at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136) at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114) at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838) at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544) at java.lang.Thread.run(Thread.java:745) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) at com.mysql.jdbc.Util.getInstance(Util.java:387) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:917) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:896) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:885) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860) at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1246) at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1241) at com.mysql.jdbc.ConnectionImpl.getMetaData(ConnectionImpl.java:2946) at com.mysql.jdbc.ConnectionImpl.getMetaData(ConnectionImpl.java:2941) at com.sun.gjc.spi.base.ConnectionHolder.getMetaData(ConnectionHolder.java:357) at com.sun.gjc.spi.jdbc40.ConnectionWrapper40.getMetaData(ConnectionWrapper40.java:114) at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.setOrDetectDatasource(DatabaseSessionImpl.java:209) ... 46 more Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 26.046 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:988) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3552) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3452) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3893) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2526) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2673) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545) at com.mysql.jdbc.ConnectionImpl.setSessionMaxRows(ConnectionImpl.java:5432) at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1960) at com.sun.gjc.spi.jdbc40.PreparedStatementWrapper40.executeQuery(PreparedStatementWrapper40.java:642) at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeSelect(DatabaseAccessor.java:1002) at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:641) at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:558) at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:1995) at org.eclipse.persistence.sessions.server.ServerSession.executeCall(ServerSession.java:570) at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242) at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228) at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelectCall(DatasourceCallQueryMechanism.java:299) at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeSelect(DatasourceCallQueryMechanism.java:281) at org.eclipse.persistence.queries.DataReadQuery.executeNonCursor(DataReadQuery.java:197) at org.eclipse.persistence.queries.DataReadQuery.executeDatabaseQuery(DataReadQuery.java:152) at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:899) at org.eclipse.persistence.queries.DataReadQuery.execute(DataReadQuery.java:137) at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3207) at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1797) at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1779) at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1730) at org.eclipse.persistence.tools.schemaframework.SchemaManager.checkTableExists(SchemaManager.java:477) at org.eclipse.persistence.tools.schemaframework.TableCreator.extendTables(TableCreator.java:431) at org.eclipse.persistence.tools.schemaframework.TableCreator.extendTablesAndConstraints(TableCreator.java:411) at org.eclipse.persistence.tools.schemaframework.TableCreator.extendTables(TableCreator.java:402) at org.eclipse.persistence.tools.schemaframework.SchemaManager.extendDefaultTables(SchemaManager.java:1189) at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.generateDefaultTables(EntityManagerFactoryProvider.java:108) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.writeDDLToDatabase(EntityManagerSetupImpl.java:3937) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.writeDDL(EntityManagerSetupImpl.java:3865) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.writeDDL(EntityManagerSetupImpl.java:3765) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:724) ... 43 more Caused by: java.net.SocketException: Software caused connection abort: recv failed at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.socketRead(SocketInputStream.java:116) at java.net.SocketInputStream.read(SocketInputStream.java:170) at java.net.SocketInputStream.read(SocketInputStream.java:141) at com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:101) at com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:144) at com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:174) at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3001) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3462) ... 78 more

2016-08-03T13:09:47.479+0200|Schwerwiegend: Exception while deploying the app [WEB] 2016-08-03T13:09:47.479+0200|Schwerwiegend: Exception during lifecycle processing org.glassfish.deployment.common.DeploymentException: Exception [EclipseLink-4019] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.DatabaseException Exception Description: Error while obtaining information about the database. Refer to the nested exception for more details. at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:762) 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 org.glassfish.persistence.jpa.JPADeployer$2.visitPUD(JPADeployer.java:451) at org.glassfish.persistence.jpa.JPADeployer$PersistenceUnitDescriptorIterator.iteratePUDs(JPADeployer.java:510) at org.glassfish.persistence.jpa.JPADeployer.iterateInitializedPUsAtApplicationPrepare(JPADeployer.java:492) at org.glassfish.persistence.jpa.JPADeployer.event(JPADeployer.java:395) at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:131) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:484) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219) at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:527) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:523) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:360) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:522) at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:546) at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1423) at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1500(CommandRunnerImpl.java:108) at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1762) at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1674) at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534) at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224) at org.glassfish.grizzly.http.server.StaticHttpHandler.service(StaticHttpHandler.java:297) at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246) at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191) at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168) at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189) at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206) at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136) at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114) at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838) at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544) at java.lang.Thread.run(Thread.java:745)

Die "max_connections" in mysql gesetzt bis 600. Also, das ist genug.

Was ist das Problem?

Answer 1

Haben Sie versucht, Verbindungspool zu verwenden? Für Eclipse-Link können Sie einen Blick auf this Link

Answer 2

Ich verbinde mich mit Glassfish mit JTA. Also habe ich einen JDBC-Verbindungspool in Glassfish konfiguriert. Wenn ich den "Ping" Button in Glassfish zum Testen der Verbindung triggere, funktioniert es.

Answer 3

https://dev.mysql.com/doc/refman/5.5/en/too-many-connections.html

B.5.2.7 Zu viele Verbindungen

Wenn Sie ein Zu viele Verbindungen Fehler, wenn Sie versuchen, den mysqld-Server zu verbinden, bedeutet dies, dass alle verfügbaren Verbindungen, die von anderen im Einsatz sind Kunden.

Die Anzahl der zulässigen Verbindungen wird über die Systemvariable max_connections gesteuert. Der Standardwert ist 151, um die Leistung zu verbessern, wenn MySQL mit dem Apache-Webserver verwendet wird. (Zuvor war der Standardwert 100.) Wenn Sie mehr Verbindungen unterstützen müssen, sollten Sie einen größeren Wert für diese Variable festlegen.