Apache Cayenne / PostgreSQL：“客户端已经太多”错误 [英] Apache Cayenne / PostgreSQL: "too many clients already" error
本文介绍了Apache Cayenne / PostgreSQL：“客户端已经太多”错误的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在使用Apache Cayenne 4 Milestone 5，但出现此错误。该应用程序尚未正式部署，但正在IntelliJ IDEA中进行测试。
I'm using Apache Cayenne 4 Milestone 5 and I'm getting this error. The application is not officially deployed but it is being tested within the IntelliJ IDEA.
Apr 03, 2017 10:19:58 PM org.postgresql.Driver connect
SEVERE: Connection error:
org.postgresql.util.PSQLException: FATAL: sorry, too many clients already
at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:438)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:222)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:194)
at org.postgresql.Driver.makeConnection(Driver.java:431)
at org.postgresql.Driver.connect(Driver.java:247)
at org.apache.cayenne.datasource.DriverDataSource.getConnection(DriverDataSource.java:159)
at org.apache.cayenne.datasource.DriverDataSource.getConnection(DriverDataSource.java:133)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createUnwrapped(UnmanagedPoolingDataSource.java:300)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createWrapped(UnmanagedPoolingDataSource.java:293)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createUnchecked(UnmanagedPoolingDataSource.java:273)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.<init>(UnmanagedPoolingDataSource.java:142)
at org.apache.cayenne.datasource.PoolingDataSourceBuilder.buildPooling(PoolingDataSourceBuilder.java:92)
at org.apache.cayenne.datasource.PoolingDataSourceBuilder.build(PoolingDataSourceBuilder.java:88)
at org.apache.cayenne.configuration.server.XMLPoolingDataSourceFactory.getDataSource(XMLPoolingDataSourceFactory.java:75)
at org.apache.cayenne.configuration.server.DelegatingDataSourceFactory.getDataSource(DelegatingDataSourceFactory.java:68)
at org.apache.cayenne.configuration.server.DefaultDataNodeFactory.createDataNode(DefaultDataNodeFactory.java:79)
at org.apache.cayenne.configuration.server.DataDomainProvider.addDataNode(DataDomainProvider.java:175)
at org.apache.cayenne.configuration.server.DataDomainProvider.createAndInitDataDomain(DataDomainProvider.java:127)
at org.apache.cayenne.configuration.server.DataDomainProvider.get(DataDomainProvider.java:91)
at org.apache.cayenne.configuration.server.DataDomainProvider.get(DataDomainProvider.java:56)
at org.apache.cayenne.di.spi.CustomProvidersProvider.get(CustomProvidersProvider.java:39)
at org.apache.cayenne.di.spi.FieldInjectingProvider.get(FieldInjectingProvider.java:43)
at org.apache.cayenne.di.spi.DefaultScopeProvider.get(DefaultScopeProvider.java:50)
at org.apache.cayenne.di.spi.DefaultInjector.getInstance(DefaultInjector.java:139)
at org.apache.cayenne.di.spi.FieldInjectingProvider.value(FieldInjectingProvider.java:105)
at org.apache.cayenne.di.spi.FieldInjectingProvider.injectMember(FieldInjectingProvider.java:68)
at org.apache.cayenne.di.spi.FieldInjectingProvider.injectMembers(FieldInjectingProvider.java:59)
at org.apache.cayenne.di.spi.FieldInjectingProvider.get(FieldInjectingProvider.java:44)
at org.apache.cayenne.di.spi.DefaultScopeProvider.get(DefaultScopeProvider.java:50)
at org.apache.cayenne.di.spi.DefaultInjector.getInstance(DefaultInjector.java:134)
at org.apache.cayenne.configuration.CayenneRuntime.newContext(CayenneRuntime.java:124)
at com.company.databases.postgresql.accountsdb.dataservices.AccountServices.loginAsEmailAddress(AccountServices.java:454)
at com.company.databases.postgresql.accountsdb.dataservices.AccountServices.login(AccountServices.java:445)
at com.company.actions.fan.account.AccountActions.login(AccountActions.java:44)
at com.company.serverapps.fans.entrypoints.standard.AccountConnections.login(AccountConnections.java:95)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:144)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:161)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:160)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:99)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:389)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:347)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:102)
at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:326)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:841)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634)
at org.eclipse.jetty.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:308)
at org.eclipse.jetty.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:262)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1621)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:541)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1592)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:188)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1239)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:168)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:481)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1561)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:166)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1141)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:213)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:564)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:320)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:251)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:279)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:110)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:124)
at org.eclipse.jetty.util.thread.Invocable.invokePreferred(Invocable.java:122)
at org.eclipse.jetty.util.thread.strategy.ExecutingExecutionStrategy.invoke(ExecutingExecutionStrategy.java:58)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.produceConsume(ExecuteProduceConsume.java:201)
at org.eclipse.jetty.util.thread.strategy.ExecuteProduceConsume.run(ExecuteProduceConsume.java:133)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:672)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:590)
at java.lang.Thread.run(Thread.java:745)
Apr 03, 2017 10:21:58 PM org.postgresql.Driver connect
SEVERE: Connection error:
org.postgresql.util.PSQLException: FATAL: sorry, too many clients already
at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:438)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:222)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:194)
at org.postgresql.Driver.makeConnection(Driver.java:431)
at org.postgresql.Driver.connect(Driver.java:247)
at org.apache.cayenne.datasource.DriverDataSource.getConnection(DriverDataSource.java:159)
at org.apache.cayenne.datasource.DriverDataSource.getConnection(DriverDataSource.java:133)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createUnwrapped(UnmanagedPoolingDataSource.java:300)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createWrapped(UnmanagedPoolingDataSource.java:293)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.createUnchecked(UnmanagedPoolingDataSource.java:273)
at org.apache.cayenne.datasource.UnmanagedPoolingDataSource.managePool(UnmanagedPoolingDataSource.java:188)
at org.apache.cayenne.datasource.PoolingDataSourceManager.run(PoolingDataSourceManager.java:71)
该应用程序正常运行，但是使用一段时间后显示此错误。此错误的原因是什么？
我每次需要事务时都使用以下方法获取运行时。
I'm using the following method to obtain the runtime each time I need a transaction.
public final static ServerRuntime getAccountsDBPostgreSQLRuntime() {
return ServerRuntime.builder().addConfig("cayenne/cayenne-AccountsDB.project.xml").build();
}
示例：
public final static Long newFanAccount() {
ServerRuntime accountsDBPostgresRuntime = AccountsDBRuntime.getAccountsDBPostgreSQLRuntime();
ObjectContext context = accountsDBPostgresRuntime.newContext();
Fan fan = context.newObject(Fan.class);
context.commitChanges();
Long fanID = (Long) Cayenne.pkForObject(fan);
return fanID;
}
推荐答案
从堆栈跟踪和该代码示例看起来像您没有在重复使用Cayenne堆栈（ServerRuntime对象），而是每次都创建一个新堆栈。除了速度慢之外，这还导致资源泄漏。每个ServerRuntime都有自己的连接池，您不会关闭它。因此，迟早的PostreSQL服务器会因打开的连接而溢出。
From the stack trace and the code example it looks like you are not reusing the Cayenne stack (ServerRuntime object), creating a new one every time instead. Aside from being slow, this also introduces a resource leak. Each ServerRuntime holds its own connection pool that you do not shut down. So sooner or later PostreSQL server is overflown with open connections.
解决方案是将ServerRuntime变成应用程序范围的单例（例如，使其成为AccountsDBRuntime的静态变量），并在需要新的ObjectContext时重用它。
The solution is to turn ServerRuntime into an app-scoped singleton (e.g. make it a static var of AccountsDBRuntime), and reuse it whenever you need a new ObjectContext.
这篇关于Apache Cayenne / PostgreSQL：“客户端已经太多”错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
