java - Neo4j 非托管扩展和 GuardTimeoutException

Question

我非常需要一些关于我在使用 Java 构建的 Neo4j 非托管扩展时遇到的问题的建议。我创建了一个非常简单的代码示例来突出我的问题。基本前提是我想设置

org.neo4j.server.webserver.limit.executiontime

对于通过 Cypher、其他端点等进入的用户查询，neo4j 服务器有合理的时间(比如说 2 分钟)。但是我也有一些批处理作业需要通过这个非托管扩展运行，因此我试图将它们分解成几个 <2 分钟的事务。我看到的问题是，即使我的每个事务都不到 2 分钟，但一旦我的进程运行了 2 分钟，我就会收到 GuardTimeoutException。

这是示例。请注意，在此示例中，我已将时间限制为 2000 毫秒，因此我不会花一整天的时间进行调试。 (虽然越来越近了!)

端点

/**
 * Sample endpoint.
@GET
@Path("test")
@Produces(MediaType.APPLICATION_JSON)
public Response test(@Context GraphDatabaseService service) {
    TestFile.test(service);
    return Response.ok().build();
}

逻辑

public static void test(final GraphDatabaseService service) {
    for (int i = 0; i < 100000; i++) {
        try (Transaction tx = service.beginTx();) {
            final Node n = service.createNode();
            n.addLabel(testLabel);
            tx.success();
            tx.close();
        }
        System.out.println("Added node");
    }
}

我可以看到每个事务只需要几分之一秒，因为我在超时前成功加载了大约 200 个节点。不过，在到达终点正好 2 秒后，我得到以下信息:

org.neo4j.kernel.guard.GuardTimeoutException: timeout occured (overtime=1)
at org.neo4j.kernel.guard.Guard$Timeout.check(Guard.java:132)
at org.neo4j.kernel.guard.Guard.check(Guard.java:43)
at org.neo4j.kernel.InternalAbstractGraphDatabase$5.createNode(InternalAbstractGraphDatabase.java:794)
at org.neo4j.kernel.impl.api.state.OldTxStateBridgeImpl.nodeCreate(OldTxStateBridgeImpl.java:120)
at org.neo4j.kernel.impl.api.state.TxStateImpl.nodeDoCreate(TxStateImpl.java:366)
at org.neo4j.kernel.impl.api.StateHandlingStatementOperations.nodeCreate(StateHandlingStatementOperations.java:99)
at org.neo4j.kernel.impl.api.ConstraintEnforcingEntityOperations.nodeCreate(ConstraintEnforcingEntityOperations.java:390)
at org.neo4j.kernel.impl.api.LockingStatementOperations.nodeCreate(LockingStatementOperations.java:207)
at org.neo4j.kernel.impl.api.OperationsFacade.nodeCreate(OperationsFacade.java:506)
at org.neo4j.kernel.InternalAbstractGraphDatabase.createNode(InternalAbstractGraphDatabase.java:1120)
at **TestFile.test(TestFile.java:15)
at **test(Jobs.java:48)
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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:139)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:698)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1506)
at org.neo4j.server.guard.GuardingRequestFilter.doFilter(GuardingRequestFilter.java:68)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1477)
at org.neo4j.server.guard.GuardingRequestFilter.doFilter(GuardingRequestFilter.java:68)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1477)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:503)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:211)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1096)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:432)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:175)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1030)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:136)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:445)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:268)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:229)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.run(AbstractConnection.java:358)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:601)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:532)
at java.lang.Thread.run(Thread.java:744)

如您所见，我已经尝试了 tx.success()、tx.close() 等任何我能想到的让所有交易在完成时死亡的方法。非常感谢任何建议!!

更新 --------------

Michael - 我已按照您建议的步骤进行操作 - 我有一个扩展 SPIPluginLifecycle 的新 Java 类，并且还在/src/main/resources/META-INF/services 中添加了新的配置文件。我可以看到该文件最终位于 META-INF/services 中的/plugins 中的 jar 中。但是，我根本看不到这个初始化类被调用。这是我在启动时看到的类和日志。

public class GraphInitializer implements SPIPluginLifecycle {
private WebServer webServer;

@Override
public Collection<Injectable<?>> start(final GraphDatabaseService graphDatabaseService, final Configuration config) {
    throw new IllegalAccessError();
}

@Override
public void stop() {

}

@Override
public Collection<Injectable<?>> start(final NeoServer neoServer) {
    System.out.println("K starting!");
    webServer = getWebServer(neoServer);
    final Database database = neoServer.getDatabase();
    final GraphDatabaseAPI graphDatabaseAPI = database.getGraph();
    final Guard guard = graphDatabaseAPI.getDependencyResolver().resolveDependency(Guard.class);
    final Filter filter = new GuardingRequestFilter(guard, 3000);
    webServer.addFilter(filter, "/*" );
    return null;
}

private WebServer getWebServer(final NeoServer neoServer) {
    if (neoServer instanceof AbstractNeoServer) {
        return ((AbstractNeoServer) neoServer).getWebServer();
    }
    throw new IllegalArgumentException("expected AbstractNeoServer");
}

日志:

2014-10-06 16:14:23.009+0000 INFO  [API] Mounted discovery module at [/]
2014-10-06 16:14:23.014+0000 INFO  [API] Mounted REST API at [/db/data/]
2014-10-06 16:14:23.017+0000 INFO  [API] Mounted management API at [/db/manage/]
2014-10-06 16:14:23.017+0000 INFO  [API] Mounted third-party JAX-RS package [***] at [/kristen]
2014-10-06 16:14:23.017+0000 INFO  [API] Mounted webadmin at [/webadmin]
2014-10-06 16:14:23.017+0000 INFO  [API] Mounted Neo4j Browser at [/browser]
2014-10-06 16:14:23.070+0000 INFO  [API] Mounting static content at [/webadmin] from [webadmin-html]
2014-10-06 16:14:23.124+0000 INFO  [API] Mounting static content at [/browser] from [browser]
12:14:23.126 [main] WARN  o.e.j.server.handler.ContextHandler - o.e.j.s.ServletContextHandler@1cb1c025{/,null,null} contextPath ends with /
12:14:23.127 [main] WARN  o.e.j.server.handler.ContextHandler - Empty contextPath
12:14:23.131 [main] INFO  org.eclipse.jetty.server.Server - jetty-9.0.5.v20130815
12:14:23.155 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.s.h.MovedContextHandler@5de15910{/,null,AVAILABLE}
12:14:23.245 [main] INFO  o.e.j.w.StandardDescriptorProcessor - NO JSP Support for /webadmin, did not find org.apache.jasper.servlet.JspServlet
12:14:23.255 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.w.WebAppContext@4b45c74e{/webadmin,jar:file:/usr/local/Cellar/neo4j/2.1.3/libexec/system/lib/neo4j-server-2.1.3-static-web.jar!/webadmin-html,AVAILABLE}
12:14:23.668 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.s.ServletContextHandler@2917eb65{/kristen,null,AVAILABLE}
12:14:23.817 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.s.ServletContextHandler@54589209{/db/manage,null,AVAILABLE}
12:14:24.003 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.s.ServletContextHandler@68a1f8e7{/db/data,null,AVAILABLE}
12:14:24.021 [main] INFO  o.e.j.w.StandardDescriptorProcessor - NO JSP Support for /browser, did not find org.apache.jasper.servlet.JspServlet
12:14:24.022 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.w.WebAppContext@438e0daa{/browser,jar:file:/usr/local/Cellar/neo4j/2.1.3/libexec/system/lib/neo4j-browser-2.1.3.jar!/browser,AVAILABLE}
12:14:24.103 [main] INFO  o.e.j.server.handler.ContextHandler - Started o.e.j.s.ServletContextHandler@1cb1c025{/,null,AVAILABLE}
12:14:24.115 [main] INFO  o.e.jetty.server.ServerConnector - Started ServerConnector@75b61dd7{HTTP/1.1}{localhost:7474}
12:14:24.503 [main] INFO  o.e.jetty.server.ServerConnector - Started ServerConnector@6464d61f{SSL-HTTP/1.1}{localhost:7473}
2014-10-06 16:14:24.503+0000 INFO  [API] Server started on: http://localhost:7474/
2014-10-06 16:14:24.504+0000 INFO  [API] Remote interface ready and available at [http://localhost:7474/]

我希望有一个新的行条目或其他东西 - 而且我添加超时的更改实际上不起作用，所以我确信这些更改没有生效。有什么我必须添加到 neo4j-server.properties、neo4j.properties 等的东西吗？我已经成功添加了设置非托管扩展的行。

谢谢!

Answer 1

小事务使它变得更慢，因为每个事务都必须刷新到磁盘。通常在一个 tx 中添加最多 50k 个节点是有意义的，这应该不到一秒钟。

对于你的保护过滤器，它只是一个 servlet 过滤器，所以你也可以只检查安装它的 Neo4j 源代码，并在你的扩展初始化时自己安装它，但排除你想要批处理的端点。

在:org.neo4j.server.AbstractNeoServer 第 488 行

    Filter filter = new GuardingRequestFilter( guard,
            getConfiguration().getInt( Configurator.WEBSERVER_LIMIT_EXECUTION_TIME_PROPERTY_KEY ) );
    webServer.addFilter( filter, "/*" );

您可以使用扩展初始化程序来添加您的自定义过滤器，如下所示:

https://github.com/neo4j-contrib/authentication-extension/blob/2.1/src/main/java/org/neo4j/server/extension/auth/AuthenticationExtensionInitializer.java#L81

你必须添加一个这样的文件，其中包含你的初始化类名:

https://github.com/neo4j-contrib/authentication-extension/blob/2.1/src/main/resources/META-INF/services/org.neo4j.server.plugins.PluginLifecycle