无法在Tomcat webapp中关闭Neo4j Jetty服务器 [英] Unable to shut down Neo4j Jetty server within Tomcat webapp

查看：100
本文介绍了无法在Tomcat webapp中关闭Neo4j Jetty服务器的处理方法，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

目前我正在开发一款使用Neo4j的webapp。我们的应用程序需要部署在Tomcat环境中（客户需求）。我们决定嵌入Neo4j，因为我们可以使用Neo4j提供的Java API，它更容易部署，并且我们获得了改进的性能。但是，我们还需要访问REST API，因为我们有一个用Angular编写的单页webapp，目前正在使用这个界面。然而，嵌入式Neo4j数据库不公开REST API。 Neo4j服务器工件包含可以使用嵌入式图形数据库引导jetty服务器的代码。所以我们的Tomcat webapp正在启动一个Jetty服务器。我们可以通过在一个端口（8080）上部署在Tomcat中的webapp以及另一个端口（7474）上的Neo4j REST接口和Neo4j浏览器来访问graphDb。虽然这有点奇怪但它工作正常，除了我们试图停止我们的webapp（例如重新部署）。关闭我们的webapp时，我们从tomcat收到这些错误：

Currently I am working on an webapp that utilizes Neo4j. Our app needs to be deployed in a Tomcat environment (customer requirement). We decided to embed Neo4j, because that way we can use the Neo4j provided Java API, it's easier to deploy and we get improved performance. However, we also need access to the REST API, because we have a single page webapp written in Angular that is currently making use this interface. The embedded Neo4j database however does not expose the REST api. The Neo4j-server artifact contains code that can bootstrap a jetty server with an embedded graph database. So our Tomcat webapp is starting a Jetty server. We can access the graphDb via the webapp deployed in Tomcat on one port (8080) and the Neo4j REST interface and Neo4j browser on another port (7474). Though this is a bit odd it works fine, except for when we try to stop our webapp (for redeployment for example). When shutting down our webapp we receive these errors from tomcat: 

SEVERE: The web application [/chainmonitor] appears to have started a thread named [GC-Monitor] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [RRD4J Sync Pool [Thread-1]] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [Statistics Gatherer[primitives]] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [pool-1-thread-1] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [pool-1-thread-2] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [DateCache] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-31-selector-3] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-32-selector-0] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-33-selector-1] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-34-selector-2] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-35-selector-4] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-36-selector-5] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-37-acceptor-0-ServerConnector@1425c689{HTTP/1.1}{localhost:7474}] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-38-acceptor-1-ServerConnector@1425c689{HTTP/1.1}{localhost:7474}] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [HashSessionScavenger-0] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: The web application [/chainmonitor] appears to have started a thread named [qtp835579386-54] but has failed to stop it. This is very likely to create a memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [org.eclipse.jetty.http.HttpFields$1] (value [org.eclipse.jetty.http.HttpFields$1@4a3d3a5e]) and a value of type [org.eclipse.jetty.http.HttpFields.DateGenerator] (value [org.eclipse.jetty.http.HttpFields$DateGenerator@24f0137b]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:17 PM org.apache.catalina.loader.WebappClassLoader checkThreadLocalMapForLeaks
SEVERE: The web application [/chainmonitor] created a ThreadLocal with key of type [scala.util.DynamicVariable$$anon$1] (value [scala.util.DynamicVariable$$anon$1@281a099d]) and a value of type [java.lang.Integer] (value [0]) but failed to remove it when the web application was stopped. Threads are going to be renewed over time to try and avoid a probable memory leak.
jun 10, 2014 6:43:27 PM org.apache.catalina.startup.HostConfig undeploy
INFO: Undeploying context [/chainmonitor]
jun 10, 2014 6:43:27 PM org.apache.catalina.startup.ExpandWar deleteDir
SEVERE: [C:\dev\apache-tomcat-7.0.54\webapps\chainmonitor\WEB-INF\lib] could not be completely deleted. The presence of the remaining files may cause problems
jun 10, 2014 6:43:27 PM org.apache.catalina.startup.ExpandWar deleteDir
SEVERE: [C:\dev\apache-tomcat-7.0.54\webapps\chainmonitor\WEB-INF] could not be completely deleted. The presence of the remaining files may cause problems
jun 10, 2014 6:43:27 PM org.apache.catalina.startup.ExpandWar deleteDir
SEVERE: [C:\dev\apache-tomcat-7.0.54\webapps\chainmonitor] could not be completely deleted. The presence of the remaining files may cause problems
jun 10, 2014 6:43:27 PM org.apache.catalina.startup.ExpandWar delete
SEVERE: [C:\dev\apache-tomcat-7.0.54\webapps\chainmonitor] could not be completely deleted. The presence of the remaining files may cause problems

我们的pom.xml如下所示：

Our pom.xml looks like this:

    <dependency>
        <groupId>org.neo4j</groupId>
        <artifactId>neo4j</artifactId>
        <version>2.0.3</version>
    </dependency>
    <dependency>
        <groupId>org.neo4j.app</groupId>
        <artifactId>neo4j-server</artifactId>
        <version>2.0.3</version>
    </dependency>

这是我们启动嵌入式数据库并启动jetty服务器的方式：

This is how we start the embedded database and start the jetty server:

graphDb = (EmbeddedGraphDatabase) new GraphDatabaseFactory().
      newEmbeddedDatabaseBuilder(dataDir).loadPropertiesFromURL(Neo4jPropertiesUrl).newGraphDatabase();
bootstrapper = new WrappingNeoServerBootstrapper(graphDb);

目前neo4j-server.properties为空。我没有尝试过很多不同的配置，但这样做似乎不是问题。

Currently neo4j-server.properties is empty. I've not tried many different configurations, but doing so doesn't seem to be a problem.

这就是我们停止嵌入式数据库和jetty服务器的方式：

This is how we stop the embedded database and jetty server:

    @Override
    public void contextDestroyed(ServletContextEvent event) {
​            graphDb.shutdown();
            bootstrapper.stop();
    }

这显然是由Tomcat的内存泄漏保护引起的（ http://wiki.apache.org/tomcat/MemoryLeakProtection ）。

This is apparently caused by Tomcat's memory leak protection (http://wiki.apache.org/tomcat/MemoryLeakProtection).

结果是我们的webapp只能通过完全杀死Tomcat进程（kill -9）来重新部署，这是非常不受欢迎的。

The result is that our webapp can only be redeployed by completely killing the Tomcat process (kill -9), which is very undesirable.

我们尝试过一堆东​​西：

We've tried a bunch of things:


  • 没有关闭嵌入式grapbDb。没有效果。

  • 没有明确关闭引导程序。没有效果。 （引导程序有自己的关闭钩子）

  • 首先关闭引导程序然后关闭嵌入式数据库。

  • 线程immolator： https://github.com/Neo4j/Neo4j/issues/1070 。代码运行并删除59个线程本地值，但没有明显的效果。有趣的是，当我在关机期间在一个循环中运行它一分钟时，它一直说它是无效的6个值。对我来说，这表明这个过程根本不起作用，因为Neo4j在关闭时需要一些时间。

  • 在关机后延迟。我们尝试这个的原因是因为在tomcat收到关闭信号之后我们需要等待几秒才能实际杀死进程，否则我们下次启动会出现错误，我们的图形数据已经损坏（有一条消息没有被正确关闭了）。延迟5秒以上似乎也有效果，因为之后我们只得到6个严重错误而不是16个。这也是我认为献祭过程根本不起作用的原因。

  • 我们尝试将嵌入式Neo4j添加到集群中，从而能够同时使用REST api和嵌入式Neo4j。然而，经过大约四个小时试图让这个工作，我们放弃了。在嵌入式Neo4j数据库启动期间，我们的web应用程序就冻结了。经过一些调试后，它看起来像Neo4j的代码中的死锁。我们尝试将所有HA超时配置设置为较小的值，但没有任何影响。

  • not shutting down the embedded grapbDb. No effect.
  • not explicitly shutting down the bootstrapper. No effect. (the bootstrapper has its own shutdown hook)
  • shutting down the bootstrapper first and then the embedded database.
  • thread immolator: https://github.com/Neo4j/Neo4j/issues/1070 . The code runs and immolates 59 thread local values, but with no apparent effect. Interestingly when I run this in a loop for a minute during the shutdown it keeps saying it immolated 6 values. To me this is an indication that this process does not work at all, because Neo4j takes some time while shutting down.
  • putting in a delay after the shutting down. The reason we tried this is because after tomcat has received a shutdown signal we need to wait a few seconds before actually killing the process otherwise we get an error on our next start that our graph data has been corrupted (with a message that is has not been properly shut down). Delaying by 5+ seconds seems to have an effect too, because afterwards we get only 6 severe errors instead of 16. This is also the reason why I think the immolation process is not working at all.
  • We tried as an alternative to add our embedded Neo4j to a cluster, thus being able to use both the REST api as wel as the embedded Neo4j. However after about four hours trying to get this to work we gave up. During the startup of the embedded Neo4j database our webapplication just froze. After some debugging it very much seemed like a deadlock within Neo4j's code. We tried to set all HA timeout configurations to some smaller values, but with no effect.

问题是由Neo4j码头服务器引起的。没有它，这个问题就不会出现。我们需要REST API。你知道我们怎么解决这个问题吗？或者您是否有另一种在Tomcat环境中使用嵌入式数据库和REST API的方法？

The problem is caused by the Neo4j jetty server. Without it this problem does not arise. We need the REST API though. Do you know how we can fix this? Or have you got an alternative way to use the embedded database and the REST API within a Tomcat environment?

我们正在使用：


  • Java：1.7.0_60

  • Tomcat 7.0.54

  • Neo4j：2.0.3（我们尝试过2.1.1但结果完全相同）

  • 在Windows 7和Linux Redhat上观察到相同的行为

  • Java: 1.7.0_60
  • Tomcat 7.0.54
  • Neo4j: 2.0.3 (we have tried 2.1.1 but got exactly the same result)
  • The same behviour has been observed on Windows 7 and Linux Redhat

推荐答案

我们有一个非常相似的设置和需求。以下是我们针对此问题提供的解决方案。 JVM运行时shutdownHook在Tomcat中不起作用，因此我们持有对包含GraphDatabaseService的包装器对象的引用，并将该包装器放在存储库管理器对象中。对存储库管理器对象中的方法使用@PreDestroy批注，该方法将在销毁存储库管理器类之前关闭存储库。

We have a very similar setup and need. Here is the solution we have for this issue. The JVM Runtime shutdownHook does not work in Tomcat, so we hold a reference to a wrapper object holding our GraphDatabaseService and place that wrapper in a repository manager object. Use the @PreDestroy annotation on a method in the repository manager object which will shutdown the repositories before the repository manager class is destroyed.

import javax.annotation.PreDestroy;

... 

@PreDestroy
public void destroy() {
    log.info("Destroying Neo4jRepositoryManager...");
    shutdown(Neo4jPropertyKeys.SANDBOX_DATABASE.getUrlKey());
    shutdown(Neo4jPropertyKeys.PRODUCTION_DATABASE.getUrlKey());
    shutdown(Neo4jPropertyKeys.TEST_DATABASE.getUrlKey());
}

private void shutdown(String urlKey) {
    if(repositories.containsKey(urlKey)) {
        LabeledNodeGraphRepository graphdb = repositories.get(urlKey);
        graphdb.getGraphDatabaseService().shutdown();
        log.info(urlKey + " shutdown...");
    }
}

<bean id="repositoryManager" class="mypath.neo4j.repository.Neo4jRepositoryManager"/>

我们的环境是：


  • Java 1.7.0_72

  • Tomcat 7.0.56

  • Neo4j 2.1.6

  • 春季4.0.5

  • 泽西岛2.1.4

  • Java 1.7.0_72
  • Tomcat 7.0.56
  • Neo4j 2.1.6
  • Spring 4.0.5
  • Jersey 2.1.4

这篇关于无法在Tomcat webapp中关闭Neo4j Jetty服务器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
相关文章
Java开发最新文章
热门教程
热门工具
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆