Question

最近，我想将db中的时态类型从neo4j-java-driver升级（org.neo4j.driver）从1.4.4升级到最新的1.7.5。升级后，一切似乎都工作顺利，直到我开始使用CLI工具（在我的代码中准备的自定义工具）时，这些工具在终止时陷入无穷循环：

Warning: unterminated thread Neo4jDriverIO-2-10 [23] [sun.nio.ch.EPollArrayWrapper.epollWait(Native Method), sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269), sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93), sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86), sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97), org.neo4j.driver.internal.shaded.io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
WARNING: Warning: unterminated thread Neo4jDriverIO-2-10[sun.nio.ch.EPollArrayWrapper.epollWait(Native Method), sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269), sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93), sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86), sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97), org.neo4j.driver.internal.shaded.io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
Warning: unterminated thread Neo4jDriverIO-2-9 [22] [sun.nio.ch.EPollArrayWrapper.epollWait(Native Method), sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269), sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93), sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86), sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97), org.neo4j.driver.internal.shaded.io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
WARNING: Warning: unterminated thread Neo4jDriverIO-2-9[sun.nio.ch.EPollArrayWrapper.epollWait(Native Method), sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269), sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93), sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86), sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97), org.neo4j.driver.internal.shaded.io.netty.channel.nio.SelectedSelectionKeySetSelector.select(SelectedSelectionKeySetSelector.java:62), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.select(NioEventLoop.java:753), org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:409), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:886), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
[..]

在从CLI程序退出之前，我试图直接在驱动程序上调用close（）方法。程序关闭后，它有所帮助，但是我仍然可以看到以下堆栈：

INFO: Closing driver instance 1162128198
Nov 14, 2019 5:03:25 PM org.neo4j.driver.internal.logging.JULogger info
INFO: Closing connection pool towards neo4j:7687
Warning: unterminated thread globalEventExecutor-1-2 [36] [sun.misc.Unsafe.park(Native Method), java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215), java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078), java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor.takeTask(GlobalEventExecutor.java:92), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor$TaskRunner.run(GlobalEventExecutor.java:245), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
WARNING: Warning: unterminated thread globalEventExecutor-1-2[sun.misc.Unsafe.park(Native Method), java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215), java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078), java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor.takeTask(GlobalEventExecutor.java:92), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor$TaskRunner.run(GlobalEventExecutor.java:245), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
Warning: unterminated thread globalEventExecutor-1-2 [36] [sun.misc.Unsafe.park(Native Method), java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215), java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078), java.util.concurrent.LinkedBlockingQueue.poll(LinkedBlockingQueue.java:467), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor.takeTask(GlobalEventExecutor.java:92), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.GlobalEventExecutor$TaskRunner.run(GlobalEventExecutor.java:245), org.neo4j.driver.internal.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30), java.lang.Thread.run(Thread.java:748)]
[..]

有什么主意为什么不能正常关闭（或者为什么要生成网状线程？），为什么我会看到这样的堆栈？

注意：

我正在使用直接螺栓连接到外部单个neo4j数据库实例。

更新

因此，我找到了看到此类日志的原因。基本上，Neo4jDriverIO线程现在是守护程序线程，而我的CLI代码一直在检查是否有任何.isDaemon属实的线程，并一直在等待这些线程被关闭。

在第一种情况下，它们从未关闭过，因为应该由JVM shutdown hook调用neo4j驱动程序中的.close（）方法，而在我们的isDaemon循环中，它从来没有出现过。

仍然是第二个问题，为什么globalEventExecutor-1-2在close（）方法期间没有关闭，而是仅在一段时间后关闭（这意味着它们以异步方式关闭）。它可能是一个错误，但还会挖掘更多。

终止Java CLI时neo4j驱动程序出现问题

0 个答案: