Java ExecuterService 死锁？
Java ExecuterService deadlock?
最近我写了一些代码来从网络上读取 JSON 数据并根据收到的数据更新 MongoDB 条目。必须对大约 500,000 个条目执行此操作。为了加速这个过程，我使用了一个带有 5 个线程和一个大小为 50 的阻塞队列的 ThreadPoolExecutor。此外，我使用 CallerRunsPolicy 来处理多余的作业。
每个工人的工作如下：
- 从 URL
读取 JSON 数据
- 解析JSON
- 更新对应的MongoDB条目
但是程序每次都卡住。有时很早，有时只在几个小时后。到目前为止，我还没有发现代码中的任何错误。处理异常但不抛出异常，所有使用的方法都应该是线程安全的。
这是程序挂起后的线程转储：
2016-01-16 23:40:05
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.66-b18 mixed mode):
"JMX server connection timeout 711" #711 daemon prio=5 os_prio=0 tid=0x000000001813d000 nid=0x4e8 in Object.wait() [0x000000004733f000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at com.sun.jmx.remote.internal.ServerCommunicatorAdmin$Timeout.run(Unknown Source)
- locked <0x00000000e26162c8> (a [I)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"RMI Scheduler(0)" #710 daemon prio=5 os_prio=0 tid=0x000000001813b800 nid=0x1ba0 waiting on condition [0x000000004723f000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000e1ce64e0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"RMI TCP Connection(1)-192.168.56.1" #709 daemon prio=5 os_prio=0 tid=0x0000000017714000 nid=0x11f0 runnable [0x000000004713e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000e25e5fe8> (a java.io.BufferedInputStream)
at java.io.FilterInputStream.read(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run6(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda/917377658.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- <0x00000000e23ce048> (a java.util.concurrent.ThreadPoolExecutor$Worker)
"RMI TCP Accept-0" #708 daemon prio=5 os_prio=0 tid=0x0000000017fa2000 nid=0xd18 runnable [0x0000000046f3e000]
java.lang.Thread.State: RUNNABLE
at java.net.DualStackPlainSocketImpl.accept0(Native Method)
at java.net.DualStackPlainSocketImpl.socketAccept(Unknown Source)
at java.net.AbstractPlainSocketImpl.accept(Unknown Source)
at java.net.PlainSocketImpl.accept(Unknown Source)
- locked <0x00000000e1ce8078> (a java.net.SocksSocketImpl)
at java.net.ServerSocket.implAccept(Unknown Source)
at java.net.ServerSocket.accept(Unknown Source)
at sun.management.jmxremote.LocalRMIServerSocketFactory.accept(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-5" #19 prio=5 os_prio=0 tid=0x000000001859e000 nid=0x628 waiting on condition [0x0000000018f9e000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-4" #18 prio=5 os_prio=0 tid=0x000000001859d800 nid=0x2208 waiting on condition [0x0000000018e9f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-3" #17 prio=5 os_prio=0 tid=0x000000001859c800 nid=0x239c waiting on condition [0x0000000018d9e000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-2" #16 prio=5 os_prio=0 tid=0x000000001859a000 nid=0x18a8 runnable [0x0000000018c9e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000f921a080> (a java.io.BufferedInputStream)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
- locked <0x00000000f921a0c0> (a sun.net.www.protocol.http.HttpURLConnection)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
- locked <0x00000000f921a0c0> (a sun.net.www.protocol.http.HttpURLConnection)
at java.net.URL.openStream(Unknown Source)
at Pr0grammDB.readURL(Pr0grammDB.java:217)
at Pr0grammDB.readJSON(Pr0grammDB.java:210)
at Pr0grammDBJob.run(Pr0grammDB.java:98)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- <0x00000000a57afa50> (a java.util.concurrent.ThreadPoolExecutor$Worker)
"pool-1-thread-1" #15 prio=5 os_prio=0 tid=0x0000000018599000 nid=0x20fc waiting on condition [0x0000000018b9f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-1" #12 daemon prio=5 os_prio=0 tid=0x0000000017ecc800 nid=0x2bd8 waiting on condition [0x000000001879f000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af298> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"cluster-ClusterId{value='569a6466a802c513644d5a51', description='null'}-127.0.0.1:27017" #11 daemon prio=5 os_prio=0 tid=0x000000001785e000 nid=0x1de8 waiting on condition [0x000000001869e000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57ad528> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.waitForSignalOrTimeout(DefaultServerMonitor.java:237)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.waitForNext(DefaultServerMonitor.java:218)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:167)
- locked <0x00000000a57ad270> (a com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"Service Thread" #9 daemon prio=9 os_prio=0 tid=0x0000000017493800 nid=0x23a8 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C1 CompilerThread2" #8 daemon prio=9 os_prio=2 tid=0x0000000015af8800 nid=0x2f5c waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C2 CompilerThread1" #7 daemon prio=9 os_prio=2 tid=0x0000000015af1800 nid=0x18c0 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C2 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x0000000015aef000 nid=0x15f8 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x0000000015aec800 nid=0x2074 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x0000000015aec000 nid=0x2c94 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Finalizer" #3 daemon prio=8 os_prio=1 tid=0x00000000022b8000 nid=0x2f14 in Object.wait() [0x0000000016e4f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000a57ebd08> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x00000000a57ebd08> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)
Locked ownable synchronizers:
- None
"Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x00000000022af000 nid=0x83c in Object.wait() [0x0000000016d4f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000a57ebf20> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Unknown Source)
at java.lang.ref.Reference$ReferenceHandler.run(Unknown Source)
- locked <0x00000000a57ebf20> (a java.lang.ref.Reference$Lock)
Locked ownable synchronizers:
- None
"main" #1 prio=5 os_prio=0 tid=0x000000000207e000 nid=0x1964 runnable [0x000000000217e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000f921c318> (a java.io.BufferedInputStream)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
- locked <0x00000000f921c358> (a sun.net.www.protocol.http.HttpURLConnection)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
- locked <0x00000000f921c358> (a sun.net.www.protocol.http.HttpURLConnection)
at java.net.URL.openStream(Unknown Source)
at Pr0grammDB.readURL(Pr0grammDB.java:217)
at Pr0grammDB.readJSON(Pr0grammDB.java:210)
at Pr0grammDBJob.run(Pr0grammDB.java:98)
at java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy.rejectedExecution(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.reject(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.execute(Unknown Source)
at Pr0grammDB.addAdditionalData(Pr0grammDB.java:114)
at Pr0grammDB.main(Pr0grammDB.java:48)
Locked ownable synchronizers:
- None
"VM Thread" os_prio=2 tid=0x0000000015ab7000 nid=0x684 runnable
"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00000000021d7800 nid=0x28e0 runnable
"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00000000021d9000 nid=0x2658 runnable
"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x00000000021da800 nid=0x273c runnable
"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x00000000021dd000 nid=0x20f8 runnable
"VM Periodic Task Thread" os_prio=2 tid=0x00000000174a2000 nid=0x824 waiting on condition
JNI global references: 385
除一个线程外，所有线程似乎都在等待。然而我不知道他们在等什么。另一个好像卡在了socketRead.
当代码挂起时，堆的使用也有些奇怪。它上升到大约 400MB，然后下降到 100MB 并重复。一个周期大约需要1小时。
也许你能帮我找出问题所在？
解决方案是向 URLConnection 添加超时，因为显然没有标准超时：
URL url = new URL(urlString);
URLConnection urlConn = url.openConnection();
urlConn.setConnectTimeout(10000);
urlConn.setReadTimeout(10000);
最近我写了一些代码来从网络上读取 JSON 数据并根据收到的数据更新 MongoDB 条目。必须对大约 500,000 个条目执行此操作。为了加速这个过程，我使用了一个带有 5 个线程和一个大小为 50 的阻塞队列的 ThreadPoolExecutor。此外，我使用 CallerRunsPolicy 来处理多余的作业。
每个工人的工作如下：
- 从 URL 读取 JSON 数据
- 解析JSON
- 更新对应的MongoDB条目
但是程序每次都卡住。有时很早，有时只在几个小时后。到目前为止，我还没有发现代码中的任何错误。处理异常但不抛出异常，所有使用的方法都应该是线程安全的。
这是程序挂起后的线程转储：
2016-01-16 23:40:05
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.66-b18 mixed mode):
"JMX server connection timeout 711" #711 daemon prio=5 os_prio=0 tid=0x000000001813d000 nid=0x4e8 in Object.wait() [0x000000004733f000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at com.sun.jmx.remote.internal.ServerCommunicatorAdmin$Timeout.run(Unknown Source)
- locked <0x00000000e26162c8> (a [I)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"RMI Scheduler(0)" #710 daemon prio=5 os_prio=0 tid=0x000000001813b800 nid=0x1ba0 waiting on condition [0x000000004723f000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000e1ce64e0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"RMI TCP Connection(1)-192.168.56.1" #709 daemon prio=5 os_prio=0 tid=0x0000000017714000 nid=0x11f0 runnable [0x000000004713e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000e25e5fe8> (a java.io.BufferedInputStream)
at java.io.FilterInputStream.read(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run6(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler$$Lambda/917377658.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- <0x00000000e23ce048> (a java.util.concurrent.ThreadPoolExecutor$Worker)
"RMI TCP Accept-0" #708 daemon prio=5 os_prio=0 tid=0x0000000017fa2000 nid=0xd18 runnable [0x0000000046f3e000]
java.lang.Thread.State: RUNNABLE
at java.net.DualStackPlainSocketImpl.accept0(Native Method)
at java.net.DualStackPlainSocketImpl.socketAccept(Unknown Source)
at java.net.AbstractPlainSocketImpl.accept(Unknown Source)
at java.net.PlainSocketImpl.accept(Unknown Source)
- locked <0x00000000e1ce8078> (a java.net.SocksSocketImpl)
at java.net.ServerSocket.implAccept(Unknown Source)
at java.net.ServerSocket.accept(Unknown Source)
at sun.management.jmxremote.LocalRMIServerSocketFactory.accept(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-5" #19 prio=5 os_prio=0 tid=0x000000001859e000 nid=0x628 waiting on condition [0x0000000018f9e000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-4" #18 prio=5 os_prio=0 tid=0x000000001859d800 nid=0x2208 waiting on condition [0x0000000018e9f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-3" #17 prio=5 os_prio=0 tid=0x000000001859c800 nid=0x239c waiting on condition [0x0000000018d9e000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-2" #16 prio=5 os_prio=0 tid=0x000000001859a000 nid=0x18a8 runnable [0x0000000018c9e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000f921a080> (a java.io.BufferedInputStream)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
- locked <0x00000000f921a0c0> (a sun.net.www.protocol.http.HttpURLConnection)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
- locked <0x00000000f921a0c0> (a sun.net.www.protocol.http.HttpURLConnection)
at java.net.URL.openStream(Unknown Source)
at Pr0grammDB.readURL(Pr0grammDB.java:217)
at Pr0grammDB.readJSON(Pr0grammDB.java:210)
at Pr0grammDBJob.run(Pr0grammDB.java:98)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- <0x00000000a57afa50> (a java.util.concurrent.ThreadPoolExecutor$Worker)
"pool-1-thread-1" #15 prio=5 os_prio=0 tid=0x0000000018599000 nid=0x20fc waiting on condition [0x0000000018b9f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af940> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
at java.util.concurrent.ArrayBlockingQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"pool-1-thread-1" #12 daemon prio=5 os_prio=0 tid=0x0000000017ecc800 nid=0x2bd8 waiting on condition [0x000000001879f000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57af298> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"cluster-ClusterId{value='569a6466a802c513644d5a51', description='null'}-127.0.0.1:27017" #11 daemon prio=5 os_prio=0 tid=0x000000001785e000 nid=0x1de8 waiting on condition [0x000000001869e000]
java.lang.Thread.State: TIMED_WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000a57ad528> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(Unknown Source)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(Unknown Source)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.waitForSignalOrTimeout(DefaultServerMonitor.java:237)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.waitForNext(DefaultServerMonitor.java:218)
at com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:167)
- locked <0x00000000a57ad270> (a com.mongodb.connection.DefaultServerMonitor$ServerMonitorRunnable)
at java.lang.Thread.run(Unknown Source)
Locked ownable synchronizers:
- None
"Service Thread" #9 daemon prio=9 os_prio=0 tid=0x0000000017493800 nid=0x23a8 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C1 CompilerThread2" #8 daemon prio=9 os_prio=2 tid=0x0000000015af8800 nid=0x2f5c waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C2 CompilerThread1" #7 daemon prio=9 os_prio=2 tid=0x0000000015af1800 nid=0x18c0 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"C2 CompilerThread0" #6 daemon prio=9 os_prio=2 tid=0x0000000015aef000 nid=0x15f8 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Attach Listener" #5 daemon prio=5 os_prio=2 tid=0x0000000015aec800 nid=0x2074 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Signal Dispatcher" #4 daemon prio=9 os_prio=2 tid=0x0000000015aec000 nid=0x2c94 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
Locked ownable synchronizers:
- None
"Finalizer" #3 daemon prio=8 os_prio=1 tid=0x00000000022b8000 nid=0x2f14 in Object.wait() [0x0000000016e4f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000a57ebd08> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
- locked <0x00000000a57ebd08> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(Unknown Source)
at java.lang.ref.Finalizer$FinalizerThread.run(Unknown Source)
Locked ownable synchronizers:
- None
"Reference Handler" #2 daemon prio=10 os_prio=2 tid=0x00000000022af000 nid=0x83c in Object.wait() [0x0000000016d4f000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000a57ebf20> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Unknown Source)
at java.lang.ref.Reference$ReferenceHandler.run(Unknown Source)
- locked <0x00000000a57ebf20> (a java.lang.ref.Reference$Lock)
Locked ownable synchronizers:
- None
"main" #1 prio=5 os_prio=0 tid=0x000000000207e000 nid=0x1964 runnable [0x000000000217e000]
java.lang.Thread.State: RUNNABLE
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
- locked <0x00000000f921c318> (a java.io.BufferedInputStream)
at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source)
at sun.net.www.http.HttpClient.parseHTTP(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
- locked <0x00000000f921c358> (a sun.net.www.protocol.http.HttpURLConnection)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
- locked <0x00000000f921c358> (a sun.net.www.protocol.http.HttpURLConnection)
at java.net.URL.openStream(Unknown Source)
at Pr0grammDB.readURL(Pr0grammDB.java:217)
at Pr0grammDB.readJSON(Pr0grammDB.java:210)
at Pr0grammDBJob.run(Pr0grammDB.java:98)
at java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy.rejectedExecution(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.reject(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.execute(Unknown Source)
at Pr0grammDB.addAdditionalData(Pr0grammDB.java:114)
at Pr0grammDB.main(Pr0grammDB.java:48)
Locked ownable synchronizers:
- None
"VM Thread" os_prio=2 tid=0x0000000015ab7000 nid=0x684 runnable
"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00000000021d7800 nid=0x28e0 runnable
"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00000000021d9000 nid=0x2658 runnable
"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x00000000021da800 nid=0x273c runnable
"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x00000000021dd000 nid=0x20f8 runnable
"VM Periodic Task Thread" os_prio=2 tid=0x00000000174a2000 nid=0x824 waiting on condition
JNI global references: 385
除一个线程外，所有线程似乎都在等待。然而我不知道他们在等什么。另一个好像卡在了socketRead.
当代码挂起时，堆的使用也有些奇怪。它上升到大约 400MB，然后下降到 100MB 并重复。一个周期大约需要1小时。
也许你能帮我找出问题所在？
解决方案是向 URLConnection 添加超时，因为显然没有标准超时：
URL url = new URL(urlString);
URLConnection urlConn = url.openConnection();
urlConn.setConnectTimeout(10000);
urlConn.setReadTimeout(10000);