休眠“明显的死锁!!!为未分配的挂起任务创建紧急线程!”
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【中文标题】休眠“明显的死锁!!!为未分配的挂起任务创建紧急线程!”【英文标题】:Hibernate "APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!" 【发布时间】:2015-05-23 09:24:24 【问题描述】:我最近在我们的日志中收到以下消息,然后是 JVM 崩溃(由于 OOME)。我不知道该怎么做,非常感谢任何指导。
2015-03-19 21:15:02,457 [Timer-0] WARN (ThreadPoolAsynchronousRunner.java [run]:608) - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@6824f21c -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
2015-03-19 21:26:29,543 [Timer-0] WARN (ThreadPoolAsynchronousRunner.java [run]:624) - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@6824f21c -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@15da1b6b (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@b35b08a (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@51cfdd17 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0)
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@19397937
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@5c7d3838
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@7aea62dd
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@55622ff2
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@74004a8
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:560)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2,5,main]
java.net.SocketOutputStream.socketWrite0(Native Method)
java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
java.net.SocketOutputStream.write(SocketOutputStream.java:153)
java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82)
java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140)
com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3227)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1917)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2060)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
com.mysql.jdbc.ConnectionImpl.configureClientCharacterSet(ConnectionImpl.java:1751)
com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3425)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2196)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.GeneratedConstructorAccessor306.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:408)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:135)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1,5,main]
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:560)
2015-03-19 21:56:59,137 [Timer-0] WARN (ThreadPoolAsynchronousRunner.java [run]:608) - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@6824f21c -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
2015-03-19 21:56:59,143 [eXistThread-18676] ERROR (XQueryServlet.java [process]:566) - Java heap space
java.lang.OutOfMemoryError: Java heap space
at org.exist.storage.btree.BTree$BTreeNode.read(BTree.java:1269)
at org.exist.storage.btree.BTree$BTreeNode.access$16(BTree.java:1239)
at org.exist.storage.btree.BTree.getBTreeNode(BTree.java:460)
at org.exist.storage.btree.BTree.scanSequential(BTree.java:413)
at org.exist.storage.btree.BTree$BTreeNode.scanNextPage(BTree.java:2039)
at org.exist.storage.btree.BTree$BTreeNode.query(BTree.java:1835)
at org.exist.storage.btree.BTree$BTreeNode.query(BTree.java:1759)
at org.exist.storage.btree.BTree$BTreeNode.query(BTree.java:1759)
at org.exist.storage.btree.BTree$BTreeNode.query(BTree.java:1759)
at org.exist.storage.btree.BTree$BTreeNode.access$12(BTree.java:1734)
at org.exist.storage.btree.BTree.query(BTree.java:379)
at org.exist.storage.structural.NativeStructuralIndexWorker.scanByType(NativeStructuralIndexWorker.java:259)
at org.exist.dom.VirtualNodeSet.getNodesFromIndex(VirtualNodeSet.java:457)
at org.exist.dom.VirtualNodeSet.realize(VirtualNodeSet.java:585)
at org.exist.dom.VirtualNodeSet.iterator(VirtualNodeSet.java:860)
at org.exist.dom.AbstractNodeSet.iterator(AbstractNodeSet.java:1)
at org.exist.storage.structural.NativeStructuralIndexWorker.findDescendantsByTagName(NativeStructuralIndexWorker.java:162)
at org.exist.xquery.LocationStep.getAttributes(LocationStep.java:645)
at org.exist.xquery.LocationStep.eval(LocationStep.java:434)
at org.exist.xquery.AbstractExpression.eval(AbstractExpression.java:71)
at org.exist.xquery.PathExpr.eval(PathExpr.java:264)
at org.exist.xquery.Predicate.selectByNodeSet(Predicate.java:446)
at org.exist.xquery.Predicate.evalPredicate(Predicate.java:326)
at org.exist.xquery.LocationStep.processPredicate(LocationStep.java:251)
at org.exist.xquery.LocationStep.applyPredicate(LocationStep.java:238)
at org.exist.xquery.LocationStep.eval(LocationStep.java:462)
at org.exist.xquery.AbstractExpression.eval(AbstractExpression.java:71)
at org.exist.xquery.PathExpr.eval(PathExpr.java:264)
at org.exist.xquery.LetExpr.eval(LetExpr.java:142)
at org.exist.xquery.LetExpr.eval(LetExpr.java:187)
at org.exist.xquery.LetExpr.eval(LetExpr.java:187)
at org.exist.xquery.BindingExpression.eval(BindingExpression.java:164)
2015-03-19 21:56:59,147 [Timer-0] WARN (ThreadPoolAsynchronousRunner.java [run]:624) - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@6824f21c -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@79180a12 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@243c6d0c (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@50191373 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2)
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@3a9d08ca
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@3ecdd11
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@44ff846d
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@5ce5850a
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@eec1d04
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@6b8d4d9d
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@53e9706d
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@23d472cf
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@4dbe4f8c
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@4c5e0203
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@54ac79fd
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@546e2bad
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@6b13cc83
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@57e185f8
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@60357d68
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@45231180
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@3021aa73
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@6bb437ca
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@2021c9e9
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@7d53637c
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@409c2c97
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@adc5929
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@241ca71a
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@42b26866
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@636b1c33
com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask@b160466
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@4af34669
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@1b53e609
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@2062ebd4
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@1b6cfe8a
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@4b7c2380
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@4f9be748
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@78108924
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@474b002
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@2ebee32f
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@3e0fe017
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@42aa175b
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@637f5bac
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@3a017b77
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@7b4f2b78
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1,5,main]
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:408)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ResultSetImpl.getInstance(ResultSetImpl.java:370)
com.mysql.jdbc.MysqlIO.buildResultSetWithRows(MysqlIO.java:2532)
com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:477)
com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:2510)
com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:1746)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2135)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1383)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4826)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:50)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4804)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnectionNoQuery(DefaultConnectionTester.java:185)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnection(DefaultConnectionTester.java:62)
com.mchange.v2.c3p0.AbstractConnectionTester.activeCheckConnection(AbstractConnectionTester.java:67)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.testPooledConnection(C3P0PooledConnectionPool.java:368)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.refurbishIdleResource(C3P0PooledConnectionPool.java:310)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask.run(BasicResourcePool.java:1999)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2,5,main]
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2596)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1383)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4826)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:50)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4804)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnectionNoQuery(DefaultConnectionTester.java:185)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnection(DefaultConnectionTester.java:62)
com.mchange.v2.c3p0.AbstractConnectionTester.activeCheckConnection(AbstractConnectionTester.java:67)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.testPooledConnection(C3P0PooledConnectionPool.java:368)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.refurbishIdleResource(C3P0PooledConnectionPool.java:310)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask.run(BasicResourcePool.java:1999)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1012)
java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:1006)
com.newrelic.agent.TransactionService.addTransaction(TransactionService.java:142)
com.newrelic.agent.Transaction.getTransaction(Transaction.java:1104)
com.newrelic.agent.Transaction.getTransaction(Transaction.java:1087)
com.newrelic.agent.TracerService$TracerServiceImpl.getTracer(TracerService.java:136)
com.newrelic.agent.TracerService.getTracer(TracerService.java:41)
com.newrelic.agent.instrumentation.InvocationPoint.invoke(InvocationPoint.java:55)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4826)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:50)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4804)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnectionNoQuery(DefaultConnectionTester.java:185)
com.mchange.v2.c3p0.impl.DefaultConnectionTester.activeCheckConnection(DefaultConnectionTester.java:62)
com.mchange.v2.c3p0.AbstractConnectionTester.activeCheckConnection(AbstractConnectionTester.java:67)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.testPooledConnection(C3P0PooledConnectionPool.java:368)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.refurbishIdleResource(C3P0PooledConnectionPool.java:310)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask.run(BasicResourcePool.java:1999)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
我们正在使用具有以下 c3p0 配置的 hibernate 和 c3p0:
我们正在为 hibernate 和 c3p0 使用以下 maven 工件:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.6.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-c3p0</artifactId>
<version>4.3.6.Final</version>
</dependency>
使用以下 c3p0 配置:
configuration = new Configuration().setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5InnoDBDialect")
.setProperty("hibernate.connection.provider_class", "org.hibernate.connection.C3P0ConnectionProvider")
.setProperty("hibernate.c3p0.idle_test_period", "1000")
.setProperty("hibernate.c3p0.min_size", "20")
.setProperty("hibernate.c3p0.max_size", "50")
.setProperty("hibernate.c3p0.timeout", "1800")
.setProperty("hibernate.c3p0.max_statements", "50")
服务器负载非常轻,每秒约 5 个查询。 (Java 8)
【问题讨论】:
【参考方案1】:我偶然发现了同样的异常,原因是db用户的密码错误...
c3p0 你是个有趣的人
【讨论】:
是的,正确的,我也遇到了这个问题。当数据库关闭时,我收到此错误消息 伙计,我希望事情就这么简单。 就我而言,这是错误的 DB URL XD【参考方案2】:所以,直接的问题是连接池试图获取新的连接,但是试图获取这些任务的任务冻结了很长一段时间,以至于 c3p0 决定任务必须死锁然后丢弃,替换了线程池。后来线程池挂在空闲的连接测试任务上。
通常,“挂起”任务看起来像上面第一个“池线程堆栈跟踪:”标签下的第二个线程:执行网络 IO 无法完成。您的情况很奇怪,因为三个线程中的两个没有卡在 IO 中。他们几乎没有开始做任何事情,但他们还没有活着。然后您会遇到 OutOfMemoryError,并且您会在空闲连接测试任务上遇到另一个明显的死锁,这些任务看起来也应该是实时的。
也许您的应用程序非常接近某种资源限制,导致运行非常缓慢?直截了当,您可能会增加此应用程序可用的内存量(或对其进行修改以减少内存占用)。当线程池第二次尝试刷新和重新创建挂起的线程时,您会遇到 OOME,这不是直接引起的,而是很可能是由不断增长的线程占用空间引起的。 (在您的日志中,以前是否有很多这些明显的死锁?如果您强制执行 JVM 线程转储,您是否看到周围有很多 com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread
实例,仍然挂在旧的、未完成的任务上?
一些通用的 cmets:如果您的负载不超过 5 次同时查询,那么为什么会有这么大的池?为什么不min_size
5-ish,最大 10-ish?您的 max_statements 设置对于池中允许的连接数来说太小了。我会完全忽略这一点,直到你让事情顺利进行。然后,为了获得更好的性能,您可以根据需要设置 more-straightforward-to-reason-about maxStatementsPerConnection
参数。
大多数情况下,您需要将应用程序的占用空间(内存?线程?)远低于分配给它的资源,方法是增加资源、减少占用空间,或修复任何可能存在的导致其资源占用增加到极限的问题.我会先让池更小,可用内存更大,然后将池配置得更小。
【讨论】:
非常感谢您的详细回复。为了回答您的问题,这是我第一次在日志中看到这些消息。我认为您可能是对的,这可能是 OOME 异常的症状,而不仅仅是 c3p0 问题。我将设置一些详细的监控,看看它告诉我有关资源使用情况的信息。谢谢! “我会先让池更小,可用内存更大,然后将池配置得更小。”使池更小和将池配置得更小有什么区别。【参考方案3】:对我来说也是身份验证问题。我刚刚将域部分添加到数据库服务器名称中,并且一切正常。非常具有误导性的错误。
【讨论】:
我希望你没有在得到答案后就删除 List以上是关于休眠“明显的死锁!!!为未分配的挂起任务创建紧急线程!”的主要内容,如果未能解决你的问题,请参考以下文章