冬眠的C3P0僵局[英] c3p0 deadlocks in Hibernate

问题描述

我是Hibernate的新手,并且已经开始使用C3P0作为Hibernate的连接池管理器,因为没有那样,我在与MySQL Server的8个小时无接触后遇到了超时问题.

切换到C3P0后,我最近遇到了一个僵局,我不确定它是怎么发生的.我虽然有所有堆栈跟踪和配置要显示.

这是配置日志

Jan 27, 2017 5:56:23 PM com.mchange.v2.log.MLog <clinit>
INFO: MLog clients using java 1.4+ standard logging.
Jan 27, 2017 5:56:23 PM com.mchange.v2.c3p0.C3P0Registry banner
INFO: Initializing c3p0-0.9.2.1 [built 20-March-2013 10:47:27 +0000; debug? true; trace: 10]
Jan 27, 2017 5:56:23 PM com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
INFO: Initializing c3p0 pool... com.mchange.v2.c3p0.PoolBackedDataSource@28c81cce [ connectionPoolDataSource -> com.mchange.v2.c3p0.WrapperConnectionPoolDataSource@35af8b6c [ acquireIncrement -> 1, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, debugUnreturnedConnectionStackTraces -> false, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hge14z9l1qg67m9nxywg8|c2db68f, idleConnectionTestPeriod -> 300, initialPoolSize -> 1, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 120, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 25, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 1, nestedDataSource -> com.mchange.v2.c3p0.DriverManagerDataSource@2e47880e [ description -> null, driverClass -> null, factoryClassLocation -> null, identityToken -> 1hge14z9l1qg67m9nxywg8|1b765a2c, jdbcUrl -> jdbc:mysql://localhost/Pokemon_Blaze_Online_Dev, properties -> {user=******, password=******} ], preferredTestQuery -> select 1;, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false; userOverrides: {} ], dataSourceName -> null, factoryClassLocation -> null, identityToken -> 1hge14z9l1qg67m9nxywg8|7e276594, numHelperThreads -> 3 ]

这是我设置的属性

<property name="hibernate.c3p0.acquire_increment">1</property>
<property name="hibernate.c3p0.idle_test_period">300</property>
<property name="hibernate.c3p0.timeout">120</property>
<property name="hibernate.c3p0.max_size">25</property>
<property name="hibernate.c3p0.min_size">1</property>
<property name="hibernate.c3p0.max_statement">0</property>
<property name="hibernate.c3p0.preferredTestQuery">select 1;</property>
<property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>

这是锁定的线程之一的线程转储.

"Request Pool-0" #71 prio=5 os_prio=0 tid=0x000000002b2df800 nid=0x1d48 in Object.wait() [0x000000003113e000]
   java.lang.Thread.State: WAITING (on object monitor)
    at java.lang.Object.wait(Native Method)
    at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1414)
    at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:606)
    - locked <0x00000006c1b3c088> (a com.mchange.v2.resourcepool.BasicResourcePool)
    at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:526)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:755)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:682)
    at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
    at org.hibernate.c3p0.internal.C3P0ConnectionProvider.getConnection(C3P0ConnectionProvider.java:90)
    at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:387)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:228)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:171)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:63)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:162)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:186)
    at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:160)
    at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1884)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1861)
    at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1838)
    at org.hibernate.loader.Loader.doQuery(Loader.java:909)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:354)
    at org.hibernate.loader.Loader.doList(Loader.java:2553)
    at org.hibernate.loader.Loader.doList(Loader.java:2539)
    at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2369)
    at org.hibernate.loader.Loader.list(Loader.java:2364)
    at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:126)
    at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1682)
    at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:380)
    at org.hibernate.internal.CriteriaImpl.uniqueResult(CriteriaImpl.java:402)
    at com.game.server.persistence.services.player.PlayerDataServiceImpl.areValidCredentials(PlayerDataServiceImpl.java:28)
    at com.game.server.manager.request.service.DefaultLoginService.login(DefaultLoginService.java:78)
    at com.game.server.manager.request.DefaultRequestManager.lambda$login$2(DefaultRequestManager.java:103)
    at com.game.server.manager.request.DefaultRequestManager$$Lambda$63/869031346.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

   Locked ownable synchronizers:
    - <0x000000079eea0890> (a java.util.concurrent.ThreadPoolExecutor$Worker)

由于我对此并不陌生,因此我无法从日志和转储中识别出问题.我还注意到C3P0创建了很多线程.

在此处输入图像说明

推荐答案

您的应用程序几乎可以肯定在泄漏连接.请参阅 c3p0的文档

tl; DR: set

<property name="hibernate.c3p0.unreturnedConnectionTimeout">30</property>
<property name="hibernate.c3p0.debugUnreturnedConnectionStackTraces">true</property>

检查您的日志中的堆栈跟踪,以检查应用程序中的连接或会话,但无法可靠地关闭().通过使用诸如试用资源之类的东西可靠地关闭事物来解决这个问题.解决问题后,请删除上述属性.

另请参见

其他推荐答案

我一次僵局,这些日志:

BasicResourcepool-获取测试 - 池已经最大化. [托管:10;最大:10]

事实证明,我有一种启动会话+事务的方法调用另一种方法,该方法也"抓住了自己的会话"并使用了它.嵌套会话 +多线 - >僵局. fwiw.

也很有用:JSTACK您的应用程序(或同等),您可能会发现一些线程粘在一个点,有些线程在另一个...现有的封锁线程可能会持有其(当前)会话,适当...

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