我在Tomcat中使用C3P0作为连接池,我看到非常令人担忧的错误:
2010-09-16 13:25:00,160 [Timer-0] WARN com.mchange.v2.async.ThreadPoolAsynchronousRunner - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@43502400 -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
2010-09-16 13:25:01,407 [Timer-0] WARN com.mchange.v2.async.ThreadPoolAsynchronousRunner - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@43502400 -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 10
Active Threads: 0
Active Tasks:
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$1RefurbishCheckinResourceTask@6e4151a7
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#6,5,main]
java.lang.Object.wait(Native Method)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2,5,main]
java.lang.Object.wait(Native Method)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1,5,main]
java.lang.Object.wait(Native Method)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
java.lang.Object.wait(Native Method)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#5,5,main]
java.lang.Object.wait(Native Method)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:534)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#4,5,main]
java.lang.Object.wait(Native Method)
... many more, exact same stack trace
第534行是:
while (true) {
Runnable …当我通过tomcat或resin启动我的项目时,我的项目将抛出错误:APPARENT DEADLOCK
我认为由c3p0引起的错误无法连接我的数据库,我更改了我的xml并用我的数据库的ip替换了域名,然后项目启动了!
我在c3p0工作之前使用了一个监听器,我可以得到正确的域名和ip,我找不到APPARENT DEADLOCK的原因.
012-10-22 16:53:04 24344 WARN [Timer-0] com.mchange.v2.async.ThreadPoolAsynchronousRunner:624 - com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@1e79aa -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@723a14 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@14313ff (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@d5f50d (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2)
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@cb560b
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@17e107c
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
java.net.PlainSocketImpl.socketConnect(Native Method)
java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
我想知道如何正确确定 c3p0 max_statements 使用什么值。我经历过一些缓存死锁，这似乎指向我的 max_statements 配置，基于我读过的所有 SO 问答。
我正在使用 mysql，当我进行一些有 4 个活动线程的多线程处理时，似乎会发生死锁。
我的配置
<property name="hibernate.connection.provider_class">org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider</property>
<property name="hibernate.c3p0.min_size">10</property>
<property name="hibernate.c3p0.max_statements">50</property>
<property name="hibernate.c3p0.max_size">50</property>
<property name="hibernate.c3p0.idle_test_period">1800</property>
<property name="hibernate.c3p0.timeout">3600</property>
例外情况
[WARN] async.ThreadPoolAsynchronousRunner com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@72df1587 -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask@e877a61
on thread: C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#2
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask@109b1150
on thread: C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#0
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask@3eb42946
on thread: C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#1
Pending Tasks:
com.mchange.v2.c3p0.stmt.GooGooStatementCache$1StmtAcquireTask@52729f95
Pool thread stack traces:
Thread[C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#0,5,main]
com.mysql.jdbc.PreparedStatement.realClose(PreparedStatement.java:2765)
com.mysql.jdbc.StatementImpl.close(StatementImpl.java:541)
com.mchange.v1.db.sql.StatementUtils.attemptClose(StatementUtils.java:53)
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask.run(GooGooStatementCache.java:938)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Thread[C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#1,5,main]
com.mysql.jdbc.PreparedStatement.realClose(PreparedStatement.java:2765)
com.mysql.jdbc.StatementImpl.close(StatementImpl.java:541)
com.mchange.v1.db.sql.StatementUtils.attemptClose(StatementUtils.java:53)
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask.run(GooGooStatementCache.java:938)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
Thread[C3P0PooledConnectionPoolManager[identityToken->1hge0wd9a1o1iea71i8u346|1a799bb]-HelperThread-#2,5,main]
com.mysql.jdbc.PreparedStatement.realClose(PreparedStatement.java:2765)
com.mysql.jdbc.StatementImpl.close(StatementImpl.java:541)
com.mchange.v1.db.sql.StatementUtils.attemptClose(StatementUtils.java:53)
com.mchange.v2.c3p0.stmt.GooGooStatementCache$StatementDestructionManager$1UncheckedStatementCloseTask.run(GooGooStatementCache.java:938)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:648)
所以我的问题是如何确定这些值应该是什么。我确信一定有办法做到这一点而无需猜测。 …