APPARENT DEADLOCK为未分配的待处理任务创建紧急线程 [英] APPARENT DEADLOCK Creating emergency threads for unassigned pending tasks
问题描述
我正在使用mybatis的mysql，我在我们的实时服务器上遇到此错误
I am using mysql with mybatis and I am greeting this error on our live server
com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@6538f8f2
-- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
我不明白为什么这个错误会因为我的C3P0设置而来？我的C3P0设置是这样的
I don't understand why this error is coming is this because of my C3P0 setting? My C3P0 settings are like this
----开始更新-----
----start Updated-----
下面是我的spring-servlet.xml配置
below is my spring-servlet.xml configuration
我更新数据源bean为
<bean id="datasource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close" p:driverClass="com.mysql.jdbc.Driver"
p:jdbcUrl="jdbc:mysql://localhost/jdb" p:user="root" p:password="root"
p:acquireIncrement="10"
p:idleConnectionTestPeriod="60"
p:maxPoolSize="100"
p:maxStatements="0"
p:minPoolSize="10"
p:initialPoolSize="10"
p:statementCacheNumDeferredCloseThreads="1" />
<!-- Declare a transaction manager -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="datasource" />
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource" />
</bean>
<!-- scan for mappers and will automatically scan the whole classpath for xmls -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
<property name="basePackage" value="com.mycom.myproject.db.mybatis.dao" />
</bean>
从我的Dao类我调用mapper方法如
and from my Dao class I call mapper method like
myDao.updateRecords()
这是我的服务类方法
@Override
public List<UserDetailedBean> selectAllUsersDetail(long groupId, List<Long> ids) {
List<UserDetailedBean> usersDetailList = null;
try {
usersDetailList = userDao.selectAllUsersDetail(groupId, ids);
} catch (Exception e) {
e.printStackTrace();
}
return usersDetailList;
}
在Dao类中我只是注入映射器。
In Dao class I just inject the mapper.
@Resource
private UserMapper userMapper;
@Override
public List<UserDetailedBean> selectAllUsersDetail(long groupId, List<Long> ids) {
return userMapper.selectAllUsersDetail(groupId,ids);
}
---结束更新------
---end updated------
如果需要任何其他信息，请告诉我。
please let me know if any other information is required.
这是完整的堆栈跟踪
[ WARN] 2013-01-08 20:13:39 com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@70497e11 -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
[ WARN] 2013-01-08 20:13:39 com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@70497e11 -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@2e81b8c5 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@4689a55d (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2)
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@76c7a0d8 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1)
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@2c1101d4
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@108f1be6
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@2370a188
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@377cf9e5
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@6dfa45d8
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@49ffa050
com.mchange.v2.resourcepool.BasicResourcePool$AsyncTestIdleResourceTask@2d760a24
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:150)
java.net.SocketInputStream.read(SocketInputStream.java:121)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2549)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3002)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2618)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1557)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4984)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:51)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4962)
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]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:150)
java.net.SocketInputStream.read(SocketInputStream.java:121)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2549)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3002)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2618)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1557)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4984)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:51)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4962)
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-#1,5,main]
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:150)
java.net.SocketInputStream.read(SocketInputStream.java:121)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2549)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3002)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2618)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2568)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1557)
com.mysql.jdbc.DatabaseMetaData$9.forEach(DatabaseMetaData.java:4984)
com.mysql.jdbc.IterateBlock.doForAll(IterateBlock.java:51)
com.mysql.jdbc.DatabaseMetaData.getTables(DatabaseMetaData.java:4962)
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)
---更新----
当我将p：statementCacheNumDeferredCloseThreads =1添加到datasouce bean时，我收到以下错误
when I added p:statementCacheNumDeferredCloseThreads="1" to datasouce bean I am getting the below error
Error creating bean with name 'sqlSessionFactory' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]:
Cannot resolve reference to bean 'datasource' while setting bean property 'dataSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'datasource' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]:
Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'statementCacheNumDeferredCloseThreads' of bean class [com.mchange.v2.c3p0.ComboPooledDataSource]:
Bean property 'statementCacheNumDeferredCloseThreads' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?
推荐答案
来自 http://www.mchange.com/projects/c3p0/#other_ds_configuration
numHelperThreads 和 maxAdministrativeTaskTime 有助于配置DataSource线程池的行为。默认情况下，每个DataSource只有三个关联的帮助程序线程。如果性能似乎在重负载下拖拽，或者如果您通过JMX观察或直接检查PooledDataSource，那么待处理任务的数量通常大于零，请尝试增加numHelperThreads。 maxAdministrativeTaskTime 对于遇到无限期挂起的任务和APPARENT DEADLOCK消息的用户可能很有用。 （有关详细信息，请参阅附录A.）
numHelperThreads and maxAdministrativeTaskTime help to configure the behavior of DataSource thread pools. By default, each DataSource has only three associated helper threads. If performance seems to drag under heavy load, or if you observe via JMX or direct inspection of a PooledDataSource, that the number of "pending tasks" is usually greater than zero, try increasing numHelperThreads. maxAdministrativeTaskTime may be useful for users experiencing tasks that hang indefinitely and "APPARENT DEADLOCK" messages. (See Appendix A for more.)
maxAdministrativeTaskTime
默认值：0
c3p0的线程池之前的秒数将尝试打断一个明显挂起的任务。很少有用。许多c3p0的函数不是由客户端线程执行的，而是由内部线程池异步执行的。 c3p0的异步直接增强了客户端性能，并通过确保在非锁定保持线程中执行缓慢的jdbc操作，最大限度地缩短了关键锁定所需的时间。但是，如果这些任务中的某些任务挂起，那就是它们既没有成功也没有因为Exception长时间失败，c3p0的线程池可能会耗尽并且备份管理任务。如果任务很慢，解决问题的最佳方法是通过 numHelperThreads 增加线程数。但是，如果任务有时无限期挂起，则可以使用此参数强制调用任务线程的interrupt（）方法（如果任务超出设定的时间限制）。 [c3p0最终将通过发出APPARENT DEADLOCK信号来恢复挂起的任务（您将在日志中看到它作为警告），替换线程池任务线程，并中断（）原始线程。但让游泳池进入APPARENT DEADLOCK然后恢复意味着在某些时期，c3p0的性能将受损。因此，如果您看到这些消息，增加numHelperThreads并设置maxAdministrativeTaskTime可能会有帮助。 maxAdministrativeTaskTime应该足够大，以至于任何合理的尝试从数据库获取连接，测试连接或两个销毁连接，都应该在设置的时间内成功或失败。零（默认值）表示任务永远不会中断，这是大多数情况下最好，最安全的策略。如果任务很慢，请分配更多线程。如果任务永远悬空，请尝试找出原因，并且在此期间设置maxAdministrativeTaskTime可能会有所帮助。
maxAdministrativeTaskTime Default: 0 Seconds before c3p0's thread pool will try to interrupt an apparently hung task. Rarely useful. Many of c3p0's functions are not performed by client threads, but asynchronously by an internal thread pool. c3p0's asynchrony enhances client performance directly, and minimizes the length of time that critical locks are held by ensuring that slow jdbc operations are performed in non-lock-holding threads. If, however, some of these tasks "hang", that is they neither succeed nor fail with an Exception for a prolonged period of time, c3p0's thread pool can become exhausted and administrative tasks backed up. If the tasks are simply slow, the best way to resolve the problem is to increase the number of threads, via numHelperThreads. But if tasks sometimes hang indefinitely, you can use this parameter to force a call to the task thread's interrupt() method if a task exceeds a set time limit. [c3p0 will eventually recover from hung tasks anyway by signalling an "APPARENT DEADLOCK" (you'll see it as a warning in the logs), replacing the thread pool task threads, and interrupt()ing the original threads. But letting the pool go into APPARENT DEADLOCK and then recover means that for some periods, c3p0's performance will be impaired. So if you're seeing these messages, increasing numHelperThreads and setting maxAdministrativeTaskTime might help. maxAdministrativeTaskTime should be large enough that any resonable attempt to acquire a Connection from the database, to test a Connection, or two destroy a Connection, would be expected to succeed or fail within the time set. Zero (the default) means tasks are never interrupted, which is the best and safest policy under most circumstances. If tasks are just slow, allocate more threads. If tasks are hanging forever, try to figure out why, and maybe setting maxAdministrativeTaskTime can help in the meantime.
The default is 3 for numHelperThreads , increase this to 8-10
setting maxAdministrativeTaskTime will help
这篇关于APPARENT DEADLOCK为未分配的待处理任务创建紧急线程的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
