连接池错误（Spring、hibernate）。 如何解决这个问题？

Question

WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@3531a5ff -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 

java.sql.SQLException: Unable to load authentication plugin 'caching_sha2_password'. at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:869) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:865) at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1746) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226) at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188) at com.Z81C3B080DAD537 DE7E10E0987A4BF52EZ.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2219) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2014) at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:776) at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47) at sun.reflect.GeneratedConstructorAccessor36.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.Z93F725A074 23FE1C889F448B33D21F46Z:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330) at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220) at com.mchange.v2.c3p0.WrapperConnectionPo olDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125) at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44) at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870) at com .mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@456d6127 -- Acquisition Attempt Failed.,. Clearing pending acquires: While trying to acquire a needed new resource. we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: java.sql.SQLException. Unable to load authentication plugin 'caching_sha2_password'. at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.869) at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.865) at com.mysql.jdbc:MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java.1746) at com.mysql.jdbc:MysqlIO.doHandshake(MysqlIO.java.1226) at com.mysql.jdbc:ConnectionImpl.coreConnect(ConnectionImpl.java.2188) at com.Z81C3B080DAD537 DE7E10E0987A4BF52EZ.jdbc:ConnectionImpl.connectOneTryOnly(ConnectionImpl.java.2219) at com.mysql.jdbc:ConnectionImpl.createNewIO(ConnectionImpl.java.2014) at com.mysql.jdbc:ConnectionImpl.(ConnectionImpl.java.776) at com.mysql.jdbc:JDBC4Connection.(JDBC4Connection.java.47) at sun.reflect.GeneratedConstructorAccessor36.newInstance(Unknown Source) at sun.reflect:DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java.45) at java.lang.reflect:Constructor.newInstance(Constructor.Z93F725A074 23FE1C889F448B33D21F46Z.423) at com.mysql.jdbc:Util.handleNewInstance(Util.java.425) at com.mysql.jdbc:ConnectionImpl.getInstance(ConnectionImpl.java.386) at com.mysql.jdbc:NonRegisteringDriver.connect(NonRegisteringDriver.java.330) at com.mchange.v2.c3p0:DriverManagerDataSource.getConnection(DriverManagerDataSource.java.175) at com.mchange.v2.c3p0:WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.220) at com.mchange.v2.c3p0:WrapperConnectionPo olDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.206) at com.mchange.v2.c3p0.impl:C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java.203) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquire(BasicResourcePool.java.1138) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java.1125) at com.mchange.v2.resourcepool:BasicResourcePool.access$700(BasicResourcePool.java.44) at com.mchange.v2.resourcepool:BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java.1870) at com .mchange.v2.async:ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@661ca68e -- Acquisition Attempt Failed.,. Clearing pending acquires: While trying to acquire a needed new resource. we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: java.sql.SQLException. Unable to load authentication plugin 'caching_sha2_password'. at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.869) at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.865) at com.mysql.jdbc:MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java.1746) at com.mysql.jdbc:MysqlIO.doHandshake(MysqlIO.java.1226) at com.mysql.jdbc:ConnectionImpl.coreConnect(ConnectionImpl.java.2188) at com.Z81C3B080DAD537 DE7E10E0987A4BF52EZ.jdbc:ConnectionImpl.connectOneTryOnly(ConnectionImpl.java.2219) at com.mysql.jdbc:ConnectionImpl.createNewIO(ConnectionImpl.java.2014) at com.mysql.jdbc:ConnectionImpl.(ConnectionImpl.java.776) at com.mysql.jdbc:JDBC4Connection.(JDBC4Connection.java.47) at sun.reflect.GeneratedConstructorAccessor36.newInstance(Unknown Source) at sun.reflect:DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java.45) at java.lang.reflect:Constructor.newInstance(Constructor.Z93F725A074 23FE1C889F448B33D21F46Z.423) at com.mysql.jdbc:Util.handleNewInstance(Util.java.425) at com.mysql.jdbc:ConnectionImpl.getInstance(ConnectionImpl.java.386) at com.mysql.jdbc:NonRegisteringDriver.connect(NonRegisteringDriver.java.330) at com.mchange.v2.c3p0:DriverManagerDataSource.getConnection(DriverManagerDataSource.java.175) at com.mchange.v2.c3p0:WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.220) at com.mchange.v2.c3p0:WrapperConnectionPo olDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.206) at com.mchange.v2.c3p0.impl:C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java.203) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquire(BasicResourcePool.java.1138) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java.1125) at com.mchange.v2.resourcepool:BasicResourcePool.access$700(BasicResourcePool.java.44) at com.mchange.v2.resourcepool:BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java.1870) at com .mchange.v2.async:ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@7439cf4b is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@7439cf4b is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@7439cf4b is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. Apr 19, 2020 11:14:30 PM org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator initiateService WARN: HHH000342: Could not obtain connection to query metadata: Connections could not be acquired from the underlying database, Apr 19: 2020 11:14.30 PM com.mchange.v2.resourcepool:BasicResourcePool WARNING. com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@3aea5402 -- Acquisition Attempt Failed,.: Clearing pending acquires. While trying to acquire a needed new resource. we failed to succeed more than the maximum number of allowed acquisition attempts (30): Last acquisition attempt exception. java.sql.SQLException. Unable to load authentication plugin 'caching_sha2_password'. at com.mysql:jdbc.SQLError.createSQLException(SQLError.java.869) at com.mysql:jdbc.SQLError.createSQLException(SQLError.java.865) at com.mysql:jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java.1746) at com.mysql:jdbc.MysqlIO.doHandshake(MysqlIO.java.1226) at com.mysql:jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java.2188) at com.Z81C3B080DAD537 DE7E10E0987A4BF52EZ:jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java.2219) at com.mysql:jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java.2014) at com.mysql:jdbc.ConnectionImpl.(ConnectionImpl.java.776) at com.mysql:jdbc.JDBC4Connection.(JDBC4Connection.java.47) at sun.reflect.GeneratedConstructorAccessor36.newInstance(Unknown Source) at sun:reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java.45) at java.lang:reflect.Constructor.newInstance(Constructor.Z93F725A074 23FE1C889F448B33D21F46Z.423) at com.mysql:jdbc.Util.handleNewInstance(Util.java.425) at com.mysql:jdbc.ConnectionImpl.getInstance(ConnectionImpl.java.386) at com.mysql:jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java.330) at com.mchange.v2:c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java.175) at com.mchange.v2:c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.220) at com.mchange.v2:c3p0.WrapperConnectionPo olDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.206) at com.mchange.v2.c3p0:impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java.203) at com.mchange.v2:resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java.1138) at com.mchange.v2:resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java.1125) at com.mchange.v2:resourcepool.BasicResourcePool.access$700(BasicResourcePool.java.44) at com.mchange.v2:resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java.1870) at com .mchange.v2:async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@7439cf4b is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@4f3eb158 -- Acquisition Attempt Failed.,. Clearing pending acquires: While trying to acquire a needed new resource. we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: java.sql.SQLException. Unable to load authentication plugin 'caching_sha2_password'. at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.869) at com.mysql.jdbc:SQLError.createSQLException(SQLError.java.865) at com.mysql.jdbc:MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java.1746) at com.mysql.jdbc:MysqlIO.doHandshake(MysqlIO.java.1226) at com.mysql.jdbc:ConnectionImpl.coreConnect(ConnectionImpl.java.2188) at com.Z81C3B080DAD537 DE7E10E0987A4BF52EZ.jdbc:ConnectionImpl.connectOneTryOnly(ConnectionImpl.java.2219) at com.mysql.jdbc:ConnectionImpl.createNewIO(ConnectionImpl.java.2014) at com.mysql.jdbc:ConnectionImpl.(ConnectionImpl.java.776) at com.mysql.jdbc:JDBC4Connection.(JDBC4Connection.java.47) at sun.reflect.GeneratedConstructorAccessor36.newInstance(Unknown Source) at sun.reflect:DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java.45) at java.lang.reflect:Constructor.newInstance(Constructor.Z93F725A074 23FE1C889F448B33D21F46Z.423) at com.mysql.jdbc:Util.handleNewInstance(Util.java.425) at com.mysql.jdbc:ConnectionImpl.getInstance(ConnectionImpl.java.386) at com.mysql.jdbc:NonRegisteringDriver.connect(NonRegisteringDriver.java.330) at com.mchange.v2.c3p0:DriverManagerDataSource.getConnection(DriverManagerDataSource.java.175) at com.mchange.v2.c3p0:WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.220) at com.mchange.v2.c3p0:WrapperConnectionPo olDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java.206) at com.mchange.v2.c3p0.impl:C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java.203) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquire(BasicResourcePool.java.1138) at com.mchange.v2.resourcepool:BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java.1125) at com.mchange.v2.resourcepool:BasicResourcePool.access$700(BasicResourcePool.java.44) at com.mchange.v2.resourcepool:BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java.1870) at com .mchange.v2.async:ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

Apr 19, 2020 11:14:30 PM com.mchange.v2.resourcepool.BasicResourcePool WARNING: Having failed to acquire a resource, com.mchange.v2.resourcepool.BasicResourcePool@7439cf4b is interrupting all Threads waiting on a resource to check out. Will try again in response to new client requests. Apr 19, 2020 11:14:30 PM org.hibernate.dialect.Dialect INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect

And this is my code

@Autowired
private Environment env;

private Logger logger = Logger.getLogger(getClass().getName());

// define a bean for ViewResolver

@Bean
public DataSource myDataSource() {

    // create connection pool
    ComboPooledDataSource myDataSource = new ComboPooledDataSource();

    // set the jdbc driver
    try {
        myDataSource.setDriverClass("com.mysql.jdbc.Driver");       
    }
    catch (PropertyVetoException exc) {
        throw new RuntimeException(exc);
    }

    // for sanity's sake, let's log url and user ... just to make sure we are reading the data
    logger.info("jdbc.url=" + env.getProperty("jdbc.url"));
    logger.info("jdbc.user=" + env.getProperty("jdbc.user"));

    // set database connection props
    myDataSource.setJdbcUrl(env.getProperty("jdbc.url"));
    myDataSource.setUser(env.getProperty("jdbc.user"));
    myDataSource.setPassword(env.getProperty("jdbc.password"));

    // set connection pool props
    myDataSource.setInitialPoolSize(getIntProperty("connection.pool.initialPoolSize"));
    myDataSource.setMinPoolSize(getIntProperty("connection.pool.minPoolSize"));
    myDataSource.setMaxPoolSize(getIntProperty("connection.pool.maxPoolSize"));     
    myDataSource.setMaxIdleTime(getIntProperty("connection.pool.maxIdleTime"));

    return myDataSource;
}

private Properties getHibernateProperties() {

    // set hibernate properties
    Properties props = new Properties();

    props.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
    props.setProperty("hibernate.show_sql", env.getProperty("hibernate.show_sql"));

    return props;               
}


// need a helper method 
// read environment property and convert to int

private int getIntProperty(String propName) {

    String propVal = env.getProperty(propName);

    // now convert to int
    int intPropVal = Integer.parseInt(propVal);

    return intPropVal;
}   

@Bean
public LocalSessionFactoryBean sessionFactory(){

    // create session factories
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();

    // set the properties
    sessionFactory.setDataSource(myDataSource());
    sessionFactory.setPackagesToScan(env.getProperty("hibernate.packagesToScan"));
    sessionFactory.setHibernateProperties(getHibernateProperties());

    return sessionFactory;
}

@Bean
@Autowired
public HibernateTransactionManager transactionManager(SessionFactory sessionFactory) {

    // setup transaction manager based on session factory
    HibernateTransactionManager txManager = new HibernateTransactionManager();
    txManager.setSessionFactory(sessionFactory);

    return txManager;
}   

}

How can i fix this?

Answer 1

Your problem is that you have no free connection to DB in your pool. I don't know how does it work in hibernate. But you should pay attention on your DB access. You should close connection after use. In JDBC just open it with "try with resources"( try() {...} ) or use "finally" block to close connection.