我的应用程序正在使用c3p0连接池连接到MySql数据库。属性在下面给出
hibernate_c3p0_max_size=30
hibernate_c3p0_min_size=1
hibernate_c3p0_acquire_increment=1
hibernate_c3p0_idle_test_period=300
hibernate_c3p0_max_statements=0
hibernate_c3p0_timeout=360
hibernate_c3p0_initialpoolsize=1
hibernate_c3p0_maxpoolsize=30
hibernate_c3p0_minpoolsize=1
使用此配置，我们可以使用80位用户进行测试，并且45分钟后崩溃了。因此，为了提高性能，我将max和max_pool_size设置为60，将min和min_pool_size设置为15，但结果令人震惊，应用程序在5分钟后停止响应。然后我将min和min_pool_size更改为1，然后应用程序在8分钟后停止响应。然后，我将max和max_pool_size更改为30，该应用程序为60个用户工作了1个小时，尽管在45分钟时达到峰值，但是以某种方式进行了管理。当池大小增加时，为什么性能会下降？？？为了获得最佳性能，我应该注意哪些事情？
下面是它崩溃时给出的错误
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@dbf2e57 -- 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:
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at sun.reflect.GeneratedConstructorAccessor142.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.Util.getInstance(Util.java:383)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:958)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:937)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:872)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2159)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2084)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
at sun.reflect.GeneratedConstructorAccessor115.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections
at sun.reflect.GeneratedConstructorAccessor142.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:400)
at com.mysql.jdbc.Util.getInstance(Util.java:383)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:958)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3847)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3783)