我配置proxool连接池已经成功，启动tomcat时没有问题，打开页面后也连接数据库成功。但是1分钟后，连接变开始失败了，再也连不上了。console下面每隔1分钟就会报一次ora12518的错误，具体如下：
2014-05-21 11:24:12,578 ERROR (Prototyper.java:105) Prototype
java.sql.SQLException: Listener refused the connection with the following error:
ORA-12518, TNS:listener could not hand off client connection
The Connection descriptor used by the client was:
localhost:1521:orcl
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:111)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:260)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:386)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:413)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:164)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:34)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:752)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)
我在网上搜索，以为是oracle的process和session还有sga不够，需要扩大，但是我按照他的说法扩大了之后还是遇到相同的问题。
大神求教！
