oracle 连接 异常 Acquisition Attempt Failed!!! Clearing pending acquires.

vgeejykiyd

　　出错代码

com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@1429b9f -- 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: Io 异常: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=186647040)(ERR=12519)(ERROR_STACK=(ERROR=
(CODE=12519)(EMFI=4))))
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:333)
at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:404)
at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:468)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:135)
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)
　　首先分析，本地主机与数据库服务器的连接状态有无异常，无。再次分析你能否操作数据库服务器的数据库，使用pl/sql developer测试发现仍能正常连接。这个时候就要借助强大的网络了。百度、Google之后，发现引起这个现象的原因可能有数据库连接数的问题。具体操作

SQL> select count(*) from v$process;
COUNT(*)
----------
44
SQL> select count(*) from v$session;
COUNT(*)
----------
39
　　基本正常。但可能是由于该模块的操作比较复杂，所以考虑修改数据库连接数。代码：

alter system set processes=250 scope=spfile;
　　运行之后，仍没有效果。
　　后来找来高手分析了一下，修改数据库连接的jdbc.properties中的cpool.maxPoolSize为20.重启之后问题解决。其实修改数据库连接数应该也没有问题，我想应该是没有重启数据库服务的原因吧。写下该文章一方面留一备忘，另外希望大拿指正。