Java Connection Pooling最佳实践?

时间:2010-09-04 20:53:37

标签: java database multithreading connection-pooling bonecp

在厌倦了c3p0的持续锁定后,我转向BoneCP,为我的数据库提供了一个替代连接池。我有一个服务器应用程序,每分钟处理大约7,000个项目,需要将这些项目记录到我们的MySQL数据库中。我目前有100个工作线程,并设置了我的游泳池:

BoneCPConfig config = new BoneCPConfig();
      config.setJdbcUrl("jdbc:mysql://"+Settings.MYSQL_HOSTNAME+"/"+Settings.MYSQL_DATABASE+"?autoReconnectForPools=true" ); 
      config.setUsername(Settings.MYSQL_USERNAME); 
      config.setPassword(Settings.MYSQL_PASSWORD);
      config.setMinConnectionsPerPartition(5);
      config.setMaxConnectionsPerPartition(10);
      config.setPartitionCount(5);
      config.setAcquireIncrement(5);
      connectionPool = new BoneCP(config); // setup the connection pool

这类应用的可接受设置是什么?我问,因为在运行一两分钟后,我在尝试呼叫池上的getConnection时遇到了BoneCP异常。谢谢你的帮助。

以下是我在工作线程中用于db调用的代码,它不能在dbConn = this.dbPool.getConnection()行上失败。我没有正确关闭连接吗?

private void insertIntoDb() {
    try {  
        Connection dbConn = this.dbPool.getConnection();

        try {
            PreparedStatement ps3 = dbConn.prepareStatement("INSERT IGNORE INTO test_table1 SET test1=?, test2=?, test3=?");
            ps3.setString(1, "some string");
            ps3.setString(2, "some other string");
            ps3.setString(3, "more strings");
            ps3.execute();
            ps3.close();

            PreparedStatement ps4 = dbConn.prepareStatement("INSERT IGNORE INTO test_table2 SET test1=?, test2=?, test3=?");
            ps4.setString(1, "some string");
            ps4.setString(2, "some other string");
            ps4.setString(3, "more strings");
            ps4.execute();
            ps4.close();

        } catch(SQLException e) {
            logger.error(e.getMessage());
        } finally {
            try {
                dbConn.close();
            } catch (SQLException e) {
                logger.error(e.getMessage());
            }
        }
    } catch(SQLException e) {
        logger.error(e.getMessage());
    }
}

这是我看到的错误:

 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.
 [java]  WARN [com.google.common.base.internal.Finalizer] (ConnectionPartition.java:141) - BoneCP detected an unclosed connection and will now attempt to close it for you. You should be closing this connection in your application - enable connectionWatch for additional debugging assistance.

ERROR pool-2-thread-39 2010-09-04 13:36:19,798 com.test.testpackage.MyTask - null
java.sql.SQLException
    at com.jolbox.bonecp.BoneCP.getConnection(BoneCP.java:381)

1 个答案:

答案 0 :(得分:15)

  

这类应用的可接受设置是什么?我问,因为在运行一两分钟后,我在尝试调用池上的getConnection时遇到了boneCP异常。谢谢你的帮助。

如果您有100名工人,为什么要将池限制为50个连接(分区数x每个分区的最大连接数,即您的情况下为5 x 10)?

  

我没有正确关闭连接吗?

看起来不错(但可能会启用connectionWatch,因为它暗示了警告的确切含义。就个人而言,我关闭了我使用的所有资源,包括语句和结果集。以防万一,这是我使用的习语:

Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;

try {
    conn = pool.getConnection();
    pstmt = conn.prepareStatement(SOME_SQL);
    pstmt.setFoo(1, foo);
    ...
    rs = pstmt.executeQuery();
    ...
} finally {
    if (rs != null) try { rs.close(); } catch (SQLException quiet) {}
    if (pstmt != null) try { pstmt.close(); } catch (SQLException quiet) {}
    if (conn != null) try { conn.close(); } catch (SQLException quiet) {}
}

您可以在实用程序类的静态方法中对上述调用进行分组。

或者您可以使用已经执行此操作的Commons DbUtils中的DbUnit.closeQuietly(Connection, Statement, ResultSet)