| /* | |
| Copyright 2007 MySQL AB, 2008 Sun Microsystems | |
| This program is free software; you can redistribute it and/or modify | |
| it under the terms of version 2 of the GNU General Public License as | |
| published by the Free Software Foundation. | |
| There are special exceptions to the terms and conditions of the GPL | |
| as it is applied to this software. View the full text of the | |
| exception in file EXCEPTIONS-CONNECTOR-J in the directory of this | |
| software distribution. | |
| This program is distributed in the hope that it will be useful, | |
| but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| GNU General Public License for more details. | |
| You should have received a copy of the GNU General Public License | |
| along with this program; if not, write to the Free Software | |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| */ | |
| package com.mysql.jdbc; | |
| import java.sql.SQLException; | |
| import java.util.List; | |
| import java.util.Map; | |
| /** | |
| * Implement this interface to provide a new load balancing strategy for URLs of | |
| * the form "jdbc:mysql:loadbalance://..", and provide the implementation class | |
| * name as the configuration parameter "loadBalanceStrategy". | |
| * | |
| * The driver will not pass in a Connection instance when calling init(), but it | |
| * will pass in the Properties, otherwise it acts like a normal Extension. | |
| * | |
| * One instance of a strategy *per* JDBC connection instance will be created. If | |
| * you need singleton-like behavior, you're on your own to provide it. | |
| */ | |
| public interface BalanceStrategy extends Extension { | |
| /** | |
| * Called by the driver to pick a new connection to route requests over. | |
| * | |
| * @param proxy | |
| * the InvocationHandler that deals with actual method calls to | |
| * the JDBC connection, and serves as a factory for new | |
| * connections for this strategy via the | |
| * createConnectionForHost() method. | |
| * | |
| * This proxy takes care of maintaining the response time list, map of | |
| * host/ports to live connections, and taking connections out of the live | |
| * connections map if they receive a network-related error while they are in | |
| * use by the application. | |
| * @param configuredHosts | |
| * the list of hosts/ports (in "host:port" form) as passed in by | |
| * the user. | |
| * @param liveConnections | |
| * a map of host/ports to "live" connections to them. | |
| * @param responseTimes | |
| * the list of response times for a <strong>transaction</strong> | |
| * for each host in the configured hosts list. | |
| * @param numRetries | |
| * the number of times the driver expects this strategy to re-try | |
| * connection attempts if creating a new connection fails. | |
| * @return the physical JDBC connection for the application to use, based | |
| * upon the strategy employed. | |
| * @throws SQLException | |
| * if a new connection can not be found or created by this | |
| * strategy. | |
| * | |
| * @see LoadBalancingConnectionProxy#createConnectionForHost(String) | |
| */ | |
| public abstract Connection pickConnection( | |
| LoadBalancingConnectionProxy proxy, List configuredHosts, | |
| Map liveConnections, long[] responseTimes, int numRetries) | |
| throws SQLException; | |
| } |