001/* 002 * HA-JDBC: High-Availability JDBC 003 * Copyright (c) 2004-2007 Paul Ferraro 004 * 005 * This library is free software; you can redistribute it and/or modify it 006 * under the terms of the GNU Lesser General Public License as published by the 007 * Free Software Foundation; either version 2.1 of the License, or (at your 008 * option) any later version. 009 * 010 * This library is distributed in the hope that it will be useful, but WITHOUT 011 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 012 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License 013 * for more details. 014 * 015 * You should have received a copy of the GNU Lesser General Public License 016 * along with this library; if not, write to the Free Software Foundation, 017 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 018 * 019 * Contact: ferraro@users.sourceforge.net 020 */ 021package net.sf.hajdbc; 022 023import java.util.Set; 024 025/** 026 * @author Paul Ferraro 027 * 028 */ 029public interface StateManager extends DatabaseActivationListener, DatabaseDeactivationListener, Lifecycle 030{ 031 /** 032 * Returns the initial state of the cluster. 033 * @return a set of database identifiers, or null, if no initial cluster state was found. 034 */ 035 public Set<String> getInitialState(); 036 037 /** 038 * Detects whether or not the membership of this state manager is empty. 039 * Used during cluster panic detection. 040 * @return true, if membership is empty, false otherwise 041 */ 042 public boolean isMembershipEmpty(); 043}