| /** |
| * Copyright (C) 2010 Cloud.com, Inc. All rights reserved. |
| * |
| * This software is licensed under the GNU General Public License v3 or later. |
| * |
| * It is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 3 of the License, or any later version. |
| * 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, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| package com.cloud.host; |
| |
| import java.util.List; |
| import java.util.Set; |
| |
| import com.cloud.utils.fsm.StateMachine; |
| |
| public enum Status { |
| Connecting(true, false, false), |
| Up(true, false, false), |
| Down(true, true, true), |
| Disconnected(true, true, true), |
| Updating(true, true, false), |
| PrepareForMaintenance(false, false, false), |
| ErrorInMaintenance(false, false, false), |
| Maintenance(false, false, false), |
| Alert(true, true, true), |
| Removed(true, false, true); |
| |
| private final boolean updateManagementServer; |
| private final boolean checkManagementServer; |
| private final boolean lostConnection; |
| |
| private Status(boolean updateConnection, boolean checkManagementServer, boolean lostConnection) { |
| this.updateManagementServer = updateConnection; |
| this.checkManagementServer = checkManagementServer; |
| this.lostConnection = lostConnection; |
| } |
| |
| public boolean updateManagementServer() { |
| return updateManagementServer; |
| } |
| |
| public boolean checkManagementServer() { |
| return checkManagementServer; |
| } |
| |
| public boolean lostConnection() { |
| return lostConnection; |
| } |
| |
| public enum Event { |
| AgentConnected(false, "Agent connected"), |
| PingTimeout(false, "Agent is behind on ping"), |
| UpdateNeeded(false, "UpdateRequested"), |
| ShutdownRequested(false, "Shutdown requested by the agent"), |
| AgentDisconnected(false, "Agent disconnected"), |
| ResetRequested(true, "Reset is requested by the user"), |
| HostDown(false, "Host is found to be down by the investigator"), |
| PreparationComplete(false, "Preparation for PrepareForMaintenance is completed"), |
| UnableToMigrate(false, "Migration for at least one VM didn't work"), |
| Ping(false, "Ping is received from the host"), |
| MaintenanceRequested(true, "PrepareForMaintenance requested by user"), |
| ManagementServerDown(false, "Management Server that the agent is connected is going down"), |
| WaitedTooLong(false, "Waited too long from the agent to reconnect on its own. Time to do HA"), |
| Remove(true, "Host is removed"), |
| Ready(false, "Host is ready for commands"); |
| |
| private final boolean isUserRequest; |
| private final String comment; |
| private Event(boolean isUserRequest, String comment) { |
| this.isUserRequest = isUserRequest; |
| this.comment = comment; |
| } |
| |
| public String getDescription() { |
| return comment; |
| } |
| |
| public boolean isUserRequest() { |
| return isUserRequest; |
| } |
| } |
| |
| public Status getNextStatus(Event e) { |
| return s_fsm.getNextState(this, e); |
| } |
| |
| public Status[] getFromStates(Event e) { |
| List<Status> from = s_fsm.getFromStates(this, e); |
| return from.toArray(new Status[from.size()]); |
| } |
| |
| public Set<Event> getPossibleEvents() { |
| return s_fsm.getPossibleEvents(this); |
| } |
| |
| public static String[] toStrings(Status... states) { |
| String[] strs = new String[states.length]; |
| for (int i = 0; i < states.length; i++) { |
| strs[i] = states[i].toString(); |
| } |
| return strs; |
| } |
| |
| protected static final StateMachine<Status, Event> s_fsm = new StateMachine<Status, Event>(); |
| static { |
| s_fsm.addTransition(null, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Connecting, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Connecting, Event.Ready, Status.Up); |
| s_fsm.addTransition(Status.Connecting, Event.PingTimeout, Status.Alert); |
| s_fsm.addTransition(Status.Connecting, Event.UpdateNeeded, Status.Updating); |
| s_fsm.addTransition(Status.Connecting, Event.MaintenanceRequested, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.Connecting, Event.ShutdownRequested, Status.Disconnected); |
| s_fsm.addTransition(Status.Connecting, Event.HostDown, Status.Alert); |
| s_fsm.addTransition(Status.Connecting, Event.Ping, Status.Connecting); |
| s_fsm.addTransition(Status.Connecting, Event.ManagementServerDown, Status.Disconnected); |
| s_fsm.addTransition(Status.Connecting, Event.AgentDisconnected, Status.Alert); |
| s_fsm.addTransition(Status.Up, Event.PingTimeout, Status.Alert); |
| s_fsm.addTransition(Status.Up, Event.MaintenanceRequested, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.Up, Event.AgentDisconnected, Status.Alert); |
| s_fsm.addTransition(Status.Up, Event.ShutdownRequested, Status.Disconnected); |
| s_fsm.addTransition(Status.Up, Event.HostDown, Status.Down); |
| s_fsm.addTransition(Status.Up, Event.Ping, Status.Up); |
| s_fsm.addTransition(Status.Up, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Up, Event.ManagementServerDown, Status.Disconnected); |
| s_fsm.addTransition(Status.Updating, Event.PingTimeout, Status.Alert); |
| s_fsm.addTransition(Status.Updating, Event.Ping, Status.Updating); |
| s_fsm.addTransition(Status.Updating, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Updating, Event.ManagementServerDown, Status.Disconnected); |
| s_fsm.addTransition(Status.Updating, Event.WaitedTooLong, Status.Alert); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.ResetRequested, Status.Disconnected); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.PreparationComplete, Status.Maintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.AgentDisconnected, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.AgentConnected, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.HostDown, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.UnableToMigrate, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.Ping, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.PrepareForMaintenance, Event.ManagementServerDown, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.MaintenanceRequested, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.ResetRequested, Status.Disconnected); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.HostDown, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.AgentDisconnected, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.AgentConnected, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.UnableToMigrate, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.PreparationComplete, Status.Maintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.Ping, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.ErrorInMaintenance, Event.ManagementServerDown, Status.ErrorInMaintenance); |
| s_fsm.addTransition(Status.Maintenance, Event.ResetRequested, Status.Disconnected); |
| s_fsm.addTransition(Status.Maintenance, Event.AgentDisconnected, Status.Maintenance); |
| s_fsm.addTransition(Status.Maintenance, Event.HostDown, Status.Maintenance); |
| s_fsm.addTransition(Status.Maintenance, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.Maintenance, Event.AgentConnected, Status.Maintenance); |
| s_fsm.addTransition(Status.Maintenance, Event.Ping, Status.Maintenance); |
| s_fsm.addTransition(Status.Maintenance, Event.ManagementServerDown, Status.Maintenance); |
| s_fsm.addTransition(Status.Disconnected, Event.PingTimeout, Status.Alert); |
| s_fsm.addTransition(Status.Disconnected, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Disconnected, Event.Ping, Status.Up); |
| s_fsm.addTransition(Status.Disconnected, Event.ManagementServerDown, Status.Disconnected); |
| s_fsm.addTransition(Status.Disconnected, Event.WaitedTooLong, Status.Alert); |
| s_fsm.addTransition(Status.Disconnected, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.Down, Event.MaintenanceRequested, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.Down, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Down, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.Down, Event.ManagementServerDown, Status.Down); |
| s_fsm.addTransition(Status.Alert, Event.MaintenanceRequested, Status.PrepareForMaintenance); |
| s_fsm.addTransition(Status.Alert, Event.AgentConnected, Status.Connecting); |
| s_fsm.addTransition(Status.Alert, Event.Ping, Status.Up); |
| s_fsm.addTransition(Status.Alert, Event.Remove, Status.Removed); |
| s_fsm.addTransition(Status.Alert, Event.ManagementServerDown, Status.Alert); |
| } |
| |
| public static void main(String[] args) { |
| System.out.println("Finite State Machine for Host:"); |
| System.out.println(s_fsm.toString()); |
| } |
| } |
