server/componentmanager/ComponentManager.java

/* 
 * i-scream central monitoring system
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program 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 2
 * of the License, or (at your option) 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.server.componentmanager;

//---IMPORTS---
import java.util.*;
import java.io.*;
import uk.org.iscream.cms.server.util.*;

/**
 * The component manager is the starting point for all
 * server side components of the iscream system.
 * It loads its initial system configuration from the
 * default properties file, it then starts all the iscream
 * components as specified in the default.properties under
 * uk.org.iscream.cms.server.ComponentList
 *
 * @author  $Author: tdb $
 * @version $Id: ComponentManager.java,v 1.39 2002/03/20 13:40:29 tdb Exp $
 */
public class ComponentManager {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.39 $";
    
    /**
     * The toString() of this class
     * As it won't be instatiated, this is needed.
     * Not also that we pass a null as the class name (as we are static)
     */
    public static final String toString = FormatName.getName("ComponentManager", null, REVISION);
    
    /**
     * The default location of the properties file for the system
     */
    public static final String DEFAULTPROPERTIES = "./etc/default.properties";
    
    /**
     * The default time to wait before retrying 
     * component.
     */
    public static final int DEFAULT_COMPONENT_START_TIMEOUT = 5;
    
//---STATIC METHODS---

    /**
     * The main method which starts the components as
     * listed in the default.properties file.
     *
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        System.out.println("-----------------------------------------");
        System.out.println("--- i-scream Server Component Manager ---");
        System.out.println("---   (c) 2001 The i-scream Project   ---");
        System.out.println("---    (http://www.i-scream.org.uk)   ---");
        System.out.println("-----------------------------------------");
        System.out.println("---          Starting System          ---");        
        
        // get the command line args
        String defaultProperties = DEFAULTPROPERTIES;
        String filterName = null;
        String filterManagerName = null;
        for(int i=0; i < args.length; i++) {
            if(args[i].equals("-h")) {
                usage();
            }
            else if(args[i].equals("-f")) {
                if(++i < args.length) {
                    filterName = args[i];
                }
                else {
                    usage();
                }
            }
            else if(args[i].equals("-fm")) {
                if(++i < args.length) {
                    filterManagerName = args[i];
                }
                else {
                    usage();
                }
            }
            else if(args[i].equals("-l")) {
                if(++i < args.length) {
                    defaultProperties = args[i];
                }
                else {
                    usage();
                }
            }
            else {
                usage();
            }
        }

        // load the default properties file into the system properties
        System.out.println(toString + ": initialising - using " + defaultProperties);
        try {
            Properties initProperties = new Properties(System.getProperties());
            initProperties.load(new FileInputStream(new File(defaultProperties)));
            System.setProperties(initProperties);
        } catch (Exception e) {
            System.err.println(toString + ": ERROR " + e.getMessage());
            usage();
        }

        // continue to bring the system up
        System.out.println(toString + ": coming up");
        
        // start the ORB by initialising the ReferenceManager
        ReferenceManager refman = ReferenceManager.getInstance();
        
        // now the ORB is running, we need to activate our RootPOA
        // so that we can start serving requests once servants start up
        refman.activatePOA();
        
        // get the list of components
        String componentList = System.getProperty("uk.org.iscream.cms.server.ComponentList");
        StringTokenizer st = new StringTokenizer(componentList, ";");
        _componentsToStart = new LinkedList();
        
        // this could be done using reflection
        // but..well..we don't ;-p
        while (st.hasMoreTokens()){
            String componentName = st.nextToken();
            Component component = null;
            
            
            // ### This is where the list of supported components is checked! ###
            if (componentName.equalsIgnoreCase("core")) {
                component = new uk.org.iscream.cms.server.core.Core();
            // note the passing of the FilterManagers's name in its constructor
            } else if (componentName.equalsIgnoreCase("filtermanager")) {
                component = new uk.org.iscream.cms.server.filtermanager.FilterManager(filterManagerName);
            } else if (componentName.equalsIgnoreCase("rootfilter")) {
                component = new uk.org.iscream.cms.server.rootfilter.RootFilter();
            } else if (componentName.equalsIgnoreCase("dbinterface")) {
                component = new uk.org.iscream.cms.server.dbinterface.DBInterface();
            } else if (componentName.equalsIgnoreCase("clientinterface")) {
                component = new uk.org.iscream.cms.server.clientinterface.ClientInterfaceMain();
            // note the passing of the Filter's name in its constructor
            } else if (componentName.equalsIgnoreCase("filter")) {
                component = new uk.org.iscream.cms.server.filter.FilterMain(filterName);
            } else if (componentName.equalsIgnoreCase("client")) {
                component = new uk.org.iscream.cms.server.client.ClientMain();
            }
            // ###  Add new component constructors in the above section! ###
            
            // build the list of components to start
            if (component != null) {
                _componentsToStart.add(component);    
            } else {
                System.err.println(toString + ": WARNING unsupported component not started: "+componentName);
            }
        }
        
        

        // get the value for timeout
        
        String confTimeout = null;
        try {
            confTimeout = System.getProperty("uk.org.iscream.cms.server.ComponentTimeout");
            confTimeout.trim();
            _startTimeout = Integer.parseInt(confTimeout);
        } catch (NumberFormatException e) {
            _startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
            System.err.println(toString + ": unable to read uk.org.iscream.cms.server.ComponentTimeout value (" + confTimeout + "), using default!");
        }
        System.out.println(toString + ": using component start timeout of " + _startTimeout + " seconds");
        
        // startup the system components
        startUp();

            // block on the ORB...in time, management functionality can be placed here.
            // if we detect a CORBA communication error, we'll restart all the components.
            // !! this doesn't appear to work !!
            while(true) {
            try {
                refman.getORB().run();
            } catch (org.omg.CORBA.COMM_FAILURE e) {
                System.out.println(toString + ": WARNING CORBA communications failure - " + e.getMessage());
                System.out.println(toString + ": WARNING CORBA connections have been lost - attempting to restart!");
            }
            startUp();
        }
    }

    /**
     * Starts the components as obtained from the configuration.
     * This method calls the start() methods on all the components.
     * If a component fails to start due to a CORBA communication
     * problem, then it catches this and tries to start it again
     * according to uk.org.iscream.cms.server.ComponentTimeout time.
     *
     * If the server dies and CORBA connections are lost, this method
     * is called again.
     */
    private static void startUp() {
        // now we try and start the beast up        
        boolean tryAgain = true;
        Component component = null;
        
        // keep trying until we've started all the components.
        // maybe add support for a limited number of retries
        while(tryAgain) {
            Iterator i = _componentsToStart.iterator();
            LinkedList failedComponents = new LinkedList();
            // go through all the components
            while(i.hasNext()) {
                // get a refence to the component
                component = (Component) i.next();
                System.out.println(toString + ": dependency checking component - " + component.toString());
                
                // check it's dependencies
                boolean depOK = component.depCheck();
                if(depOK) {
                    System.out.println(toString + ": starting component - " + component.toString());
                    // it should be ok to start the component
                        try {    
                            // start the component
                        component.start();
                    } catch (ComponentStartException e) {
                        // if we get this then there was a problem
                        // that we can't recover from
                        System.err.println(toString + ": ERROR starting component - " + component.toString());
                        System.err.println(toString + ": component reports - " + e.getMessage());
                        System.exit(1);
                    }
                }
                else {
                    // it seems the depedencies failed
                    // so we want to try again after a delay
                    System.err.println(toString + ": WARNING Component reported dependency failure");
                    System.err.println(toString + ": This could be because it can't communicate with components it needs.");
                    
                    // make a list of the failed components
                    failedComponents.add(component);
                }
            }
            
            // if we had some failed components that we can retry
            if (failedComponents.size() > 0) {
                System.err.println(toString + ": WARNING One or more components failed to start correctly.");
                System.err.println(toString + ": Will try again in " + _startTimeout + " seconds");
            
                // our list is now the failed list
                _componentsToStart = failedComponents;
                
                // sleep for a given timeout
                try {    
                    Thread.sleep(_startTimeout * 1000);
                } catch (InterruptedException e) {
                    // we're not bothered
                }
            // otherwise we started everything
            } else {
                // so we set to exit the loop
                tryAgain = false;
            }
        }
                
            System.out.println(toString + ": running");
        }

    /**
     * A simple method to print the usage of this class.
     * It never returns, but instead exits to the system
     * with a value 1, to indicate the system did not start
     * properly.
     */
    public static void usage() {
        System.out.println("USAGE: java uk.org.iscream.cms.server.componentmanager.ComponentManager <option>");
        System.out.println("   or: java -jar iscream.jar <option>");
        System.out.println("WHERE <option>:");
        System.out.println("      -l <filename> - the location of initial system properties");
        System.out.println("                      the default is ./etc/default.properties");
        System.out.println("      -f <name>     - the name of the filter (if there is one configured");
        System.out.println("      -fm <name>    - the name of the filter manager (if there is one configured");
        System.out.println("      -h            - this help screen");
        System.exit(1);
    }

//---CONSTRUCTORS---

//---PUBLIC METHODS---

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---
    
//---STATIC ATTRIBUTES---

    private static LinkedList _componentsToStart;
    private static int _startTimeout = 0;

}
Revision:	1.40
Committed:	Sat May 18 18:16:01 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.39:	+21 -2 lines
Log Message:	i-scream is now licensed under the GPL. I've added the GPL headers to every source file, and put a full copy of the license in the appropriate places. I think I've covered everything. This is going to be a mad commit ;)
#	Content
1	/*
2	* i-scream central monitoring system
3	* Copyright (C) 2000-2002 i-scream
4	*
5	* This program is free software; you can redistribute it and/or
6	* modify it under the terms of the GNU General Public License
7	* as published by the Free Software Foundation; either version 2
8	* of the License, or (at your option) any later version.
9	*
10	* This program is distributed in the hope that it will be useful,
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	* GNU General Public License for more details.
14	*
15	* You should have received a copy of the GNU General Public License
16	* along with this program; if not, write to the Free Software
17	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18	*/
19
20	//---PACKAGE DECLARATION---
21	package uk.org.iscream.cms.server.componentmanager;
22
23	//---IMPORTS---
24	import java.util.*;
25	import java.io.*;
26	import uk.org.iscream.cms.server.util.*;
27
28	/**
29	* The component manager is the starting point for all
30	* server side components of the iscream system.
31	* It loads its initial system configuration from the
32	* default properties file, it then starts all the iscream
33	* components as specified in the default.properties under
34	* uk.org.iscream.cms.server.ComponentList
35	*
36	* @author $Author: tdb $
37	* @version $Id: ComponentManager.java,v 1.39 2002/03/20 13:40:29 tdb Exp $
38	*/
39	public class ComponentManager {
40
41	//---FINAL ATTRIBUTES---
42
43	/**
44	* The current CVS revision of this class
45	*/
46	public static final String REVISION = "$Revision: 1.39 $";
47
48	/**
49	* The toString() of this class
50	* As it won't be instatiated, this is needed.
51	* Not also that we pass a null as the class name (as we are static)
52	*/
53	public static final String toString = FormatName.getName("ComponentManager", null, REVISION);
54
55	/**
56	* The default location of the properties file for the system
57	*/
58	public static final String DEFAULTPROPERTIES = "./etc/default.properties";
59
60	/**
61	* The default time to wait before retrying
62	* component.
63	*/
64	public static final int DEFAULT_COMPONENT_START_TIMEOUT = 5;
65
66	//---STATIC METHODS---
67
68	/**
69	* The main method which starts the components as
70	* listed in the default.properties file.
71	*
72	* @param args the command line arguments
73	*/
74	public static void main(String[] args) {
75	System.out.println("-----------------------------------------");
76	System.out.println("--- i-scream Server Component Manager ---");
77	System.out.println("--- (c) 2001 The i-scream Project ---");
78	System.out.println("--- (http://www.i-scream.org.uk) ---");
79	System.out.println("-----------------------------------------");
80	System.out.println("--- Starting System ---");
81
82	// get the command line args
83	String defaultProperties = DEFAULTPROPERTIES;
84	String filterName = null;
85	String filterManagerName = null;
86	for(int i=0; i < args.length; i++) {
87	if(args[i].equals("-h")) {
88	usage();
89	}
90	else if(args[i].equals("-f")) {
91	if(++i < args.length) {
92	filterName = args[i];
93	}
94	else {
95	usage();
96	}
97	}
98	else if(args[i].equals("-fm")) {
99	if(++i < args.length) {
100	filterManagerName = args[i];
101	}
102	else {
103	usage();
104	}
105	}
106	else if(args[i].equals("-l")) {
107	if(++i < args.length) {
108	defaultProperties = args[i];
109	}
110	else {
111	usage();
112	}
113	}
114	else {
115	usage();
116	}
117	}
118
119	// load the default properties file into the system properties
120	System.out.println(toString + ": initialising - using " + defaultProperties);
121	try {
122	Properties initProperties = new Properties(System.getProperties());
123	initProperties.load(new FileInputStream(new File(defaultProperties)));
124	System.setProperties(initProperties);
125	} catch (Exception e) {
126	System.err.println(toString + ": ERROR " + e.getMessage());
127	usage();
128	}
129
130	// continue to bring the system up
131	System.out.println(toString + ": coming up");
132
133	// start the ORB by initialising the ReferenceManager
134	ReferenceManager refman = ReferenceManager.getInstance();
135
136	// now the ORB is running, we need to activate our RootPOA
137	// so that we can start serving requests once servants start up
138	refman.activatePOA();
139
140	// get the list of components
141	String componentList = System.getProperty("uk.org.iscream.cms.server.ComponentList");
142	StringTokenizer st = new StringTokenizer(componentList, ";");
143	_componentsToStart = new LinkedList();
144
145	// this could be done using reflection
146	// but..well..we don't ;-p
147	while (st.hasMoreTokens()){
148	String componentName = st.nextToken();
149	Component component = null;
150
151
152	// ### This is where the list of supported components is checked! ###
153	if (componentName.equalsIgnoreCase("core")) {
154	component = new uk.org.iscream.cms.server.core.Core();
155	// note the passing of the FilterManagers's name in its constructor
156	} else if (componentName.equalsIgnoreCase("filtermanager")) {
157	component = new uk.org.iscream.cms.server.filtermanager.FilterManager(filterManagerName);
158	} else if (componentName.equalsIgnoreCase("rootfilter")) {
159	component = new uk.org.iscream.cms.server.rootfilter.RootFilter();
160	} else if (componentName.equalsIgnoreCase("dbinterface")) {
161	component = new uk.org.iscream.cms.server.dbinterface.DBInterface();
162	} else if (componentName.equalsIgnoreCase("clientinterface")) {
163	component = new uk.org.iscream.cms.server.clientinterface.ClientInterfaceMain();
164	// note the passing of the Filter's name in its constructor
165	} else if (componentName.equalsIgnoreCase("filter")) {
166	component = new uk.org.iscream.cms.server.filter.FilterMain(filterName);
167	} else if (componentName.equalsIgnoreCase("client")) {
168	component = new uk.org.iscream.cms.server.client.ClientMain();
169	}
170	// ### Add new component constructors in the above section! ###
171
172	// build the list of components to start
173	if (component != null) {
174	_componentsToStart.add(component);
175	} else {
176	System.err.println(toString + ": WARNING unsupported component not started: "+componentName);
177	}
178	}
179
180
181
182	// get the value for timeout
183
184	String confTimeout = null;
185	try {
186	confTimeout = System.getProperty("uk.org.iscream.cms.server.ComponentTimeout");
187	confTimeout.trim();
188	_startTimeout = Integer.parseInt(confTimeout);
189	} catch (NumberFormatException e) {
190	_startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
191	System.err.println(toString + ": unable to read uk.org.iscream.cms.server.ComponentTimeout value (" + confTimeout + "), using default!");
192	}
193	System.out.println(toString + ": using component start timeout of " + _startTimeout + " seconds");
194
195	// startup the system components
196	startUp();
197
198	// block on the ORB...in time, management functionality can be placed here.
199	// if we detect a CORBA communication error, we'll restart all the components.
200	// !! this doesn't appear to work !!
201	while(true) {
202	try {
203	refman.getORB().run();
204	} catch (org.omg.CORBA.COMM_FAILURE e) {
205	System.out.println(toString + ": WARNING CORBA communications failure - " + e.getMessage());
206	System.out.println(toString + ": WARNING CORBA connections have been lost - attempting to restart!");
207	}
208	startUp();
209	}
210	}
211
212	/**
213	* Starts the components as obtained from the configuration.
214	* This method calls the start() methods on all the components.
215	* If a component fails to start due to a CORBA communication
216	* problem, then it catches this and tries to start it again
217	* according to uk.org.iscream.cms.server.ComponentTimeout time.
218	*
219	* If the server dies and CORBA connections are lost, this method
220	* is called again.
221	*/
222	private static void startUp() {
223	// now we try and start the beast up
224	boolean tryAgain = true;
225	Component component = null;
226
227	// keep trying until we've started all the components.
228	// maybe add support for a limited number of retries
229	while(tryAgain) {
230	Iterator i = _componentsToStart.iterator();
231	LinkedList failedComponents = new LinkedList();
232	// go through all the components
233	while(i.hasNext()) {
234	// get a refence to the component
235	component = (Component) i.next();
236	System.out.println(toString + ": dependency checking component - " + component.toString());
237
238	// check it's dependencies
239	boolean depOK = component.depCheck();
240	if(depOK) {
241	System.out.println(toString + ": starting component - " + component.toString());
242	// it should be ok to start the component
243	try {
244	// start the component
245	component.start();
246	} catch (ComponentStartException e) {
247	// if we get this then there was a problem
248	// that we can't recover from
249	System.err.println(toString + ": ERROR starting component - " + component.toString());
250	System.err.println(toString + ": component reports - " + e.getMessage());
251	System.exit(1);
252	}
253	}
254	else {
255	// it seems the depedencies failed
256	// so we want to try again after a delay
257	System.err.println(toString + ": WARNING Component reported dependency failure");
258	System.err.println(toString + ": This could be because it can't communicate with components it needs.");
259
260	// make a list of the failed components
261	failedComponents.add(component);
262	}
263	}
264
265	// if we had some failed components that we can retry
266	if (failedComponents.size() > 0) {
267	System.err.println(toString + ": WARNING One or more components failed to start correctly.");
268	System.err.println(toString + ": Will try again in " + _startTimeout + " seconds");
269
270	// our list is now the failed list
271	_componentsToStart = failedComponents;
272
273	// sleep for a given timeout
274	try {
275	Thread.sleep(_startTimeout * 1000);
276	} catch (InterruptedException e) {
277	// we're not bothered
278	}
279	// otherwise we started everything
280	} else {
281	// so we set to exit the loop
282	tryAgain = false;
283	}
284	}
285
286	System.out.println(toString + ": running");
287	}
288
289	/**
290	* A simple method to print the usage of this class.
291	* It never returns, but instead exits to the system
292	* with a value 1, to indicate the system did not start
293	* properly.
294	*/
295	public static void usage() {
296	System.out.println("USAGE: java uk.org.iscream.cms.server.componentmanager.ComponentManager <option>");
297	System.out.println(" or: java -jar iscream.jar <option>");
298	System.out.println("WHERE <option>:");
299	System.out.println(" -l <filename> - the location of initial system properties");
300	System.out.println(" the default is ./etc/default.properties");
301	System.out.println(" -f <name> - the name of the filter (if there is one configured");
302	System.out.println(" -fm <name> - the name of the filter manager (if there is one configured");
303	System.out.println(" -h - this help screen");
304	System.exit(1);
305	}
306
307	//---CONSTRUCTORS---
308
309	//---PUBLIC METHODS---
310
311	//---PRIVATE METHODS---
312
313	//---ACCESSOR/MUTATOR METHODS---
314
315	//---ATTRIBUTES---
316
317	//---STATIC ATTRIBUTES---
318
319	private static LinkedList _componentsToStart;
320	private static int _startTimeout = 0;
321
322	}