server/componentmanager/ComponentManager.java

//---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 1.38 2001/05/29 17:02:34 tdb Exp $
 */
public class ComponentManager {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.38 $";
    
    /**
     * 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:	1.39
Committed:	Wed Mar 20 13:40:29 2002 UTC (22 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.38:	+27 -6 lines
Log Message:	FilterManager's can now have their own individual configurations. I want to run more than one, and I want them to have different setups. Specifying a name for a FilterManager is similar to that of a Filter. There is a "-fm" flag to the startup which allows you to set it. It will then request a configuration of "FilterManager.<name>".
#	User	Rev	Content
1	ajm	1.1	//---PACKAGE DECLARATION---
2	tdb	1.38	package uk.org.iscream.cms.server.componentmanager;
3	ajm	1.1
4			//---IMPORTS---
5			import java.util.*;
6			import java.io.*;
7	tdb	1.38	import uk.org.iscream.cms.server.util.*;
8	ajm	1.1
9			/**
10	ajm	1.2	* The component manager is the starting point for all
11			* server side components of the iscream system.
12			* It loads its initial system configuration from the
13			* default properties file, it then starts all the iscream
14			* components as specified in the default.properties under
15	tdb	1.38	* uk.org.iscream.cms.server.ComponentList
16	ajm	1.1	*
17	tdb	1.39	* @author $Author: tdb $
18			* @version $Id: ComponentManager.java,v 1.38 2001/05/29 17:02:34 tdb Exp $
19	ajm	1.1	*/
20			public class ComponentManager {
21
22			//---FINAL ATTRIBUTES---
23
24			/**
25			* The current CVS revision of this class
26			*/
27	tdb	1.39	public static final String REVISION = "$Revision: 1.38 $";
28	ajm	1.1
29			/**
30			* The toString() of this class
31			* As it won't be instatiated, this is needed.
32	ajm	1.2	* Not also that we pass a null as the class name (as we are static)
33	ajm	1.1	*/
34	ajm	1.2	public static final String toString = FormatName.getName("ComponentManager", null, REVISION);
35	ajm	1.1
36			/**
37			* The default location of the properties file for the system
38			*/
39	ajm	1.2	public static final String DEFAULTPROPERTIES = "./etc/default.properties";
40	ajm	1.1
41	ajm	1.22	/**
42			* The default time to wait before retrying
43			* component.
44			*/
45			public static final int DEFAULT_COMPONENT_START_TIMEOUT = 5;
46
47	ajm	1.1	//---STATIC METHODS---
48
49			/**
50	ajm	1.2	* The main method which starts the components as
51			* listed in the default.properties file.
52	ajm	1.1	*
53			* @param args the command line arguments
54			*/
55			public static void main(String[] args) {
56	ajm	1.36	System.out.println("-----------------------------------------");
57	tdb	1.11	System.out.println("--- i-scream Server Component Manager ---");
58	tdb	1.37	System.out.println("--- (c) 2001 The i-scream Project ---");
59	ajm	1.36	System.out.println("--- (http://www.i-scream.org.uk) ---");
60			System.out.println("-----------------------------------------");
61	ajm	1.2	System.out.println("--- Starting System ---");
62
63	ajm	1.1	// get the command line args
64			String defaultProperties = DEFAULTPROPERTIES;
65			String filterName = null;
66	tdb	1.39	String filterManagerName = null;
67	tdb	1.11	for(int i=0; i < args.length; i++) {
68	tdb	1.12	if(args[i].equals("-h")) {
69	ajm	1.1	usage();
70	tdb	1.11	}
71	tdb	1.12	else if(args[i].equals("-f")) {
72	tdb	1.39	if(++i < args.length) {
73			filterName = args[i];
74			}
75			else {
76			usage();
77			}
78			}
79			else if(args[i].equals("-fm")) {
80			if(++i < args.length) {
81			filterManagerName = args[i];
82			}
83			else {
84			usage();
85			}
86	tdb	1.11	}
87	tdb	1.12	else if(args[i].equals("-l")) {
88	tdb	1.39	if(++i < args.length) {
89			defaultProperties = args[i];
90			}
91			else {
92			usage();
93			}
94	tdb	1.11	}
95			else {
96			usage();
97			}
98	ajm	1.1	}
99
100			// load the default properties file into the system properties
101			System.out.println(toString + ": initialising - using " + defaultProperties);
102			try {
103			Properties initProperties = new Properties(System.getProperties());
104			initProperties.load(new FileInputStream(new File(defaultProperties)));
105			System.setProperties(initProperties);
106			} catch (Exception e) {
107			System.err.println(toString + ": ERROR " + e.getMessage());
108			usage();
109			}
110
111			// continue to bring the system up
112			System.out.println(toString + ": coming up");
113
114			// start the ORB by initialising the ReferenceManager
115	ajm	1.2	ReferenceManager refman = ReferenceManager.getInstance();
116	ajm	1.1
117	ajm	1.2	// now the ORB is running, we need to activate our RootPOA
118			// so that we can start serving requests once servants start up
119	ajm	1.1	refman.activatePOA();
120
121	ajm	1.2	// get the list of components
122	tdb	1.38	String componentList = System.getProperty("uk.org.iscream.cms.server.ComponentList");
123	ajm	1.1	StringTokenizer st = new StringTokenizer(componentList, ";");
124	tdb	1.33	_componentsToStart = new LinkedList();
125	ajm	1.13
126	ajm	1.1	// this could be done using reflection
127			// but..well..we don't ;-p
128			while (st.hasMoreTokens()){
129			String componentName = st.nextToken();
130			Component component = null;
131	ajm	1.13
132	ajm	1.2
133			// ### This is where the list of supported components is checked! ###
134			if (componentName.equalsIgnoreCase("core")) {
135	tdb	1.38	component = new uk.org.iscream.cms.server.core.Core();
136	tdb	1.39	// note the passing of the FilterManagers's name in its constructor
137	ajm	1.3	} else if (componentName.equalsIgnoreCase("filtermanager")) {
138	tdb	1.39	component = new uk.org.iscream.cms.server.filtermanager.FilterManager(filterManagerName);
139	ajm	1.4	} else if (componentName.equalsIgnoreCase("rootfilter")) {
140	tdb	1.38	component = new uk.org.iscream.cms.server.rootfilter.RootFilter();
141	ajm	1.5	} else if (componentName.equalsIgnoreCase("dbinterface")) {
142	tdb	1.38	component = new uk.org.iscream.cms.server.dbinterface.DBInterface();
143	ajm	1.6	} else if (componentName.equalsIgnoreCase("clientinterface")) {
144	tdb	1.38	component = new uk.org.iscream.cms.server.clientinterface.ClientInterfaceMain();
145	ajm	1.7	// note the passing of the Filter's name in its constructor
146			} else if (componentName.equalsIgnoreCase("filter")) {
147	tdb	1.38	component = new uk.org.iscream.cms.server.filter.FilterMain(filterName);
148	tdb	1.30	} else if (componentName.equalsIgnoreCase("client")) {
149	tdb	1.38	component = new uk.org.iscream.cms.server.client.ClientMain();
150	ajm	1.1	}
151	ajm	1.2	// ### Add new component constructors in the above section! ###
152	ajm	1.3
153	ajm	1.22	// build the list of components to start
154	ajm	1.1	if (component != null) {
155	ajm	1.32	_componentsToStart.add(component);
156	ajm	1.13	} else {
157	tdb	1.33	System.err.println(toString + ": WARNING unsupported component not started: "+componentName);
158	ajm	1.13	}
159			}
160
161	ajm	1.32
162	ajm	1.22
163			// get the value for timeout
164	ajm	1.32
165	ajm	1.28	String confTimeout = null;
166	ajm	1.22	try {
167	tdb	1.38	confTimeout = System.getProperty("uk.org.iscream.cms.server.ComponentTimeout");
168	ajm	1.29	confTimeout.trim();
169	ajm	1.32	_startTimeout = Integer.parseInt(confTimeout);
170	ajm	1.22	} catch (NumberFormatException e) {
171	ajm	1.32	_startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
172	tdb	1.38	System.err.println(toString + ": unable to read uk.org.iscream.cms.server.ComponentTimeout value (" + confTimeout + "), using default!");
173	ajm	1.22	}
174	ajm	1.32	System.out.println(toString + ": using component start timeout of " + _startTimeout + " seconds");
175	ajm	1.22
176	ajm	1.31	// startup the system components
177			startUp();
178
179			// block on the ORB...in time, management functionality can be placed here.
180			// if we detect a CORBA communication error, we'll restart all the components.
181	tdb	1.33	// !! this doesn't appear to work !!
182	ajm	1.31	while(true) {
183			try {
184			refman.getORB().run();
185	ajm	1.32	} catch (org.omg.CORBA.COMM_FAILURE e) {
186	ajm	1.31	System.out.println(toString + ": WARNING CORBA communications failure - " + e.getMessage());
187			System.out.println(toString + ": WARNING CORBA connections have been lost - attempting to restart!");
188			}
189			startUp();
190			}
191			}
192
193			/**
194			* Starts the components as obtained from the configuration.
195			* This method calls the start() methods on all the components.
196			* If a component fails to start due to a CORBA communication
197			* problem, then it catches this and tries to start it again
198	tdb	1.38	* according to uk.org.iscream.cms.server.ComponentTimeout time.
199	ajm	1.31	*
200			* If the server dies and CORBA connections are lost, this method
201			* is called again.
202			*/
203			private static void startUp() {
204	ajm	1.32	// now we try and start the beast up
205			boolean tryAgain = true;
206			Component component = null;
207
208	ajm	1.22	// keep trying until we've started all the components.
209			// maybe add support for a limited number of retries
210	ajm	1.13	while(tryAgain) {
211	ajm	1.32	Iterator i = _componentsToStart.iterator();
212	tdb	1.33	LinkedList failedComponents = new LinkedList();
213	ajm	1.22	// go through all the components
214	ajm	1.13	while(i.hasNext()) {
215	tdb	1.33	// get a refence to the component
216			component = (Component) i.next();
217	tdb	1.35	System.out.println(toString + ": dependency checking component - " + component.toString());
218	tdb	1.33
219			// check it's dependencies
220			boolean depOK = component.depCheck();
221			if(depOK) {
222	tdb	1.35	System.out.println(toString + ": starting component - " + component.toString());
223	tdb	1.33	// it should be ok to start the component
224			try {
225			// start the component
226			component.start();
227			} catch (ComponentStartException e) {
228			// if we get this then there was a problem
229			// that we can't recover from
230			System.err.println(toString + ": ERROR starting component - " + component.toString());
231			System.err.println(toString + ": component reports - " + e.getMessage());
232			System.exit(1);
233			}
234			}
235			else {
236			// it seems the depedencies failed
237			// so we want to try again after a delay
238			System.err.println(toString + ": WARNING Component reported dependency failure");
239	ajm	1.14	System.err.println(toString + ": This could be because it can't communicate with components it needs.");
240	ajm	1.22
241			// make a list of the failed components
242	ajm	1.20	failedComponents.add(component);
243	ajm	1.1	}
244	ajm	1.13	}
245	ajm	1.22
246			// if we had some failed components that we can retry
247	ajm	1.21	if (failedComponents.size() > 0) {
248	ajm	1.14	System.err.println(toString + ": WARNING One or more components failed to start correctly.");
249	ajm	1.32	System.err.println(toString + ": Will try again in " + _startTimeout + " seconds");
250	ajm	1.22
251			// our list is now the failed list
252	ajm	1.32	_componentsToStart = failedComponents;
253	ajm	1.22
254			// sleep for a given timeout
255	ajm	1.18	try {
256	ajm	1.32	Thread.sleep(_startTimeout * 1000);
257	ajm	1.17	} catch (InterruptedException e) {
258			// we're not bothered
259			}
260	ajm	1.22	// otherwise we started everything
261	ajm	1.18	} else {
262	ajm	1.22	// so we set to exit the loop
263	ajm	1.18	tryAgain = false;
264	ajm	1.1	}
265			}
266	ajm	1.13
267	ajm	1.3	System.out.println(toString + ": running");
268	ajm	1.31	}
269	ajm	1.3
270			/**
271	ajm	1.1	* A simple method to print the usage of this class.
272			* It never returns, but instead exits to the system
273			* with a value 1, to indicate the system did not start
274			* properly.
275			*/
276			public static void usage() {
277	tdb	1.38	System.out.println("USAGE: java uk.org.iscream.cms.server.componentmanager.ComponentManager <option>");
278	tdb	1.8	System.out.println(" or: java -jar iscream.jar <option>");
279	ajm	1.1	System.out.println("WHERE <option>:");
280			System.out.println(" -l <filename> - the location of initial system properties");
281	ajm	1.2	System.out.println(" the default is ./etc/default.properties");
282	ajm	1.1	System.out.println(" -f <name> - the name of the filter (if there is one configured");
283	tdb	1.39	System.out.println(" -fm <name> - the name of the filter manager (if there is one configured");
284	ajm	1.1	System.out.println(" -h - this help screen");
285			System.exit(1);
286			}
287
288			//---CONSTRUCTORS---
289
290			//---PUBLIC METHODS---
291
292			//---PRIVATE METHODS---
293
294			//---ACCESSOR/MUTATOR METHODS---
295
296			//---ATTRIBUTES---
297
298			//---STATIC ATTRIBUTES---
299	ajm	1.32
300	tdb	1.33	private static LinkedList _componentsToStart;
301	ajm	1.32	private static int _startTimeout = 0;
302	ajm	1.1
303			}