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>".
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.org.iscream.cms.server.componentmanager;
3
4	//---IMPORTS---
5	import java.util.*;
6	import java.io.*;
7	import uk.org.iscream.cms.server.util.*;
8
9	/**
10	* 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	* uk.org.iscream.cms.server.ComponentList
16	*
17	* @author $Author: tdb $
18	* @version $Id: ComponentManager.java,v 1.38 2001/05/29 17:02:34 tdb Exp $
19	*/
20	public class ComponentManager {
21
22	//---FINAL ATTRIBUTES---
23
24	/**
25	* The current CVS revision of this class
26	*/
27	public static final String REVISION = "$Revision: 1.38 $";
28
29	/**
30	* The toString() of this class
31	* As it won't be instatiated, this is needed.
32	* Not also that we pass a null as the class name (as we are static)
33	*/
34	public static final String toString = FormatName.getName("ComponentManager", null, REVISION);
35
36	/**
37	* The default location of the properties file for the system
38	*/
39	public static final String DEFAULTPROPERTIES = "./etc/default.properties";
40
41	/**
42	* The default time to wait before retrying
43	* component.
44	*/
45	public static final int DEFAULT_COMPONENT_START_TIMEOUT = 5;
46
47	//---STATIC METHODS---
48
49	/**
50	* The main method which starts the components as
51	* listed in the default.properties file.
52	*
53	* @param args the command line arguments
54	*/
55	public static void main(String[] args) {
56	System.out.println("-----------------------------------------");
57	System.out.println("--- i-scream Server Component Manager ---");
58	System.out.println("--- (c) 2001 The i-scream Project ---");
59	System.out.println("--- (http://www.i-scream.org.uk) ---");
60	System.out.println("-----------------------------------------");
61	System.out.println("--- Starting System ---");
62
63	// get the command line args
64	String defaultProperties = DEFAULTPROPERTIES;
65	String filterName = null;
66	String filterManagerName = null;
67	for(int i=0; i < args.length; i++) {
68	if(args[i].equals("-h")) {
69	usage();
70	}
71	else if(args[i].equals("-f")) {
72	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	}
87	else if(args[i].equals("-l")) {
88	if(++i < args.length) {
89	defaultProperties = args[i];
90	}
91	else {
92	usage();
93	}
94	}
95	else {
96	usage();
97	}
98	}
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	ReferenceManager refman = ReferenceManager.getInstance();
116
117	// now the ORB is running, we need to activate our RootPOA
118	// so that we can start serving requests once servants start up
119	refman.activatePOA();
120
121	// get the list of components
122	String componentList = System.getProperty("uk.org.iscream.cms.server.ComponentList");
123	StringTokenizer st = new StringTokenizer(componentList, ";");
124	_componentsToStart = new LinkedList();
125
126	// 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
132
133	// ### This is where the list of supported components is checked! ###
134	if (componentName.equalsIgnoreCase("core")) {
135	component = new uk.org.iscream.cms.server.core.Core();
136	// note the passing of the FilterManagers's name in its constructor
137	} else if (componentName.equalsIgnoreCase("filtermanager")) {
138	component = new uk.org.iscream.cms.server.filtermanager.FilterManager(filterManagerName);
139	} else if (componentName.equalsIgnoreCase("rootfilter")) {
140	component = new uk.org.iscream.cms.server.rootfilter.RootFilter();
141	} else if (componentName.equalsIgnoreCase("dbinterface")) {
142	component = new uk.org.iscream.cms.server.dbinterface.DBInterface();
143	} else if (componentName.equalsIgnoreCase("clientinterface")) {
144	component = new uk.org.iscream.cms.server.clientinterface.ClientInterfaceMain();
145	// note the passing of the Filter's name in its constructor
146	} else if (componentName.equalsIgnoreCase("filter")) {
147	component = new uk.org.iscream.cms.server.filter.FilterMain(filterName);
148	} else if (componentName.equalsIgnoreCase("client")) {
149	component = new uk.org.iscream.cms.server.client.ClientMain();
150	}
151	// ### Add new component constructors in the above section! ###
152
153	// build the list of components to start
154	if (component != null) {
155	_componentsToStart.add(component);
156	} else {
157	System.err.println(toString + ": WARNING unsupported component not started: "+componentName);
158	}
159	}
160
161
162
163	// get the value for timeout
164
165	String confTimeout = null;
166	try {
167	confTimeout = System.getProperty("uk.org.iscream.cms.server.ComponentTimeout");
168	confTimeout.trim();
169	_startTimeout = Integer.parseInt(confTimeout);
170	} catch (NumberFormatException e) {
171	_startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
172	System.err.println(toString + ": unable to read uk.org.iscream.cms.server.ComponentTimeout value (" + confTimeout + "), using default!");
173	}
174	System.out.println(toString + ": using component start timeout of " + _startTimeout + " seconds");
175
176	// 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	// !! this doesn't appear to work !!
182	while(true) {
183	try {
184	refman.getORB().run();
185	} catch (org.omg.CORBA.COMM_FAILURE e) {
186	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	* according to uk.org.iscream.cms.server.ComponentTimeout time.
199	*
200	* If the server dies and CORBA connections are lost, this method
201	* is called again.
202	*/
203	private static void startUp() {
204	// now we try and start the beast up
205	boolean tryAgain = true;
206	Component component = null;
207
208	// keep trying until we've started all the components.
209	// maybe add support for a limited number of retries
210	while(tryAgain) {
211	Iterator i = _componentsToStart.iterator();
212	LinkedList failedComponents = new LinkedList();
213	// go through all the components
214	while(i.hasNext()) {
215	// get a refence to the component
216	component = (Component) i.next();
217	System.out.println(toString + ": dependency checking component - " + component.toString());
218
219	// check it's dependencies
220	boolean depOK = component.depCheck();
221	if(depOK) {
222	System.out.println(toString + ": starting component - " + component.toString());
223	// 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	System.err.println(toString + ": This could be because it can't communicate with components it needs.");
240
241	// make a list of the failed components
242	failedComponents.add(component);
243	}
244	}
245
246	// if we had some failed components that we can retry
247	if (failedComponents.size() > 0) {
248	System.err.println(toString + ": WARNING One or more components failed to start correctly.");
249	System.err.println(toString + ": Will try again in " + _startTimeout + " seconds");
250
251	// our list is now the failed list
252	_componentsToStart = failedComponents;
253
254	// sleep for a given timeout
255	try {
256	Thread.sleep(_startTimeout * 1000);
257	} catch (InterruptedException e) {
258	// we're not bothered
259	}
260	// otherwise we started everything
261	} else {
262	// so we set to exit the loop
263	tryAgain = false;
264	}
265	}
266
267	System.out.println(toString + ": running");
268	}
269
270	/**
271	* 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	System.out.println("USAGE: java uk.org.iscream.cms.server.componentmanager.ComponentManager <option>");
278	System.out.println(" or: java -jar iscream.jar <option>");
279	System.out.println("WHERE <option>:");
280	System.out.println(" -l <filename> - the location of initial system properties");
281	System.out.println(" the default is ./etc/default.properties");
282	System.out.println(" -f <name> - the name of the filter (if there is one configured");
283	System.out.println(" -fm <name> - the name of the filter manager (if there is one configured");
284	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
300	private static LinkedList _componentsToStart;
301	private static int _startTimeout = 0;
302
303	}