server/componentmanager/ComponentManager.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.componentmanager;

//---IMPORTS---
import java.util.*;
import java.io.*;
import uk.ac.ukc.iscream.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.ac.ukc.iscream.ComponentList
 *
 * @author  $Author: ajm4 $
 * @version $Id: ComponentManager.java,v 1.24 2001/02/23 17:56:25 ajm4 Exp $
 */
public class ComponentManager {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.24 $";
    
    /**
     * 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("--- i-scream Server Component Manager ---");
        System.out.println("---          Starting System          ---");        
        
        // get the command line args
        String defaultProperties = DEFAULTPROPERTIES;
        String filterName = null;
        for(int i=0; i < args.length; i++) {
            if(args[i].equals("-h")) {
                usage();
            }
            else if(args[i].equals("-f")) {
                i++; filterName = args[i];
            }
            else if(args[i].equals("-l")) {
                i++; defaultProperties = args[i];
            }
            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.ac.ukc.iscream.ComponentList");
        StringTokenizer st = new StringTokenizer(componentList, ";");
        ArrayList componentsToStart = new ArrayList();
        
        // 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.ac.ukc.iscream.core.Core();
            } else if (componentName.equalsIgnoreCase("filtermanager")) {
                component = new uk.ac.ukc.iscream.filtermanager.FilterManager();
            } else if (componentName.equalsIgnoreCase("rootfilter")) {
                component = new uk.ac.ukc.iscream.rootfilter.RootFilter();
            } else if (componentName.equalsIgnoreCase("dbinterface")) {
                component = new uk.ac.ukc.iscream.dbinterface.DBInterface();
            } else if (componentName.equalsIgnoreCase("clientinterface")) {
                component = new uk.ac.ukc.iscream.clientinterface.ClientInterfaceMain();
            // note the passing of the Filter's name in its constructor
            } else if (componentName.equalsIgnoreCase("filter")) {
                component = new uk.ac.ukc.iscream.filter.FilterMain(filterName);
            }
            // ###  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");
            }
        }
        
        // now we try and start the beast up        
        boolean tryAgain = true;
        Component component = null;

        // get the value for timeout
        int startTimeout;
        try {
            String confTimeout = System.getProperty("uk.ac.ukc.iscream.ComponentTimeout")
            startTimeout = Integer.parseInt(confTimeout);
        } catch (NumberFormatException e) {
            startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
            System.err.println(toString + ": unable to read uk.ac.ukc.iscream.ComponentTimeout value (" + confTimeout + "), using default!");
        }
        System.out.println(toString + ": using component start timeout of " + startTimeout + " seconds");
        
        // keep trying until we've started all the components.
        // maybe add support for a limited number of retries
        while(tryAgain) {
            Iterator i = componentsToStart.iterator();
            ArrayList failedComponents = new ArrayList();
            // go through all the components
            while(i.hasNext()) {
                try {
                    component = (Component) i.next();
                    System.out.println(toString + ": starting component - " + component.toString());
                    
                    // start the component
                    component.start();
                    
                // if we get this then there was a problem
                // that we can't recover from
                } catch (ComponentStartException e) {
                    System.err.println(toString + ": ERROR starting component - " + component.toString());
                    System.err.println(toString + ": component reports - " + e.getMessage());
                    System.exit(1);

                // if we get this exception then we've tried
                // to talk to something which may not be up yet
                // so we want to try again in a minute                
                } catch(ComponentCORBAException e2) {
                    System.err.println(toString + ": WARNING Component reported CORBA communications failure");
                    System.err.println(toString + ": This could be because it can't communicate with components it needs.");
                    System.err.println(toString + ": component reports - " + e2.getMessage());
                    
                    // 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");

            // block on the ORB...in time, management functionality can be placed here.
        refman.getORB().run();
    }

    /**
     * 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.ac.ukc.iscream.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("      -h            - this help screen");
        System.exit(1);
    }

//---CONSTRUCTORS---

//---PUBLIC METHODS---

//---PRIVATE METHODS---

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

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

}
Revision:	1.25
Committed:	Fri Feb 23 18:00:29 2001 UTC (23 years, 2 months ago) by ajm
Branch:	MAIN
Changes since 1.24:	+5 -4 lines
Log Message:	debug code added
#	User	Rev	Content
1	ajm	1.1	//---PACKAGE DECLARATION---
2			package uk.ac.ukc.iscream.componentmanager;
3
4			//---IMPORTS---
5			import java.util.*;
6			import java.io.*;
7	tdb	1.10	import uk.ac.ukc.iscream.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			* uk.ac.ukc.iscream.ComponentList
16	ajm	1.1	*
17	ajm	1.14	* @author $Author: ajm4 $
18	ajm	1.25	* @version $Id: ComponentManager.java,v 1.24 2001/02/23 17:56:25 ajm4 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	ajm	1.25	public static final String REVISION = "$Revision: 1.24 $";
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	tdb	1.11	System.out.println("--- i-scream Server Component Manager ---");
57	ajm	1.2	System.out.println("--- Starting System ---");
58
59	ajm	1.1	// get the command line args
60			String defaultProperties = DEFAULTPROPERTIES;
61			String filterName = null;
62	tdb	1.11	for(int i=0; i < args.length; i++) {
63	tdb	1.12	if(args[i].equals("-h")) {
64	ajm	1.1	usage();
65	tdb	1.11	}
66	tdb	1.12	else if(args[i].equals("-f")) {
67	tdb	1.11	i++; filterName = args[i];
68			}
69	tdb	1.12	else if(args[i].equals("-l")) {
70	tdb	1.11	i++; defaultProperties = args[i];
71			}
72			else {
73			usage();
74			}
75	ajm	1.1	}
76
77			// load the default properties file into the system properties
78			System.out.println(toString + ": initialising - using " + defaultProperties);
79			try {
80			Properties initProperties = new Properties(System.getProperties());
81			initProperties.load(new FileInputStream(new File(defaultProperties)));
82			System.setProperties(initProperties);
83			} catch (Exception e) {
84			System.err.println(toString + ": ERROR " + e.getMessage());
85			usage();
86			}
87
88			// continue to bring the system up
89			System.out.println(toString + ": coming up");
90
91			// start the ORB by initialising the ReferenceManager
92	ajm	1.2	ReferenceManager refman = ReferenceManager.getInstance();
93	ajm	1.1
94	ajm	1.2	// now the ORB is running, we need to activate our RootPOA
95			// so that we can start serving requests once servants start up
96	ajm	1.1	refman.activatePOA();
97
98	ajm	1.2	// get the list of components
99	ajm	1.1	String componentList = System.getProperty("uk.ac.ukc.iscream.ComponentList");
100			StringTokenizer st = new StringTokenizer(componentList, ";");
101	ajm	1.13	ArrayList componentsToStart = new ArrayList();
102
103	ajm	1.1	// this could be done using reflection
104			// but..well..we don't ;-p
105			while (st.hasMoreTokens()){
106			String componentName = st.nextToken();
107			Component component = null;
108	ajm	1.13
109	ajm	1.2
110			// ### This is where the list of supported components is checked! ###
111			if (componentName.equalsIgnoreCase("core")) {
112	ajm	1.1	component = new uk.ac.ukc.iscream.core.Core();
113	ajm	1.3	} else if (componentName.equalsIgnoreCase("filtermanager")) {
114			component = new uk.ac.ukc.iscream.filtermanager.FilterManager();
115	ajm	1.4	} else if (componentName.equalsIgnoreCase("rootfilter")) {
116			component = new uk.ac.ukc.iscream.rootfilter.RootFilter();
117	ajm	1.5	} else if (componentName.equalsIgnoreCase("dbinterface")) {
118			component = new uk.ac.ukc.iscream.dbinterface.DBInterface();
119	ajm	1.6	} else if (componentName.equalsIgnoreCase("clientinterface")) {
120			component = new uk.ac.ukc.iscream.clientinterface.ClientInterfaceMain();
121	ajm	1.7	// note the passing of the Filter's name in its constructor
122			} else if (componentName.equalsIgnoreCase("filter")) {
123			component = new uk.ac.ukc.iscream.filter.FilterMain(filterName);
124	ajm	1.1	}
125	ajm	1.2	// ### Add new component constructors in the above section! ###
126	ajm	1.3
127	ajm	1.22	// build the list of components to start
128	ajm	1.1	if (component != null) {
129	ajm	1.13	componentsToStart.add(component);
130			} else {
131			System.err.println(toString + ": WARNING unsupported component not started");
132			}
133			}
134
135	ajm	1.22	// now we try and start the beast up
136	ajm	1.13	boolean tryAgain = true;
137	ajm	1.15	Component component = null;
138	ajm	1.22
139			// get the value for timeout
140			int startTimeout;
141			try {
142	ajm	1.25	String confTimeout = System.getProperty("uk.ac.ukc.iscream.ComponentTimeout")
143			startTimeout = Integer.parseInt(confTimeout);
144	ajm	1.22	} catch (NumberFormatException e) {
145			startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
146	ajm	1.25	System.err.println(toString + ": unable to read uk.ac.ukc.iscream.ComponentTimeout value (" + confTimeout + "), using default!");
147	ajm	1.22	}
148	ajm	1.24	System.out.println(toString + ": using component start timeout of " + startTimeout + " seconds");
149	ajm	1.22
150			// keep trying until we've started all the components.
151			// maybe add support for a limited number of retries
152	ajm	1.13	while(tryAgain) {
153			Iterator i = componentsToStart.iterator();
154	ajm	1.19	ArrayList failedComponents = new ArrayList();
155	ajm	1.22	// go through all the components
156	ajm	1.13	while(i.hasNext()) {
157			try {
158	ajm	1.16	component = (Component) i.next();
159	ajm	1.13	System.out.println(toString + ": starting component - " + component.toString());
160	ajm	1.22
161			// start the component
162	ajm	1.2	component.start();
163	ajm	1.22
164			// if we get this then there was a problem
165			// that we can't recover from
166	ajm	1.2	} catch (ComponentStartException e) {
167	ajm	1.14	System.err.println(toString + ": ERROR starting component - " + component.toString());
168	ajm	1.2	System.err.println(toString + ": component reports - " + e.getMessage());
169	ajm	1.1	System.exit(1);
170	ajm	1.22
171			// if we get this exception then we've tried
172			// to talk to something which may not be up yet
173			// so we want to try again in a minute
174	ajm	1.14	} catch(ComponentCORBAException e2) {
175			System.err.println(toString + ": WARNING Component reported CORBA communications failure");
176			System.err.println(toString + ": This could be because it can't communicate with components it needs.");
177	ajm	1.13	System.err.println(toString + ": component reports - " + e2.getMessage());
178	ajm	1.22
179			// make a list of the failed components
180	ajm	1.20	failedComponents.add(component);
181	ajm	1.1	}
182	ajm	1.13	}
183	ajm	1.22
184			// if we had some failed components that we can retry
185	ajm	1.21	if (failedComponents.size() > 0) {
186	ajm	1.14	System.err.println(toString + ": WARNING One or more components failed to start correctly.");
187	ajm	1.22	System.err.println(toString + ": Will try again in " + startTimeout + " seconds");
188
189			// our list is now the failed list
190			componentsToStart = failedComponents;
191
192			// sleep for a given timeout
193	ajm	1.18	try {
194	ajm	1.22	Thread.sleep(startTimeout * 1000);
195	ajm	1.17	} catch (InterruptedException e) {
196			// we're not bothered
197			}
198	ajm	1.22	// otherwise we started everything
199	ajm	1.18	} else {
200	ajm	1.22	// so we set to exit the loop
201	ajm	1.18	tryAgain = false;
202	ajm	1.1	}
203			}
204	ajm	1.13
205	ajm	1.3	System.out.println(toString + ": running");
206	ajm	1.13
207	ajm	1.2	// block on the ORB...in time, management functionality can be placed here.
208	ajm	1.1	refman.getORB().run();
209			}
210	ajm	1.3
211			/**
212	ajm	1.1	* A simple method to print the usage of this class.
213			* It never returns, but instead exits to the system
214			* with a value 1, to indicate the system did not start
215			* properly.
216			*/
217			public static void usage() {
218			System.out.println("USAGE: java uk.ac.ukc.iscream.componentmanager.ComponentManager <option>");
219	tdb	1.8	System.out.println(" or: java -jar iscream.jar <option>");
220	ajm	1.1	System.out.println("WHERE <option>:");
221			System.out.println(" -l <filename> - the location of initial system properties");
222	ajm	1.2	System.out.println(" the default is ./etc/default.properties");
223	ajm	1.1	System.out.println(" -f <name> - the name of the filter (if there is one configured");
224			System.out.println(" -h - this help screen");
225			System.exit(1);
226			}
227
228			//---CONSTRUCTORS---
229
230			//---PUBLIC METHODS---
231
232			//---PRIVATE METHODS---
233
234			//---ACCESSOR/MUTATOR METHODS---
235
236			//---ATTRIBUTES---
237
238			//---STATIC ATTRIBUTES---
239
240			}