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root/i-scream/projects/cms/source/server/uk/org/iscream/cms/server/componentmanager/ComponentManager.java
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Comparing projects/cms/source/server/uk/org/iscream/cms/server/componentmanager/ComponentManager.java (file contents):
Revision 1.11 by tdb, Sun Jan 28 05:14:46 2001 UTC vs.
Revision 1.34 by tdb, Wed Mar 14 23:25:29 2001 UTC

# Line 1 | Line 1
1   //---PACKAGE DECLARATION---
2 < package uk.ac.ukc.iscream.componentmanager;
2 > package uk.org.iscream.componentmanager;
3  
4   //---IMPORTS---
5   import java.util.*;
6   import java.io.*;
7 < import uk.ac.ukc.iscream.util.*;
7 > import uk.org.iscream.util.*;
8  
9   /**
10   * The component manager is the starting point for all
# Line 12 | Line 12 | import uk.ac.ukc.iscream.util.*;
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
15 > * uk.org.iscream.ComponentList
16   *
17   * @author  $Author$
18   * @version $Id$
# Line 38 | Line 38 | public class ComponentManager {
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      /**
# Line 54 | Line 60 | public class ComponentManager {
60          String defaultProperties = DEFAULTPROPERTIES;
61          String filterName = null;
62          for(int i=0; i < args.length; i++) {
63 <            if(args[i].equals("-h") {
63 >            if(args[i].equals("-h")) {
64                  usage();
65              }
66 <            else if(args[i].equals("-f") {
66 >            else if(args[i].equals("-f")) {
67                  i++; filterName = args[i];
68              }
69 <            else if(args[i].equals("-l") {
69 >            else if(args[i].equals("-l")) {
70                  i++; defaultProperties = args[i];
71              }
72              else {
# Line 90 | Line 96 | public class ComponentManager {
96          refman.activatePOA();
97          
98          // get the list of components
99 <        String componentList = System.getProperty("uk.ac.ukc.iscream.ComponentList");
99 >        String componentList = System.getProperty("uk.org.iscream.ComponentList");
100          StringTokenizer st = new StringTokenizer(componentList, ";");
101 +        _componentsToStart = new LinkedList();
102          
103          // 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;
101            System.out.println(toString + ": starting component - " + componentName);
108              
109 +            
110              // ### This is where the list of supported components is checked! ###
111              if (componentName.equalsIgnoreCase("core")) {
112 <                component = new uk.ac.ukc.iscream.core.Core();
112 >                component = new uk.org.iscream.core.Core();
113              } else if (componentName.equalsIgnoreCase("filtermanager")) {
114 <                component = new uk.ac.ukc.iscream.filtermanager.FilterManager();
114 >                component = new uk.org.iscream.filtermanager.FilterManager();
115              } else if (componentName.equalsIgnoreCase("rootfilter")) {
116 <                component = new uk.ac.ukc.iscream.rootfilter.RootFilter();
116 >                component = new uk.org.iscream.rootfilter.RootFilter();
117              } else if (componentName.equalsIgnoreCase("dbinterface")) {
118 <                component = new uk.ac.ukc.iscream.dbinterface.DBInterface();
118 >                component = new uk.org.iscream.dbinterface.DBInterface();
119              } else if (componentName.equalsIgnoreCase("clientinterface")) {
120 <                component = new uk.ac.ukc.iscream.clientinterface.ClientInterfaceMain();
120 >                component = new uk.org.iscream.clientinterface.ClientInterfaceMain();
121              // 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);
123 >                component = new uk.org.iscream.filter.FilterMain(filterName);
124 >            } else if (componentName.equalsIgnoreCase("client")) {
125 >                component = new uk.org.iscream.client.ClientMain();
126              }
127              // ###  Add new component constructors in the above section! ###
128              
129 +            // build the list of components to start
130              if (component != null) {
131 <                try {
122 <                    component.start();
123 <                } catch (ComponentStartException e) {
124 <                    System.err.println(toString + ": ERROR starting component - " + componentName);
125 <                    System.err.println(toString + ": component reports - " + e.getMessage());
126 <                    System.exit(1);
127 <                }
131 >                _componentsToStart.add(component);    
132              } else {
133 <                System.err.println(toString + ": WARNING unsupported component not started");
133 >                System.err.println(toString + ": WARNING unsupported component not started: "+componentName);
134              }
135          }
136 <            System.out.println(toString + ": running");
137 <            
136 >        
137 >        
138 >
139 >        // get the value for timeout
140 >        
141 >        String confTimeout = null;
142 >        try {
143 >            confTimeout = System.getProperty("uk.org.iscream.ComponentTimeout");
144 >            confTimeout.trim();
145 >            _startTimeout = Integer.parseInt(confTimeout);
146 >        } catch (NumberFormatException e) {
147 >            _startTimeout = DEFAULT_COMPONENT_START_TIMEOUT;
148 >            System.err.println(toString + ": unable to read uk.org.iscream.ComponentTimeout value (" + confTimeout + "), using default!");
149 >        }
150 >        System.out.println(toString + ": using component start timeout of " + _startTimeout + " seconds");
151 >        
152 >        // startup the system components
153 >        startUp();
154 >
155              // block on the ORB...in time, management functionality can be placed here.
156 <        refman.getORB().run();
156 >            // if we detect a CORBA communication error, we'll restart all the components.
157 >            // !! this doesn't appear to work !!
158 >            while(true) {
159 >            try {
160 >                refman.getORB().run();
161 >            } catch (org.omg.CORBA.COMM_FAILURE e) {
162 >                System.out.println(toString + ": WARNING CORBA communications failure - " + e.getMessage());
163 >                System.out.println(toString + ": WARNING CORBA connections have been lost - attempting to restart!");
164 >            }
165 >            startUp();
166 >        }
167      }
168  
169      /**
170 +     * Starts the components as obtained from the configuration.
171 +     * This method calls the start() methods on all the components.
172 +     * If a component fails to start due to a CORBA communication
173 +     * problem, then it catches this and tries to start it again
174 +     * according to uk.org.iscream.ComponentTimeout time.
175 +     *
176 +     * If the server dies and CORBA connections are lost, this method
177 +     * is called again.
178 +     */
179 +    private static void startUp() {
180 +        // now we try and start the beast up        
181 +        boolean tryAgain = true;
182 +        Component component = null;
183 +        
184 +        // keep trying until we've started all the components.
185 +        // maybe add support for a limited number of retries
186 +        while(tryAgain) {
187 +            Iterator i = _componentsToStart.iterator();
188 +            LinkedList failedComponents = new LinkedList();
189 +            // go through all the components
190 +            while(i.hasNext()) {
191 +                // get a refence to the component
192 +                component = (Component) i.next();
193 +                System.out.println(toString + ": starting component - " + component.toString());
194 +                
195 +                // check it's dependencies
196 +                boolean depOK = component.depCheck();
197 +                if(depOK) {
198 +                    // it should be ok to start the component
199 +                        try {    
200 +                            // start the component
201 +                        component.start();
202 +                    } catch (ComponentStartException e) {
203 +                        // if we get this then there was a problem
204 +                        // that we can't recover from
205 +                        System.err.println(toString + ": ERROR starting component - " + component.toString());
206 +                        System.err.println(toString + ": component reports - " + e.getMessage());
207 +                        System.exit(1);
208 +                    }
209 +                }
210 +                else {
211 +                    // it seems the depedencies failed
212 +                    // so we want to try again after a delay
213 +                    System.err.println(toString + ": WARNING Component reported dependency failure");
214 +                    System.err.println(toString + ": This could be because it can't communicate with components it needs.");
215 +                    
216 +                    // make a list of the failed components
217 +                    failedComponents.add(component);
218 +                }
219 +            }
220 +            
221 +            // if we had some failed components that we can retry
222 +            if (failedComponents.size() > 0) {
223 +                System.err.println(toString + ": WARNING One or more components failed to start correctly.");
224 +                System.err.println(toString + ": Will try again in " + _startTimeout + " seconds");
225 +            
226 +                // our list is now the failed list
227 +                _componentsToStart = failedComponents;
228 +                
229 +                // sleep for a given timeout
230 +                try {    
231 +                    Thread.sleep(_startTimeout * 1000);
232 +                } catch (InterruptedException e) {
233 +                    // we're not bothered
234 +                }
235 +            // otherwise we started everything
236 +            } else {
237 +                // so we set to exit the loop
238 +                tryAgain = false;
239 +            }
240 +        }
241 +                
242 +            System.out.println(toString + ": running");
243 +        }
244 +
245 +    /**
246       * A simple method to print the usage of this class.
247       * It never returns, but instead exits to the system
248       * with a value 1, to indicate the system did not start
249       * properly.
250       */
251      public static void usage() {
252 <        System.out.println("USAGE: java uk.ac.ukc.iscream.componentmanager.ComponentManager <option>");
252 >        System.out.println("USAGE: java uk.org.iscream.componentmanager.ComponentManager <option>");
253          System.out.println("   or: java -jar iscream.jar <option>");
254          System.out.println("WHERE <option>:");
255          System.out.println("      -l <filename> - the location of initial system properties");
# Line 163 | Line 270 | public class ComponentManager {
270   //---ATTRIBUTES---
271      
272   //---STATIC ATTRIBUTES---
273 +
274 +    private static LinkedList _componentsToStart;
275 +    private static int _startTimeout = 0;
276  
277   }

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