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root/i-scream/projects/cms/source/server/uk/org/iscream/cms/server/componentmanager/ComponentManager.java

Comparing projects/cms/source/server/uk/org/iscream/cms/server/componentmanager/ComponentManager.java (file contents):
Revision 1.17 by ajm, Fri Feb 23 16:36:38 2001 UTC vs.
Revision 1.33 by tdb, Wed Mar 14 01:34:25 2001 UTC

#	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 92 | Line 98 | public class ComponentManager {
98		// get the list of components
99		String componentList = System.getProperty("uk.ac.ukc.iscream.ComponentList");
100		StringTokenizer st = new StringTokenizer(componentList, ";");
101	+	_componentsToStart = new LinkedList();
102
96	–
97	–	ArrayList componentsToStart = new ArrayList();
98	–
103		// this could be done using reflection
104		// but..well..we don't ;-p
105		while (st.hasMoreTokens()){
#	Line 117 | Line 121 | public class ComponentManager {
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);
124	+	} else if (componentName.equalsIgnoreCase("client")) {
125	+	component = new uk.ac.ukc.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	<	componentsToStart.add(component);
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
137	+
138	+
139	+	// get the value for timeout
140	+
141	+	String confTimeout = null;
142	+	try {
143	+	confTimeout = System.getProperty("uk.ac.ukc.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.ac.ukc.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	+	// 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.ac.ukc.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();
187	>	Iterator i = _componentsToStart.iterator();
188	>	LinkedList failedComponents = new LinkedList();
189	>	// go through all the components
190		while(i.hasNext()) {
191	<	try {
192	<	component = (Component) i.next();
193	<	System.out.println(toString + ": starting component - " + component.toString());
194	<	component.start();
195	<	componentsToStart.remove(componentsToStart.indexOf(component));
196	<	} catch (ComponentStartException e) {
197	<	System.err.println(toString + ": ERROR starting component - " + component.toString());
198	<	System.err.println(toString + ": component reports - " + e.getMessage());
199	<	System.exit(1);
200	<	} catch(ComponentCORBAException e2) {
201	<	System.err.println(toString + ": WARNING Component reported CORBA communications failure");
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	<	System.err.println(toString + ": component reports - " + e2.getMessage());
215	>
216	>	// make a list of the failed components
217	>	failedComponents.add(component);
218		}
219		}
220	<	if (componentsToStart.size() > 0) {
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 5 seconds");
225	<	Thread.sleep(5000);
226	<	} else {
227	<	try {
228	<	tryAgain = false;
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
165	–	// block on the ORB...in time, management functionality can be placed here.
166	–	refman.getORB().run();
167	–	}
168	–
245		/**
246		* A simple method to print the usage of this class.
247		* It never returns, but instead exits to the system
#	Line 194 | 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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