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 |
|
/** |
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 ArrayList(); |
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()){ |
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"); |
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 |
+ |
while(true) { |
158 |
+ |
try { |
159 |
+ |
refman.getORB().run(); |
160 |
+ |
} catch (org.omg.CORBA.COMM_FAILURE e) { |
161 |
+ |
System.out.println(toString + ": WARNING CORBA communications failure - " + e.getMessage()); |
162 |
+ |
System.out.println(toString + ": WARNING CORBA connections have been lost - attempting to restart!"); |
163 |
+ |
} |
164 |
+ |
startUp(); |
165 |
+ |
} |
166 |
+ |
} |
167 |
+ |
|
168 |
+ |
/** |
169 |
+ |
* Starts the components as obtained from the configuration. |
170 |
+ |
* This method calls the start() methods on all the components. |
171 |
+ |
* If a component fails to start due to a CORBA communication |
172 |
+ |
* problem, then it catches this and tries to start it again |
173 |
+ |
* according to uk.ac.ukc.iscream.ComponentTimeout time. |
174 |
+ |
* |
175 |
+ |
* If the server dies and CORBA connections are lost, this method |
176 |
+ |
* is called again. |
177 |
+ |
*/ |
178 |
+ |
private static void startUp() { |
179 |
+ |
// now we try and start the beast up |
180 |
|
boolean tryAgain = true; |
181 |
|
Component component = null; |
182 |
+ |
|
183 |
+ |
// keep trying until we've started all the components. |
184 |
+ |
// maybe add support for a limited number of retries |
185 |
|
while(tryAgain) { |
186 |
< |
Iterator i = componentsToStart.iterator(); |
186 |
> |
Iterator i = _componentsToStart.iterator(); |
187 |
|
ArrayList failedComponents = new ArrayList(); |
188 |
+ |
// go through all the components |
189 |
|
while(i.hasNext()) { |
190 |
|
try { |
191 |
|
component = (Component) i.next(); |
192 |
|
System.out.println(toString + ": starting component - " + component.toString()); |
193 |
+ |
|
194 |
+ |
// start the component |
195 |
|
component.start(); |
196 |
+ |
|
197 |
+ |
// if we get this then there was a problem |
198 |
+ |
// that we can't recover from |
199 |
|
} catch (ComponentStartException e) { |
200 |
|
System.err.println(toString + ": ERROR starting component - " + component.toString()); |
201 |
|
System.err.println(toString + ": component reports - " + e.getMessage()); |
202 |
|
System.exit(1); |
203 |
+ |
|
204 |
+ |
// if we get this exception then we've tried |
205 |
+ |
// to talk to something which may not be up yet |
206 |
+ |
// so we want to try again in a minute |
207 |
|
} catch(ComponentCORBAException e2) { |
208 |
|
System.err.println(toString + ": WARNING Component reported CORBA communications failure"); |
209 |
|
System.err.println(toString + ": This could be because it can't communicate with components it needs."); |
210 |
|
System.err.println(toString + ": component reports - " + e2.getMessage()); |
211 |
+ |
|
212 |
+ |
// make a list of the failed components |
213 |
|
failedComponents.add(component); |
214 |
|
} |
215 |
|
} |
216 |
< |
if (componentsToStart.size() > 0) { |
216 |
> |
|
217 |
> |
// if we had some failed components that we can retry |
218 |
> |
if (failedComponents.size() > 0) { |
219 |
|
System.err.println(toString + ": WARNING One or more components failed to start correctly."); |
220 |
< |
System.err.println(toString + ": Will try again in 5 seconds"); |
220 |
> |
System.err.println(toString + ": Will try again in " + _startTimeout + " seconds"); |
221 |
> |
|
222 |
> |
// our list is now the failed list |
223 |
> |
_componentsToStart = failedComponents; |
224 |
> |
|
225 |
> |
// sleep for a given timeout |
226 |
|
try { |
227 |
< |
Thread.sleep(5000); |
227 |
> |
Thread.sleep(_startTimeout * 1000); |
228 |
|
} catch (InterruptedException e) { |
229 |
|
// we're not bothered |
230 |
|
} |
231 |
+ |
// otherwise we started everything |
232 |
|
} else { |
233 |
+ |
// so we set to exit the loop |
234 |
|
tryAgain = false; |
235 |
|
} |
162 |
– |
componentsToStart = failedComponents; |
236 |
|
} |
237 |
|
|
238 |
|
System.out.println(toString + ": running"); |
239 |
+ |
} |
240 |
|
|
167 |
– |
// block on the ORB...in time, management functionality can be placed here. |
168 |
– |
refman.getORB().run(); |
169 |
– |
} |
170 |
– |
|
241 |
|
/** |
242 |
|
* A simple method to print the usage of this class. |
243 |
|
* It never returns, but instead exits to the system |
266 |
|
//---ATTRIBUTES--- |
267 |
|
|
268 |
|
//---STATIC ATTRIBUTES--- |
269 |
+ |
|
270 |
+ |
private static ArrayList _componentsToStart; |
271 |
+ |
private static int _startTimeout = 0; |
272 |
|
|
273 |
|
} |