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root/i-scream/projects/cms/source/server/uk/org/iscream/cms/server/client/monitors/Heartbeat__Monitor.java

Comparing projects/cms/source/server/uk/org/iscream/cms/server/client/monitors/Heartbeat__Monitor.java (file contents):
Revision 1.15 by tdb, Thu Mar 22 22:29:40 2001 UTC vs.
Revision 1.21 by tdb, Mon Nov 26 12:56:33 2001 UTC

#	Line 1 | Line 1
1		//---PACKAGE DECLARATION---
2	<	package uk.org.iscream.client.monitors;
2	>	package uk.org.iscream.cms.server.client.monitors;
3
4		//---IMPORTS---
5		import java.util.HashMap;
6		import java.util.Iterator;
7	<	import uk.org.iscream.client.*;
8	<	import uk.org.iscream.core.*;
9	<	import uk.org.iscream.util.*;
10	<	import uk.org.iscream.componentmanager.*;
7	>	import java.util.StringTokenizer;
8	>	import uk.org.iscream.cms.server.client.*;
9	>	import uk.org.iscream.cms.server.core.*;
10	>	import uk.org.iscream.cms.server.util.*;
11	>	import uk.org.iscream.cms.server.componentmanager.*;
12
13		/**
14	<	* This Monitor watches heartbeats
14	>	* This Monitor watches heartbeats.
15	>	* It generates an alert when a heartbeat that is expected
16	>	* does not arrive. Unlike all the other monitors, this one
17	>	* is driven by an event *not* occuring, rather than an
18	>	* event occuring. This means it must be actively checking
19	>	* for missing heartbeat's, and thus has an extra inner class
20	>	* thread.
21		*
22		* @author  $Author$
23		* @version $Id$
#	Line 24 | Line 31 | public class Heartbeat__Monitor extends MonitorSkeleto
31		*/
32		public final String REVISION = "$Revision$";
33
34	+	/**
35	+	* A description of this monitor
36	+	*/
37		public final String DESC = "Monitors Heartbeats.";
38
39	+	/**
40	+	* The default (used if not configured) period at
41	+	* which to check for old heartbeats. (in seconds)
42	+	*/
43		public final int DEFAULT_CHECK_PERIOD = 60;
44
45		//---STATIC METHODS---
46
47		//---CONSTRUCTORS---
48	<
48	>
49	>	/**
50	>	* Constructs a new Heartbeat monitor, and starts off
51	>	* the worker thread.
52	>	*/
53		public Heartbeat__Monitor() {
54	<	new Thread(this).start();
54	>	super();
55	>	createInitialHosts();
56		new HeartbeatWorker().start();
57		}
58
59		//---PUBLIC METHODS---
60
61	+	/**
62	+	* Analyse a packet of data. In this case, this will just
63	+	* register the fact that a heartbeat has arrived.
64	+	*
65	+	* @param packet The packet of data to analyse
66	+	*/
67		public void analysePacket(XMLPacket packet) {
68		String source = packet.getParam("packet.attributes.machine_name");
69		if (!_hosts.containsKey(source)) {
70		synchronized(this) {
71	<	HashMap registerHash = new HashMap();
47	<	registerHash.put(source, new Register(source, _name));
48	<	_hosts.put(source, new HeartbeatHolder(registerHash));
71	>	_hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
72		}
73		}
74		HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
#	Line 56 | Line 79 | public class Heartbeat__Monitor extends MonitorSkeleto
79		* Overrides the {@link java.lang.Object#toString() Object.toString()}
80		* method to provide clean logging (every class should have this).
81		*
82	<	* This uses the uk.org.iscream.util.NameFormat class
82	>	* This uses the uk.org.iscream.cms.server.util.NameFormat class
83		* to format the toString()
84		*
85		* @return the name of this class and its CVS revision
#	Line 76 | Line 99 | public class Heartbeat__Monitor extends MonitorSkeleto
99		}
100
101		//---PRIVATE METHODS---
79	–
80	–	private boolean analyseHB(String source) {
81	–	ConfigurationProxy cp = ConfigurationProxy.getInstance();
82	–	HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
83	–	Register reg = (Register) ((HashMap) hbHolder.getRegisterHash()).get(source);
84	–
85	–	// get host's HB interval (seconds)
86	–	// this should always exist, thus we set to 0
87	–	int hostHBinterval = 0;
88	–	try {
89	–	hostHBinterval = Integer.parseInt(cp.getProperty("Host."+source, "Host.TCPUpdateTime"));
90	–	} catch (PropertyNotFoundException e) {
91	–	hostHBinterval = 0;
92	–	_logger.write(toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
93	–	} catch (NumberFormatException e) {
94	–	hostHBinterval = 0;
95	–	_logger.write(toString(), Logger.WARNING, "Erronous TCPUpdateTime value in configuration using default of " + hostHBinterval + " seconds");
96	–	}
97	–
98	–	// get host's last HB time (seconds)
99	–	long lastHeartbeat = hbHolder.getLastHeartbeat();
100	–	// time since last heartbeat (seconds)
101	–	long timeSinceLastHB = (System.currentTimeMillis()/1000) - lastHeartbeat;
102	–	// time since (or until if negative) the expected heartbeat
103	–	long timeSinceExpectedHB = timeSinceLastHB - (long) hostHBinterval;
104	–
105	–	// best do a check in case the expected heartbeat is in the future
106	–	if(timeSinceExpectedHB < 0) {
107	–	timeSinceExpectedHB = 0;
108	–	}
109	–
110	–	// find out the threshold level we're at
111	–	int newThreshold = checkAttributeThreshold(timeSinceExpectedHB, reg);
112	–
113	–	// process the alert
114	–	processAlert(newThreshold, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
115	–
116	–	if(reg.getLastAlertLevel() == Alert.alertFINAL) {
117	–	return true;
118	–	}
119	–	return false;
120	–	}
102
103	+	/**
104	+	* Checks whether the time since the last heartbeat
105	+	* is beyond the threshold(s).
106	+	*
107	+	* @param timeSinceLastHB a long time since the last heartbeat arrived
108	+	* @param reg the Register for this host
109	+	* @return the level which has been breached, if any
110	+	*/
111		private int checkAttributeThreshold(long timeSinceLastHB, Register reg) {
112		for(int thresholdLevel = Alert.thresholdLevels.length - 1; thresholdLevel >= 0; thresholdLevel--) {
113		if (reg.getThreshold(thresholdLevel) != -1.0) {
#	Line 129 | Line 118 | public class Heartbeat__Monitor extends MonitorSkeleto
118		}
119		return Alert.thresholdNORMAL;
120		}
121	+
122	+	/**
123	+	* Gets an initial list of hosts from the config
124	+	* and adds a fake set of heartbeats for them.
125	+	* If the hosts don't respond within the timeout
126	+	* period an alert will be raised.
127	+	*
128	+	* The effect of this is to allow us to know about
129	+	* hosts which weren't on when we started up, and
130	+	* will thus never have generated a heartbeat - yet
131	+	* will still want to know they're not responding.
132	+	*/
133	+	private void createInitialHosts() {
134	+	// get the initial list of hosts from the config
135	+	String initialHosts = "";
136	+	try {
137	+	initialHosts = _cp.getProperty(_name, "Monitor.Heartbeat.initialHosts");
138	+	} catch (PropertyNotFoundException e) {
139	+	// just leave initialHosts empty
140	+	_logger.write(Heartbeat__Monitor.this.toString(), Logger.DEBUG, "No initial list of hosts set, defaulting to none.");
141	+	}
142	+
143	+	// parse through the initial hosts adding them
144	+	StringTokenizer st = new StringTokenizer(initialHosts, ";");
145	+	while (st.hasMoreTokens()) {
146	+	String source = st.nextToken();
147	+	// check if they already exist, don't want to add them twice
148	+	if (!_hosts.containsKey(source)) {
149	+	synchronized(this) {
150	+	_hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
151	+	}
152	+	}
153	+	HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
154	+	// set a "fake" heartbeat
155	+	lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
156	+	}
157	+	}
158
159		//---ACCESSOR/MUTATOR METHODS---
160	<
160	>
161	>	/**
162	>	* Returns a reference to the Queue we're getting data
163	>	* from. This is specific to this monitor.
164	>	*
165	>	* @return a reference to a Queue to get data from
166	>	*/
167		protected Queue getQueue() {
168		return MonitorManager.getInstance().getHeartbeatQueue();
169		}
#	Line 153 | Line 185 | public class Heartbeat__Monitor extends MonitorSkeleto
185		* A reference to the configuration proxy in use
186		*/
187		private ConfigurationProxy _cp = ConfigurationProxy.getInstance();
188	<
188	>
189	>	/**
190	>	* A HashMap of hosts, with associated HeartbeatHolder's.
191	>	*/
192		private HashMap _hosts = new HashMap();
193	<
193	>
194	>	/**
195	>	* A reference to the system logger.
196	>	*/
197		private Logger _logger = ReferenceManager.getInstance().getLogger();
198
199		//---STATIC ATTRIBUTES---
200
201		//---INNER CLASSES---
202	<
202	>
203	>	/**
204	>	* This inner class simply holding some information
205	>	* about a specific host.
206	>	*/
207		private class HeartbeatHolder {
208
209	<	public HeartbeatHolder(HashMap registerHash) {
210	<	_registerHash = registerHash;
209	>	/**
210	>	* Construct a new HeartbeatHolder.
211	>	*/
212	>	public HeartbeatHolder(Register register) {
213	>	_register = register;
214		}
215
216	+	/**
217	+	* Set the time of the last heartbeat
218	+	*/
219		public void setLastHeartbeat(long lastHeartbeat) {
220		_lastHeartbeat = lastHeartbeat;
221		}
222
223	+	/**
224	+	* Get the time of the last heartbeat
225	+	*/
226		public long getLastHeartbeat() {
227		return _lastHeartbeat;
228		}
229
230	<	public HashMap getRegisterHash() {
231	<	return _registerHash;
230	>	/**
231	>	* Get the Register
232	>	*/
233	>	public Register getRegister() {
234	>	return _register;
235		}
236
237	+	/**
238	+	* last heartbeat time
239	+	*/
240		private long _lastHeartbeat;
241	<	private HashMap _registerHash;
241	>
242	>	/**
243	>	* register ref
244	>	*/
245	>	private Register _register;
246		}
247
248	+	/**
249	+	* This worker thread just checks all the hosts and then
250	+	* waits a period of time before doing it again. It sends
251	+	* Alerts as required.
252	+	*/
253		private class HeartbeatWorker extends Thread {
254
255	+	/**
256	+	* The main run method of this worker thread. It simply
257	+	* checks through all the hosts it has stored, running
258	+	* the analyseHB method on each. It then removes any
259	+	* that have passed a FINAL, and waits a (configured)
260	+	* length of time before doing it again.
261	+	*/
262		public void run() {
263		ConfigurationProxy cp = ConfigurationProxy.getInstance();
264		while(true) {
#	Line 195 | Line 268 | public class Heartbeat__Monitor extends MonitorSkeleto
268		checkPeriod = Integer.parseInt(cp.getProperty(_name, "Monitor.Heartbeat.checkPeriod"));
269		} catch (PropertyNotFoundException e) {
270		checkPeriod = DEFAULT_CHECK_PERIOD;
271	<	_logger.write(this.toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
271	>	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
272		} catch (NumberFormatException e) {
273		checkPeriod = DEFAULT_CHECK_PERIOD;
274	<	_logger.write(this.toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
274	>	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
275		}
276
277	<	synchronized(this) {
277	>	synchronized(Heartbeat__Monitor.this) {
278		// perform the checks (use HB hash, although they *should* be the same)
279		Iterator i = _hosts.keySet().iterator();
280		while(i.hasNext()) {
#	Line 209 | Line 282 | public class Heartbeat__Monitor extends MonitorSkeleto
282		String source = (String) i.next();
283		// check it
284		boolean remove = analyseHB(source);
285	+	// remove it if it's passed a FINAL
286		if(remove) {
287		i.remove();
288		}
#	Line 219 | Line 293 | public class Heartbeat__Monitor extends MonitorSkeleto
293		try {Thread.sleep(checkPeriod * 1000);} catch (InterruptedException e) {}
294		}
295		}
296	+
297	+	/**
298	+	* Analyses a given host's state, and if need be generates
299	+	* a relevant Alert. Note that it also checks if the last
300	+	* alert sent is FINAL, in which case it returns true to
301	+	* indicate removal of this host.
302	+	*
303	+	* @param source the host to check
304	+	* @return whether this host can be deleted
305	+	*/
306	+	private boolean analyseHB(String source) {
307	+	ConfigurationProxy cp = ConfigurationProxy.getInstance();
308	+	HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
309	+	Register reg = hbHolder.getRegister();
310	+
311	+	// get host's HB interval (seconds)
312	+	// this should always exist, thus we set to 0
313	+	int hostHBinterval = 0;
314	+	try {
315	+	hostHBinterval = Integer.parseInt(cp.getProperty("Host."+source, "Host.TCPUpdateTime"));
316	+	} catch (PropertyNotFoundException e) {
317	+	hostHBinterval = 0;
318	+	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
319	+	} catch (NumberFormatException e) {
320	+	hostHBinterval = 0;
321	+	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous TCPUpdateTime value in configuration using default of " + hostHBinterval + " seconds");
322	+	}
323	+
324	+	// get host's last HB time (seconds)
325	+	long lastHeartbeat = hbHolder.getLastHeartbeat();
326	+	// time since last heartbeat (seconds)
327	+	long timeSinceLastHB = (System.currentTimeMillis()/1000) - lastHeartbeat;
328	+	// time since (or until if negative) the expected heartbeat
329	+	long timeSinceExpectedHB = timeSinceLastHB - (long) hostHBinterval;
330	+
331	+	// best do a check in case the expected heartbeat is in the future
332	+	if(timeSinceExpectedHB < 0) {
333	+	timeSinceExpectedHB = 0;
334	+	}
335	+
336	+	// find out the threshold level we're at
337	+	int newThreshold = checkAttributeThreshold(timeSinceExpectedHB, reg);
338	+
339	+	// process the alert
340	+	Heartbeat__Monitor.this.processAlert(newThreshold, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
341	+
342	+	if(reg.getLastAlertLevel() == Alert.alertFINAL) {
343	+	return true;
344	+	}
345	+	return false;
346	+	}
347		}
223	–
348		}

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