client/monitors/Heartbeat__Monitor.java

/* 
 * i-scream central monitoring system
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.server.client.monitors;

//---IMPORTS---
import java.util.HashMap;
import java.util.Iterator;
import java.util.StringTokenizer;
import uk.org.iscream.cms.server.client.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.util.*;
import uk.org.iscream.cms.server.componentmanager.*;

/**
 * This Monitor watches heartbeats.
 * It generates an alert when a heartbeat that is expected
 * does not arrive. Unlike all the other monitors, this one
 * is driven by an event *not* occuring, rather than an
 * event occuring. This means it must be actively checking
 * for missing heartbeat's, and thus has an extra inner class
 * thread.
 *
 * @author  $Author: tdb $
 * @version $Id: Heartbeat__Monitor.java,v 1.21 2001/11/26 12:56:33 tdb Exp $
 */
public class Heartbeat__Monitor extends MonitorSkeleton {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.21 $";
    
    /**
     * A description of this monitor
     */
    public final String DESC = "Monitors Heartbeats.";
    
    /**
     * The default (used if not configured) period at
     * which to check for old heartbeats. (in seconds)
     */
    public final int DEFAULT_CHECK_PERIOD = 60;
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Constructs a new Heartbeat monitor, and starts off
     * the worker thread.
     */
    public Heartbeat__Monitor() {
        super();
        createInitialHosts();
        new HeartbeatWorker().start();
    }

//---PUBLIC METHODS---
    
    /**
     * Analyse a packet of data. In this case, this will just
     * register the fact that a heartbeat has arrived.
     *
     * @param packet The packet of data to analyse
     */
    public void analysePacket(XMLPacket packet) {
        String source = packet.getParam("packet.attributes.machine_name");
        if (!_hosts.containsKey(source)) {
            synchronized(this) {
                _hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
            }
        }
        HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
        lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.cms.server.util.NameFormat class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

    /**
     * return the String representation of what the monitor does
     */
    public String getDescription(){
        return DESC;
    }

//---PRIVATE METHODS---
    
    /**
     * Checks whether the time since the last heartbeat
     * is beyond the threshold(s).
     *
     * @param timeSinceLastHB a long time since the last heartbeat arrived
     * @param reg the Register for this host
     * @return the level which has been breached, if any
     */
    private int checkAttributeThreshold(long timeSinceLastHB, Register reg) {
        for(int thresholdLevel = Alert.thresholdLevels.length - 1; thresholdLevel >= 0; thresholdLevel--) {
            if (reg.getThreshold(thresholdLevel) != -1.0) {
                if (((long) reg.getThreshold(thresholdLevel)) < timeSinceLastHB) {
                    return thresholdLevel;
                }
            }
        }
        return Alert.thresholdNORMAL;
    }
    
    /**
     * Gets an initial list of hosts from the config
     * and adds a fake set of heartbeats for them.
     * If the hosts don't respond within the timeout
     * period an alert will be raised.
     *
     * The effect of this is to allow us to know about
     * hosts which weren't on when we started up, and
     * will thus never have generated a heartbeat - yet
     * will still want to know they're not responding.
     */
    private void createInitialHosts() {
        // get the initial list of hosts from the config
        String initialHosts = "";
        try {
            initialHosts = _cp.getProperty(_name, "Monitor.Heartbeat.initialHosts");
        } catch (PropertyNotFoundException e) {
            // just leave initialHosts empty
            _logger.write(Heartbeat__Monitor.this.toString(), Logger.DEBUG, "No initial list of hosts set, defaulting to none.");
        }
        
        // parse through the initial hosts adding them
        StringTokenizer st = new StringTokenizer(initialHosts, ";");
        while (st.hasMoreTokens()) {
            String source = st.nextToken();
            // check if they already exist, don't want to add them twice
            if (!_hosts.containsKey(source)) {
                synchronized(this) {
                    _hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
                }
            }
            HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
            // set a "fake" heartbeat
            lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
        }
    }

//---ACCESSOR/MUTATOR METHODS---
    
    /**
     * Returns a reference to the Queue we're getting data
     * from. This is specific to this monitor.
     *
     * @return a reference to a Queue to get data from
     */
    protected Queue getQueue() {
        return MonitorManager.getInstance().getHeartbeatQueue();
    }
    
//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = "Heartbeat";
    
    /**
     * A reference to the configuration proxy in use
     */
    private ConfigurationProxy _cp = ConfigurationProxy.getInstance();
    
    /**
     * A HashMap of hosts, with associated HeartbeatHolder's.
     */
    private HashMap _hosts = new HashMap();
    
    /**
     * A reference to the system logger.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();

//---STATIC ATTRIBUTES---

//---INNER CLASSES---
    
    /**
     * This inner class simply holding some information
     * about a specific host.
     */
    private class HeartbeatHolder {
        
        /**
         * Construct a new HeartbeatHolder.
         */
        public HeartbeatHolder(Register register) {
            _register = register;
        }
        
        /**
         * Set the time of the last heartbeat
         */
        public void setLastHeartbeat(long lastHeartbeat) {
            _lastHeartbeat = lastHeartbeat;
        }
        
        /**
         * Get the time of the last heartbeat
         */
        public long getLastHeartbeat() {
            return _lastHeartbeat;
        }
        
        /**
         * Get the Register
         */
        public Register getRegister() {
            return _register;
        }
        
        /**
         * last heartbeat time
         */
        private long _lastHeartbeat;
        
        /**
         * register ref
         */
        private Register _register;
    }
    
    /**
     * This worker thread just checks all the hosts and then
     * waits a period of time before doing it again. It sends
     * Alerts as required.
     */
    private class HeartbeatWorker extends Thread {
        
        /**
         * The main run method of this worker thread. It simply
         * checks through all the hosts it has stored, running
         * the analyseHB method on each. It then removes any
         * that have passed a FINAL, and waits a (configured)
         * length of time before doing it again.
         */
        public void run() {
            ConfigurationProxy cp = ConfigurationProxy.getInstance();
            while(true) {
                // this cycle period of this monitor's checks
                int checkPeriod = 0;
                try {
                    checkPeriod = Integer.parseInt(cp.getProperty(_name, "Monitor.Heartbeat.checkPeriod"));
                } catch (PropertyNotFoundException e) {
                    checkPeriod = DEFAULT_CHECK_PERIOD;
                    _logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
                } catch (NumberFormatException e) {
                    checkPeriod = DEFAULT_CHECK_PERIOD;
                    _logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
                }
                
                synchronized(Heartbeat__Monitor.this) {
                    // perform the checks (use HB hash, although they *should* be the same)
                    Iterator i = _hosts.keySet().iterator();
                    while(i.hasNext()) {
                        // get host
                        String source = (String) i.next();
                        // check it
                        boolean remove = analyseHB(source);
                        // remove it if it's passed a FINAL
                        if(remove) {
                            i.remove();
                        }
                    }
                }
                
                // wait a while
                try {Thread.sleep(checkPeriod * 1000);} catch (InterruptedException e) {}
            }
        }
        
        /**
         * Analyses a given host's state, and if need be generates
         * a relevant Alert. Note that it also checks if the last
         * alert sent is FINAL, in which case it returns true to
         * indicate removal of this host.
         *
         * @param source the host to check
         * @return whether this host can be deleted
         */
        private boolean analyseHB(String source) {
            ConfigurationProxy cp = ConfigurationProxy.getInstance();
            HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
            Register reg = hbHolder.getRegister();
            
            // get host's HB interval (seconds)
            // this should always exist, thus we set to 0
            int hostHBinterval = 0;
            try {
                hostHBinterval = Integer.parseInt(cp.getProperty("Host."+source, "Host.TCPUpdateTime"));
            } catch (PropertyNotFoundException e) {
                hostHBinterval = 0;
                _logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
            } catch (NumberFormatException e) {
                hostHBinterval = 0;
                _logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous TCPUpdateTime value in configuration using default of " + hostHBinterval + " seconds");
            }
            
            // get host's last HB time (seconds)
            long lastHeartbeat = hbHolder.getLastHeartbeat();
            // time since last heartbeat (seconds)
            long timeSinceLastHB = (System.currentTimeMillis()/1000) - lastHeartbeat;
            // time since (or until if negative) the expected heartbeat
            long timeSinceExpectedHB = timeSinceLastHB - (long) hostHBinterval;
            
            // best do a check in case the expected heartbeat is in the future
            if(timeSinceExpectedHB < 0) {
                timeSinceExpectedHB = 0;
            }
            
            // find out the threshold level we're at
            int newThreshold = checkAttributeThreshold(timeSinceExpectedHB, reg);
            
            // process the alert
            Heartbeat__Monitor.this.processAlert(newThreshold, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
            
            if(reg.getLastAlertLevel() == Alert.alertFINAL) {
                return true;
            }
            return false;
        }
    }
}
Revision:	1.22
Committed:	Sat May 18 18:16:00 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.21:	+22 -3 lines
Log Message:	i-scream is now licensed under the GPL. I've added the GPL headers to every source file, and put a full copy of the license in the appropriate places. I think I've covered everything. This is going to be a mad commit ;)
#	Content
1	/*
2	* i-scream central monitoring system
3	* Copyright (C) 2000-2002 i-scream
4	*
5	* This program is free software; you can redistribute it and/or
6	* modify it under the terms of the GNU General Public License
7	* as published by the Free Software Foundation; either version 2
8	* of the License, or (at your option) any later version.
9	*
10	* This program is distributed in the hope that it will be useful,
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	* GNU General Public License for more details.
14	*
15	* You should have received a copy of the GNU General Public License
16	* along with this program; if not, write to the Free Software
17	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18	*/
19
20	//---PACKAGE DECLARATION---
21	package uk.org.iscream.cms.server.client.monitors;
22
23	//---IMPORTS---
24	import java.util.HashMap;
25	import java.util.Iterator;
26	import java.util.StringTokenizer;
27	import uk.org.iscream.cms.server.client.*;
28	import uk.org.iscream.cms.server.core.*;
29	import uk.org.iscream.cms.server.util.*;
30	import uk.org.iscream.cms.server.componentmanager.*;
31
32	/**
33	* This Monitor watches heartbeats.
34	* It generates an alert when a heartbeat that is expected
35	* does not arrive. Unlike all the other monitors, this one
36	* is driven by an event not occuring, rather than an
37	* event occuring. This means it must be actively checking
38	* for missing heartbeat's, and thus has an extra inner class
39	* thread.
40	*
41	* @author $Author: tdb $
42	* @version $Id: Heartbeat__Monitor.java,v 1.21 2001/11/26 12:56:33 tdb Exp $
43	*/
44	public class Heartbeat__Monitor extends MonitorSkeleton {
45
46	//---FINAL ATTRIBUTES---
47
48	/**
49	* The current CVS revision of this class
50	*/
51	public final String REVISION = "$Revision: 1.21 $";
52
53	/**
54	* A description of this monitor
55	*/
56	public final String DESC = "Monitors Heartbeats.";
57
58	/**
59	* The default (used if not configured) period at
60	* which to check for old heartbeats. (in seconds)
61	*/
62	public final int DEFAULT_CHECK_PERIOD = 60;
63
64	//---STATIC METHODS---
65
66	//---CONSTRUCTORS---
67
68	/**
69	* Constructs a new Heartbeat monitor, and starts off
70	* the worker thread.
71	*/
72	public Heartbeat__Monitor() {
73	super();
74	createInitialHosts();
75	new HeartbeatWorker().start();
76	}
77
78	//---PUBLIC METHODS---
79
80	/**
81	* Analyse a packet of data. In this case, this will just
82	* register the fact that a heartbeat has arrived.
83	*
84	* @param packet The packet of data to analyse
85	*/
86	public void analysePacket(XMLPacket packet) {
87	String source = packet.getParam("packet.attributes.machine_name");
88	if (!_hosts.containsKey(source)) {
89	synchronized(this) {
90	_hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
91	}
92	}
93	HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
94	lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
95	}
96
97	/**
98	* Overrides the {@link java.lang.Object#toString() Object.toString()}
99	* method to provide clean logging (every class should have this).
100	*
101	* This uses the uk.org.iscream.cms.server.util.NameFormat class
102	* to format the toString()
103	*
104	* @return the name of this class and its CVS revision
105	*/
106	public String toString() {
107	return FormatName.getName(
108	_name,
109	getClass().getName(),
110	REVISION);
111	}
112
113	/**
114	* return the String representation of what the monitor does
115	*/
116	public String getDescription(){
117	return DESC;
118	}
119
120	//---PRIVATE METHODS---
121
122	/**
123	* Checks whether the time since the last heartbeat
124	* is beyond the threshold(s).
125	*
126	* @param timeSinceLastHB a long time since the last heartbeat arrived
127	* @param reg the Register for this host
128	* @return the level which has been breached, if any
129	*/
130	private int checkAttributeThreshold(long timeSinceLastHB, Register reg) {
131	for(int thresholdLevel = Alert.thresholdLevels.length - 1; thresholdLevel >= 0; thresholdLevel--) {
132	if (reg.getThreshold(thresholdLevel) != -1.0) {
133	if (((long) reg.getThreshold(thresholdLevel)) < timeSinceLastHB) {
134	return thresholdLevel;
135	}
136	}
137	}
138	return Alert.thresholdNORMAL;
139	}
140
141	/**
142	* Gets an initial list of hosts from the config
143	* and adds a fake set of heartbeats for them.
144	* If the hosts don't respond within the timeout
145	* period an alert will be raised.
146	*
147	* The effect of this is to allow us to know about
148	* hosts which weren't on when we started up, and
149	* will thus never have generated a heartbeat - yet
150	* will still want to know they're not responding.
151	*/
152	private void createInitialHosts() {
153	// get the initial list of hosts from the config
154	String initialHosts = "";
155	try {
156	initialHosts = _cp.getProperty(_name, "Monitor.Heartbeat.initialHosts");
157	} catch (PropertyNotFoundException e) {
158	// just leave initialHosts empty
159	_logger.write(Heartbeat__Monitor.this.toString(), Logger.DEBUG, "No initial list of hosts set, defaulting to none.");
160	}
161
162	// parse through the initial hosts adding them
163	StringTokenizer st = new StringTokenizer(initialHosts, ";");
164	while (st.hasMoreTokens()) {
165	String source = st.nextToken();
166	// check if they already exist, don't want to add them twice
167	if (!_hosts.containsKey(source)) {
168	synchronized(this) {
169	_hosts.put(source, new HeartbeatHolder(new Register(source, _name)));
170	}
171	}
172	HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
173	// set a "fake" heartbeat
174	lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
175	}
176	}
177
178	//---ACCESSOR/MUTATOR METHODS---
179
180	/**
181	* Returns a reference to the Queue we're getting data
182	* from. This is specific to this monitor.
183	*
184	* @return a reference to a Queue to get data from
185	*/
186	protected Queue getQueue() {
187	return MonitorManager.getInstance().getHeartbeatQueue();
188	}
189
190	//---ATTRIBUTES---
191
192	/**
193	* This is the friendly identifier of the
194	* component this class is running in.
195	* eg, a Filter may be called "filter1",
196	* If this class does not have an owning
197	* component, a name from the configuration
198	* can be placed here. This name could also
199	* be changed to null for utility classes.
200	*/
201	private String _name = "Heartbeat";
202
203	/**
204	* A reference to the configuration proxy in use
205	*/
206	private ConfigurationProxy _cp = ConfigurationProxy.getInstance();
207
208	/**
209	* A HashMap of hosts, with associated HeartbeatHolder's.
210	*/
211	private HashMap _hosts = new HashMap();
212
213	/**
214	* A reference to the system logger.
215	*/
216	private Logger _logger = ReferenceManager.getInstance().getLogger();
217
218	//---STATIC ATTRIBUTES---
219
220	//---INNER CLASSES---
221
222	/**
223	* This inner class simply holding some information
224	* about a specific host.
225	*/
226	private class HeartbeatHolder {
227
228	/**
229	* Construct a new HeartbeatHolder.
230	*/
231	public HeartbeatHolder(Register register) {
232	_register = register;
233	}
234
235	/**
236	* Set the time of the last heartbeat
237	*/
238	public void setLastHeartbeat(long lastHeartbeat) {
239	_lastHeartbeat = lastHeartbeat;
240	}
241
242	/**
243	* Get the time of the last heartbeat
244	*/
245	public long getLastHeartbeat() {
246	return _lastHeartbeat;
247	}
248
249	/**
250	* Get the Register
251	*/
252	public Register getRegister() {
253	return _register;
254	}
255
256	/**
257	* last heartbeat time
258	*/
259	private long _lastHeartbeat;
260
261	/**
262	* register ref
263	*/
264	private Register _register;
265	}
266
267	/**
268	* This worker thread just checks all the hosts and then
269	* waits a period of time before doing it again. It sends
270	* Alerts as required.
271	*/
272	private class HeartbeatWorker extends Thread {
273
274	/**
275	* The main run method of this worker thread. It simply
276	* checks through all the hosts it has stored, running
277	* the analyseHB method on each. It then removes any
278	* that have passed a FINAL, and waits a (configured)
279	* length of time before doing it again.
280	*/
281	public void run() {
282	ConfigurationProxy cp = ConfigurationProxy.getInstance();
283	while(true) {
284	// this cycle period of this monitor's checks
285	int checkPeriod = 0;
286	try {
287	checkPeriod = Integer.parseInt(cp.getProperty(_name, "Monitor.Heartbeat.checkPeriod"));
288	} catch (PropertyNotFoundException e) {
289	checkPeriod = DEFAULT_CHECK_PERIOD;
290	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
291	} catch (NumberFormatException e) {
292	checkPeriod = DEFAULT_CHECK_PERIOD;
293	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
294	}
295
296	synchronized(Heartbeat__Monitor.this) {
297	// perform the checks (use HB hash, although they should be the same)
298	Iterator i = _hosts.keySet().iterator();
299	while(i.hasNext()) {
300	// get host
301	String source = (String) i.next();
302	// check it
303	boolean remove = analyseHB(source);
304	// remove it if it's passed a FINAL
305	if(remove) {
306	i.remove();
307	}
308	}
309	}
310
311	// wait a while
312	try {Thread.sleep(checkPeriod * 1000);} catch (InterruptedException e) {}
313	}
314	}
315
316	/**
317	* Analyses a given host's state, and if need be generates
318	* a relevant Alert. Note that it also checks if the last
319	* alert sent is FINAL, in which case it returns true to
320	* indicate removal of this host.
321	*
322	* @param source the host to check
323	* @return whether this host can be deleted
324	*/
325	private boolean analyseHB(String source) {
326	ConfigurationProxy cp = ConfigurationProxy.getInstance();
327	HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
328	Register reg = hbHolder.getRegister();
329
330	// get host's HB interval (seconds)
331	// this should always exist, thus we set to 0
332	int hostHBinterval = 0;
333	try {
334	hostHBinterval = Integer.parseInt(cp.getProperty("Host."+source, "Host.TCPUpdateTime"));
335	} catch (PropertyNotFoundException e) {
336	hostHBinterval = 0;
337	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
338	} catch (NumberFormatException e) {
339	hostHBinterval = 0;
340	_logger.write(Heartbeat__Monitor.this.toString(), Logger.WARNING, "Erronous TCPUpdateTime value in configuration using default of " + hostHBinterval + " seconds");
341	}
342
343	// get host's last HB time (seconds)
344	long lastHeartbeat = hbHolder.getLastHeartbeat();
345	// time since last heartbeat (seconds)
346	long timeSinceLastHB = (System.currentTimeMillis()/1000) - lastHeartbeat;
347	// time since (or until if negative) the expected heartbeat
348	long timeSinceExpectedHB = timeSinceLastHB - (long) hostHBinterval;
349
350	// best do a check in case the expected heartbeat is in the future
351	if(timeSinceExpectedHB < 0) {
352	timeSinceExpectedHB = 0;
353	}
354
355	// find out the threshold level we're at
356	int newThreshold = checkAttributeThreshold(timeSinceExpectedHB, reg);
357
358	// process the alert
359	Heartbeat__Monitor.this.processAlert(newThreshold, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
360
361	if(reg.getLastAlertLevel() == Alert.alertFINAL) {
362	return true;
363	}
364	return false;
365	}
366	}
367	}