client/monitors/Heartbeat__Monitor.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.client.monitors;

//---IMPORTS---
import java.util.HashMap;
import java.util.Iterator;
import uk.ac.ukc.iscream.client.*;
import uk.ac.ukc.iscream.core.*;
import uk.ac.ukc.iscream.util.*;
import uk.ac.ukc.iscream.componentmanager.*;

/**
 * This Monitor watches heartbeats
 *
 * @author  $Author: tdb1 $
 * @version $Id: Heartbeat__Monitor.java,v 1.8 2001/03/07 01:22:47 tdb1 Exp $
 */
public class Heartbeat__Monitor extends MonitorSkeleton implements Runnable {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.8 $";
    
    public final String DESC = "Monitors Heartbeats.";
    
    public final int DEFAULT_CHECK_PERIOD = 60;
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    public Heartbeat__Monitor() {
        new Thread(this).start();
    }

//---PUBLIC METHODS---
    
    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(toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
            } catch (NumberFormatException e) {
                checkPeriod = DEFAULT_CHECK_PERIOD;
                _logger.write(toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
            }
            
            synchronized(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);
                    if(remove) {
                        i.remove();
                    }
                }
            }
            
            // wait a while
            try {Thread.sleep(checkPeriod * 1000);} catch (InterruptedException e) {}
        }
    }
    
    public synchronized void analysePacket(XMLPacket packet) {
        if (packet.getParam("packet.attributes.type").equals("heartbeat")) {
            String source = packet.getParam("packet.attributes.machine_name");
            if (!_hosts.containsKey(source)) {
                HashMap registerHash = new HashMap();
                registerHash.put(source, new Register(source, _name, 1));
                _hosts.put(source, new HeartbeatHolder(registerHash));
            }
            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.ac.ukc.iscream.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---

    private boolean analyseHB(String source) {
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
        Register reg = (Register) ((HashMap) hbHolder.getRegisterHash()).get(source);
        
        // 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(toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
        } catch (NumberFormatException e) {
            hostHBinterval = 0;
            _logger.write(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
        processAlert(newThreshold, 0, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
        
        if(reg.getLastAlertLevel(0) == Alert.alertFINAL) {
            return true;
        }
        return false;
    }
    
    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;
    }

//---ACCESSOR/MUTATOR METHODS---

//---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();

    private HashMap _hosts = new HashMap();

//---STATIC ATTRIBUTES---

//---INNER CLASSES---

    private class HeartbeatHolder {
        
        public HeartbeatHolder(HashMap registerHash) {
            _registerHash = registerHash;
        }
        
        public void setLastHeartbeat(long lastHeartbeat) {
            _lastHeartbeat = lastHeartbeat;
        }
        
        public long getLastHeartbeat() {
            return _lastHeartbeat;
        }
        
        public HashMap getRegisterHash() {
            return _registerHash;
        }
        
        private long _lastHeartbeat;
        private HashMap _registerHash;
    }   

}
Revision:	1.9
Committed:	Wed Mar 7 17:18:48 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.8:	+14 -12 lines
Log Message:	Added some synchronization. We managed to get a ConcurrentModificationException in the server :)
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2			package uk.ac.ukc.iscream.client.monitors;
3
4			//---IMPORTS---
5			import java.util.HashMap;
6			import java.util.Iterator;
7			import uk.ac.ukc.iscream.client.*;
8			import uk.ac.ukc.iscream.core.*;
9			import uk.ac.ukc.iscream.util.*;
10			import uk.ac.ukc.iscream.componentmanager.*;
11
12			/**
13			* This Monitor watches heartbeats
14			*
15	tdb	1.7	* @author $Author: tdb1 $
16	tdb	1.9	* @version $Id: Heartbeat__Monitor.java,v 1.8 2001/03/07 01:22:47 tdb1 Exp $
17	tdb	1.1	*/
18	tdb	1.7	public class Heartbeat__Monitor extends MonitorSkeleton implements Runnable {
19	tdb	1.1
20			//---FINAL ATTRIBUTES---
21
22			/**
23			* The current CVS revision of this class
24			*/
25	tdb	1.9	public final String REVISION = "$Revision: 1.8 $";
26	tdb	1.1
27			public final String DESC = "Monitors Heartbeats.";
28
29	tdb	1.3	public final int DEFAULT_CHECK_PERIOD = 60;
30
31	tdb	1.1	//---STATIC METHODS---
32
33			//---CONSTRUCTORS---
34
35	tdb	1.2	public Heartbeat__Monitor() {
36	tdb	1.3	new Thread(this).start();
37	tdb	1.2	}
38
39	tdb	1.1	//---PUBLIC METHODS---
40
41			public void run() {
42			ConfigurationProxy cp = ConfigurationProxy.getInstance();
43			while(true) {
44	tdb	1.3	// this cycle period of this monitor's checks
45			int checkPeriod = 0;
46			try {
47			checkPeriod = Integer.parseInt(cp.getProperty(_name, "Monitor.Heartbeat.checkPeriod"));
48			} catch (PropertyNotFoundException e) {
49			checkPeriod = DEFAULT_CHECK_PERIOD;
50			_logger.write(toString(), Logger.WARNING, "Monitor.Heartbeat.checkPeriod value unavailable using default of " + checkPeriod + " seconds");
51			} catch (NumberFormatException e) {
52			checkPeriod = DEFAULT_CHECK_PERIOD;
53			_logger.write(toString(), Logger.WARNING, "Erronous Monitor.Heartbeat.checkPeriod value in configuration using default of " + checkPeriod + " seconds");
54			}
55	tdb	1.1
56	tdb	1.9	synchronized(this) {
57			// perform the checks (use HB hash, although they should be the same)
58			Iterator i = _hosts.keySet().iterator();
59			while(i.hasNext()) {
60			// get host
61			String source = (String) i.next();
62			// check it
63			boolean remove = analyseHB(source);
64			if(remove) {
65			i.remove();
66			}
67	tdb	1.6	}
68	tdb	1.1	}
69
70			// wait a while
71			try {Thread.sleep(checkPeriod * 1000);} catch (InterruptedException e) {}
72			}
73			}
74
75	tdb	1.9	public synchronized void analysePacket(XMLPacket packet) {
76	tdb	1.1	if (packet.getParam("packet.attributes.type").equals("heartbeat")) {
77			String source = packet.getParam("packet.attributes.machine_name");
78	tdb	1.6	if (!_hosts.containsKey(source)) {
79			HashMap registerHash = new HashMap();
80			registerHash.put(source, new Register(source, _name, 1));
81			_hosts.put(source, new HeartbeatHolder(registerHash));
82	tdb	1.1	}
83	tdb	1.6	HeartbeatHolder lastHeartbeat = (HeartbeatHolder) _hosts.get(source);
84	tdb	1.2	lastHeartbeat.setLastHeartbeat(System.currentTimeMillis()/1000);
85	tdb	1.1	}
86			}
87
88			/**
89			* Overrides the {@link java.lang.Object#toString() Object.toString()}
90			* method to provide clean logging (every class should have this).
91			*
92			* This uses the uk.ac.ukc.iscream.util.NameFormat class
93			* to format the toString()
94			*
95			* @return the name of this class and its CVS revision
96			*/
97			public String toString() {
98			return FormatName.getName(
99			_name,
100			getClass().getName(),
101			REVISION);
102			}
103
104			/**
105			* return the String representation of what the monitor does
106			*/
107			public String getDescription(){
108			return DESC;
109			}
110
111			//---PRIVATE METHODS---
112	tdb	1.7
113			private boolean analyseHB(String source) {
114			ConfigurationProxy cp = ConfigurationProxy.getInstance();
115			HeartbeatHolder hbHolder = (HeartbeatHolder) _hosts.get(source);
116			Register reg = (Register) ((HashMap) hbHolder.getRegisterHash()).get(source);
117
118			// get host's HB interval (seconds)
119			// this should always exist, thus we set to 0
120			int hostHBinterval = 0;
121			try {
122			hostHBinterval = Integer.parseInt(cp.getProperty("Host."+source, "Host.TCPUpdateTime"));
123			} catch (PropertyNotFoundException e) {
124			hostHBinterval = 0;
125			_logger.write(toString(), Logger.WARNING, "TCPUpdateTime value unavailable using default of " + hostHBinterval + " seconds");
126			} catch (NumberFormatException e) {
127			hostHBinterval = 0;
128			_logger.write(toString(), Logger.WARNING, "Erronous TCPUpdateTime value in configuration using default of " + hostHBinterval + " seconds");
129			}
130
131			// get host's last HB time (seconds)
132			long lastHeartbeat = hbHolder.getLastHeartbeat();
133			// time since last heartbeat (seconds)
134			long timeSinceLastHB = (System.currentTimeMillis()/1000) - lastHeartbeat;
135	tdb	1.8	// time since (or until if negative) the expected heartbeat
136			long timeSinceExpectedHB = timeSinceLastHB + (long) hostHBinterval;
137
138			// best do a check in case the expected heartbeat is in the future
139			if(timeSinceExpectedHB < 0) {
140			timeSinceExpectedHB = 0;
141			}
142	tdb	1.7
143			// find out the threshold level we're at
144	tdb	1.8	int newThreshold = checkAttributeThreshold(timeSinceExpectedHB, reg);
145	tdb	1.7
146			// process the alert
147	tdb	1.8	processAlert(newThreshold, 0, "Heartbeat", reg, source, String.valueOf(timeSinceExpectedHB));
148	tdb	1.7
149			if(reg.getLastAlertLevel(0) == Alert.alertFINAL) {
150			return true;
151			}
152			return false;
153			}
154	tdb	1.1
155	tdb	1.2	private int checkAttributeThreshold(long timeSinceLastHB, Register reg) {
156	tdb	1.1	for(int thresholdLevel = Alert.thresholdLevels.length - 1; thresholdLevel >= 0; thresholdLevel--) {
157			if (reg.getThreshold(thresholdLevel) != -1.0) {
158	tdb	1.2	if (((long) reg.getThreshold(thresholdLevel)) < timeSinceLastHB) {
159	tdb	1.1	return thresholdLevel;
160			}
161			}
162			}
163	tdb	1.7	return Alert.thresholdNORMAL;
164	tdb	1.1	}
165
166			//---ACCESSOR/MUTATOR METHODS---
167
168			//---ATTRIBUTES---
169
170			/**
171			* This is the friendly identifier of the
172			* component this class is running in.
173			* eg, a Filter may be called "filter1",
174			* If this class does not have an owning
175			* component, a name from the configuration
176			* can be placed here. This name could also
177			* be changed to null for utility classes.
178			*/
179			private String _name = "Heartbeat";
180
181			/**
182			* A reference to the configuration proxy in use
183			*/
184			private ConfigurationProxy _cp = ConfigurationProxy.getInstance();
185
186	tdb	1.6	private HashMap _hosts = new HashMap();
187	tdb	1.1
188			//---STATIC ATTRIBUTES---
189
190			//---INNER CLASSES---
191
192			private class HeartbeatHolder {
193
194	tdb	1.6	public HeartbeatHolder(HashMap registerHash) {
195			_registerHash = registerHash;
196			}
197
198	tdb	1.2	public void setLastHeartbeat(long lastHeartbeat) {
199	tdb	1.1	_lastHeartbeat = lastHeartbeat;
200			}
201
202	tdb	1.2	public long getLastHeartbeat() {
203	tdb	1.1	return _lastHeartbeat;
204			}
205
206	tdb	1.6	public HashMap getRegisterHash() {
207			return _registerHash;
208			}
209
210	tdb	1.2	private long _lastHeartbeat;
211	tdb	1.6	private HashMap _registerHash;
212	tdb	1.1	}
213
214			}