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1
7 package org.jboss.web.loadbalancer.monitor;
8
9 import java.io.IOException  ;
10 import java.util.ArrayList ;
11 import javax.management.ObjectName ;
12 import javax.servlet.http.HttpServletResponse ;
13
14 import org.apache.commons.httpclient.HttpClient;
15 import org.apache.commons.httpclient.HttpMethod;
16 import org.apache.commons.httpclient.methods.GetMethod;
17 import org.jboss.logging.Logger;
18 import org.jboss.mx.util.MBeanProxyExt;
19 import org.jboss.system.ServiceMBeanSupport;
20 import org.jboss.web.loadbalancer.scheduler.AbstractSchedulerMBean;
21 import org.jboss.web.loadbalancer.scheduler.Host;
22 import org.jboss.web.loadbalancer.util.Constants;
23
24
32 public abstract class AbstractMonitor
33 extends ServiceMBeanSupport
34 implements AbstractMonitorMBean, Runnable
35 {
36 protected boolean keepRunning = true;
37 protected long interval = 15000;
38 protected AbstractSchedulerMBean scheduler;
39 protected Logger log = Logger.getLogger(this.getClass());
40 protected ObjectName schedulerObjectName;
41 protected int timeout;
42 protected String path;
43 protected Thread monitorThread;
44
45 protected void startService() throws java.lang.Exception
46 {
47 scheduler = (AbstractSchedulerMBean)
49 MBeanProxyExt.create(AbstractSchedulerMBean.class,
50 schedulerObjectName);
51
52 this.setKeepRunning(true);
54 monitorThread = new Thread (this, "LoadbalancerMonitor");
55 monitorThread.setDaemon(true);
56 monitorThread.start();
57 }
58
59 protected void stopService() throws java.lang.Exception
60 {
61 this.setKeepRunning(false);
62 monitorThread.interrupt();
63 monitorThread.join();
64 }
65
66 protected void destroyService() throws java.lang.Exception
67 {
68 monitorThread = null;
69 }
70
71
76 protected abstract boolean checkHostStatus(HttpMethod method);
77
78 protected void monitorHosts()
79 {
80 ArrayList list = (ArrayList ) scheduler.getHostsDown().clone();
82
83 for (int i = 0; i < list.size(); ++i)
84 {
85 Host checkHost = (Host) list.get(i);
86
87 if (checkHost.getState()==Constants.STATE_NODE_FORCED_DOWN)
88 {
89 log.debug("Ignoring Host "+checkHost+" because it is forced down");
90 continue;
91 }
92
93 if (checkHost(checkHost))
94 {
95 log.info("Host " + checkHost + " is up again - adding to up list");
96 checkHost.markNodeUp();
97 }
98 }
99
100 list = (ArrayList ) scheduler.getHostsUp().clone();
102
103 for (int i = 0; i < list.size(); ++i)
104 {
105 Host checkHost = (Host) list.get(i);
106
107 if (checkHost.getState()==Constants.STATE_NODE_FORCED_DOWN)
108 {
109 log.debug("Ignoring Host "+checkHost+" because it is forced down");
110 continue;
111 }
112
113 if (!checkHost(checkHost))
114 {
115 log.error("Host " + checkHost + " is DOWN - adding to down list");
116 checkHost.markNodeDown();
117 }
118 }
119 }
120
121
126 protected boolean checkHost(Host host)
127 {
128 log.debug("Checking host " + host.getUrl() + path);
129
130 HttpClient httpClient = new HttpClient();
132 httpClient.setConnectionTimeout(this.getTimeout());
133 httpClient.setTimeout(this.getTimeout());
134
135 GetMethod method = new GetMethod(host.getUrl().toExternalForm() + path);
137 method.setFollowRedirects(false);
138 method.setDoAuthentication(false);
139
140 try
141 {
142 httpClient.executeMethod(method);
144
145 if (method.getStatusCode() >= HttpServletResponse.SC_BAD_REQUEST)
147 {
148 log.error("Server is up but sends error: " + method.getStatusLine());
149 return false;
150 }
151 return checkHostStatus(method);
152 }
153 catch (IOException ex)
154 {
155 log.error("Check for host " + host.getUrl() + " failed", ex);
156 return false;
157 }
158 finally
159 {
160 method.recycle();
161 }
162 }
163
164 public void run()
166 {
167 while (keepRunning)
168 {
169 try
170 {
171 Thread.sleep(interval);
172 monitorHosts();
173 }
174 catch (InterruptedException ex)
175 {
176 }
177 }
178 }
179
180 public boolean isKeepRunning()
181 {
182 return keepRunning;
183 }
184
185 public void setKeepRunning(boolean keepRunning)
186 {
187 this.keepRunning = keepRunning;
188 }
189
190
193 public void setPath(String path)
194 {
195 if (path.startsWith("/"))
196 {
197 this.path = path.substring(1);
198 }
199 else
200 {
201 this.path = path;
202 }
203 }
204
205
208 public String getPath()
209 {
210 return "/" + path;
211 }
212
213
216 public void setInterval(long interval)
217 {
218 this.interval = interval;
219 }
220
221
224 public long getInterval()
225 {
226 return interval;
227 }
228
229
232 public int getTimeout()
233 {
234 return timeout;
235 }
236
237
240 public void setTimeout(int timeout)
241 {
242 this.timeout = timeout;
243 }
244
245
248 public ObjectName getScheduler()
249 {
250 return schedulerObjectName;
251 }
252
253
256 public void setScheduler(ObjectName schedulerObjectName)
257 {
258 this.schedulerObjectName = schedulerObjectName;
259 }
260 } |
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