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1
7 package org.jboss.web.loadbalancer;
8
9 import java.io.IOException  ;
10 import java.io.InputStream ;
11 import java.io.OutputStream ;
12 import java.util.Enumeration ;
13 import java.util.HashSet ;
14 import java.util.Set ;
15 import javax.management.ObjectName ;
16 import javax.servlet.ServletException ;
17 import javax.servlet.http.Cookie ;
18
19 import org.apache.commons.httpclient.Header;
20 import org.apache.commons.httpclient.HttpClient;
21 import org.apache.commons.httpclient.HttpMethod;
22 import org.apache.commons.httpclient.HttpState;
23 import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
24 import org.apache.commons.httpclient.cookie.CookiePolicy;
25 import org.apache.commons.httpclient.methods.DeleteMethod;
26 import org.apache.commons.httpclient.methods.GetMethod;
27 import org.apache.commons.httpclient.methods.HeadMethod;
28 import org.apache.commons.httpclient.methods.OptionsMethod;
29 import org.apache.commons.httpclient.methods.PostMethod;
30 import org.apache.commons.httpclient.methods.PutMethod;
31 import org.jboss.logging.Logger;
32 import org.jboss.web.loadbalancer.scheduler.NoHostAvailableException;
33 import org.jboss.web.loadbalancer.scheduler.SchedulerMBean;
34 import org.jboss.web.loadbalancer.util.Constants;
35 import org.jboss.web.loadbalancer.util.Request;
36
37
45 public class Loadbalancer
46 implements LoadbalancerMBean
47 {
48 protected static Logger log = Logger.getLogger(Loadbalancer.class);
49
50 protected MultiThreadedHttpConnectionManager connectionManager;
52
53 protected static Set ignorableHeader = new HashSet ();
55
56 protected int connectionTimeout = 20000;
57
58 protected SchedulerMBean scheduler;
59 protected ObjectName schedulerName;
60
61 protected static final int MAX_RETRIES = 5;
62
63 static
64 {
65 ignorableHeader.add("content-length");
70 ignorableHeader.add("server");
71 ignorableHeader.add("transfer-encoding");
72 ignorableHeader.add("cookie");
73 ignorableHeader.add("set-cookie");
74 ignorableHeader.add("host");
75 }
76
77 protected Loadbalancer(SchedulerMBean scheduler, int timeout) throws ServletException
78 {
79 this.scheduler=scheduler;
80 this.connectionTimeout=timeout;
81
82 connectionManager = new MultiThreadedHttpConnectionManager();
83
84 connectionManager.setMaxConnectionsPerHost(Integer.MAX_VALUE);
86 connectionManager.setMaxTotalConnections(Integer.MAX_VALUE);
87 }
88
89
97 protected void createMethod(Request schedRequest) throws NoHostAvailableException
98 {
99 String url = null;
100 HttpMethod method = null;
101
102 scheduler.getHost(schedRequest);
103
104 url = schedRequest.getHost().getUrl().toExternalForm();
106
107 String path = url.substring(0, url.length() - 1) + schedRequest.getRequest().getRequestURI();
108
109 switch (schedRequest.getRequestMethod())
110 {
111 case Constants.HTTP_METHOD_GET:
112 method = new GetMethod(path);
113 break;
114 case Constants.HTTP_METHOD_POST:
115 method = new PostMethod(path);
116 break;
117 case Constants.HTTP_METHOD_DELETE:
118 method = new DeleteMethod(path);
119 break;
120 case Constants.HTTP_METHOD_HEAD:
121 method = new HeadMethod(path);
122 break;
123 case Constants.HTTP_METHOD_OPTIONS:
124 method = new OptionsMethod(path);
125 break;
126 case Constants.HTTP_METHOD_PUT:
127 method = new PutMethod(path);
128 break;
129 default:
130 throw new IllegalStateException ("Unknown Request Method " +
131 schedRequest.getRequest().getMethod());
132 }
133 schedRequest.setMethod(method);
134 }
135
136
142 protected void addRequestData(Request schedRequest)
143 {
144 HttpMethod method=schedRequest.getMethod();
145
146 if (schedRequest.getRequest().getQueryString() != null)
148 {
149 method.setQueryString(schedRequest.getRequest().getQueryString());
150 }
151
152 if (method instanceof PostMethod)
154 {
155 PostMethod postMethod = (PostMethod) method;
156
157 Enumeration paramNames = schedRequest.getRequest().getParameterNames();
158 while (paramNames.hasMoreElements())
159 {
160 String paramName = (String ) paramNames.nextElement();
161 postMethod.addParameter(paramName, schedRequest.getRequest().getParameter(paramName));
162 }
163 }
164 }
165
166
173 protected void prepareServerRequest(Request schedRequest)
174 {
175 HttpMethod method=schedRequest.getMethod();
176
177 HttpClient client = new HttpClient(connectionManager);
179 client.setStrictMode(false);
180 client.setTimeout(connectionTimeout);
181 client.setConnectionTimeout(connectionTimeout);
182 client.getState().setCookiePolicy(CookiePolicy.COMPATIBILITY);
183
184 method.setFollowRedirects(false);
186 method.setDoAuthentication(false);
187
188 Enumeration reqHeaders = schedRequest.getRequest().getHeaderNames();
190 while (reqHeaders.hasMoreElements())
191 {
192 String headerName = (String ) reqHeaders.nextElement();
193 String headerValue = schedRequest.getRequest().getHeader(headerName);
194
195 if (!ignorableHeader.contains(headerName.toLowerCase()))
196 {
197 method.setRequestHeader(headerName, headerValue);
198 }
199 }
200
201 Cookie [] cookies = schedRequest.getRequest().getCookies();
203 HttpState state = client.getState();
204 for (int i = 0; cookies != null && i < cookies.length; ++i)
205 {
206 Cookie cookie = cookies[i];
207
208 org.apache.commons.httpclient.Cookie reqCookie =
209 new org.apache.commons.httpclient.Cookie();
210
211 reqCookie.setName(cookie.getName());
212 reqCookie.setValue(cookie.getValue());
213
214 if (cookie.getPath() != null)
216 {
217 reqCookie.setPath(cookie.getPath());
218 }
219 else
220 {
221 reqCookie.setPath("/");
222 }
223
224 reqCookie.setSecure(cookie.getSecure());
225
226 reqCookie.setDomain(method.getHostConfiguration().getHost());
227 state.addCookie(reqCookie);
228 }
229 schedRequest.setClient(client);
230 }
231
232
240 protected void handleRequest(Request schedRequest) throws ServletException , IOException
241 {
242
243 boolean reschedule = false;
244
245 try
246 {
247 prepareServerRequest(schedRequest);
249
250 int tries = 0;
251 while (tries < MAX_RETRIES)
253 {
254 try
255 {
256 long t1=System.currentTimeMillis();
258 schedRequest.getHost().incCurrentConnections();
259
260 schedRequest.getClient().executeMethod(schedRequest.getMethod());
261
262 schedRequest.getHost().decCurrentConnections();
263
264 long t2=System.currentTimeMillis();
265 schedRequest.getHost().addRequest((int)(t2-t1));
266 break;
267 }
268 catch (IOException ex)
269 {
270 try
271 {
272 schedRequest.getHost().decCurrentConnections();
273 schedRequest.getMethod().recycle();
274 }
275 catch (Exception e)
276 {
277 }
279
280 tries++;
281 log.info("Connect retry no. " + tries, ex);
282 }
283 }
284 if (tries < MAX_RETRIES)
286 {
287 parseServerResponse(schedRequest);
289 }
290 else
291 {
292 log.error("Max retries reached - giving up. Host will be marked down");
293
294 schedRequest.getHost().markNodeDown();
296 reschedule = true;
297 }
298 }
299 finally
300 {
301 try
302 {
303 schedRequest.getMethod().recycle();
304 }
305 catch (Exception e)
306 {
307 }
309 }
310 if (reschedule)
312 {
313 String redirectURI = schedRequest.getRequest().getRequestURI();
314
315 if (schedRequest.getRequest().getQueryString() != null)
316 {
317 redirectURI += "?" + schedRequest.getRequest().getQueryString();
318 }
319 schedRequest.getResponse().sendRedirect(redirectURI);
321 }
322 }
323
324
333 protected void parseServerResponse(Request schedRequest) throws ServletException , IOException
334 {
335 schedRequest.getResponse().setStatus(schedRequest.getMethod().getStatusCode());
336
337 org.apache.commons.httpclient.Cookie[] respCookies =
339 schedRequest.getClient().getState().getCookies();
340
341 for (int i = 0; i < respCookies.length; ++i)
342 {
343 Cookie cookie =
344 new Cookie (respCookies[i].getName(), respCookies[i].getValue());
345
346 if (respCookies[i].getPath() != null)
347 {
348 cookie.setPath(respCookies[i].getPath());
349 }
350 schedRequest.getResponse().addCookie(cookie);
351 }
352
353 Header[] header = schedRequest.getMethod().getResponseHeaders();
355
356 for (int i = 0; i < header.length; ++i)
357 {
358 if (!ignorableHeader.contains(header[i].getName().toLowerCase()))
359 {
360 schedRequest.getResponse().setHeader(header[i].getName(), header[i].getValue());
361 }
362 }
363
364 copyServerResponse(schedRequest);
365 }
366
367
373 protected void copyServerResponse(Request schedRequest) throws IOException
374 {
375
376 InputStream bodyStream = schedRequest.getMethod().getResponseBodyAsStream();
377
378 if (bodyStream == null)
380 {
381 log.debug("No request body");
382 return;
383 }
384
385 byte[] buffer = new byte[2048];
386 int numBytes;
387 OutputStream out = schedRequest.getResponse().getOutputStream();
388
389 while ( (numBytes = bodyStream.read(buffer)) != -1)
391 {
392 out.write(buffer, 0, numBytes);
393 if (log.isDebugEnabled())
394 {
395 log.debug("Copied " + numBytes + " bytes");
396 }
397 }
398 }
399
400
405 public int getConnectionTimeout()
406 {
407 return this.connectionTimeout;
408 }
409
410
414 public void setConnectionTimeout(int newTimeout)
415 {
416 this.connectionTimeout = newTimeout;
417 }
418
419
423 public int getConnectionsInUse()
424 {
425 return connectionManager.getConnectionsInUse();
426 }
427 }
428 |
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