J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.jvmstat.monitor; |
| 27 | |
| 28 | import java.util.*; |
| 29 | import java.net.*; |
| 30 | import java.lang.reflect.*; |
| 31 | |
| 32 | import sun.jvmstat.monitor.event.HostListener; |
| 33 | |
| 34 | /** |
| 35 | * An abstraction for a host that contains instrumented Java Virtual |
| 36 | * Machines. The class provides abstract factory methods for creating |
| 37 | * concrete instances of this class and factory methods for creating |
| 38 | * {@link MonitoredVm} instances. Concrete implementations of this class |
| 39 | * provide methods for managing the communications protocols and provide |
| 40 | * for event notification. |
| 41 | * |
| 42 | * @author Brian Doherty |
| 43 | * @since 1.5 |
| 44 | * |
| 45 | * @see HostIdentifier |
| 46 | * @see VmIdentifier |
| 47 | * @see MonitoredVm |
| 48 | * @see HostListener |
| 49 | */ |
| 50 | public abstract class MonitoredHost { |
| 51 | private static Map<HostIdentifier, MonitoredHost> monitoredHosts = |
| 52 | new HashMap<HostIdentifier, MonitoredHost>(); |
| 53 | |
| 54 | /* |
| 55 | * The monitoring implementation override mechanism. The value of |
| 56 | * this property is used as the class name for the concrete MonitoredHost |
| 57 | * subclass that implements the monitoring APIs. Setting this property |
| 58 | * will cause the remaining override mechanisms to be ignored. When |
| 59 | * this mechanism is used, the HostIdentifier scheme name, which |
| 60 | * indicates the communications protocol, is not used to locate a |
| 61 | * the protocol specific package. However, the HostIdentifier is |
| 62 | * still passed to the corresponding single arg constructor. |
| 63 | * This property is not expected to be set in normal circumstances. |
| 64 | */ |
| 65 | private static final String IMPL_OVERRIDE_PROP_NAME = |
| 66 | "sun.jvmstat.monitor.MonitoredHost"; |
| 67 | |
| 68 | /* |
| 69 | * The monitoring package name override mechanism. The value |
| 70 | * the this property is used as base package name for the |
| 71 | * monitoring implementation package. This property is not |
| 72 | * expected to be set under normal circumstances. |
| 73 | */ |
| 74 | private static final String IMPL_PKG_PROP_NAME = |
| 75 | "sun.jvmstat.monitor.package"; |
| 76 | private static final String IMPL_PACKAGE = |
| 77 | System.getProperty(IMPL_PKG_PROP_NAME, "sun.jvmstat.perfdata"); |
| 78 | |
| 79 | /* |
| 80 | * The default optimized local protocol override mechanism. The value |
| 81 | * of this property is used to construct the default package name |
| 82 | * for the default optimized local protocol as follows: |
| 83 | * <IMPL_PACKAGE>.monitor.<LOCAL_PROTOCOL> |
| 84 | * This property is not expected to be set under normal circumstances. |
| 85 | */ |
| 86 | private static final String LOCAL_PROTOCOL_PROP_NAME = |
| 87 | "sun.jvmstat.monitor.local"; |
| 88 | private static final String LOCAL_PROTOCOL = |
| 89 | System.getProperty(LOCAL_PROTOCOL_PROP_NAME, "local"); |
| 90 | |
| 91 | /* |
| 92 | * The default remote protocol override mechanism. The value of |
| 93 | * this property is used to construct the default package name |
| 94 | * for the default remote protocol protocol as follows: |
| 95 | * <IMPL_PACKAGE>.monitor.protocol.<REMOTE_PROTOCOL> |
| 96 | * This property is not expected to be set under normal circumstances. |
| 97 | */ |
| 98 | private static final String REMOTE_PROTOCOL_PROP_NAME = |
| 99 | "sun.jvmstat.monitor.remote"; |
| 100 | private static final String REMOTE_PROTOCOL = |
| 101 | System.getProperty(REMOTE_PROTOCOL_PROP_NAME, "rmi"); |
| 102 | |
| 103 | /* |
| 104 | * The default class name of the MonitoredHost implementation subclass. |
| 105 | * There is no override mechanism for this variable, other than the |
| 106 | * IMPL_OVERRIDE_PROP_NAME override, which is larger in scope. A concrete |
| 107 | * instance of this class is expected to be found in: |
| 108 | * <IMPL_PACKAGE>.monitor.protocol.<protocol>.<MONITORED_HOST_CLASS> |
| 109 | */ |
| 110 | private static final String MONITORED_HOST_CLASS = "MonitoredHostProvider"; |
| 111 | |
| 112 | /** |
| 113 | * The HostIdentifier for this MonitoredHost instance. |
| 114 | */ |
| 115 | protected HostIdentifier hostId; |
| 116 | |
| 117 | /** |
| 118 | * The polling interval, in milliseconds, for this MonitoredHost instance. |
| 119 | */ |
| 120 | protected int interval; |
| 121 | |
| 122 | /** |
| 123 | * The last Exception encountered while polling this MonitoredHost. |
| 124 | */ |
| 125 | protected Exception lastException; |
| 126 | |
| 127 | /** |
| 128 | * Factory method to construct MonitoredHost instances to manage |
| 129 | * connections to the host indicated by <tt>hostIdString</tt> |
| 130 | * |
| 131 | * @param hostIdString a String representation of a {@link HostIdentifier} |
| 132 | * @return MonitoredHost - the MonitoredHost instance for communicating |
| 133 | * with the indicated host using the protocol |
| 134 | * specified in hostIdString. |
| 135 | * @throws MonitorException Thrown if monitoring errors occur. |
| 136 | * @throws URISyntaxException Thrown when the hostIdString is poorly |
| 137 | * formed. This exception may get encapsulated |
| 138 | * into MonitorException in a future revision. |
| 139 | */ |
| 140 | public static MonitoredHost getMonitoredHost(String hostIdString) |
| 141 | throws MonitorException, URISyntaxException { |
| 142 | HostIdentifier hostId = new HostIdentifier(hostIdString); |
| 143 | return getMonitoredHost(hostId); |
| 144 | } |
| 145 | |
| 146 | /** |
| 147 | * Factory method to construct a MonitoredHost instance to manage the |
| 148 | * connection to the Java Virtual Machine indicated by <tt>vmid</tt>. |
| 149 | * |
| 150 | * This method provide a convenient short cut for attaching to a specific |
| 151 | * instrumented Java Virtual Machine. The information in the VmIdentifier |
| 152 | * is used to construct a corresponding HostIdentifier, which in turn is |
| 153 | * used to create the MonitoredHost instance. |
| 154 | * |
| 155 | * @param vmid The identifier for the target Java Virtual Machine. |
| 156 | * @return MonitoredHost - The MonitoredHost object needed to attach to |
| 157 | * the target Java Virtual Machine. |
| 158 | * |
| 159 | * @throws MonitorException Thrown if monitoring errors occur. |
| 160 | */ |
| 161 | public static MonitoredHost getMonitoredHost(VmIdentifier vmid) |
| 162 | throws MonitorException { |
| 163 | // use the VmIdentifier to construct the corresponding HostIdentifier |
| 164 | HostIdentifier hostId = new HostIdentifier(vmid); |
| 165 | return getMonitoredHost(hostId); |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * Factory method to construct a MonitoredHost instance to manage the |
| 170 | * connection to the host indicated by <tt>hostId</tt>. |
| 171 | * |
| 172 | * @param hostId the identifier for the target host. |
| 173 | * @return MonitoredHost - The MonitoredHost object needed to attach to |
| 174 | * the target host. |
| 175 | * |
| 176 | * @throws MonitorException Thrown if monitoring errors occur. |
| 177 | */ |
| 178 | public static MonitoredHost getMonitoredHost(HostIdentifier hostId) |
| 179 | throws MonitorException { |
| 180 | /* |
| 181 | * determine the class name to load. If the system property is set, |
| 182 | * use the indicated class. otherwise, use the default class. |
| 183 | */ |
| 184 | String classname = System.getProperty(IMPL_OVERRIDE_PROP_NAME); |
| 185 | MonitoredHost mh = null; |
| 186 | |
| 187 | synchronized(monitoredHosts) { |
| 188 | mh = monitoredHosts.get(hostId); |
| 189 | if (mh != null) { |
| 190 | if (mh.isErrored()) { |
| 191 | monitoredHosts.remove(hostId); |
| 192 | } else { |
| 193 | return mh; |
| 194 | } |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | hostId = resolveHostId(hostId); |
| 199 | |
| 200 | if (classname == null) { |
| 201 | // construct the class name |
| 202 | classname = IMPL_PACKAGE + ".monitor.protocol." |
| 203 | + hostId.getScheme() + "." + MONITORED_HOST_CLASS; |
| 204 | } |
| 205 | |
| 206 | try { |
| 207 | // run the constructor taking a single String parameter. |
| 208 | Class<?> c = Class.forName(classname); |
| 209 | |
| 210 | Constructor cons = c.getConstructor( |
| 211 | new Class[] { hostId.getClass() } |
| 212 | ); |
| 213 | |
| 214 | mh = (MonitoredHost)cons.newInstance(new Object[] { hostId } ); |
| 215 | |
| 216 | synchronized(monitoredHosts) { |
| 217 | monitoredHosts.put(mh.hostId, mh); |
| 218 | } |
| 219 | return mh; |
| 220 | } catch (ClassNotFoundException e) { |
| 221 | // from Class.forName(); |
| 222 | throw new IllegalArgumentException("Could not find " + classname |
| 223 | + ": " + e.getMessage(), e); |
| 224 | } catch (NoSuchMethodException e) { |
| 225 | // from Class.getConstructor(); |
| 226 | throw new IllegalArgumentException( |
| 227 | "Expected constructor missing in " + classname + ": " |
| 228 | + e.getMessage(), e); |
| 229 | } catch (IllegalAccessException e) { |
| 230 | // from Constructor.newInstance() |
| 231 | throw new IllegalArgumentException( |
| 232 | "Unexpected constructor access in " + classname + ": " |
| 233 | + e.getMessage(), e); |
| 234 | } catch (InstantiationException e) { |
| 235 | throw new IllegalArgumentException(classname + "is abstract: " |
| 236 | + e.getMessage(), e); |
| 237 | } catch (InvocationTargetException e) { |
| 238 | Throwable cause = e.getCause(); |
| 239 | if (cause instanceof MonitorException) { |
| 240 | throw (MonitorException)cause; |
| 241 | } |
| 242 | throw new RuntimeException("Unexpected exception", e); |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * Method to resolve unspecified components of the given HostIdentifier |
| 248 | * by constructing a new HostIdentifier that replaces the unspecified |
| 249 | * components with the default values. |
| 250 | * |
| 251 | * @param hostId the unresolved HostIdentifier. |
| 252 | * @return HostIdentifier - a resolved HostIdentifier. |
| 253 | * |
| 254 | * @throws MonitorException Thrown if monitoring errors occur. |
| 255 | */ |
| 256 | protected static HostIdentifier resolveHostId(HostIdentifier hostId) |
| 257 | throws MonitorException { |
| 258 | String hostname = hostId.getHost(); |
| 259 | String scheme = hostId.getScheme(); |
| 260 | StringBuffer sb = new StringBuffer(); |
| 261 | |
| 262 | assert hostname != null; |
| 263 | |
| 264 | if (scheme == null) { |
| 265 | if (hostname.compareTo("localhost") == 0) { |
| 266 | scheme = LOCAL_PROTOCOL; |
| 267 | } else { |
| 268 | scheme = REMOTE_PROTOCOL; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | sb.append(scheme).append(":").append(hostId.getSchemeSpecificPart()); |
| 273 | |
| 274 | String frag = hostId.getFragment(); |
| 275 | if (frag != null) { |
| 276 | sb.append("#").append(frag); |
| 277 | } |
| 278 | |
| 279 | try { |
| 280 | return new HostIdentifier(sb.toString()); |
| 281 | } catch (URISyntaxException e) { |
| 282 | // programming error - HostIdentifier was valid. |
| 283 | assert false; |
| 284 | throw new IllegalArgumentException("Malformed URI created: " |
| 285 | + sb.toString()); |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | /** |
| 290 | * Return the resolved HostIdentifier for this MonitoredHost. |
| 291 | * |
| 292 | * @return HostIdentifier - the resolved HostIdentifier. |
| 293 | */ |
| 294 | public HostIdentifier getHostIdentifier() { |
| 295 | return hostId; |
| 296 | } |
| 297 | |
| 298 | /* ---- Methods to support polled MonitoredHost Implementations ----- */ |
| 299 | |
| 300 | /** |
| 301 | * Set the polling interval for this MonitoredHost. |
| 302 | * |
| 303 | * @param interval the polling interval, in milliseconds |
| 304 | */ |
| 305 | public void setInterval(int interval) { |
| 306 | this.interval = interval; |
| 307 | } |
| 308 | |
| 309 | /** |
| 310 | * Get the polling interval. |
| 311 | * |
| 312 | * @return int - the polling interval in milliseconds for this MonitoredHost |
| 313 | */ |
| 314 | public int getInterval() { |
| 315 | return interval; |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Set the last exception encountered while polling this MonitoredHost. |
| 320 | * |
| 321 | * @param lastException the last exception encountered; |
| 322 | */ |
| 323 | public void setLastException(Exception lastException) { |
| 324 | this.lastException = lastException; |
| 325 | } |
| 326 | |
| 327 | /** |
| 328 | * Get the last exception encountered while polling this MonitoredHost. |
| 329 | * |
| 330 | * @return Exception - the last exception occurred while polling this |
| 331 | * MonitoredHost, or <tt>null</tt> if no exception |
| 332 | * has occurred or the exception has been cleared, |
| 333 | */ |
| 334 | public Exception getLastException() { |
| 335 | return lastException; |
| 336 | } |
| 337 | |
| 338 | /** |
| 339 | * Clear the last exception. |
| 340 | */ |
| 341 | public void clearLastException() { |
| 342 | lastException = null; |
| 343 | } |
| 344 | |
| 345 | /** |
| 346 | * Test if this MonitoredHost is in the errored state. If this method |
| 347 | * returns true, then the Exception returned by getLastException() |
| 348 | * indicates the Exception that caused the error condition. |
| 349 | * |
| 350 | * @return boolean - true if the MonitoredHost instance has experienced |
| 351 | * an error, or false if it hasn't or if any past |
| 352 | * error has been cleared. |
| 353 | */ |
| 354 | public boolean isErrored() { |
| 355 | return lastException != null; |
| 356 | } |
| 357 | |
| 358 | /** |
| 359 | * Get the MonitoredVm for the given Java Virtual Machine. The default |
| 360 | * sampling interval is used for the MonitoredVm instance. |
| 361 | * |
| 362 | * @param id the VmIdentifier specifying the target Java Virtual Machine. |
| 363 | * @return MonitoredVm - the MonitoredVm instance for the target Java |
| 364 | * Virtual Machine. |
| 365 | * @throws MonitorException Thrown if monitoring errors occur. |
| 366 | */ |
| 367 | public abstract MonitoredVm getMonitoredVm(VmIdentifier id) |
| 368 | throws MonitorException; |
| 369 | |
| 370 | /** |
| 371 | * Get the MonitoredVm for the given Java Virtual Machine. The sampling |
| 372 | * interval is set to the given interval. |
| 373 | * |
| 374 | * @param id the VmIdentifier specifying the target Java Virtual Machine. |
| 375 | * @param interval the sampling interval for the target Java Virtual Machine. |
| 376 | * @return MonitoredVm - the MonitoredVm instance for the target Java |
| 377 | * Virtual Machine. |
| 378 | * @throws MonitorException Thrown if monitoring errors occur. |
| 379 | */ |
| 380 | public abstract MonitoredVm getMonitoredVm(VmIdentifier id, int interval) |
| 381 | throws MonitorException; |
| 382 | |
| 383 | /** |
| 384 | * Detach from the indicated MonitoredVm. |
| 385 | * |
| 386 | * @param vm the monitored Java Virtual Machine. |
| 387 | * @throws MonitorException Thrown if monitoring errors occur. |
| 388 | */ |
| 389 | public abstract void detach(MonitoredVm vm) throws MonitorException; |
| 390 | |
| 391 | /** |
| 392 | * Add a HostListener. The given listener is added to the list |
| 393 | * of HostListener objects to be notified of MonitoredHost related events. |
| 394 | * |
| 395 | * @param listener the HostListener to add. |
| 396 | * @throws MonitorException Thrown if monitoring errors occur. |
| 397 | */ |
| 398 | public abstract void addHostListener(HostListener listener) |
| 399 | throws MonitorException; |
| 400 | |
| 401 | /** |
| 402 | * Remove a HostListener. The given listener is removed from the list |
| 403 | * of HostListener objects to be notified of MonitoredHost related events. |
| 404 | * |
| 405 | * @param listener the HostListener to add. |
| 406 | * @throws MonitorException Thrown if monitoring errors occur. |
| 407 | */ |
| 408 | public abstract void removeHostListener(HostListener listener) |
| 409 | throws MonitorException; |
| 410 | |
| 411 | /** |
| 412 | * Return the current set of active Java Virtual Machines for this |
| 413 | * MonitoredHost. The returned Set contains {@link Integer} instances |
| 414 | * holding the local virtual machine identifier, or <em>lvmid</em> |
| 415 | * for each instrumented Java Virtual Machine currently available. |
| 416 | * |
| 417 | * @return Set - the current set of active Java Virtual Machines associated |
| 418 | * with this MonitoredHost, or the empty set of none. |
| 419 | * @throws MonitorException Thrown if monitoring errors occur. |
| 420 | */ |
| 421 | public abstract Set<Integer> activeVms() throws MonitorException; |
| 422 | } |