netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/sal/connect/netconf/sal/KeepaliveSalFacade.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netconf.sal.connect.netconf.sal;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getSourceNode;
  12 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_NODEID;
  13 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_PATH;
  14 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_RUNNING_QNAME;
  15
  16 import com.google.common.util.concurrent.FutureCallback;
  17 import com.google.common.util.concurrent.Futures;
  18 import com.google.common.util.concurrent.ListenableFuture;
  19 import com.google.common.util.concurrent.MoreExecutors;
  20 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  21 import java.util.concurrent.ScheduledExecutorService;
  22 import java.util.concurrent.ScheduledFuture;
  23 import java.util.concurrent.TimeUnit;
  24 import java.util.concurrent.atomic.AtomicBoolean;
  25 import org.opendaylight.mdsal.dom.api.DOMActionService;
  26 import org.opendaylight.mdsal.dom.api.DOMNotification;
  27 import org.opendaylight.mdsal.dom.api.DOMRpcAvailabilityListener;
  28 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  29 import org.opendaylight.mdsal.dom.api.DOMRpcService;
  30 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  31 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  32 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  33 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  34 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  35 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  36 import org.opendaylight.yangtools.rfc8528.data.api.MountPointContext;
  37 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  38 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  39 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 /**
  44  * SalFacade proxy that invokes keepalive RPCs to prevent session shutdown from remote device
  45  * and to detect incorrect session drops (netconf session is inactive, but TCP/SSH connection is still present).
  46  * The keepalive RPC is a get-config with empty filter.
  47  */
  48 public final class KeepaliveSalFacade implements RemoteDeviceHandler<NetconfSessionPreferences> {
  49
  50     private static final Logger LOG = LoggerFactory.getLogger(KeepaliveSalFacade.class);
  51
  52     // 2 minutes keepalive delay by default
  53     private static final long DEFAULT_DELAY = TimeUnit.MINUTES.toSeconds(2);
  54
  55     // 1 minute transaction timeout by default
  56     private static final long DEFAULT_TRANSACTION_TIMEOUT_MILLI = TimeUnit.MILLISECONDS.toMillis(60000);
  57
  58     private final RemoteDeviceId id;
  59     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  60     private final ScheduledExecutorService executor;
  61     private final long keepaliveDelaySeconds;
  62     private final ResetKeepalive resetKeepaliveTask;
  63     private final long defaultRequestTimeoutMillis;
  64
  65     private volatile NetconfDeviceCommunicator listener;
  66     private volatile ScheduledFuture<?> currentKeepalive;
  67     private volatile DOMRpcService currentDeviceRpc;
  68     private final AtomicBoolean lastKeepAliveSucceeded = new AtomicBoolean(false);
  69
  70     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  71                               final ScheduledExecutorService executor, final long keepaliveDelaySeconds,
  72                               final long defaultRequestTimeoutMillis) {
  73         this.id = id;
  74         this.salFacade = salFacade;
  75         this.executor = executor;
  76         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  77         this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
  78         this.resetKeepaliveTask = new ResetKeepalive();
  79     }
  80
  81     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  82                               final ScheduledExecutorService executor) {
  83         this(id, salFacade, executor, DEFAULT_DELAY, DEFAULT_TRANSACTION_TIMEOUT_MILLI);
  84     }
  85
  86     /**
  87      * Set the netconf session listener whenever ready.
  88      *
  89      * @param listener netconf session listener
  90      */
  91     public void setListener(final NetconfDeviceCommunicator listener) {
  92         this.listener = listener;
  93     }
  94
  95     /**
  96      * Just cancel current keepalive task.
  97      * If its already started, let it finish ... not such a big deal.
  98      *
  99      * <p>
 100      * Then schedule next keepalive.
 101      */
 102     void resetKeepalive() {
 103         LOG.trace("{}: Resetting netconf keepalive timer", id);
 104         if (currentKeepalive != null) {
 105             currentKeepalive.cancel(false);
 106         }
 107         scheduleKeepalives();
 108     }
 109
 110     /**
 111      * Cancel current keepalive and also reset current deviceRpc.
 112      */
 113     private void stopKeepalives() {
 114         if (currentKeepalive != null) {
 115             currentKeepalive.cancel(false);
 116         }
 117         currentDeviceRpc = null;
 118     }
 119
 120     void reconnect() {
 121         checkState(listener != null, "%s: Unable to reconnect, session listener is missing", id);
 122         stopKeepalives();
 123         LOG.info("{}: Reconnecting inactive netconf session", id);
 124         listener.disconnect();
 125     }
 126
 127     @Override
 128     public void onDeviceConnected(final MountPointContext remoteSchemaContext,
 129                           final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc) {
 130         onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc, null);
 131     }
 132
 133     @Override
 134     public void onDeviceConnected(final MountPointContext remoteSchemaContext,
 135             final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc,
 136             final DOMActionService deviceAction) {
 137         this.currentDeviceRpc = deviceRpc;
 138         final DOMRpcService deviceRpc1 =
 139                 new KeepaliveDOMRpcService(deviceRpc, resetKeepaliveTask, defaultRequestTimeoutMillis, executor,
 140                         new ResponseWaitingScheduler());
 141
 142         salFacade.onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc1, deviceAction);
 143
 144         LOG.debug("{}: Netconf session initiated, starting keepalives", id);
 145         scheduleKeepalives();
 146     }
 147
 148     private void scheduleKeepalives() {
 149         lastKeepAliveSucceeded.set(true);
 150         checkState(currentDeviceRpc != null);
 151         LOG.trace("{}: Scheduling keepalives every  {} {}", id, keepaliveDelaySeconds, TimeUnit.SECONDS);
 152         currentKeepalive = executor.scheduleWithFixedDelay(new Keepalive(),
 153           keepaliveDelaySeconds, keepaliveDelaySeconds, TimeUnit.SECONDS);
 154     }
 155
 156     @Override
 157     public void onDeviceDisconnected() {
 158         stopKeepalives();
 159         salFacade.onDeviceDisconnected();
 160     }
 161
 162     @Override
 163     public void onDeviceFailed(final Throwable throwable) {
 164         stopKeepalives();
 165         salFacade.onDeviceFailed(throwable);
 166     }
 167
 168     @Override
 169     public void onNotification(final DOMNotification domNotification) {
 170         resetKeepalive();
 171         salFacade.onNotification(domNotification);
 172     }
 173
 174     @Override
 175     public void close() {
 176         stopKeepalives();
 177         salFacade.close();
 178     }
 179
 180     // Keepalive RPC static resources
 181     private static final ContainerNode KEEPALIVE_PAYLOAD = NetconfMessageTransformUtil.wrap(NETCONF_GET_CONFIG_NODEID,
 182             getSourceNode(NETCONF_RUNNING_QNAME), NetconfMessageTransformUtil.EMPTY_FILTER);
 183
 184     /**
 185      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 186      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 187      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 188      * is considered inactive/failed.
 189      */
 190     private class Keepalive implements Runnable, FutureCallback<DOMRpcResult> {
 191
 192         @Override
 193         public void run() {
 194             LOG.trace("{}: Invoking keepalive RPC", id);
 195
 196             try {
 197                 final boolean lastJobSucceeded = lastKeepAliveSucceeded.getAndSet(false);
 198                 if (!lastJobSucceeded) {
 199                     onFailure(new IllegalStateException("Previous keepalive timed out"));
 200                 } else {
 201                     Futures.addCallback(currentDeviceRpc.invokeRpc(NETCONF_GET_CONFIG_PATH, KEEPALIVE_PAYLOAD), this,
 202                         MoreExecutors.directExecutor());
 203                 }
 204             } catch (final NullPointerException e) {
 205                 LOG.debug("{}: Skipping keepalive while reconnecting", id);
 206                 // Empty catch block intentional
 207                 // Do nothing. The currentDeviceRpc was null and it means we hit the reconnect window and
 208                 // attempted to send keepalive while we were reconnecting. Next keepalive will be scheduled
 209                 // after reconnect so no action necessary here.
 210             }
 211         }
 212
 213         @SuppressFBWarnings(value = "RCN_REDUNDANT_NULLCHECK_OF_NONNULL_VALUE",
 214                 justification = "Unrecognised NullableDecl")
 215         @Override
 216         public void onSuccess(final DOMRpcResult result) {
 217             // No matter what response we got, rpc-reply or rpc-error,
 218             // we got it from device so the netconf session is OK
 219             if (result == null) {
 220                 LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", id);
 221                 reconnect();
 222                 return;
 223             }
 224
 225             if (result.getResult() != null) {
 226                 lastKeepAliveSucceeded.set(true);
 227             }  else if (result.getErrors() != null) {
 228                 LOG.warn("{}: Keepalive RPC failed with error: {}", id, result.getErrors());
 229                 lastKeepAliveSucceeded.set(true);
 230             } else {
 231                 LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", id);
 232                 reconnect();
 233             }
 234         }
 235
 236         @Override
 237         public void onFailure(final Throwable throwable) {
 238             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, throwable);
 239             reconnect();
 240         }
 241     }
 242
 243     /**
 244      * Reset keepalive after each RPC response received.
 245      */
 246     private class ResetKeepalive implements FutureCallback<DOMRpcResult> {
 247         @Override
 248         public void onSuccess(final DOMRpcResult result) {
 249             // No matter what response we got,
 250             // rpc-reply or rpc-error, we got it from device so the netconf session is OK.
 251             resetKeepalive();
 252         }
 253
 254         @Override
 255         public void onFailure(final Throwable throwable) {
 256             // User/Application RPC failed (The RPC did not reach the remote device or ..
 257             // TODO what other reasons could cause this ?)
 258             // There is no point in keeping this session. Reconnect.
 259             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, throwable);
 260             reconnect();
 261         }
 262     }
 263
 264     private final class ResponseWaitingScheduler {
 265
 266         private ScheduledFuture<?> schedule;
 267
 268         public void initScheduler(final Runnable runnable) {
 269             if (currentKeepalive != null) {
 270                 currentKeepalive.cancel(true);
 271             } else {
 272                 LOG.trace("Keepalive does not exist.");
 273             }
 274             scheduleKeepalives();
 275             //Listening on the result should be done before the keepalive rpc will be send
 276             final long delay = keepaliveDelaySeconds * 1000 - 500;
 277             schedule = executor.schedule(runnable, delay, TimeUnit.MILLISECONDS);
 278         }
 279
 280         public void stopScheduler() {
 281             if (schedule != null) {
 282                 schedule.cancel(true);
 283             } else {
 284                 LOG.trace("Scheduler does not exist.");
 285             }
 286         }
 287     }
 288
 289     private static final class ResponseWaiting implements Runnable {
 290
 291         private final ListenableFuture<DOMRpcResult> rpcResultFuture;
 292         private final ResponseWaitingScheduler responseWaitingScheduler;
 293
 294         ResponseWaiting(final ResponseWaitingScheduler responseWaitingScheduler,
 295                 final ListenableFuture<DOMRpcResult> rpcResultFuture) {
 296             this.responseWaitingScheduler = responseWaitingScheduler;
 297             this.rpcResultFuture = rpcResultFuture;
 298         }
 299
 300         public void start() {
 301             LOG.trace("Start to waiting for result.");
 302             responseWaitingScheduler.initScheduler(this);
 303         }
 304
 305         public void stop() {
 306             LOG.info("Stop to waiting for result.");
 307             responseWaitingScheduler.stopScheduler();
 308         }
 309
 310         @Override
 311         public void run() {
 312             if (!rpcResultFuture.isCancelled() && !rpcResultFuture.isDone()) {
 313                 LOG.trace("Waiting for result");
 314                 responseWaitingScheduler.initScheduler(this);
 315             } else {
 316                 LOG.trace("Result has been cancelled or done.");
 317             }
 318         }
 319     }
 320
 321     /*
 322      * Request timeout task is called once the defaultRequestTimeoutMillis is
 323      * reached. At this moment, if the request is not yet finished, we cancel
 324      * it.
 325      */
 326     private static final class RequestTimeoutTask implements Runnable {
 327         private final ListenableFuture<DOMRpcResult> rpcResultFuture;
 328         private final ResponseWaiting responseWaiting;
 329
 330         RequestTimeoutTask(final ListenableFuture<DOMRpcResult> rpcResultFuture,
 331             final ResponseWaiting responseWaiting) {
 332             this.rpcResultFuture = rpcResultFuture;
 333             this.responseWaiting = responseWaiting;
 334         }
 335
 336         @Override
 337         public void run() {
 338             if (!rpcResultFuture.isDone()) {
 339                 rpcResultFuture.cancel(true);
 340             }
 341             if (responseWaiting != null) {
 342                 responseWaiting.stop();
 343             }
 344         }
 345     }
 346
 347     /**
 348      * DOMRpcService proxy that attaches reset-keepalive-task and schedule
 349      * request-timeout-task to each RPC invocation.
 350      */
 351     public static final class KeepaliveDOMRpcService implements DOMRpcService {
 352
 353         private final DOMRpcService deviceRpc;
 354         private final ResetKeepalive resetKeepaliveTask;
 355         private final long defaultRequestTimeoutMillis;
 356         private final ScheduledExecutorService executor;
 357         private final ResponseWaitingScheduler responseWaitingScheduler;
 358
 359         KeepaliveDOMRpcService(final DOMRpcService deviceRpc, final ResetKeepalive resetKeepaliveTask,
 360                 final long defaultRequestTimeoutMillis, final ScheduledExecutorService executor,
 361                 final ResponseWaitingScheduler responseWaitingScheduler) {
 362             this.deviceRpc = deviceRpc;
 363             this.resetKeepaliveTask = resetKeepaliveTask;
 364             this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
 365             this.executor = executor;
 366             this.responseWaitingScheduler = responseWaitingScheduler;
 367         }
 368
 369         public DOMRpcService getDeviceRpc() {
 370             return deviceRpc;
 371         }
 372
 373         @Override
 374         public ListenableFuture<DOMRpcResult> invokeRpc(final SchemaPath type, final NormalizedNode<?, ?> input) {
 375             final ListenableFuture<DOMRpcResult> rpcResultFuture = deviceRpc.invokeRpc(type, input);
 376             final ResponseWaiting responseWaiting = new ResponseWaiting(responseWaitingScheduler, rpcResultFuture);
 377             responseWaiting.start();
 378             Futures.addCallback(rpcResultFuture, resetKeepaliveTask, MoreExecutors.directExecutor());
 379
 380             final RequestTimeoutTask timeoutTask = new RequestTimeoutTask(rpcResultFuture, responseWaiting);
 381             executor.schedule(timeoutTask, defaultRequestTimeoutMillis, TimeUnit.MILLISECONDS);
 382
 383             return rpcResultFuture;
 384         }
 385
 386         @Override
 387         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(final T listener) {
 388             // There is no real communication with the device (yet), no reset here
 389             return deviceRpc.registerRpcListener(listener);
 390         }
 391     }
 392 }