plugins/netconf-client-mdsal/src/main/java/org/opendaylight/netconf/client/mdsal/spi/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.client.mdsal.spi;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.netconf.client.mdsal.impl.NetconfBaseOps.getSourceNode;
  13 import static org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_NODEID;
  14 import static org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil.NETCONF_RUNNING_NODEID;
  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 com.google.common.util.concurrent.SettableFuture;
  21 import io.netty.util.Timeout;
  22 import io.netty.util.TimerTask;
  23 import java.util.concurrent.CancellationException;
  24 import java.util.concurrent.TimeUnit;
  25 import javax.xml.transform.dom.DOMSource;
  26 import org.checkerframework.checker.lock.qual.GuardedBy;
  27 import org.eclipse.jdt.annotation.NonNull;
  28 import org.opendaylight.mdsal.dom.api.DOMNotification;
  29 import org.opendaylight.mdsal.dom.api.DOMRpcAvailabilityListener;
  30 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  31 import org.opendaylight.netconf.client.mdsal.NetconfDeviceCommunicator;
  32 import org.opendaylight.netconf.client.mdsal.NetconfDeviceSchema;
  33 import org.opendaylight.netconf.client.mdsal.api.NetconfSessionPreferences;
  34 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceHandler;
  35 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceId;
  36 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices;
  37 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices.Rpcs;
  38 import org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil;
  39 import org.opendaylight.netconf.common.NetconfTimer;
  40 import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.base._1._0.rev110601.GetConfig;
  41 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  42 import org.opendaylight.yangtools.yang.common.QName;
  43 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  44 import org.slf4j.Logger;
  45 import org.slf4j.LoggerFactory;
  46
  47 /**
  48  * SalFacade proxy that invokes keepalive RPCs to prevent session shutdown from remote device
  49  * and to detect incorrect session drops (netconf session is inactive, but TCP/SSH connection is still present).
  50  * The keepalive RPC is a get-config with empty filter.
  51  */
  52 public final class KeepaliveSalFacade implements RemoteDeviceHandler {
  53     private static final Logger LOG = LoggerFactory.getLogger(KeepaliveSalFacade.class);
  54
  55     // 2 minutes keepalive delay by default
  56     private static final long DEFAULT_DELAY = TimeUnit.MINUTES.toSeconds(2);
  57
  58     // 1 minute transaction timeout by default
  59     private static final long DEFAULT_TRANSACTION_TIMEOUT_MILLI = TimeUnit.MILLISECONDS.toMillis(60000);
  60
  61     private final RemoteDeviceHandler deviceHandler;
  62     private final RemoteDeviceId deviceId;
  63     private final NetconfTimer timer;
  64     private final long keepaliveDelaySeconds;
  65     private final long timeoutNanos;
  66     private final long delayNanos;
  67
  68     private volatile NetconfDeviceCommunicator listener;
  69     private volatile KeepaliveTask task;
  70
  71     public KeepaliveSalFacade(final RemoteDeviceId deviceId, final RemoteDeviceHandler deviceHandler,
  72             final NetconfTimer timer, final long keepaliveDelaySeconds, final long requestTimeoutMillis) {
  73         this.deviceId = requireNonNull(deviceId);
  74         this.deviceHandler = requireNonNull(deviceHandler);
  75         this.timer = requireNonNull(timer);
  76         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  77         delayNanos = TimeUnit.SECONDS.toNanos(keepaliveDelaySeconds);
  78         timeoutNanos = TimeUnit.MILLISECONDS.toNanos(requestTimeoutMillis);
  79     }
  80
  81     public KeepaliveSalFacade(final RemoteDeviceId deviceId, final RemoteDeviceHandler deviceHandler,
  82             final NetconfTimer timer) {
  83         this(deviceId, deviceHandler, timer, 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      * Cancel current keepalive and free it.
  97      */
  98     private synchronized void stopKeepalives() {
  99         final var localTask = task;
 100         if (localTask != null) {
 101             localTask.disableKeepalive();
 102             task = null;
 103         }
 104     }
 105
 106     private void disableKeepalive() {
 107         final var localTask = task;
 108         if (localTask != null) {
 109             localTask.disableKeepalive();
 110         }
 111     }
 112
 113     private void enableKeepalive() {
 114         final var localTask = task;
 115         if (localTask != null) {
 116             localTask.enableKeepalive();
 117         }
 118     }
 119
 120     private void disconnect() {
 121         checkState(listener != null, "%s: Unable to reconnect, session listener is missing", deviceId);
 122         stopKeepalives();
 123         LOG.info("{}: Reconnecting inactive netconf session", deviceId);
 124         listener.disconnect();
 125     }
 126
 127     @Override
 128     public void onDeviceConnected(final NetconfDeviceSchema deviceSchema,
 129             final NetconfSessionPreferences sessionPreferences, final RemoteDeviceServices services) {
 130         final var devRpc = services.rpcs();
 131         task = new KeepaliveTask(devRpc);
 132
 133         final Rpcs keepaliveRpcs;
 134         if (devRpc instanceof Rpcs.Normalized normalized) {
 135             keepaliveRpcs = new NormalizedKeepaliveRpcs(normalized);
 136         } else if (devRpc instanceof Rpcs.Schemaless schemaless) {
 137             keepaliveRpcs = new SchemalessKeepaliveRpcs(schemaless);
 138         } else {
 139             throw new IllegalStateException("Unhandled " + devRpc);
 140         }
 141
 142         deviceHandler.onDeviceConnected(deviceSchema, sessionPreferences, new RemoteDeviceServices(keepaliveRpcs,
 143             // FIXME: wrap with keepalive
 144             services.actions()));
 145
 146         // We have performed a callback, which might have termined keepalives
 147         final var localTask = task;
 148         if (localTask != null) {
 149             LOG.debug("{}: Netconf session initiated, starting keepalives", deviceId);
 150             LOG.trace("{}: Scheduling keepalives every {}s", deviceId, keepaliveDelaySeconds);
 151             localTask.enableKeepalive();
 152         }
 153     }
 154
 155     @Override
 156     public void onDeviceDisconnected() {
 157         stopKeepalives();
 158         deviceHandler.onDeviceDisconnected();
 159     }
 160
 161     @Override
 162     public void onDeviceFailed(final Throwable throwable) {
 163         stopKeepalives();
 164         deviceHandler.onDeviceFailed(throwable);
 165     }
 166
 167     @Override
 168     public void onNotification(final DOMNotification domNotification) {
 169         final var localTask = task;
 170         if (localTask != null) {
 171             localTask.recordActivity();
 172         }
 173         deviceHandler.onNotification(domNotification);
 174     }
 175
 176     @Override
 177     public void close() {
 178         stopKeepalives();
 179         deviceHandler.close();
 180     }
 181
 182     private <T> @NonNull ListenableFuture<T> scheduleTimeout(final ListenableFuture<T> invokeFuture) {
 183         final var timeout = new RequestTimeoutTask<>(invokeFuture);
 184         scheduleTimeout(invokeFuture, timeout);
 185         return timeout.userFuture;
 186     }
 187
 188     private void scheduleTimeout(final ListenableFuture<?> future, final TimeoutTask timeoutTask) {
 189         final var timeout = timer.newTimeout(timeoutTask, timeoutNanos, TimeUnit.NANOSECONDS);
 190         future.addListener(() -> timeout.cancel(), MoreExecutors.directExecutor());
 191     }
 192
 193     /**
 194      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 195      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 196      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 197      * is considered inactive/failed.
 198      */
 199     private final class KeepaliveTask implements TimerTask, FutureCallback<DOMRpcResult> {
 200         // Keepalive RPC static resources
 201         static final @NonNull ContainerNode KEEPALIVE_PAYLOAD = NetconfMessageTransformUtil.wrap(
 202             NETCONF_GET_CONFIG_NODEID, getSourceNode(NETCONF_RUNNING_NODEID), NetconfMessageTransformUtil.EMPTY_FILTER);
 203
 204         private final Rpcs devRpc;
 205
 206         @GuardedBy("this")
 207         private boolean suppressed = false;
 208
 209         private volatile long lastActivity;
 210
 211         KeepaliveTask(final Rpcs devRpc) {
 212             this.devRpc = requireNonNull(devRpc);
 213         }
 214
 215         @Override
 216         public void run(final Timeout timeout) {
 217             final long local = lastActivity;
 218             final long now = System.nanoTime();
 219             final long inFutureNanos = local + delayNanos - now;
 220             if (inFutureNanos > 0) {
 221                 reschedule(inFutureNanos);
 222             } else {
 223                 sendKeepalive(now);
 224             }
 225         }
 226
 227         void recordActivity() {
 228             lastActivity = System.nanoTime();
 229         }
 230
 231         synchronized void disableKeepalive() {
 232             // unsuppressed -> suppressed
 233             suppressed = true;
 234         }
 235
 236         synchronized void enableKeepalive() {
 237             recordActivity();
 238             if (suppressed) {
 239                 // suppressed -> unsuppressed
 240                 suppressed = false;
 241             } else {
 242                 // unscheduled -> unsuppressed
 243                 reschedule();
 244             }
 245         }
 246
 247         private synchronized void sendKeepalive(final long now) {
 248             if (suppressed) {
 249                 LOG.debug("{}: Skipping keepalive while disabled", deviceId);
 250                 // suppressed -> unscheduled
 251                 suppressed = false;
 252                 return;
 253             }
 254
 255             LOG.trace("{}: Invoking keepalive RPC", deviceId);
 256             final var deviceFuture = devRpc.invokeNetconf(GetConfig.QNAME, KEEPALIVE_PAYLOAD);
 257             lastActivity = now;
 258
 259             scheduleTimeout(deviceFuture, new TimeoutTask(deviceFuture));
 260             Futures.addCallback(deviceFuture, this, MoreExecutors.directExecutor());
 261         }
 262
 263         @Override
 264         public void onSuccess(final DOMRpcResult result) {
 265             // No matter what response we got, rpc-reply or rpc-error,
 266             // we got it from device so the netconf session is OK
 267             if (result == null) {
 268                 LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", deviceId);
 269                 disconnect();
 270                 return;
 271             }
 272
 273             if (result.value() != null) {
 274                 reschedule();
 275             } else {
 276                 final var errors = result.errors();
 277                 if (!errors.isEmpty()) {
 278                     LOG.warn("{}: Keepalive RPC failed with error: {}", deviceId, errors);
 279                     reschedule();
 280                 } else {
 281                     LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", deviceId);
 282                     disconnect();
 283                 }
 284             }
 285         }
 286
 287         @Override
 288         public void onFailure(final Throwable throwable) {
 289             if (throwable instanceof CancellationException) {
 290                 LOG.warn("{}: Keepalive RPC timed out. Reconnecting netconf session.", deviceId);
 291             } else {
 292                 LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", deviceId, throwable);
 293             }
 294             disconnect();
 295         }
 296
 297         private void reschedule() {
 298             reschedule(delayNanos);
 299         }
 300
 301         private void reschedule(final long delay) {
 302             timer.newTimeout(this, delay, TimeUnit.NANOSECONDS);
 303         }
 304     }
 305
 306     private static class TimeoutTask implements TimerTask {
 307         private final ListenableFuture<?> future;
 308
 309         TimeoutTask(final ListenableFuture<?> future) {
 310             this.future = requireNonNull(future);
 311         }
 312
 313         @Override
 314         public final void run(final Timeout timeout) {
 315             future.cancel(true);
 316         }
 317     }
 318
 319     /*
 320      * Request timeout task is called once the requestTimeoutMillis is reached. At that moment, if the request is not
 321      * yet finished, we cancel it.
 322      */
 323     private final class RequestTimeoutTask<V> extends TimeoutTask implements FutureCallback<V> {
 324         private final @NonNull SettableFuture<V> userFuture = SettableFuture.create();
 325
 326         RequestTimeoutTask(final ListenableFuture<V> rpcResultFuture) {
 327             super(rpcResultFuture);
 328             // Note: this will also wire run() to onFailure()
 329             Futures.addCallback(rpcResultFuture, this, MoreExecutors.directExecutor());
 330         }
 331
 332         @Override
 333         public void onSuccess(final V result) {
 334             // No matter what response we got,
 335             // rpc-reply or rpc-error, we got it from device so the netconf session is OK.
 336             userFuture.set(result);
 337             enableKeepalive();
 338         }
 339
 340         @Override
 341         public void onFailure(final Throwable throwable) {
 342             // User/Application RPC failed (The RPC did not reach the remote device or it has timeed out)
 343             if (throwable instanceof CancellationException) {
 344                 LOG.warn("{}: RPC timed out. Reconnecting netconf session", deviceId);
 345             } else {
 346                 LOG.warn("{}: RPC failed. Reconnecting netconf session", deviceId, throwable);
 347             }
 348             userFuture.setException(throwable);
 349             // There is no point in keeping this session. Reconnect.
 350             disconnect();
 351         }
 352     }
 353
 354     /**
 355      * Proxy for {@link Rpcs} which attaches a reset-keepalive-task and schedule request-timeout-task to each RPC
 356      * invocation. Version for {@link Rpcs.Normalized}.
 357      */
 358     private final class NormalizedKeepaliveRpcs implements Rpcs.Normalized {
 359         private final Rpcs.Normalized delegate;
 360
 361         NormalizedKeepaliveRpcs(final Rpcs.Normalized delegate) {
 362             this.delegate = requireNonNull(delegate);
 363         }
 364
 365         @Override
 366         public ListenableFuture<? extends DOMRpcResult> invokeRpc(final QName type, final ContainerNode input) {
 367             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 368             disableKeepalive();
 369             return scheduleTimeout(delegate.invokeRpc(type, input));
 370         }
 371
 372         @Override
 373         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(
 374             final T rpcListener) {
 375             // There is no real communication with the device (yet), hence no recordActivity() or anything
 376             return delegate.registerRpcListener(rpcListener);
 377         }
 378     }
 379
 380     /**
 381      * Proxy for {@link Rpcs} which attaches a reset-keepalive-task and schedule request-timeout-task to each RPC
 382      * invocation. Version for {@link Rpcs.Schemaless}.
 383      */
 384     private final class SchemalessKeepaliveRpcs implements Rpcs.Schemaless {
 385         private final Rpcs.Schemaless delegate;
 386
 387         SchemalessKeepaliveRpcs(final Rpcs.Schemaless delegate) {
 388             this.delegate = requireNonNull(delegate);
 389         }
 390
 391         @Override
 392         public ListenableFuture<? extends DOMRpcResult> invokeNetconf(final QName type, final ContainerNode input) {
 393             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 394             disableKeepalive();
 395             return scheduleTimeout(delegate.invokeNetconf(type, input));
 396         }
 397
 398         @Override
 399         public ListenableFuture<? extends DOMSource> invokeRpc(final QName type, final DOMSource input) {
 400             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 401             disableKeepalive();
 402             return scheduleTimeout(delegate.invokeRpc(type, input));
 403         }
 404     }
 405 }