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_GET_CONFIG_QNAME;
  15 import static org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil.NETCONF_RUNNING_NODEID;
  16
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import com.google.common.util.concurrent.Futures;
  19 import com.google.common.util.concurrent.ListenableFuture;
  20 import com.google.common.util.concurrent.MoreExecutors;
  21 import com.google.common.util.concurrent.SettableFuture;
  22 import java.util.concurrent.ScheduledExecutorService;
  23 import java.util.concurrent.TimeUnit;
  24 import javax.xml.transform.dom.DOMSource;
  25 import org.checkerframework.checker.lock.qual.GuardedBy;
  26 import org.eclipse.jdt.annotation.NonNull;
  27 import org.opendaylight.mdsal.dom.api.DOMNotification;
  28 import org.opendaylight.mdsal.dom.api.DOMRpcAvailabilityListener;
  29 import org.opendaylight.mdsal.dom.api.DOMRpcResult;
  30 import org.opendaylight.netconf.client.mdsal.NetconfDeviceCommunicator;
  31 import org.opendaylight.netconf.client.mdsal.NetconfDeviceSchema;
  32 import org.opendaylight.netconf.client.mdsal.api.NetconfSessionPreferences;
  33 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceHandler;
  34 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceId;
  35 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices;
  36 import org.opendaylight.netconf.client.mdsal.api.RemoteDeviceServices.Rpcs;
  37 import org.opendaylight.netconf.client.mdsal.impl.NetconfMessageTransformUtil;
  38 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  39 import org.opendaylight.yangtools.yang.common.QName;
  40 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  41 import org.slf4j.Logger;
  42 import org.slf4j.LoggerFactory;
  43
  44 /**
  45  * SalFacade proxy that invokes keepalive RPCs to prevent session shutdown from remote device
  46  * and to detect incorrect session drops (netconf session is inactive, but TCP/SSH connection is still present).
  47  * The keepalive RPC is a get-config with empty filter.
  48  */
  49 public final class KeepaliveSalFacade implements RemoteDeviceHandler {
  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 RemoteDeviceHandler salFacade;
  59     private final ScheduledExecutorService executor;
  60
  61     private final long keepaliveDelaySeconds;
  62     private final long timeoutNanos;
  63     private final long delayNanos;
  64
  65     private final RemoteDeviceId id;
  66
  67     private volatile NetconfDeviceCommunicator listener;
  68     private volatile KeepaliveTask task;
  69
  70     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler salFacade,
  71             final ScheduledExecutorService executor, final long keepaliveDelaySeconds,
  72             final long requestTimeoutMillis) {
  73         this.id = id;
  74         this.salFacade = salFacade;
  75         this.executor = requireNonNull(executor);
  76         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  77         delayNanos = TimeUnit.SECONDS.toNanos(keepaliveDelaySeconds);
  78         timeoutNanos = TimeUnit.MILLISECONDS.toNanos(requestTimeoutMillis);
  79     }
  80
  81     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler 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      * 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     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 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         salFacade.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", id);
 150             LOG.trace("{}: Scheduling keepalives every {}s", id, keepaliveDelaySeconds);
 151             localTask.enableKeepalive();
 152         }
 153     }
 154
 155     @Override
 156     public void onDeviceDisconnected() {
 157         stopKeepalives();
 158         salFacade.onDeviceDisconnected();
 159     }
 160
 161     @Override
 162     public void onDeviceFailed(final Throwable throwable) {
 163         stopKeepalives();
 164         salFacade.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         salFacade.onNotification(domNotification);
 174     }
 175
 176     @Override
 177     public void close() {
 178         stopKeepalives();
 179         salFacade.close();
 180     }
 181
 182     private <T> @NonNull ListenableFuture<T> scheduleTimeout(final ListenableFuture<T> invokeFuture) {
 183         final var timeout = new RequestTimeoutTask<>(invokeFuture);
 184         final var timeoutFuture = executor.schedule(timeout, timeoutNanos, TimeUnit.NANOSECONDS);
 185         invokeFuture.addListener(() -> timeoutFuture.cancel(false), MoreExecutors.directExecutor());
 186         return timeout.userFuture;
 187     }
 188
 189     /**
 190      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 191      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 192      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 193      * is considered inactive/failed.
 194      */
 195     private final class KeepaliveTask implements Runnable, FutureCallback<DOMRpcResult> {
 196         // Keepalive RPC static resources
 197         static final @NonNull ContainerNode KEEPALIVE_PAYLOAD = NetconfMessageTransformUtil.wrap(
 198             NETCONF_GET_CONFIG_NODEID, getSourceNode(NETCONF_RUNNING_NODEID), NetconfMessageTransformUtil.EMPTY_FILTER);
 199
 200         private final Rpcs devRpc;
 201
 202         @GuardedBy("this")
 203         private boolean suppressed = false;
 204
 205         private volatile long lastActivity;
 206
 207         KeepaliveTask(final Rpcs devRpc) {
 208             this.devRpc = requireNonNull(devRpc);
 209         }
 210
 211         @Override
 212         public void run() {
 213             final long local = lastActivity;
 214             final long now = System.nanoTime();
 215             final long inFutureNanos = local + delayNanos - now;
 216             if (inFutureNanos > 0) {
 217                 reschedule(inFutureNanos);
 218             } else {
 219                 sendKeepalive(now);
 220             }
 221         }
 222
 223         void recordActivity() {
 224             lastActivity = System.nanoTime();
 225         }
 226
 227         synchronized void disableKeepalive() {
 228             // unsuppressed -> suppressed
 229             suppressed = true;
 230         }
 231
 232         synchronized void enableKeepalive() {
 233             recordActivity();
 234             if (suppressed) {
 235                 // suppressed -> unsuppressed
 236                 suppressed = false;
 237             } else {
 238                 // unscheduled -> unsuppressed
 239                 reschedule();
 240             }
 241         }
 242
 243         private synchronized void sendKeepalive(final long now) {
 244             if (suppressed) {
 245                 LOG.debug("{}: Skipping keepalive while disabled", id);
 246                 // suppressed -> unscheduled
 247                 suppressed = false;
 248                 return;
 249             }
 250
 251             LOG.trace("{}: Invoking keepalive RPC", id);
 252             final var deviceFuture = devRpc.invokeNetconf(NETCONF_GET_CONFIG_QNAME, KEEPALIVE_PAYLOAD);
 253             lastActivity = now;
 254             Futures.addCallback(deviceFuture, this, MoreExecutors.directExecutor());
 255         }
 256
 257         @Override
 258         public void onSuccess(final DOMRpcResult result) {
 259             // No matter what response we got, rpc-reply or rpc-error,
 260             // we got it from device so the netconf session is OK
 261             if (result == null) {
 262                 LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", id);
 263                 reconnect();
 264                 return;
 265             }
 266
 267             if (result.value() != null) {
 268                 reschedule();
 269             } else {
 270                 final var errors = result.errors();
 271                 if (!errors.isEmpty()) {
 272                     LOG.warn("{}: Keepalive RPC failed with error: {}", id, errors);
 273                     reschedule();
 274                 } else {
 275                     LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", id);
 276                     reconnect();
 277                 }
 278             }
 279         }
 280
 281         @Override
 282         public void onFailure(final Throwable throwable) {
 283             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, throwable);
 284             reconnect();
 285         }
 286
 287         private void reschedule() {
 288             reschedule(delayNanos);
 289         }
 290
 291         private void reschedule(final long delay) {
 292             executor.schedule(this, delay, TimeUnit.NANOSECONDS);
 293         }
 294     }
 295
 296     /*
 297      * Request timeout task is called once the requestTimeoutMillis is reached. At that moment, if the request is not
 298      * yet finished, we cancel it.
 299      */
 300     private final class RequestTimeoutTask<V> implements FutureCallback<V>, Runnable {
 301         private final @NonNull SettableFuture<V> userFuture = SettableFuture.create();
 302         private final @NonNull ListenableFuture<? extends V> rpcResultFuture;
 303
 304         RequestTimeoutTask(final ListenableFuture<V> rpcResultFuture) {
 305             this.rpcResultFuture = requireNonNull(rpcResultFuture);
 306             Futures.addCallback(rpcResultFuture, this, MoreExecutors.directExecutor());
 307         }
 308
 309         @Override
 310         public void run() {
 311             // Note: this will loop to onFailure()
 312             rpcResultFuture.cancel(true);
 313         }
 314
 315         @Override
 316         public void onSuccess(final V result) {
 317             // No matter what response we got,
 318             // rpc-reply or rpc-error, we got it from device so the netconf session is OK.
 319             userFuture.set(result);
 320             enableKeepalive();
 321         }
 322
 323         @Override
 324         public void onFailure(final Throwable throwable) {
 325             // User/Application RPC failed (The RPC did not reach the remote device or ...)
 326             // FIXME: what other reasons could cause this ?)
 327             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, throwable);
 328             userFuture.setException(throwable);
 329             // There is no point in keeping this session. Reconnect.
 330             reconnect();
 331         }
 332     }
 333
 334     /**
 335      * Proxy for {@link Rpcs} which attaches a reset-keepalive-task and schedule request-timeout-task to each RPC
 336      * invocation. Version for {@link Rpcs.Normalized}.
 337      */
 338     private final class NormalizedKeepaliveRpcs implements Rpcs.Normalized {
 339         private final Rpcs.Normalized delegate;
 340
 341         NormalizedKeepaliveRpcs(final Rpcs.Normalized delegate) {
 342             this.delegate = requireNonNull(delegate);
 343         }
 344
 345         @Override
 346         public ListenableFuture<? extends DOMRpcResult> invokeRpc(final QName type, final ContainerNode input) {
 347             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 348             disableKeepalive();
 349             return scheduleTimeout(delegate.invokeRpc(type, input));
 350         }
 351
 352         @Override
 353         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(
 354             final T rpcListener) {
 355             // There is no real communication with the device (yet), hence no recordActivity() or anything
 356             return delegate.registerRpcListener(rpcListener);
 357         }
 358     }
 359
 360     /**
 361      * Proxy for {@link Rpcs} which attaches a reset-keepalive-task and schedule request-timeout-task to each RPC
 362      * invocation. Version for {@link Rpcs.Schemaless}.
 363      */
 364     private final class SchemalessKeepaliveRpcs implements Rpcs.Schemaless {
 365         private final Rpcs.Schemaless delegate;
 366
 367         SchemalessKeepaliveRpcs(final Rpcs.Schemaless delegate) {
 368             this.delegate = requireNonNull(delegate);
 369         }
 370
 371         @Override
 372         public ListenableFuture<? extends DOMRpcResult> invokeNetconf(final QName type, final ContainerNode input) {
 373             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 374             disableKeepalive();
 375             return scheduleTimeout(delegate.invokeNetconf(type, input));
 376         }
 377
 378         @Override
 379         public ListenableFuture<? extends DOMSource> invokeRpc(final QName type, final DOMSource input) {
 380             // FIXME: what happens if we disable keepalive and then invokeRpc() throws?
 381             disableKeepalive();
 382             return scheduleTimeout(delegate.invokeRpc(type, input));
 383         }
 384     }
 385 }