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 org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getSourceNode;
  11 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_QNAME;
  12 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_RUNNING_QNAME;
  13 import static org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.toPath;
  14
  15 import com.google.common.base.Preconditions;
  16 import com.google.common.util.concurrent.CheckedFuture;
  17 import com.google.common.util.concurrent.FutureCallback;
  18 import com.google.common.util.concurrent.Futures;
  19 import com.google.common.util.concurrent.MoreExecutors;
  20 import java.util.concurrent.ScheduledExecutorService;
  21 import java.util.concurrent.ScheduledFuture;
  22 import java.util.concurrent.TimeUnit;
  23 import javax.annotation.Nonnull;
  24 import javax.annotation.Nullable;
  25 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  26 import org.opendaylight.controller.md.sal.dom.api.DOMRpcAvailabilityListener;
  27 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  28 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  29 import org.opendaylight.controller.md.sal.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.yang.data.api.schema.ContainerNode;
  37 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  38 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  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
  69     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  70                               final ScheduledExecutorService executor, final long keepaliveDelaySeconds,
  71                               final long defaultRequestTimeoutMillis) {
  72         this.id = id;
  73         this.salFacade = salFacade;
  74         this.executor = executor;
  75         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  76         this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
  77         this.resetKeepaliveTask = new ResetKeepalive();
  78     }
  79
  80     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  81                               final ScheduledExecutorService executor) {
  82         this(id, salFacade, executor, DEFAULT_DELAY, DEFAULT_TRANSACTION_TIMEOUT_MILLI);
  83     }
  84
  85     /**
  86      * Set the netconf session listener whenever ready.
  87      *
  88      * @param listener netconf session listener
  89      */
  90     public void setListener(final NetconfDeviceCommunicator listener) {
  91         this.listener = listener;
  92     }
  93
  94     /**
  95      * Just cancel current keepalive task.
  96      * If its already started, let it finish ... not such a big deal.
  97      *
  98      * <p>
  99      * Then schedule next keepalive.
 100      */
 101     void resetKeepalive() {
 102         LOG.trace("{}: Resetting netconf keepalive timer", id);
 103         if (currentKeepalive != null) {
 104             currentKeepalive.cancel(false);
 105         }
 106         scheduleKeepalive();
 107     }
 108
 109     /**
 110      * Cancel current keepalive and also reset current deviceRpc.
 111      */
 112     private void stopKeepalives() {
 113         if (currentKeepalive != null) {
 114             currentKeepalive.cancel(false);
 115         }
 116         currentDeviceRpc = null;
 117     }
 118
 119     void reconnect() {
 120         Preconditions.checkState(listener != null, "%s: Unable to reconnect, session listener is missing", id);
 121         stopKeepalives();
 122         LOG.info("{}: Reconnecting inactive netconf session", id);
 123         listener.disconnect();
 124     }
 125
 126     @Override
 127     public void onDeviceConnected(final SchemaContext remoteSchemaContext,
 128                           final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc) {
 129         this.currentDeviceRpc = deviceRpc;
 130         final DOMRpcService deviceRpc1 =
 131                 new KeepaliveDOMRpcService(deviceRpc, resetKeepaliveTask, defaultRequestTimeoutMillis, executor);
 132         salFacade.onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc1);
 133
 134         LOG.debug("{}: Netconf session initiated, starting keepalives", id);
 135         scheduleKeepalive();
 136     }
 137
 138     private void scheduleKeepalive() {
 139         Preconditions.checkState(currentDeviceRpc != null);
 140         LOG.trace("{}: Scheduling next keepalive in {} {}", id, keepaliveDelaySeconds, TimeUnit.SECONDS);
 141         currentKeepalive = executor.schedule(new Keepalive(currentKeepalive), keepaliveDelaySeconds, TimeUnit.SECONDS);
 142     }
 143
 144     @Override
 145     public void onDeviceDisconnected() {
 146         stopKeepalives();
 147         salFacade.onDeviceDisconnected();
 148     }
 149
 150     @Override
 151     public void onDeviceFailed(final Throwable throwable) {
 152         stopKeepalives();
 153         salFacade.onDeviceFailed(throwable);
 154     }
 155
 156     @Override
 157     public void onNotification(final DOMNotification domNotification) {
 158         resetKeepalive();
 159         salFacade.onNotification(domNotification);
 160     }
 161
 162     @Override
 163     public void close() {
 164         stopKeepalives();
 165         salFacade.close();
 166     }
 167
 168     // Keepalive RPC static resources
 169     private static final SchemaPath PATH = toPath(NETCONF_GET_CONFIG_QNAME);
 170     private static final ContainerNode KEEPALIVE_PAYLOAD = NetconfMessageTransformUtil.wrap(NETCONF_GET_CONFIG_QNAME,
 171             getSourceNode(NETCONF_RUNNING_QNAME), NetconfMessageTransformUtil.EMPTY_FILTER);
 172
 173     /**
 174      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 175      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 176      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 177      * is considered inactive/failed.
 178      */
 179     private class Keepalive implements Runnable, FutureCallback<DOMRpcResult> {
 180
 181         private final ScheduledFuture<?> previousKeepalive;
 182
 183         Keepalive(final ScheduledFuture<?> previousKeepalive) {
 184             this.previousKeepalive = previousKeepalive;
 185         }
 186
 187         @Override
 188         public void run() {
 189             LOG.trace("{}: Invoking keepalive RPC", id);
 190
 191             try {
 192                 if (previousKeepalive != null && !previousKeepalive.isDone()) {
 193                     onFailure(new IllegalStateException("Previous keepalive timed out"));
 194                 } else {
 195                     Futures.addCallback(currentDeviceRpc.invokeRpc(PATH, KEEPALIVE_PAYLOAD), this,
 196                                         MoreExecutors.directExecutor());
 197                 }
 198             } catch (NullPointerException e) {
 199                 LOG.debug("{}: Skipping keepalive while reconnecting", id);
 200                 // Empty catch block intentional
 201                 // Do nothing. The currentDeviceRpc was null and it means we hit the reconnect window and
 202                 // attempted to send keepalive while we were reconnecting. Next keepalive will be scheduled
 203                 // after reconnect so no action necessary here.
 204             }
 205         }
 206
 207         @Override
 208         public void onSuccess(final DOMRpcResult result) {
 209             // No matter what response we got, rpc-reply or rpc-error,
 210             // we got it from device so the netconf session is OK
 211             if (result != null && result.getResult() != null) {
 212                 LOG.debug("{}: Keepalive RPC successful with response: {}", id, result.getResult());
 213                 scheduleKeepalive();
 214             } else if (result != null && !result.getErrors().isEmpty()) {
 215                 LOG.warn("{}: Keepalive RPC failed with error: {}", id, result.getErrors());
 216                 scheduleKeepalive();
 217             } else {
 218                 LOG.warn("{} Keepalive RPC returned null with response. Reconnecting netconf session", id);
 219                 reconnect();
 220             }
 221         }
 222
 223         @Override
 224         public void onFailure(@Nonnull final Throwable throwable) {
 225             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, throwable);
 226             reconnect();
 227         }
 228     }
 229
 230     /**
 231      * Reset keepalive after each RPC response received.
 232      */
 233     private class ResetKeepalive implements FutureCallback<DOMRpcResult> {
 234         @Override
 235         public void onSuccess(@Nullable final DOMRpcResult result) {
 236             // No matter what response we got,
 237             // rpc-reply or rpc-error, we got it from device so the netconf session is OK.
 238             resetKeepalive();
 239         }
 240
 241         @Override
 242         public void onFailure(@Nonnull final Throwable throwable) {
 243             // User/Application RPC failed (The RPC did not reach the remote device or ..
 244             // TODO what other reasons could cause this ?)
 245             // There is no point in keeping this session. Reconnect.
 246             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, throwable);
 247             reconnect();
 248         }
 249     }
 250
 251     /*
 252      * Request timeout task is called once the defaultRequestTimeoutMillis is
 253      * reached. At this moment, if the request is not yet finished, we cancel
 254      * it.
 255      */
 256     private static final class RequestTimeoutTask implements Runnable {
 257
 258         private final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultFuture;
 259
 260         RequestTimeoutTask(final CheckedFuture<DOMRpcResult, DOMRpcException> rpcResultFuture) {
 261             this.rpcResultFuture = rpcResultFuture;
 262         }
 263
 264         @Override
 265         public void run() {
 266             if (!rpcResultFuture.isDone()) {
 267                 rpcResultFuture.cancel(true);
 268             }
 269         }
 270     }
 271
 272     /**
 273      * DOMRpcService proxy that attaches reset-keepalive-task and schedule
 274      * request-timeout-task to each RPC invocation.
 275      */
 276     public static final class KeepaliveDOMRpcService implements DOMRpcService {
 277
 278         private final DOMRpcService deviceRpc;
 279         private final ResetKeepalive resetKeepaliveTask;
 280         private final long defaultRequestTimeoutMillis;
 281         private final ScheduledExecutorService executor;
 282
 283         KeepaliveDOMRpcService(final DOMRpcService deviceRpc, final ResetKeepalive resetKeepaliveTask,
 284                 final long defaultRequestTimeoutMillis, final ScheduledExecutorService executor) {
 285             this.deviceRpc = deviceRpc;
 286             this.resetKeepaliveTask = resetKeepaliveTask;
 287             this.defaultRequestTimeoutMillis = defaultRequestTimeoutMillis;
 288             this.executor = executor;
 289         }
 290
 291         public DOMRpcService getDeviceRpc() {
 292             return deviceRpc;
 293         }
 294
 295         @Nonnull
 296         @Override
 297         public CheckedFuture<DOMRpcResult, DOMRpcException> invokeRpc(@Nonnull final SchemaPath type,
 298                                                                       final NormalizedNode<?, ?> input) {
 299             final CheckedFuture<DOMRpcResult, DOMRpcException> domRpcResultDOMRpcExceptionCheckedFuture =
 300                     deviceRpc.invokeRpc(type, input);
 301             Futures.addCallback(domRpcResultDOMRpcExceptionCheckedFuture, resetKeepaliveTask,
 302                                 MoreExecutors.directExecutor());
 303
 304             final RequestTimeoutTask timeoutTask = new RequestTimeoutTask(domRpcResultDOMRpcExceptionCheckedFuture);
 305             executor.schedule(timeoutTask, defaultRequestTimeoutMillis, TimeUnit.MILLISECONDS);
 306
 307             return domRpcResultDOMRpcExceptionCheckedFuture;
 308         }
 309
 310         @Override
 311         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(
 312                 @Nonnull final T listener) {
 313             // There is no real communication with the device (yet), no reset here
 314             return deviceRpc.registerRpcListener(listener);
 315         }
 316     }
 317 }