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 java.util.concurrent.ScheduledExecutorService;
  20 import java.util.concurrent.ScheduledFuture;
  21 import java.util.concurrent.TimeUnit;
  22 import javax.annotation.Nonnull;
  23 import javax.annotation.Nullable;
  24 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  25 import org.opendaylight.controller.md.sal.dom.api.DOMRpcAvailabilityListener;
  26 import org.opendaylight.controller.md.sal.dom.api.DOMRpcException;
  27 import org.opendaylight.controller.md.sal.dom.api.DOMRpcResult;
  28 import org.opendaylight.controller.md.sal.dom.api.DOMRpcService;
  29 import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
  30 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  31 import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
  32 import org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil;
  33 import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
  34 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  35 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  36 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  37 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  38 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * SalFacade proxy that invokes keepalive RPCs to prevent session shutdown from remote device
  44  * and to detect incorrect session drops (netconf session is inactive, but TCP/SSH connection is still present).
  45  * The keepalive RPC is a get-config with empty filter.
  46  */
  47 public final class KeepaliveSalFacade implements RemoteDeviceHandler<NetconfSessionPreferences> {
  48
  49     private static final Logger LOG = LoggerFactory.getLogger(KeepaliveSalFacade.class);
  50
  51     // 2 minutes keepalive delay by default
  52     private static final long DEFAULT_DELAY = TimeUnit.MINUTES.toSeconds(2);
  53
  54     private final RemoteDeviceId id;
  55     private final RemoteDeviceHandler<NetconfSessionPreferences> salFacade;
  56     private final ScheduledExecutorService executor;
  57     private final long keepaliveDelaySeconds;
  58     private final ResetKeepalive resetKeepaliveTask;
  59
  60     private volatile NetconfDeviceCommunicator listener;
  61     private volatile ScheduledFuture<?> currentKeepalive;
  62     private volatile DOMRpcService currentDeviceRpc;
  63
  64     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  65                               final ScheduledExecutorService executor, final long keepaliveDelaySeconds) {
  66         this.id = id;
  67         this.salFacade = salFacade;
  68         this.executor = executor;
  69         this.keepaliveDelaySeconds = keepaliveDelaySeconds;
  70         this.resetKeepaliveTask = new ResetKeepalive();
  71     }
  72
  73     public KeepaliveSalFacade(final RemoteDeviceId id, final RemoteDeviceHandler<NetconfSessionPreferences> salFacade,
  74                               final ScheduledExecutorService executor) {
  75         this(id, salFacade, executor, DEFAULT_DELAY);
  76     }
  77
  78     /**
  79      * Set the netconf session listener whenever ready
  80      *
  81      * @param listener netconf session listener
  82      */
  83     public void setListener(final NetconfDeviceCommunicator listener) {
  84         this.listener = listener;
  85     }
  86
  87     /**
  88      * Just cancel current keepalive task.
  89      * If its already started, let it finish ... not such a big deal.
  90      *
  91      * Then schedule next keepalive.
  92      */
  93     private void resetKeepalive() {
  94         LOG.trace("{}: Resetting netconf keepalive timer", id);
  95         if(currentKeepalive != null) {
  96             currentKeepalive.cancel(false);
  97         }
  98         scheduleKeepalive();
  99     }
 100
 101     /**
 102      * Cancel current keepalive and also reset current deviceRpc
 103      */
 104     private void stopKeepalives() {
 105         if(currentKeepalive != null) {
 106             currentKeepalive.cancel(false);
 107         }
 108         currentDeviceRpc = null;
 109     }
 110
 111     private void reconnect() {
 112         Preconditions.checkState(listener != null, "%s: Unable to reconnect, session listener is missing", id);
 113         stopKeepalives();
 114         LOG.info("{}: Reconnecting inactive netconf session", id);
 115         listener.disconnect();
 116     }
 117
 118     @Override
 119     public void onDeviceConnected(final SchemaContext remoteSchemaContext, final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc) {
 120         this.currentDeviceRpc = deviceRpc;
 121         final DOMRpcService deviceRpc1 = new KeepaliveDOMRpcService(deviceRpc, resetKeepaliveTask);
 122         salFacade.onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc1);
 123
 124         LOG.debug("{}: Netconf session initiated, starting keepalives", id);
 125         scheduleKeepalive();
 126     }
 127
 128     private void scheduleKeepalive() {
 129         Preconditions.checkState(currentDeviceRpc != null);
 130         LOG.trace("{}: Scheduling next keepalive in {} {}", id, keepaliveDelaySeconds, TimeUnit.SECONDS);
 131         currentKeepalive = executor.schedule(new Keepalive(currentKeepalive), keepaliveDelaySeconds, TimeUnit.SECONDS);
 132     }
 133
 134     @Override
 135     public void onDeviceDisconnected() {
 136         stopKeepalives();
 137         salFacade.onDeviceDisconnected();
 138     }
 139
 140     @Override
 141     public void onDeviceFailed(final Throwable throwable) {
 142         stopKeepalives();
 143         salFacade.onDeviceFailed(throwable);
 144     }
 145
 146     @Override
 147     public void onNotification(final DOMNotification domNotification) {
 148         resetKeepalive();
 149         salFacade.onNotification(domNotification);
 150     }
 151
 152     @Override
 153     public void close() {
 154         stopKeepalives();
 155         salFacade.close();
 156     }
 157
 158     // Keepalive RPC static resources
 159     private static final SchemaPath PATH = toPath(NETCONF_GET_CONFIG_QNAME);
 160     private static final ContainerNode KEEPALIVE_PAYLOAD =
 161             NetconfMessageTransformUtil.wrap(NETCONF_GET_CONFIG_QNAME, getSourceNode(NETCONF_RUNNING_QNAME), NetconfMessageTransformUtil.EMPTY_FILTER);
 162
 163     /**
 164      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 165      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 166      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 167      * is considered inactive/failed.
 168      */
 169     private class Keepalive implements Runnable, FutureCallback<DOMRpcResult> {
 170
 171         private final ScheduledFuture<?> previousKeepalive;
 172
 173         public Keepalive(final ScheduledFuture<?> previousKeepalive) {
 174             this.previousKeepalive = previousKeepalive;
 175         }
 176
 177         @Override
 178         public void run() {
 179             LOG.trace("{}: Invoking keepalive RPC", id);
 180
 181             try {
 182                 if(previousKeepalive != null && !previousKeepalive.isDone()) {
 183                     onFailure(new IllegalStateException("Previous keepalive timed out"));
 184                 } else {
 185                     Futures.addCallback(currentDeviceRpc.invokeRpc(PATH, KEEPALIVE_PAYLOAD), this);
 186                 }
 187             } catch (NullPointerException e) {
 188                 LOG.debug("{}: Skipping keepalive while reconnecting", id);
 189                 // Empty catch block intentional
 190                 // Do nothing. The currentDeviceRpc was null and it means we hit the reconnect window and
 191                 // attempted to send keepalive while we were reconnecting. Next keepalive will be scheduled
 192                 // after reconnect so no action necessary here.
 193             }
 194         }
 195
 196         @Override
 197         public void onSuccess(final DOMRpcResult result) {
 198             if (result != null && result.getResult() != null) {
 199                 LOG.debug("{}: Keepalive RPC successful with response: {}", id, result.getResult());
 200                 scheduleKeepalive();
 201             } else {
 202                 LOG.warn("{} Keepalive RPC returned null with response: {}. Reconnecting netconf session", id, result);
 203                 reconnect();
 204             }
 205         }
 206
 207         @Override
 208         public void onFailure(@Nonnull final Throwable t) {
 209             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, t);
 210             reconnect();
 211         }
 212     }
 213
 214     /**
 215      * Reset keepalive after each RPC response received
 216      */
 217     private class ResetKeepalive implements com.google.common.util.concurrent.FutureCallback<DOMRpcResult> {
 218         @Override
 219         public void onSuccess(@Nullable final DOMRpcResult result) {
 220             // No matter what response we got, rpc-reply or rpc-error, we got it from device so the netconf session is OK
 221             resetKeepalive();
 222         }
 223
 224         @Override
 225         public void onFailure(@Nonnull final Throwable t) {
 226             // User/Application RPC failed (The RPC did not reach the remote device.
 227             // There is no point in keeping this session. Reconnect.
 228             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, t);
 229             reconnect();
 230         }
 231     }
 232
 233     /**
 234      * DOMRpcService proxy that attaches reset-keepalive-task to each RPC invocation.
 235      */
 236     private static final class KeepaliveDOMRpcService implements DOMRpcService {
 237
 238         private final DOMRpcService deviceRpc;
 239         private ResetKeepalive resetKeepaliveTask;
 240
 241         public KeepaliveDOMRpcService(final DOMRpcService deviceRpc, final ResetKeepalive resetKeepaliveTask) {
 242             this.deviceRpc = deviceRpc;
 243             this.resetKeepaliveTask = resetKeepaliveTask;
 244         }
 245
 246         @Nonnull
 247         @Override
 248         public CheckedFuture<DOMRpcResult, DOMRpcException> invokeRpc(@Nonnull final SchemaPath type, final NormalizedNode<?, ?> input) {
 249             final CheckedFuture<DOMRpcResult, DOMRpcException> domRpcResultDOMRpcExceptionCheckedFuture = deviceRpc.invokeRpc(type, input);
 250             Futures.addCallback(domRpcResultDOMRpcExceptionCheckedFuture, resetKeepaliveTask);
 251             return domRpcResultDOMRpcExceptionCheckedFuture;
 252         }
 253
 254         @Override
 255         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(@Nonnull final T listener) {
 256             // There is no real communication with the device (yet), no reset here
 257             return deviceRpc.registerRpcListener(listener);
 258         }
 259     }
 260 }