opendaylight/md-sal/sal-netconf-connector/src/main/java/org/opendaylight/controller/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.controller.sal.connect.netconf.sal;
   9
  10 import static org.opendaylight.controller.sal.connect.netconf.util.NetconfBaseOps.getSourceNode;
  11 import static org.opendaylight.controller.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_GET_CONFIG_QNAME;
  12 import static org.opendaylight.controller.sal.connect.netconf.util.NetconfMessageTransformUtil.NETCONF_RUNNING_QNAME;
  13 import static org.opendaylight.controller.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.controller.sal.connect.api.RemoteDeviceHandler;
  30 import org.opendaylight.controller.sal.connect.netconf.listener.NetconfDeviceCommunicator;
  31 import org.opendaylight.controller.sal.connect.netconf.listener.NetconfSessionPreferences;
  32 import org.opendaylight.controller.sal.connect.netconf.util.NetconfMessageTransformUtil;
  33 import org.opendaylight.controller.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         currentKeepalive.cancel(false);
  96         scheduleKeepalive();
  97     }
  98
  99     /**
 100      * Cancel current keepalive and also reset current deviceRpc
 101      */
 102     private void stopKeepalives() {
 103         currentKeepalive.cancel(false);
 104         currentDeviceRpc = null;
 105     }
 106
 107     private void reconnect() {
 108         Preconditions.checkState(listener != null, "%s: Unable to reconnect, session listener is missing", id);
 109         stopKeepalives();
 110         LOG.info("{}: Reconnecting inactive netconf session", id);
 111         listener.disconnect();
 112     }
 113
 114     @Override
 115     public void onDeviceConnected(final SchemaContext remoteSchemaContext, final NetconfSessionPreferences netconfSessionPreferences, final DOMRpcService deviceRpc) {
 116         this.currentDeviceRpc = deviceRpc;
 117         final DOMRpcService deviceRpc1 = new KeepaliveDOMRpcService(deviceRpc, resetKeepaliveTask);
 118         salFacade.onDeviceConnected(remoteSchemaContext, netconfSessionPreferences, deviceRpc1);
 119
 120         LOG.debug("{}: Netconf session initiated, starting keepalives", id);
 121         scheduleKeepalive();
 122     }
 123
 124     private void scheduleKeepalive() {
 125         Preconditions.checkState(currentDeviceRpc != null);
 126         LOG.trace("{}: Scheduling next keepalive in {} {}", id, keepaliveDelaySeconds, TimeUnit.SECONDS);
 127         currentKeepalive = executor.schedule(new Keepalive(), keepaliveDelaySeconds, TimeUnit.SECONDS);
 128     }
 129
 130     @Override
 131     public void onDeviceDisconnected() {
 132         stopKeepalives();
 133         salFacade.onDeviceDisconnected();
 134     }
 135
 136     @Override
 137     public void onDeviceFailed(final Throwable throwable) {
 138         stopKeepalives();
 139         salFacade.onDeviceFailed(throwable);
 140     }
 141
 142     @Override
 143     public void onNotification(final DOMNotification domNotification) {
 144         resetKeepalive();
 145         salFacade.onNotification(domNotification);
 146     }
 147
 148     @Override
 149     public void close() {
 150         stopKeepalives();
 151         salFacade.close();
 152     }
 153
 154     // Keepalive RPC static resources
 155     private static final SchemaPath PATH = toPath(NETCONF_GET_CONFIG_QNAME);
 156     private static final ContainerNode KEEPALIVE_PAYLOAD =
 157             NetconfMessageTransformUtil.wrap(NETCONF_GET_CONFIG_QNAME, getSourceNode(NETCONF_RUNNING_QNAME), NetconfMessageTransformUtil.EMPTY_FILTER);
 158
 159     /**
 160      * Invoke keepalive RPC and check the response. In case of any received response the keepalive
 161      * is considered successful and schedules next keepalive with a fixed delay. If the response is unsuccessful (no
 162      * response received, or the rcp could not even be sent) immediate reconnect is triggered as netconf session
 163      * is considered inactive/failed.
 164      */
 165     private class Keepalive implements Runnable, FutureCallback<DOMRpcResult> {
 166
 167         @Override
 168         public void run() {
 169             LOG.trace("{}: Invoking keepalive RPC", id);
 170
 171             try {
 172                 Futures.addCallback(currentDeviceRpc.invokeRpc(PATH, KEEPALIVE_PAYLOAD), this);
 173             } catch (NullPointerException e) {
 174                 LOG.debug("{}: Skipping keepalive while reconnecting", id);
 175                 // Empty catch block intentional
 176                 // Do nothing. The currentDeviceRpc was null and it means we hit the reconnect window and
 177                 // attempted to send keepalive while we were reconnecting. Next keepalive will be scheduled
 178                 // after reconnect so no action necessary here.
 179             }
 180         }
 181
 182         @Override
 183         public void onSuccess(final DOMRpcResult result) {
 184             LOG.debug("{}: Keepalive RPC successful with response: {}", id, result.getResult());
 185             scheduleKeepalive();
 186         }
 187
 188         @Override
 189         public void onFailure(@Nonnull final Throwable t) {
 190             LOG.warn("{}: Keepalive RPC failed. Reconnecting netconf session.", id, t);
 191             reconnect();
 192         }
 193     }
 194
 195     /**
 196      * Reset keepalive after each RPC response received
 197      */
 198     private class ResetKeepalive implements com.google.common.util.concurrent.FutureCallback<DOMRpcResult> {
 199         @Override
 200         public void onSuccess(@Nullable final DOMRpcResult result) {
 201             // No matter what response we got, rpc-reply or rpc-error, we got it from device so the netconf session is OK
 202             resetKeepalive();
 203         }
 204
 205         @Override
 206         public void onFailure(@Nonnull final Throwable t) {
 207             // User/Application RPC failed (The RPC did not reach the remote device or .. TODO what other reasons could cause this ?)
 208             // There is no point in keeping this session. Reconnect.
 209             LOG.warn("{}: Rpc failure detected. Reconnecting netconf session", id, t);
 210             reconnect();
 211         }
 212     }
 213
 214     /**
 215      * DOMRpcService proxy that attaches reset-keepalive-task to each RPC invocation.
 216      */
 217     private static final class KeepaliveDOMRpcService implements DOMRpcService {
 218
 219         private final DOMRpcService deviceRpc;
 220         private ResetKeepalive resetKeepaliveTask;
 221
 222         public KeepaliveDOMRpcService(final DOMRpcService deviceRpc, final ResetKeepalive resetKeepaliveTask) {
 223             this.deviceRpc = deviceRpc;
 224             this.resetKeepaliveTask = resetKeepaliveTask;
 225         }
 226
 227         @Nonnull
 228         @Override
 229         public CheckedFuture<DOMRpcResult, DOMRpcException> invokeRpc(@Nonnull final SchemaPath type, final NormalizedNode<?, ?> input) {
 230             final CheckedFuture<DOMRpcResult, DOMRpcException> domRpcResultDOMRpcExceptionCheckedFuture = deviceRpc.invokeRpc(type, input);
 231             Futures.addCallback(domRpcResultDOMRpcExceptionCheckedFuture, resetKeepaliveTask);
 232             return domRpcResultDOMRpcExceptionCheckedFuture;
 233         }
 234
 235         @Override
 236         public <T extends DOMRpcAvailabilityListener> ListenerRegistration<T> registerRpcListener(@Nonnull final T listener) {
 237             // There is no real communication with the device (yet), no reset here
 238             return deviceRpc.registerRpcListener(listener);
 239         }
 240     }
 241 }