Bump upstreams
[bgpcep.git] / bgp / rib-impl / src / main / java / org / opendaylight / protocol / bgp / rib / impl / BGPPeer.java
index 69b8044eed29c441eb4dd097857a626239c6a2e9..cf98d83220be5d687f26249eefda50ac819feb29 100644 (file)
@@ -8,93 +8,99 @@
 package org.opendaylight.protocol.bgp.rib.impl;
 
 import static java.util.Objects.requireNonNull;
+import static org.opendaylight.protocol.bgp.rib.spi.RIBNodeIdentifiers.ADJRIBOUT_NID;
+import static org.opendaylight.protocol.bgp.rib.spi.RIBNodeIdentifiers.TABLES_NID;
 
 import com.google.common.base.MoreObjects;
-import com.google.common.base.MoreObjects.ToStringHelper;
-import com.google.common.base.Objects;
+import com.google.common.base.Stopwatch;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.ImmutableClassToInstanceMap;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
-import com.google.common.net.InetAddresses;
+import com.google.common.util.concurrent.FluentFuture;
+import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
-import javax.annotation.concurrent.GuardedBy;
-import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionChain;
-import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
-import org.opendaylight.controller.md.sal.dom.api.DOMTransactionChain;
-import org.opendaylight.controller.sal.binding.api.BindingAwareBroker.RoutedRpcRegistration;
-import org.opendaylight.controller.sal.binding.api.RpcProviderRegistry;
+import org.checkerframework.checker.lock.qual.GuardedBy;
+import org.checkerframework.checker.lock.qual.Holding;
+import org.eclipse.jdt.annotation.NonNull;
+import org.opendaylight.mdsal.binding.api.RpcProviderService;
+import org.opendaylight.mdsal.common.api.CommitInfo;
+import org.opendaylight.protocol.bgp.openconfig.spi.BGPTableTypeRegistryConsumer;
 import org.opendaylight.protocol.bgp.parser.BGPDocumentedException;
 import org.opendaylight.protocol.bgp.parser.BGPError;
 import org.opendaylight.protocol.bgp.parser.impl.message.update.LocalPreferenceAttributeParser;
 import org.opendaylight.protocol.bgp.parser.spi.MessageUtil;
+import org.opendaylight.protocol.bgp.parser.spi.RevisedErrorHandlingSupport;
+import org.opendaylight.protocol.bgp.rib.impl.config.BgpPeer;
+import org.opendaylight.protocol.bgp.rib.impl.config.GracefulRestartUtil;
+import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
 import org.opendaylight.protocol.bgp.rib.impl.spi.RIB;
-import org.opendaylight.protocol.bgp.rib.impl.state.BGPPeerStateImpl;
 import org.opendaylight.protocol.bgp.rib.impl.state.BGPSessionStateProvider;
 import org.opendaylight.protocol.bgp.rib.spi.BGPSession;
 import org.opendaylight.protocol.bgp.rib.spi.BGPSessionListener;
 import org.opendaylight.protocol.bgp.rib.spi.BGPTerminationReason;
-import org.opendaylight.protocol.bgp.rib.spi.Peer;
 import org.opendaylight.protocol.bgp.rib.spi.RIBSupport;
 import org.opendaylight.protocol.bgp.rib.spi.RouterIds;
-import org.opendaylight.protocol.bgp.rib.spi.policy.BGPRouteEntryImportParameters;
-import org.opendaylight.protocol.bgp.rib.spi.state.BGPAfiSafiState;
-import org.opendaylight.protocol.bgp.rib.spi.state.BGPErrorHandlingState;
 import org.opendaylight.protocol.bgp.rib.spi.state.BGPSessionState;
 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTimersState;
 import org.opendaylight.protocol.bgp.rib.spi.state.BGPTransportState;
-import org.opendaylight.protocol.concepts.AbstractRegistration;
 import org.opendaylight.protocol.util.Ipv4Util;
-import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.DestinationIpv4Builder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.destination.ipv4.Ipv4Prefixes;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.ipv4.prefixes.destination.ipv4.Ipv4PrefixesBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.update.attributes.mp.reach.nlri.advertized.routes.destination.type.DestinationIpv4CaseBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.Update;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.path.attributes.Attributes;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.path.attributes.AttributesBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev171207.update.message.Nlri;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.BgpAddPathTableType;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.BgpTableType;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.RouteRefresh;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.SendReceive;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.mp.capabilities.add.path.capability.AddressFamilies;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpReachNlri;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpReachNlriBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpUnreachNlri;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.MpUnreachNlriBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.mp.reach.nlri.AdvertizedRoutesBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev171207.update.attributes.mp.unreach.nlri.WithdrawnRoutesBuilder;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev171207.BgpPeerRpcService;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev171207.PeerContext;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.PeerId;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.PeerRole;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib.rib.PeerKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib.rib.peer.AdjRibOut;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.rib.Tables;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.rib.TablesKey;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.AddressFamily;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.Ipv4AddressFamily;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.SubsequentAddressFamily;
-import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev130919.UnicastSubsequentAddressFamily;
-import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.AsNumber;
+import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddressNoZone;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev180329.ipv4.prefixes.DestinationIpv4Builder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev180329.ipv4.prefixes.destination.ipv4.Ipv4Prefixes;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev180329.ipv4.prefixes.destination.ipv4.Ipv4PrefixesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.inet.rev180329.update.attributes.mp.reach.nlri.advertized.routes.destination.type.DestinationIpv4CaseBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.Update;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.open.message.BgpParameters;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.Attributes;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.path.attributes.AttributesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev200120.update.message.Nlri;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.BgpAddPathTableType;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.BgpTableType;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.RouteRefresh;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.SendReceive;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.reach.MpReachNlri;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.reach.MpReachNlriBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.reach.mp.reach.nlri.AdvertizedRoutesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.unreach.MpUnreachNlri;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.unreach.MpUnreachNlriBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.attributes.unreach.mp.unreach.nlri.WithdrawnRoutesBuilder;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.GracefulRestartCapability;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev180329.mp.capabilities.add.path.capability.AddressFamilies;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev180329.ResetSession;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev180329.RestartGracefully;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.peer.rpc.rev180329.RouteRefreshRequest;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.PeerRole;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.bgp.rib.rib.PeerKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.rib.TablesKey;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.ClusterIdentifier;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.Ipv4AddressFamily;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.RouteTarget;
+import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.types.rev200120.UnicastSubsequentAddressFamily;
+import org.opendaylight.yangtools.concepts.Registration;
 import org.opendaylight.yangtools.yang.binding.KeyedInstanceIdentifier;
 import org.opendaylight.yangtools.yang.binding.Notification;
+import org.opendaylight.yangtools.yang.binding.Rpc;
+import org.opendaylight.yangtools.yang.common.Empty;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -102,60 +108,73 @@ import org.slf4j.LoggerFactory;
  * Class representing a peer. We have a single instance for each peer, which provides translation from BGP events into
  * RIB actions.
  */
-public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportParameters,
-        BGPSessionListener, Peer, TransactionChainListener {
+public class BGPPeer extends AbstractPeer implements BGPSessionListener {
     private static final Logger LOG = LoggerFactory.getLogger(BGPPeer.class);
+    private static final TablesKey IPV4_UCAST_TABLE_KEY =
+        new TablesKey(Ipv4AddressFamily.VALUE, UnicastSubsequentAddressFamily.VALUE);
 
-    private Set<TablesKey> tables = Collections.emptySet();
     private final RIB rib;
-    private final String name;
+
+    // FIXME: Alright, this right here is a ton of state which has intertwined initialization and dependencies Split
+    //        these out into separate behavior objects. This also has relationship with state in AbstractPeer -- which
+    //        hints at an obvious layer of indirection. Yeah, yeah, we can always add one of those, but the point
+    //        is that this class is a mutable meeting point, whereas the behaviour has captured invariants.
+    private final LoadingCache<NodeIdentifierWithPredicates, YangInstanceIdentifier> tablesIId =
+        CacheBuilder.newBuilder().build(new CacheLoader<NodeIdentifierWithPredicates, YangInstanceIdentifier>() {
+            @Override
+            public YangInstanceIdentifier load(final NodeIdentifierWithPredicates key) {
+                return peerRibOutIId.node(TABLES_NID).node(key).toOptimized();
+            }
+        });
+
+    private ImmutableSet<TablesKey> tables = ImmutableSet.of();
     private final Map<TablesKey, AdjRibOutListener> adjRibOutListenerSet = new HashMap<>();
-    private final RpcProviderRegistry rpcRegistry;
-    private final PeerRole peerRole;
-    private final InstanceIdentifier<AdjRibOut> peerRibOutIId;
-    private final KeyedInstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib
-            .rev171207.bgp.rib.rib.Peer, PeerKey> peerIId;
-    @GuardedBy("this")
-    private AbstractRegistration trackerRegistration;
-    private final PeerId peerId;
-    private final LoadingCache<TablesKey, KeyedInstanceIdentifier<Tables, TablesKey>> tablesIId
-            = CacheBuilder.newBuilder()
-            .build(new CacheLoader<TablesKey, KeyedInstanceIdentifier<Tables, TablesKey>>() {
-                @Override
-                public KeyedInstanceIdentifier<Tables, TablesKey> load(final TablesKey tablesKey) {
-                    return BGPPeer.this.peerRibOutIId.child(Tables.class, tablesKey);
-                }
-            });
+    private final List<RouteTarget> rtMemberships = new ArrayList<>();
+    private final RpcProviderService rpcRegistry;
+    private final BGPTableTypeRegistryConsumer tableTypeRegistry;
+    private final BgpPeer bgpPeer;
 
+    // FIXME: This should be a constant co-located with ApplicationPeer.peerId
+    private YangInstanceIdentifier peerRibOutIId;
     @GuardedBy("this")
-    private BGPSession session;
-    @GuardedBy("this")
-    private byte[] rawIdentifier;
+    private Registration trackerRegistration;
+
     @GuardedBy("this")
-    private DOMTransactionChain chain;
+    private BGPSession currentSession;
     @GuardedBy("this")
     private AdjRibInWriter ribWriter;
     @GuardedBy("this")
     private EffectiveRibInWriter effRibInWriter;
-    private RoutedRpcRegistration<BgpPeerRpcService> rpcRegistration;
-    private Map<TablesKey, SendReceive> addPathTableMaps = Collections.emptyMap();
-
-    public BGPPeer(final IpAddress neighborAddress, final RIB rib, final PeerRole role,
-            final RpcProviderRegistry rpcRegistry,
+    private Registration rpcRegistration;
+    private ImmutableMap<TablesKey, SendReceive> addPathTableMaps = ImmutableMap.of();
+    // FIXME: This should be a constant co-located with ApplicationPeer.peerId
+    private YangInstanceIdentifier peerPath;
+    // FIXME: This is for supportsTable() -- a trivial behavior thing, where 'peer-down' type states always return false
+    private boolean sessionUp;
+    private boolean llgrSupport;
+    private Stopwatch peerRestartStopwatch;
+    private long currentSelectionDeferralTimerSeconds;
+    private final List<TablesKey> missingEOT = new ArrayList<>();
+
+    public BGPPeer(
+            final BGPTableTypeRegistryConsumer tableTypeRegistry,
+            final IpAddressNoZone neighborAddress,
+            final String peerGroupName,
+            final RIB rib,
+            final PeerRole role,
+            final ClusterIdentifier clusterId,
+            final AsNumber localAs,
+            final RpcProviderService rpcRegistry,
             final Set<TablesKey> afiSafisAdvertized,
-            final Set<TablesKey> afiSafisGracefulAdvertized) {
-        //FIXME BUG-6971 Once Peer Group is implemented, pass it
-        super(rib.getInstanceIdentifier(), null, neighborAddress, afiSafisAdvertized,
-                afiSafisGracefulAdvertized);
-        this.peerRole = role;
+            final Set<TablesKey> afiSafisGracefulAdvertized,
+            final Map<TablesKey, Integer> llGracefulTablesAdvertised,
+            final BgpPeer bgpPeer) {
+        super(rib, Ipv4Util.toStringIP(neighborAddress), peerGroupName, role, clusterId,
+                localAs, neighborAddress, afiSafisAdvertized, afiSafisGracefulAdvertized, llGracefulTablesAdvertised);
+        this.tableTypeRegistry = requireNonNull(tableTypeRegistry);
         this.rib = requireNonNull(rib);
-        this.name = Ipv4Util.toStringIP(neighborAddress);
         this.rpcRegistry = rpcRegistry;
-        this.peerId = RouterIds.createPeerId(neighborAddress);
-        this.peerIId = getInstanceIdentifier().child(org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns
-                .yang.bgp.rib.rev171207.bgp.rib.rib.Peer.class, new PeerKey(this.peerId));
-        this.peerRibOutIId = this.peerIId.child(AdjRibOut.class);
-        this.chain = rib.createPeerDOMChain(this);
+        this.bgpPeer = bgpPeer;
     }
 
     private static Attributes nextHopToAttribute(final Attributes attrs, final MpReachNlri mpReach) {
@@ -177,11 +196,14 @@ public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportPara
         final List<Ipv4Prefixes> prefixes = message.getNlri().stream()
                 .map(n -> new Ipv4PrefixesBuilder().setPrefix(n.getPrefix()).setPathId(n.getPathId()).build())
                 .collect(Collectors.toList());
-        final MpReachNlriBuilder b = new MpReachNlriBuilder().setAfi(Ipv4AddressFamily.class).setSafi(
-                UnicastSubsequentAddressFamily.class).setAdvertizedRoutes(
-                new AdvertizedRoutesBuilder().setDestinationType(
-                        new DestinationIpv4CaseBuilder().setDestinationIpv4(
-                                new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build()).build()).build());
+        final MpReachNlriBuilder b = new MpReachNlriBuilder()
+            .setAfi(Ipv4AddressFamily.VALUE)
+            .setSafi(UnicastSubsequentAddressFamily.VALUE)
+            .setAdvertizedRoutes(new AdvertizedRoutesBuilder()
+                .setDestinationType(new DestinationIpv4CaseBuilder()
+                    .setDestinationIpv4(new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build())
+                    .build())
+                .build());
         if (message.getAttributes() != null) {
             b.setCNextHop(message.getAttributes().getCNextHop());
         }
@@ -201,65 +223,65 @@ public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportPara
 
             Optional<Nlri> nlriAnounced = Optional.empty();
             if (isAnyNlriAnnounced) {
-                nlriAnounced = message.getNlri().stream().filter(n -> Objects.equal(n.getPrefix(), w.getPrefix())
-                        && Objects.equal(n.getPathId(), w.getPathId()))
+                nlriAnounced = message.getNlri().stream().filter(n -> Objects.equals(n.getPrefix(), w.getPrefix())
+                        && Objects.equals(n.getPathId(), w.getPathId()))
                         .findAny();
             }
             if (!nlriAnounced.isPresent()) {
                 prefixes.add(new Ipv4PrefixesBuilder().setPrefix(w.getPrefix()).setPathId(w.getPathId()).build());
             }
         });
-        return new MpUnreachNlriBuilder().setAfi(Ipv4AddressFamily.class).setSafi(UnicastSubsequentAddressFamily.class)
+        return new MpUnreachNlriBuilder().setAfi(Ipv4AddressFamily.VALUE).setSafi(UnicastSubsequentAddressFamily.VALUE)
                 .setWithdrawnRoutes(new WithdrawnRoutesBuilder().setDestinationType(new org.opendaylight.yang.gen.v1
-                        .urn.opendaylight.params.xml.ns.yang.bgp.inet.rev171207.update.attributes.mp.unreach.nlri
+                        .urn.opendaylight.params.xml.ns.yang.bgp.inet.rev180329.update.attributes.mp.unreach.nlri
                         .withdrawn.routes.destination.type.DestinationIpv4CaseBuilder().setDestinationIpv4(
-                        new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build()).build()).build()).build();
+                            new DestinationIpv4Builder().setIpv4Prefixes(prefixes).build()).build()).build()).build();
     }
 
-    private static Map<TablesKey, SendReceive> mapTableTypesFamilies(final List<AddressFamilies> addPathTablesType) {
-        return ImmutableMap.copyOf(addPathTablesType.stream().collect(Collectors.toMap(af -> new TablesKey(af.getAfi(),
-                        af.getSafi()), BgpAddPathTableType::getSendReceive)));
+    private static ImmutableMap<TablesKey, SendReceive> mapTableTypesFamilies(
+            final List<AddressFamilies> addPathTablesType) {
+        return addPathTablesType.stream().collect(ImmutableMap.toImmutableMap(
+            af -> new TablesKey(af.getAfi(), af.getSafi()), BgpAddPathTableType::getSendReceive));
     }
 
     public synchronized void instantiateServiceInstance() {
-        this.ribWriter = AdjRibInWriter.create(this.rib.getYangRibId(), this.peerRole, this.chain);
+        createDomChain();
+        ribWriter = AdjRibInWriter.create(rib.getYangRibId(), getRole(), this);
         setActive(true);
     }
 
-    // FIXME ListenableFuture<?> should be used once closeServiceInstance uses wildcard too
     @Override
-    public synchronized ListenableFuture<Void> close() {
-        final ListenableFuture<Void> future = releaseConnection();
-        this.chain.close();
+    public synchronized FluentFuture<? extends CommitInfo> close() {
+        final FluentFuture<? extends CommitInfo> future = releaseConnection(true);
+        closeDomChain();
         setActive(false);
         return future;
     }
 
     @Override
-    public void onMessage(final BGPSession session, final Notification msg) throws BGPDocumentedException {
-        if (!(msg instanceof Update) && !(msg instanceof RouteRefresh)) {
-            LOG.info("Ignoring unhandled message class {}", msg.getClass());
-            return;
-        }
-        if (msg instanceof Update) {
-            onUpdateMessage((Update) msg);
+    public void onMessage(final BGPSession session, final Notification<?> msg) throws BGPDocumentedException {
+        if (msg instanceof Update update) {
+            onUpdateMessage(update);
+        } else if (msg instanceof RouteRefresh routeRefresh) {
+            onRouteRefreshMessage(routeRefresh);
         } else {
-            onRouteRefreshMessage((RouteRefresh) msg);
+            LOG.info("Ignoring unhandled message class {}", msg.getClass());
         }
     }
 
     private void onRouteRefreshMessage(final RouteRefresh message) {
-        final Class<? extends AddressFamily> rrAfi = message.getAfi();
-        final Class<? extends SubsequentAddressFamily> rrSafi = message.getSafi();
+        final var rrAfi = message.getAfi();
+        final var rrSafi = message.getSafi();
 
         final TablesKey key = new TablesKey(rrAfi, rrSafi);
-        final AdjRibOutListener listener = this.adjRibOutListenerSet.get(key);
-        if (listener != null) {
-            listener.close();
-            this.adjRibOutListenerSet.remove(key);
-            createAdjRibOutListener(key, listener.isMpSupported());
-        } else {
-            LOG.info("Ignoring RouteRefresh message. Afi/Safi is not supported: {}, {}.", rrAfi, rrSafi);
+        synchronized (this) {
+            final AdjRibOutListener listener = adjRibOutListenerSet.remove(key);
+            if (listener != null) {
+                listener.close();
+                createAdjRibOutListener(key, listener.isMpSupported());
+            } else {
+                LOG.info("Ignoring RouteRefresh message. Afi/Safi is not supported: {}, {}.", rrAfi, rrSafi);
+            }
         }
     }
 
@@ -271,7 +293,7 @@ public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportPara
     private void checkMandatoryAttributesPresence(final Update message) throws BGPDocumentedException {
         if (MessageUtil.isAnyNlriPresent(message)) {
             final Attributes attrs = message.getAttributes();
-            if (this.peerRole == PeerRole.Ibgp && (attrs == null || attrs.getLocalPref() == null)) {
+            if (getRole() == PeerRole.Ibgp && (attrs == null || attrs.getLocalPref() == null)) {
                 throw new BGPDocumentedException(BGPError.MANDATORY_ATTR_MISSING_MSG + "LOCAL_PREF",
                         BGPError.WELL_KNOWN_ATTR_MISSING,
                         new byte[]{LocalPreferenceAttributeParser.TYPE});
@@ -298,257 +320,457 @@ public class BGPPeer extends BGPPeerStateImpl implements BGPRouteEntryImportPara
             mpReach = MessageUtil.getMpReachNlri(attrs);
         }
         if (mpReach != null) {
-            this.ribWriter.updateRoutes(mpReach, nextHopToAttribute(attrs, mpReach));
+            ribWriter.updateRoutes(mpReach, nextHopToAttribute(attrs, mpReach));
         }
-        MpUnreachNlri mpUnreach;
+        final MpUnreachNlri mpUnreach;
         if (message.getWithdrawnRoutes() != null) {
             mpUnreach = prefixesToMpUnreach(message, isAnyNlriAnnounced);
         } else {
             mpUnreach = MessageUtil.getMpUnreachNlri(attrs);
         }
+        final boolean endOfRib = BgpPeerUtil.isEndOfRib(message);
         if (mpUnreach != null) {
-            this.ribWriter.removeRoutes(mpUnreach);
+            if (endOfRib) {
+                final TablesKey tablesKey = new TablesKey(mpUnreach.getAfi(), mpUnreach.getSafi());
+                ribWriter.removeStaleRoutes(tablesKey);
+                missingEOT.remove(tablesKey);
+                handleGracefulEndOfRib();
+            } else {
+                ribWriter.removeRoutes(mpUnreach);
+            }
+        } else if (endOfRib) {
+            ribWriter.removeStaleRoutes(IPV4_UCAST_TABLE_KEY);
+            missingEOT.remove(IPV4_UCAST_TABLE_KEY);
+            handleGracefulEndOfRib();
+        }
+    }
+
+    @Holding("this")
+    private void handleGracefulEndOfRib() {
+        if (isLocalRestarting()) {
+            if (missingEOT.isEmpty()) {
+                createEffRibInWriter();
+                effRibInWriter.init();
+                registerPrefixesCounters(effRibInWriter, effRibInWriter);
+                for (final TablesKey key : getAfiSafisAdvertized()) {
+                    createAdjRibOutListener(key, true);
+                }
+                setLocalRestartingState(false);
+                setGracefulPreferences(false, Collections.emptySet());
+            }
         }
     }
 
     @Override
     public synchronized void onSessionUp(final BGPSession session) {
-        this.session = session;
-        if (this.session instanceof BGPSessionStateProvider) {
-            ((BGPSessionStateProvider) this.session).registerMessagesCounter(this);
+        currentSession = session;
+        sessionUp = true;
+
+        final var chain = rib.createPeerDOMChain();
+        ribOutChain = chain;
+        chain.addCallback(new FutureCallback<Empty>() {
+            @Override
+            public void onSuccess(final Empty result) {
+                LOG.debug("RibOut transaction chain {} successful.", chain);
+            }
+
+            @Override
+            public void onFailure(final Throwable cause) {
+                onRibOutChainFailed(cause);
+            }
+        });
+
+        if (currentSession instanceof BGPSessionStateProvider stateProvider) {
+            stateProvider.registerMessagesCounter(this);
         }
+        final GracefulRestartCapability advertisedGracefulRestartCapability =
+                session.getAdvertisedGracefulRestartCapability();
+        final var advertisedTables = advertisedGracefulRestartCapability.getTables();
+        final var advertisedLLTables = session.getAdvertisedLlGracefulRestartCapability().getTables();
+
         final List<AddressFamilies> addPathTablesType = session.getAdvertisedAddPathTableTypes();
         final Set<BgpTableType> advertizedTableTypes = session.getAdvertisedTableTypes();
-        final List<BgpTableType> advertizedGracefulRestartTableTypes = session.getAdvertisedGracefulRestartTableTypes();
-        LOG.info("Session with peer {} went up with tables {} and Add Path tables {}", this.name,
+        LOG.info("Session with peer {} went up with tables {} and Add Path tables {}", getName(),
                 advertizedTableTypes, addPathTablesType);
-        this.rawIdentifier = InetAddresses.forString(session.getBgpId().getValue()).getAddress();
         final Set<TablesKey> setTables = advertizedTableTypes.stream().map(t -> new TablesKey(t.getAfi(), t.getSafi()))
                 .collect(Collectors.toSet());
-        this.tables = ImmutableSet.copyOf(setTables);
+        tables = ImmutableSet.copyOf(setTables);
 
-        setAdvertizedGracefulRestartTableTypes(advertizedGracefulRestartTableTypes.stream()
-                .map(t -> new TablesKey(t.getAfi(), t.getSafi())).collect(Collectors.toList()));
-        this.addPathTableMaps = ImmutableMap.copyOf(mapTableTypesFamilies(addPathTablesType));
-        this.trackerRegistration = this.rib.getPeerTracker().registerPeer(this);
+        addPathTableMaps = mapTableTypesFamilies(addPathTablesType);
+        final boolean restartingLocally = isLocalRestarting();
+        if (!restartingLocally) {
+            addBgp4Support();
+        }
+        if (!isRestartingGracefully()) {
+            peerId = RouterIds.createPeerId(session.getBgpId());
+
+            final KeyedInstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib
+                .rev180329.bgp.rib.rib.Peer, PeerKey> peerIId = getInstanceIdentifier().child(org.opendaylight.yang.gen
+                    .v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.bgp.rib.rib.Peer.class,
+                    new PeerKey(peerId));
+            peerPath = createPeerPath(peerId);
+            peerRibOutIId = peerPath.node(ADJRIBOUT_NID);
+            trackerRegistration = rib.getPeerTracker().registerPeer(this);
+            createEffRibInWriter();
+            registerPrefixesCounters(effRibInWriter, effRibInWriter);
+
+            effRibInWriter.init();
+            ribWriter = ribWriter.transform(peerId, peerPath, rib.getRibSupportContext(),
+                    tables, addPathTableMaps);
+
+            if (rpcRegistry != null) {
+                final var bgpPeerHandler = new BgpPeerRpc(this, session, tables);
+                rpcRegistration = rpcRegistry.registerRpcImplementations(
+                    ImmutableClassToInstanceMap.<Rpc<?, ?>>builder()
+                        .put(ResetSession.class, bgpPeerHandler::resetSession)
+                        .put(RestartGracefully.class, bgpPeerHandler::restartGracefully)
+                        .put(RouteRefreshRequest.class, bgpPeerHandler::routeRefreshRequest)
+                        .build(),
+                    ImmutableSet.of(rib.getInstanceIdentifier().child(
+                        org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev180329.bgp.rib.rib
+                        .Peer.class, new PeerKey(peerId))));
+            }
+        } else {
+            final Set<TablesKey> forwardingTables;
+            if (advertisedTables == null) {
+                forwardingTables = Collections.emptySet();
+            } else {
+                forwardingTables = advertisedTables.values().stream()
+                        .filter(table -> table.getAfiFlags() != null)
+                        .filter(table -> table.getAfiFlags().getForwardingState())
+                        .map(table -> new TablesKey(table.getAfi(), table.getSafi()))
+                        .collect(Collectors.toSet());
+            }
+            ribWriter.clearTables(Sets.difference(tables, forwardingTables));
+            if (restartingLocally) {
+                effRibInWriter.close();
+                peerRestartStopwatch = Stopwatch.createStarted();
+                handleSelectionReferralTimer();
+                missingEOT.addAll(tables);
+            }
+        }
+        if (advertisedTables == null || advertisedTables.isEmpty()) {
+            setAdvertizedGracefulRestartTableTypes(Collections.emptyList());
+        } else {
+            setAdvertizedGracefulRestartTableTypes(advertisedTables.values().stream()
+                    .map(t -> new TablesKey(t.getAfi(), t.getSafi())).collect(Collectors.toList()));
+        }
+        setAfiSafiGracefulRestartState(advertisedGracefulRestartCapability.getRestartTime().toJava(), false,
+            restartingLocally);
+
+        final Map<TablesKey, Integer> llTablesReceived;
+        if (advertisedLLTables != null) {
+            llTablesReceived = new HashMap<>();
+            for (var table : advertisedLLTables.values()) {
+                llTablesReceived.put(new TablesKey(table.getAfi(), table.getSafi()),
+                    table.getLongLivedStaleTime().getValue().intValue());
+            }
+        } else {
+            llTablesReceived = Collections.emptyMap();
+        }
+        setAdvertizedLlGracefulRestartTableTypes(llTablesReceived);
 
-        for (final TablesKey key : this.tables) {
-            createAdjRibOutListener(key, true);
+        if (!llTablesReceived.isEmpty()) {
+            llgrSupport = true;
+            // FIXME: propagate preserved tables
+        } else {
+            // FIXME: clear preserved tables
+            llgrSupport = false;
         }
 
-        addBgp4Support();
+        if (!restartingLocally) {
+            if (!setTables.contains(IPV4_UCAST_TABLE_KEY)) {
+                createAdjRibOutListener(IPV4_UCAST_TABLE_KEY, false);
+            }
+            for (final TablesKey key : getAfiSafisAdvertized()) {
+                createAdjRibOutListener(key, true);
+            }
+        }
 
-        this.effRibInWriter = EffectiveRibInWriter.create(this, this.rib, this.rib.createPeerChain(this),
-                this.peerIId, this.tables);
+        // SpotBugs does not grok Optional.ifPresent() and thinks we are using unsynchronized access
+        final Optional<RevisedErrorHandlingSupport> errorHandling = bgpPeer.getErrorHandling();
+        if (errorHandling.isPresent()) {
+            currentSession.addDecoderConstraint(RevisedErrorHandlingSupport.class, errorHandling.orElseThrow());
+        }
+    }
 
+    private boolean isRestartingGracefully() {
+        return isLocalRestarting() || isPeerRestarting();
+    }
 
-        registerPrefixesCounters(this.effRibInWriter, this.effRibInWriter);
-        this.ribWriter = this.ribWriter.transform(this.peerId, this.rib.getRibSupportContext(), this.tables,
-                this.addPathTableMaps);
+    private synchronized void createEffRibInWriter() {
+        final var chain = rib.createPeerDOMChain();
+        chain.addCallback(this);
 
-        if (this.rpcRegistry != null) {
-            this.rpcRegistration = this.rpcRegistry.addRoutedRpcImplementation(BgpPeerRpcService.class,
-                    new BgpPeerRpc(this, session, this.tables));
-            final KeyedInstanceIdentifier<org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib
-                    .rev171207.bgp.rib.rib.Peer, PeerKey> path = this.rib.getInstanceIdentifier()
-                    .child(org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.rib.rev171207.bgp.rib
-                             .rib.Peer.class, new PeerKey(this.peerId));
-            this.rpcRegistration.registerPath(PeerContext.class, path);
-        }
+        effRibInWriter = new EffectiveRibInWriter(this, rib, chain, peerPath, tables, tableTypeRegistry, rtMemberships,
+            rtCache);
     }
 
     //try to add a support for old-school BGP-4, if peer did not advertise IPv4-Unicast MP capability
-    private synchronized void addBgp4Support() {
-        final TablesKey key = new TablesKey(Ipv4AddressFamily.class, UnicastSubsequentAddressFamily.class);
-        if (!this.tables.contains(key)) {
-            final HashSet<TablesKey> newSet = new HashSet<>(this.tables);
-            newSet.add(key);
-            this.tables = ImmutableSet.copyOf(newSet);
-            createAdjRibOutListener(key, false);
+    @Holding("this")
+    private void addBgp4Support() {
+        if (!tables.contains(IPV4_UCAST_TABLE_KEY)) {
+            final HashSet<TablesKey> newSet = new HashSet<>(tables);
+            newSet.add(IPV4_UCAST_TABLE_KEY);
+            tables = ImmutableSet.copyOf(newSet);
         }
     }
 
-    private synchronized void createAdjRibOutListener(final TablesKey key,
-            final boolean mpSupport) {
-        final RIBSupport ribSupport = this.rib.getRibSupportContext().getRIBSupport(key);
+    @Holding("this")
+    private void createAdjRibOutListener(final TablesKey key, final boolean mpSupport) {
+        final RIBSupport<?, ?> ribSupport = rib.getRibSupportContext().getRIBSupport(key);
 
         // not particularly nice
-        if (ribSupport != null && this.session instanceof BGPSessionImpl) {
-            final ChannelOutputLimiter limiter = ((BGPSessionImpl) this.session).getLimiter();
-            final AdjRibOutListener adjRibOut = AdjRibOutListener.create(this.peerId, key,
-                    this.rib.getYangRibId(), this.rib.getCodecsRegistry(), ribSupport,
-                    this.rib.getService(), limiter, mpSupport);
-            this.adjRibOutListenerSet.put(key, adjRibOut);
+        if (ribSupport != null && currentSession instanceof BGPSessionImpl bgpSession) {
+            final AdjRibOutListener adjRibOut = AdjRibOutListener.create(peerId, rib.getYangRibId(),
+                rib.getCodecsRegistry(), ribSupport, rib.getService(), bgpSession.getLimiter(), mpSupport);
+            adjRibOutListenerSet.put(key, adjRibOut);
             registerPrefixesSentCounter(key, adjRibOut);
         }
     }
 
-    private synchronized ListenableFuture<Void> cleanup() {
-        // FIXME: BUG-196: support graceful
-        this.adjRibOutListenerSet.values().forEach(AdjRibOutListener::close);
-        this.adjRibOutListenerSet.clear();
-        if (this.effRibInWriter != null) {
-            this.effRibInWriter.close();
-        }
-        this.tables = Collections.emptySet();
-        this.addPathTableMaps = Collections.emptyMap();
-        if (this.ribWriter != null) {
-            return this.ribWriter.removePeer();
-        }
-        return Futures.immediateFuture(null);
-    }
-
     @Override
-    public synchronized void onSessionDown(final BGPSession session, final Exception e) {
-        if (e.getMessage().equals(BGPSessionImpl.END_OF_INPUT)) {
-            LOG.info("Session with peer {} went down", this.name);
+    public synchronized void onSessionDown(final BGPSession session, final Exception exc) {
+        if (exc.getMessage().equals(BGPSessionImpl.END_OF_INPUT)) {
+            LOG.info("Session with peer {} went down", getName());
         } else {
-            LOG.info("Session with peer {} went down", this.name, e);
+            LOG.info("Session with peer {} went down", getName(), exc);
         }
-        releaseConnection();
+        releaseConnectionGracefully();
     }
 
     @Override
     public synchronized void onSessionTerminated(final BGPSession session, final BGPTerminationReason cause) {
-        LOG.info("Session with peer {} terminated: {}", this.name, cause);
-        releaseConnection();
+        LOG.info("Session with peer {} terminated: {}", getName(), cause);
+        releaseConnectionGracefully();
     }
 
     @Override
     public String toString() {
-        return addToStringAttributes(MoreObjects.toStringHelper(this)).toString();
-    }
-
-    protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
-        toStringHelper.add("name", this.name);
-        toStringHelper.add("tables", this.tables);
-        return toStringHelper;
+        return MoreObjects.toStringHelper(this).add("name", getName()).add("tables", tables).toString();
     }
 
     @Override
-    public String getName() {
-        return this.name;
+    public synchronized FluentFuture<? extends CommitInfo> releaseConnection() {
+        return releaseConnection(true);
     }
 
-    @Override
-    public synchronized ListenableFuture<Void> releaseConnection() {
-        if (this.rpcRegistration != null) {
-            this.rpcRegistration.close();
+    /**
+     * On transaction chain failure, we don't want to wait for future.
+     *
+     * @param isWaitForSubmitted if true, wait for submitted future before closing binding chain. if false, don't wait.
+     */
+    @Holding("this")
+    private @NonNull FluentFuture<? extends CommitInfo> releaseConnection(final boolean isWaitForSubmitted) {
+        LOG.info("Closing session with peer");
+        sessionUp = false;
+        adjRibOutListenerSet.values().forEach(AdjRibOutListener::close);
+        adjRibOutListenerSet.clear();
+        final FluentFuture<? extends CommitInfo> future;
+        // FIXME: this is a typical example of something which should be handled by a behavior into which we have
+        //        transitioned way before this method is called. This really begs to be an abstract base class with
+        //        a 'clearTables' or similar callout
+        if (isRestartingGracefully()) {
+            final Set<TablesKey> gracefulTables = getGracefulTables();
+            ribWriter.storeStaleRoutes(gracefulTables);
+            future = ribWriter.clearTables(Sets.difference(tables, gracefulTables));
+            if (isPeerRestarting()) {
+                peerRestartStopwatch = Stopwatch.createStarted();
+                handleRestartTimer();
+            }
+        } else {
+            future = terminateConnection();
         }
-        closeRegistration();
-        final ListenableFuture<Void> future = cleanup();
+        releaseRibOutChain(isWaitForSubmitted);
+
+        closeSession();
+        return future;
+    }
 
-        if (this.session != null) {
+    @Holding("this")
+    @SuppressWarnings("checkstyle:illegalCatch")
+    private void closeSession() {
+        if (currentSession != null) {
             try {
-                this.session.close();
+                if (isRestartingGracefully()) {
+                    currentSession.closeWithoutMessage();
+                } else {
+                    currentSession.close();
+                }
             } catch (final Exception e) {
                 LOG.warn("Error closing session with peer", e);
             }
-            this.session = null;
+            currentSession = null;
+        }
+    }
+
+    private Set<TablesKey> getGracefulTables() {
+        return tables.stream()
+                .filter(this::isGracefulRestartReceived)
+                .filter(this::isGracefulRestartAdvertized)
+                .collect(Collectors.toSet());
+    }
+
+    private synchronized FluentFuture<? extends CommitInfo> terminateConnection() {
+        if (trackerRegistration != null) {
+            trackerRegistration.close();
+            trackerRegistration = null;
+        }
+        if (rpcRegistration != null) {
+            rpcRegistration.close();
         }
+        ribWriter.releaseChain();
+
+        if (effRibInWriter != null) {
+            effRibInWriter.close();
+        }
+        tables = ImmutableSet.of();
+        addPathTableMaps = ImmutableMap.of();
+        final var future = removePeer(peerPath);
         resetState();
+
         return future;
     }
 
-    private synchronized void closeRegistration() {
-        if (this.trackerRegistration != null) {
-            this.trackerRegistration.close();
-            this.trackerRegistration = null;
+    /**
+     * If Graceful Restart Timer expires, remove all routes advertised by peer.
+     */
+    private synchronized void handleRestartTimer() {
+        if (!isPeerRestarting()) {
+            return;
+        }
+
+        final long peerRestartTimeNanos = TimeUnit.SECONDS.toNanos(getPeerRestartTime());
+        final long elapsedNanos = peerRestartStopwatch.elapsed(TimeUnit.NANOSECONDS);
+        if (elapsedNanos >= peerRestartTimeNanos) {
+            setAfiSafiGracefulRestartState(0, false, false);
+            onSessionTerminated(currentSession, new BGPTerminationReason(BGPError.HOLD_TIMER_EXPIRED));
         }
+
+        currentSession.schedule(this::handleRestartTimer, peerRestartTimeNanos - elapsedNanos, TimeUnit.NANOSECONDS);
     }
 
-    @Override
-    public synchronized byte[] getRawIdentifier() {
-        return Arrays.copyOf(this.rawIdentifier, this.rawIdentifier.length);
+    private synchronized void handleSelectionReferralTimer() {
+        if (!isLocalRestarting()) {
+            return;
+        }
+
+        final long referalTimerNanos = TimeUnit.SECONDS.toNanos(currentSelectionDeferralTimerSeconds);
+        final long elapsedNanos = peerRestartStopwatch.elapsed(TimeUnit.NANOSECONDS);
+        if (elapsedNanos >= referalTimerNanos) {
+            missingEOT.clear();
+            handleGracefulEndOfRib();
+        }
+        currentSession.schedule(this::handleSelectionReferralTimer, referalTimerNanos - elapsedNanos,
+            TimeUnit.NANOSECONDS);
     }
 
-    @Override
-    public PeerId getPeerId() {
-        return this.peerId;
+    @Holding("this")
+    private void releaseConnectionGracefully() {
+        if (getPeerRestartTime() > 0) {
+            setRestartingState();
+        }
+        releaseConnection(true);
     }
 
     @SuppressFBWarnings("IS2_INCONSISTENT_SYNC")
     @Override
     public SendReceive getSupportedAddPathTables(final TablesKey tableKey) {
-        return this.addPathTableMaps.get(tableKey);
+        return addPathTableMaps.get(tableKey);
     }
 
     @Override
     public boolean supportsTable(final TablesKey tableKey) {
-        return this.tables.contains(tableKey);
-    }
-
-    @Override
-    public PeerRole getRole() {
-        return this.peerRole;
+        return sessionUp && getAfiSafisAdvertized().contains(tableKey) && tables.contains(tableKey);
     }
 
     @Override
-    public KeyedInstanceIdentifier<Tables, TablesKey> getRibOutIId(final TablesKey tablesKey) {
-        return this.tablesIId.getUnchecked(tablesKey);
+    public YangInstanceIdentifier getRibOutIId(final NodeIdentifierWithPredicates tablekey) {
+        return tablesIId.getUnchecked(tablekey);
     }
 
     @Override
-    public synchronized void onTransactionChainFailed(final TransactionChain<?, ?> chain,
-            final AsyncTransaction<?, ?> transaction, final Throwable cause) {
-        LOG.error("Transaction chain failed.", cause);
-        this.chain.close();
-        this.chain = this.rib.createPeerDOMChain(this);
-        this.ribWriter = AdjRibInWriter.create(this.rib.getYangRibId(), this.peerRole, this.chain);
-        releaseConnection();
+    public synchronized void onFailure(final Throwable cause) {
+        LOG.error("Transaction domChain failed.", cause);
+        releaseConnection(true);
     }
 
-    @Override
-    public void onTransactionChainSuccessful(final TransactionChain<?, ?> chain) {
-        LOG.debug("Transaction chain {} successful.", chain);
+    private synchronized void onRibOutChainFailed(final Throwable cause) {
+        LOG.error("RibOut transaction chain failed.", cause);
+        releaseConnection(false);
     }
 
     @Override
     public synchronized void markUptodate(final TablesKey tablesKey) {
-        this.ribWriter.markTableUptodate(tablesKey);
-    }
-
-    @Override
-    public BGPErrorHandlingState getBGPErrorHandlingState() {
-        return this;
-    }
-
-    @Override
-    public BGPAfiSafiState getBGPAfiSafiState() {
-        return this;
+        ribWriter.markTableUptodate(tablesKey);
     }
 
     @Override
     public synchronized BGPSessionState getBGPSessionState() {
-        if (this.session instanceof BGPSessionStateProvider) {
-            return ((BGPSessionStateProvider) this.session).getBGPSessionState();
+        if (currentSession instanceof BGPSessionStateProvider stateProvider) {
+            return stateProvider.getBGPSessionState();
         }
         return null;
     }
 
     @Override
     public synchronized BGPTimersState getBGPTimersState() {
-        if (this.session instanceof BGPSessionStateProvider) {
-            return ((BGPSessionStateProvider) this.session).getBGPTimersState();
+        if (currentSession instanceof BGPSessionStateProvider stateProvider) {
+            return stateProvider.getBGPTimersState();
         }
         return null;
     }
 
     @Override
     public synchronized BGPTransportState getBGPTransportState() {
-        if (this.session instanceof BGPSessionStateProvider) {
-            return ((BGPSessionStateProvider) this.session).getBGPTransportState();
+        if (currentSession instanceof BGPSessionStateProvider stateProvider) {
+            return stateProvider.getBGPTransportState();
         }
         return null;
     }
 
     @Override
-    public PeerRole getFromPeerRole() {
-        return getRole();
+    public List<RouteTarget> getMemberships() {
+        return rtMemberships;
     }
 
     @Override
-    public PeerId getFromPeerId() {
-        return getPeerId();
+    public synchronized ListenableFuture<?> restartGracefully(final long selectionDeferralTimerSeconds) {
+        final Set<TablesKey> tablesToPreserve = getGracefulTables();
+        if (tablesToPreserve == null || tablesToPreserve.isEmpty()) {
+            LOG.info("Peer {} is not capable of graceful restart or have no matching graceful tables.", peerId);
+            return Futures.immediateFailedFuture(new UnsupportedOperationException(
+                    "Peer is not capable of graceful restart"));
+        }
+        setGracefulPreferences(true, tablesToPreserve);
+        currentSelectionDeferralTimerSeconds = selectionDeferralTimerSeconds;
+        setLocalRestartingState(true);
+        return releaseConnection(true);
+    }
+
+    @Override
+    boolean supportsLLGR() {
+        return llgrSupport;
+    }
+
+    private synchronized void setGracefulPreferences(final boolean localRestarting,
+                                                     final Set<TablesKey> preservedTables) {
+        final Set<TablesKey> gracefulTables = tables.stream()
+                .filter(this::isGracefulRestartAdvertized)
+                .collect(Collectors.toSet());
+        final BgpParameters bgpParameters = GracefulRestartUtil.getGracefulBgpParameters(
+                bgpPeer.getBgpFixedCapabilities(), gracefulTables, preservedTables,
+                bgpPeer.getGracefulRestartTimer(), localRestarting, Collections.emptySet());
+        final BGPSessionPreferences oldPrefs = rib.getDispatcher().getBGPPeerRegistry()
+                .getPeerPreferences(getNeighborAddress());
+        final BGPSessionPreferences newPrefs = new BGPSessionPreferences(
+                oldPrefs.getMyAs(),
+                oldPrefs.getHoldTime(),
+                oldPrefs.getBgpId(),
+                oldPrefs.getExpectedRemoteAs(),
+                Collections.singletonList(bgpParameters),
+                oldPrefs.getMd5Password());
+        rib.getDispatcher().getBGPPeerRegistry()
+                .updatePeerPreferences(getNeighborAddress(), newPrefs);
     }
 }