opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/sharding/PrefixedShardConfigWriter.java

   1 /*
   2  * Copyright (c) 2017 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
   9 package org.opendaylight.controller.cluster.sharding;
  10
  11 import com.google.common.util.concurrent.AsyncFunction;
  12 import com.google.common.util.concurrent.Futures;
  13 import com.google.common.util.concurrent.ListenableFuture;
  14 import java.util.Collection;
  15 import java.util.concurrent.ExecutionException;
  16 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  17 import org.opendaylight.controller.cluster.databroker.actors.dds.ClientLocalHistory;
  18 import org.opendaylight.controller.cluster.databroker.actors.dds.ClientSnapshot;
  19 import org.opendaylight.controller.cluster.databroker.actors.dds.ClientTransaction;
  20 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  21 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  22 import org.opendaylight.mdsal.common.api.ReadFailedException;
  23 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteCursor;
  24 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  27 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeWithValue;
  29 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.LeafSetEntryNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  32 import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.ListNodeBuilder;
  33 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableContainerNodeBuilder;
  34 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafNodeBuilder;
  35 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafSetEntryNodeBuilder;
  36 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafSetNodeBuilder;
  37 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableMapEntryNodeBuilder;
  38 import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableMapNodeBuilder;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * Writes and removes prefix-based shards' configuration
  44  * to prefix-shard-configuration. This classed is meant to be utilized
  45  * by {@link DistributedShardedDOMDataTree} for updating
  46  * prefix-shard-configuration upon creating and de-spawning prefix-based shards.
  47  */
  48 class PrefixedShardConfigWriter {
  49
  50     private static final Logger LOG = LoggerFactory.getLogger(PrefixedShardConfigWriter.class);
  51
  52     private final ClientLocalHistory history;
  53
  54     PrefixedShardConfigWriter(final DataStoreClient client) {
  55         history = client.createLocalHistory();
  56         writeInitialParent();
  57     }
  58
  59     ListenableFuture<Void> writeConfig(final YangInstanceIdentifier path, final Collection<MemberName> replicas) {
  60         LOG.debug("Writing config for {}, replicas {}", path, replicas);
  61
  62         return doSubmit(doWrite(path, replicas));
  63     }
  64
  65     ListenableFuture<Void> removeConfig(final YangInstanceIdentifier path) {
  66         LOG.debug("Removing config for {}.", path);
  67
  68         return doSubmit(doDelete(path));
  69     }
  70
  71     private void writeInitialParent() {
  72         final ClientTransaction tx = history.createTransaction();
  73
  74         final DOMDataTreeWriteCursor cursor = tx.openCursor();
  75
  76         final ContainerNode root = ImmutableContainerNodeBuilder.create()
  77                 .withNodeIdentifier(new NodeIdentifier(ClusterUtils.PREFIX_SHARDS_QNAME))
  78                 .withChild(ImmutableMapNodeBuilder.create()
  79                         .withNodeIdentifier(new NodeIdentifier(ClusterUtils.SHARD_LIST_QNAME))
  80                         .build())
  81                 .build();
  82
  83         cursor.merge(ClusterUtils.PREFIX_SHARDS_PATH.getLastPathArgument(), root);
  84         cursor.close();
  85
  86         final DOMStoreThreePhaseCommitCohort cohort = tx.ready();
  87
  88         submitBlocking(cohort);
  89     }
  90
  91     private static void submitBlocking(final DOMStoreThreePhaseCommitCohort cohort) {
  92         try {
  93             doSubmit(cohort).get();
  94         } catch (final InterruptedException | ExecutionException e) {
  95             LOG.error("Unable to write initial shard config parent.", e);
  96         }
  97     }
  98
  99     private static ListenableFuture<Void> doSubmit(final DOMStoreThreePhaseCommitCohort cohort) {
 100         final AsyncFunction<Boolean, Void> validateFunction = input -> cohort.preCommit();
 101         final AsyncFunction<Void, Void> prepareFunction = input -> cohort.commit();
 102
 103         final ListenableFuture<Void> prepareFuture = Futures.transform(cohort.canCommit(), validateFunction);
 104         return Futures.transform(prepareFuture, prepareFunction);
 105     }
 106
 107     boolean checkDefaultIsPresent() {
 108         final NodeIdentifierWithPredicates pag =
 109                 new NodeIdentifierWithPredicates(ClusterUtils.SHARD_LIST_QNAME, ClusterUtils.SHARD_PREFIX_QNAME,
 110                 YangInstanceIdentifier.EMPTY);
 111
 112         final YangInstanceIdentifier defaultId = ClusterUtils.SHARD_LIST_PATH.node(pag);
 113
 114         final ClientSnapshot snapshot = history.takeSnapshot();
 115         try {
 116             return snapshot.exists(defaultId).checkedGet();
 117         } catch (final ReadFailedException e) {
 118             LOG.error("Presence check of default shard in configuration failed.", e);
 119             return false;
 120         } finally {
 121             snapshot.abort();
 122         }
 123     }
 124
 125     private DOMStoreThreePhaseCommitCohort doWrite(final YangInstanceIdentifier path,
 126                                                    final Collection<MemberName> replicas) {
 127
 128         final ListNodeBuilder<Object, LeafSetEntryNode<Object>> replicaListBuilder =
 129                 ImmutableLeafSetNodeBuilder.create().withNodeIdentifier(
 130                         new NodeIdentifier(ClusterUtils.SHARD_REPLICA_QNAME));
 131
 132         replicas.forEach(name -> replicaListBuilder.withChild(
 133                 ImmutableLeafSetEntryNodeBuilder.create()
 134                         .withNodeIdentifier(new NodeWithValue<>(ClusterUtils.SHARD_REPLICA_QNAME, name.getName()))
 135                         .withValue(name.getName())
 136                         .build()));
 137
 138         final MapEntryNode newEntry = ImmutableMapEntryNodeBuilder.create()
 139                 .withNodeIdentifier(
 140                         new NodeIdentifierWithPredicates(ClusterUtils.SHARD_LIST_QNAME, ClusterUtils.SHARD_PREFIX_QNAME,
 141                                 path))
 142                 .withChild(ImmutableLeafNodeBuilder.create()
 143                         .withNodeIdentifier(new NodeIdentifier(ClusterUtils.SHARD_PREFIX_QNAME))
 144                         .withValue(path)
 145                         .build())
 146                 .withChild(ImmutableContainerNodeBuilder.create()
 147                         .withNodeIdentifier(new NodeIdentifier(ClusterUtils.SHARD_REPLICAS_QNAME))
 148                         .withChild(replicaListBuilder.build())
 149                         .build())
 150                 .build();
 151
 152         final ClientTransaction tx = history.createTransaction();
 153         final DOMDataTreeWriteCursor cursor = tx.openCursor();
 154
 155         ClusterUtils.SHARD_LIST_PATH.getPathArguments().forEach(cursor::enter);
 156
 157         cursor.write(newEntry.getIdentifier(), newEntry);
 158         cursor.close();
 159
 160         return tx.ready();
 161     }
 162
 163     private DOMStoreThreePhaseCommitCohort doDelete(final YangInstanceIdentifier path) {
 164
 165         final ClientTransaction tx = history.createTransaction();
 166         final DOMDataTreeWriteCursor cursor = tx.openCursor();
 167
 168         ClusterUtils.SHARD_LIST_PATH.getPathArguments().forEach(cursor::enter);
 169
 170         cursor.delete(
 171                 new NodeIdentifierWithPredicates(ClusterUtils.SHARD_LIST_QNAME, ClusterUtils.SHARD_PREFIX_QNAME, path));
 172         cursor.close();
 173
 174         return tx.ready();
 175     }
 176 }