Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package brooklyn.entity.nosql.riak; import static brooklyn.util.JavaGroovyEquivalents.groovyTruth; import java.util.Collection; import java.util.List; import java.util.Map; import javax.annotation.Nullable; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import brooklyn.entity.Entity; import brooklyn.entity.basic.Attributes; import brooklyn.entity.basic.Entities; import brooklyn.entity.basic.EntityInternal; import brooklyn.entity.basic.Lifecycle; import brooklyn.entity.basic.ServiceStateLogic; import brooklyn.entity.basic.ServiceStateLogic.ServiceNotUpLogic; import brooklyn.entity.group.AbstractMembershipTrackingPolicy; import brooklyn.entity.group.DynamicClusterImpl; import brooklyn.entity.proxying.EntitySpec; import brooklyn.entity.trait.Startable; import brooklyn.location.Location; import brooklyn.policy.PolicySpec; import brooklyn.util.time.Time; import com.google.common.base.Joiner; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.base.Predicate; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import com.google.common.collect.Maps; public class RiakClusterImpl extends DynamicClusterImpl implements RiakCluster { private static final Logger log = LoggerFactory.getLogger(RiakClusterImpl.class); private transient Object mutex = new Object[0]; public void init() { super.init(); log.info("Initializing the riak cluster..."); setAttribute(IS_CLUSTER_INIT, false); } @Override public void start(Collection<? extends Location> locations) { super.start(locations); connectSensors(); Time.sleep(getConfig(DELAY_BEFORE_ADVERTISING_CLUSTER)); //FIXME: add a quorum to tolerate failed nodes before setting on fire. Optional<Entity> anyNode = Iterables.tryFind(getMembers(), new Predicate<Entity>() { @Override public boolean apply(@Nullable Entity entity) { return (entity instanceof RiakNode && hasMemberJoinedCluster(entity) && entity.getAttribute(RiakNode.SERVICE_UP)); } }); if (anyNode.isPresent()) { log.info("Planning and Committing cluster changes on node: {}, cluster: {}", anyNode.get().getId(), getId()); Entities.invokeEffector(this, anyNode.get(), RiakNode.COMMIT_RIAK_CLUSTER).blockUntilEnded(); setAttribute(IS_CLUSTER_INIT, true); } else { log.warn("No Riak Nodes are found on the cluster: {}. Initialization Failed", getId()); ServiceStateLogic.setExpectedState(this, Lifecycle.ON_FIRE); } } protected EntitySpec<?> getMemberSpec() { return getConfig(MEMBER_SPEC, EntitySpec.create(RiakNode.class)); } protected void connectSensors() { addPolicy(PolicySpec.create(MemberTrackingPolicy.class).displayName("Controller targets tracker") .configure("sensorsToTrack", ImmutableSet.of(RiakNode.SERVICE_UP)).configure("group", this)); } protected void onServerPoolMemberChanged(Entity member) { synchronized (mutex) { log.trace("For {}, considering membership of {} which is in locations {}", new Object[] { this, member, member.getLocations() }); Map<Entity, String> nodes = getAttribute(RIAK_CLUSTER_NODES); if (belongsInServerPool(member)) { // TODO can we discover the nodes by asking the riak cluster, rather than assuming what we add will be in there? // TODO and can we do join as part of node starting? if (nodes == null) { nodes = Maps.newLinkedHashMap(); } String riakName = getRiakName(member); Preconditions.checkNotNull(riakName); // flag a first node to be the first node in the riak cluster. Boolean firstNode = getAttribute(IS_FIRST_NODE_SET); if (!Boolean.TRUE.equals(firstNode)) { setAttribute(IS_FIRST_NODE_SET, Boolean.TRUE); nodes.put(member, riakName); setAttribute(RIAK_CLUSTER_NODES, nodes); ((EntityInternal) member).setAttribute(RiakNode.RIAK_NODE_HAS_JOINED_CLUSTER, Boolean.TRUE); log.info("Adding riak node {}: {}; {} to cluster", new Object[] { this, member, getRiakName(member) }); } else { // TODO: be wary of erroneous nodes but are still flagged 'in cluster' // add the new node to be part of the riak cluster. Optional<Entity> anyNodeInCluster = Iterables.tryFind(nodes.keySet(), new Predicate<Entity>() { @Override public boolean apply(@Nullable Entity node) { return (node instanceof RiakNode && hasMemberJoinedCluster(node)); } }); if (anyNodeInCluster.isPresent()) { if (!nodes.containsKey(member) && !hasMemberJoinedCluster(member)) { String anyNodeName = anyNodeInCluster.get().getAttribute(RiakNode.RIAK_NODE_NAME); Entities.invokeEffectorWithArgs(this, member, RiakNode.JOIN_RIAK_CLUSTER, anyNodeName); if (getAttribute(IS_CLUSTER_INIT)) { Entities.invokeEffector(RiakClusterImpl.this, anyNodeInCluster.get(), RiakNode.COMMIT_RIAK_CLUSTER); } nodes.put(member, riakName); setAttribute(RIAK_CLUSTER_NODES, nodes); log.info("Adding riak node {}: {}; {} to cluster", new Object[] { this, member, getRiakName(member) }); } } else { log.error("isFirstNodeSet , but no cluster members found to add {}", member.getId()); } } } else { if (nodes != null && nodes.containsKey(member)) { final Entity memberToBeRemoved = member; Optional<Entity> anyNodeInCluster = Iterables.tryFind(nodes.keySet(), new Predicate<Entity>() { @Override public boolean apply(@Nullable Entity node) { return (node instanceof RiakNode && hasMemberJoinedCluster(node) && !node.equals(memberToBeRemoved)); } }); if (anyNodeInCluster.isPresent()) { Entities.invokeEffectorWithArgs(this, anyNodeInCluster.get(), RiakNode.LEAVE_RIAK_CLUSTER, getRiakName(memberToBeRemoved)); } nodes.remove(member); setAttribute(RIAK_CLUSTER_NODES, nodes); log.info("Removing riak node {}: {}; {} from cluster", new Object[] { this, member, getRiakName(member) }); } } ServiceNotUpLogic.updateNotUpIndicatorRequiringNonEmptyMap(this, RIAK_CLUSTER_NODES); if (log.isTraceEnabled()) log.trace("Done {} checkEntity {}", this, member); calculateClusterAddresses(); } } private void calculateClusterAddresses() { List<String> addresses = Lists.newArrayList(); for (Entity entity : this.getMembers()) { if (entity instanceof RiakNode && entity.getAttribute(Attributes.SERVICE_UP)) { RiakNode riakNode = (RiakNode) entity; addresses.add(riakNode.getAttribute(Attributes.SUBNET_HOSTNAME) + ":" + riakNode.getAttribute(RiakNode.RIAK_WEB_PORT)); } } setAttribute(RiakCluster.NODE_LIST, Joiner.on(",").join(addresses)); } protected boolean belongsInServerPool(Entity member) { if (!groovyTruth(member.getAttribute(Startable.SERVICE_UP))) { if (log.isTraceEnabled()) log.trace("Members of {}, checking {}, eliminating because not up", this, member); return false; } if (!getMembers().contains(member)) { if (log.isTraceEnabled()) log.trace("Members of {}, checking {}, eliminating because not member", this, member); return false; } if (log.isTraceEnabled()) log.trace("Members of {}, checking {}, approving", this, member); return true; } private String getRiakName(Entity node) { return node.getAttribute(RiakNode.RIAK_NODE_NAME); } private boolean hasMemberJoinedCluster(Entity member) { return ((RiakNode) member).hasJoinedCluster(); } public static class MemberTrackingPolicy extends AbstractMembershipTrackingPolicy { @Override protected void onEntityEvent(EventType type, Entity entity) { ((RiakClusterImpl) super.entity).onServerPoolMemberChanged(entity); } } }