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.group; import java.util.Map; import java.util.Set; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import brooklyn.entity.Entity; import brooklyn.entity.basic.AbstractEntity; import brooklyn.entity.basic.AbstractGroupImpl; import brooklyn.entity.basic.Entities; import brooklyn.entity.effector.Effectors; import brooklyn.entity.trait.Startable; import brooklyn.management.Task; import brooklyn.util.exceptions.Exceptions; import brooklyn.util.task.DynamicTasks; import brooklyn.util.task.Tasks; import brooklyn.util.text.Strings; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Maps; public class QuarantineGroupImpl extends AbstractGroupImpl implements QuarantineGroup { private static final Logger LOG = LoggerFactory.getLogger(AbstractEntity.class); @Override protected void initEnrichers() { //don't want enrichers (i.e. quorum checks) } @Override public void expungeMembers(boolean stopFirst) { Set<Entity> members = ImmutableSet.copyOf(getMembers()); RuntimeException exception = null; if (stopFirst) { Map<Entity, Task<?>> tasks = Maps.newLinkedHashMap(); for (Entity member : members) { if (member instanceof Startable) { Task<Void> task = Effectors.invocation(member, Startable.STOP, ImmutableMap.of()).asTask(); tasks.put(member, task); } } DynamicTasks.queueIfPossible( Tasks.parallel("stopping " + tasks.size() + " member" + Strings.s(tasks.size()) + " (parallel)", tasks.values())) .orSubmitAsync(this); try { waitForTasksOnExpungeMembers(tasks); } catch (RuntimeException e) { Exceptions.propagateIfFatal(e); exception = e; LOG.warn("Problem stopping members of quarantine group " + this + " (rethrowing after unmanaging members): " + e); } } for (Entity member : members) { removeMember(member); Entities.unmanage(member); } if (exception != null) { throw exception; } } // TODO Quite like DynamicClusterImpl.waitForTasksOnEntityStart protected Map<Entity, Throwable> waitForTasksOnExpungeMembers(Map<? extends Entity, ? extends Task<?>> tasks) { // TODO Could have CompoundException, rather than propagating first Map<Entity, Throwable> errors = Maps.newLinkedHashMap(); for (Map.Entry<? extends Entity, ? extends Task<?>> entry : tasks.entrySet()) { Entity member = entry.getKey(); Task<?> task = entry.getValue(); try { task.get(); } catch (InterruptedException e) { throw Exceptions.propagate(e); } catch (Throwable t) { Throwable interesting = Exceptions.getFirstInteresting(t); LOG.error("Quarantine group " + this + " failed to stop quarantined entity " + member + " (removing): " + interesting, interesting); LOG.debug("Trace for: Quarantine group " + this + " failed to stop quarantined entity " + member + " (removing): " + t, t); // previously we unwrapped but now there is no need I think errors.put(member, t); } } return errors; } }