/**
* 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 org.apache.hadoop.hbase.chaos.policies;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.hadoop.hbase.chaos.actions.Action;
import org.apache.hadoop.hbase.chaos.monkies.PolicyBasedChaosMonkey;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.util.StringUtils;
/**
* A policy, which picks a random action according to the given weights,
* and performs it every configurable period.
*/
public class PeriodicRandomActionPolicy extends PeriodicPolicy {
private List<Pair<Action, Integer>> actions;
public PeriodicRandomActionPolicy(long periodMs, List<Pair<Action, Integer>> actions) {
super(periodMs);
this.actions = actions;
}
public PeriodicRandomActionPolicy(long periodMs, Pair<Action, Integer>... actions) {
// We don't expect it to be modified.
this(periodMs, Arrays.asList(actions));
}
public PeriodicRandomActionPolicy(long periodMs, Action... actions) {
super(periodMs);
this.actions = new ArrayList<Pair<Action, Integer>>(actions.length);
for (Action action : actions) {
this.actions.add(new Pair<Action, Integer>(action, 1));
}
}
@Override
protected void runOneIteration() {
Action action = PolicyBasedChaosMonkey.selectWeightedRandomItem(actions);
try {
action.perform();
} catch (Exception ex) {
LOG.warn("Exception occured during performing action: "
+ StringUtils.stringifyException(ex));
}
}
@Override
public void init(PolicyContext context) throws Exception {
super.init(context);
for (Pair<Action, Integer> action : actions) {
action.getFirst().init(this.context);
}
}
}