| /* |
| * 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.slider.server.appmaster.monkey; |
| |
| import com.codahale.metrics.Counter; |
| import com.codahale.metrics.MetricRegistry; |
| import com.google.common.base.Preconditions; |
| import org.apache.commons.lang.StringUtils; |
| import org.apache.slider.api.InternalKeys; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Entry in the chaos list |
| */ |
| public class ChaosEntry { |
| |
| protected static final Logger log = |
| LoggerFactory.getLogger(ChaosEntry.class); |
| public final String name; |
| public final ChaosTarget target; |
| public final long probability; |
| |
| private final MetricRegistry metrics; |
| private final Counter invocationCounter; |
| |
| |
| /** |
| * Constructor -includes validation of all arguments |
| * @param name entry name |
| * @param target target |
| * @param probability probability of occurring |
| */ |
| public ChaosEntry(String name, ChaosTarget target, long probability, |
| MetricRegistry metrics) { |
| Preconditions.checkArgument(!StringUtils.isEmpty(name), "missing name"); |
| Preconditions.checkArgument(target != null, "null target"); |
| Preconditions.checkArgument(probability > 0, "negative probability"); |
| Preconditions.checkArgument(probability <= InternalKeys.PROBABILITY_PERCENT_100, |
| "probability over 100%: "+ probability); |
| this.name = name; |
| this.target = target; |
| this.probability = probability; |
| this.metrics = metrics; |
| invocationCounter = |
| metrics.counter(MetricRegistry.name(ChaosEntry.class, name)); |
| } |
| |
| /** |
| * Trigger the chaos action |
| */ |
| public void invokeChaos() { |
| log.info("Invoking {}", name); |
| invocationCounter.inc(); |
| target.chaosAction(); |
| } |
| |
| /** |
| * Invoke Chaos if the trigger value is in range of the probability |
| * @param value trigger value, 0-10K |
| * @return true if the chaos method was invoked |
| */ |
| public boolean maybeInvokeChaos(long value) { |
| log.debug("Probability {} trigger={}", probability, value); |
| if (value < probability) { |
| invokeChaos(); |
| return true; |
| } |
| return false; |
| } |
| } |