CustomDownSampler.java

/**
 * 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.yarn.server.applicationhistoryservice.metrics.timeline.aggregators;

import java.util.List;

/**
 * Interface to add a custom downsampler.
 * Each configured downsampler will be executed during an aggregation cycle.
 */
public interface CustomDownSampler {

  /**
   * Gatekeeper to check the configs. If this fails, the downsampling is not done.
   * @return
   */
  public boolean validateConfigs();

  /**
   * Return the set of statements that needs to be executed for the downsampling.
   * @param startTime
   * @param endTime
   * @param tableName
   * @return
   */
  public List<String> prepareDownSamplingStatement(Long startTime, Long endTime, String tableName);

}