org.apache.hadoop.hive.ql.stats.StatsPublisher Maven / Gradle / Ivy
/**
* 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.hive.ql.stats;
import java.util.Map;
/**
* An interface for any possible implementation for publishing statics.
*/
public interface StatsPublisher {
/**
* This method does the necessary one-time initializations, possibly creating the tables and
* database (if not exist).
* This method is usually called in the Hive client side rather than by the mappers/reducers
* so that it is initialized only once.
* @param hconf HiveConf that contains the configurations parameters used to connect to
* intermediate stats database.
* @return true if initialization is successful, false otherwise.
*/
public boolean init(StatsCollectionContext context);
/**
* This method connects to the intermediate statistics database.
* @param hconf HiveConf that contains the connection parameters.
* @return true if connection is successful, false otherwise.
*/
public boolean connect(StatsCollectionContext context);
/**
* This method publishes a given statistic into a disk storage, possibly HBase or MySQL.
*
* @param fileID
* : a string identification the statistics to be published by all mappers/reducers
* and then gathered. The statID is unique per output partition per task, e.g.,:
* the output directory name (uniq per FileSinkOperator) +
* the partition specs (only for dynamic partitions) +
* taskID (last component of task file)
* @param stats
* : a map containing key-value pairs, where key is a string representing the statistic
* to be published,
* and value is a string representing the value for the given statistic
* @return true if successful, false otherwise
*/
public boolean publishStat(String fileID, Map stats);
/**
* This method closes the connection to the temporary storage.
*/
public boolean closeConnection(StatsCollectionContext context);
}