tez-runtime-library/src/main/java/org/apache/tez/runtime/library/output/UnorderedPartitionedKVOutput.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.tez.runtime.library.output;

import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.tez.common.Preconditions;
import com.google.common.annotations.VisibleForTesting;

import org.apache.tez.common.TezUtils;
import org.apache.tez.runtime.library.common.shuffle.ShuffleUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.conf.Configuration;
import org.apache.tez.common.TezCommonUtils;
import org.apache.tez.common.TezRuntimeFrameworkConfigs;
import org.apache.tez.common.counters.TaskCounter;
import org.apache.tez.dag.api.TezConfiguration;
import org.apache.tez.runtime.api.AbstractLogicalOutput;
import org.apache.tez.runtime.api.Event;
import org.apache.tez.runtime.api.LogicalOutput;
import org.apache.tez.runtime.api.OutputContext;
import org.apache.tez.runtime.api.Writer;
import org.apache.tez.runtime.library.api.TezRuntimeConfiguration;
import org.apache.tez.runtime.library.common.MemoryUpdateCallbackHandler;
import org.apache.tez.runtime.library.common.writers.UnorderedPartitionedKVWriter;

/**
 * {@link UnorderedPartitionedKVOutput} is a {@link LogicalOutput} which can be used to
 * write Key-Value pairs. The key-value pairs are written to the correct partition based on the
 * configured Partitioner.
 */
@Public
public class UnorderedPartitionedKVOutput extends AbstractLogicalOutput {

  private static final Logger LOG = LoggerFactory.getLogger(UnorderedPartitionedKVOutput.class);

  @VisibleForTesting
  Configuration conf;
  private MemoryUpdateCallbackHandler memoryUpdateCallbackHandler;
  private UnorderedPartitionedKVWriter kvWriter;
  private final AtomicBoolean isStarted = new AtomicBoolean(false);

  public UnorderedPartitionedKVOutput(OutputContext outputContext, int numPhysicalOutputs) {
    super(outputContext, numPhysicalOutputs);
  }

  @Override
  public synchronized List<Event> initialize() throws Exception {
    this.conf = TezUtils.createConfFromBaseConfAndPayload(getContext());
    this.conf.setStrings(TezRuntimeFrameworkConfigs.LOCAL_DIRS, getContext().getWorkDirs());
    this.conf.setInt(TezRuntimeFrameworkConfigs.TEZ_RUNTIME_NUM_EXPECTED_PARTITIONS,
        getNumPhysicalOutputs());
    this.memoryUpdateCallbackHandler = new MemoryUpdateCallbackHandler();
    getContext().requestInitialMemory(
        UnorderedPartitionedKVWriter.getInitialMemoryRequirement(conf,
            getContext().getTotalMemoryAvailableToTask()), memoryUpdateCallbackHandler);
    return Collections.emptyList();
  }

  @Override
  public synchronized void start() throws Exception {
    if (!isStarted.get()) {
      memoryUpdateCallbackHandler.validateUpdateReceived();
      this.kvWriter = new UnorderedPartitionedKVWriter(getContext(), conf, getNumPhysicalOutputs(),
          memoryUpdateCallbackHandler.getMemoryAssigned());
      isStarted.set(true);
    }
  }

  @Override
  public synchronized Writer getWriter() throws Exception {
    Preconditions.checkState(isStarted.get(), "Cannot get writer before starting the Output");
    return kvWriter;
  }

  @Override
  public void handleEvents(List<Event> outputEvents) {
  }

  @Override
  public synchronized List<Event> close() throws Exception {
    List<Event> returnEvents = null;
    if (isStarted.get()) {
      returnEvents = kvWriter.close();
      kvWriter = null;
    } else {
      LOG.warn(getContext().getInputOutputVertexNames() +
          ": Attempting to close output {} of type {} before it was started. Generating empty events",
          getContext().getDestinationVertexName(), this.getClass().getSimpleName());
      returnEvents = new LinkedList<Event>();
      ShuffleUtils
          .generateEventsForNonStartedOutput(returnEvents, getNumPhysicalOutputs(), getContext(),
              false, true, TezCommonUtils.newBestCompressionDeflater());
    }

    // This works for non-started outputs since new counters will be created with an initial value of 0
    long outputSize = getContext().getCounters().findCounter(TaskCounter.OUTPUT_BYTES).getValue();
    getContext().getStatisticsReporter().reportDataSize(outputSize);
    long outputRecords = getContext().getCounters()
        .findCounter(TaskCounter.OUTPUT_RECORDS).getValue();
    getContext().getStatisticsReporter().reportItemsProcessed(outputRecords);

    return returnEvents;
  }

  private static final Set<String> confKeys = new HashSet<String>();

  static {
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_IFILE_READAHEAD);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_IFILE_READAHEAD_BYTES);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_IO_FILE_BUFFER_SIZE);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_INDEX_CACHE_MEMORY_LIMIT_BYTES);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_UNORDERED_OUTPUT_BUFFER_SIZE_MB);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_UNORDERED_OUTPUT_MAX_PER_BUFFER_SIZE_BYTES);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_PARTITIONER_CLASS);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_KEY_CLASS);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_VALUE_CLASS);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_COMPRESS);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_COMPRESS_CODEC);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_EMPTY_PARTITION_INFO_VIA_EVENTS_ENABLED);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_TRANSFER_DATA_VIA_EVENTS_ENABLED);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_TRANSFER_DATA_VIA_EVENTS_MAX_SIZE);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_TRANSFER_DATA_VIA_EVENTS_SUPPORT_IN_MEM_FILE);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_CONVERT_USER_PAYLOAD_TO_HISTORY_TEXT);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_PIPELINED_SHUFFLE_ENABLED);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_ENABLE_FINAL_MERGE_IN_OUTPUT);
    confKeys.add(TezConfiguration.TEZ_COUNTERS_MAX);
    confKeys.add(TezConfiguration.TEZ_COUNTERS_GROUP_NAME_MAX_LENGTH);
    confKeys.add(TezConfiguration.TEZ_COUNTERS_COUNTER_NAME_MAX_LENGTH);
    confKeys.add(TezConfiguration.TEZ_COUNTERS_MAX_GROUPS);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_CLEANUP_FILES_ON_INTERRUPT);
    confKeys.add(TezRuntimeConfiguration.TEZ_RUNTIME_REPORT_PARTITION_STATS);
    confKeys.add(TezConfiguration.TEZ_AM_SHUFFLE_AUXILIARY_SERVICE_ID);
    confKeys.add(
        TezRuntimeConfiguration.TEZ_RUNTIME_UNORDERED_PARTITIONED_KVWRITER_BUFFER_MERGE_PERCENT);
  }

  // TODO Maybe add helper methods to extract keys
  // TODO Maybe add constants or an Enum to access the keys

  @InterfaceAudience.Private
  public static Set<String> getConfigurationKeySet() {
    return Collections.unmodifiableSet(confKeys);
  }
}