org.apache.pinot.broker.routing.segmentpartition.SegmentPartitionMetadataManager 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.pinot.broker.routing.segmentpartition;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.Nullable;
import org.apache.helix.model.ExternalView;
import org.apache.helix.model.IdealState;
import org.apache.helix.zookeeper.datamodel.ZNRecord;
import org.apache.pinot.broker.routing.segmentmetadata.SegmentZkMetadataFetchListener;
import org.apache.pinot.core.routing.TablePartitionInfo;
import org.apache.pinot.core.routing.TablePartitionInfo.PartitionInfo;
import org.apache.pinot.segment.spi.partition.PartitionFunction;
import org.apache.pinot.spi.utils.CommonConstants.Helix.StateModel.SegmentStateModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * The {@code PartitionDataManager} manages partitions of a table. It manages
 *   1. all the online segments associated with the partition and their allocated servers
 *   2. all the replica of a specific segment.
 * It provides API to query
 *   1. For each partition ID, what are the servers that contains ALL segments belong to this partition ID.
 *   2. For each server, what are all the partition IDs and list of segments of those partition IDs on this server.
 */
public class SegmentPartitionMetadataManager implements SegmentZkMetadataFetchListener {
  private static final Logger LOGGER = LoggerFactory.getLogger(SegmentPartitionMetadataManager.class);
  private static final int INVALID_PARTITION_ID = -1;

  private final String _tableNameWithType;

  // static content, if anything changes for the following. a rebuild of routing table is needed.
  private final String _partitionColumn;
  private final String _partitionFunctionName;
  private final int _numPartitions;

  // cache-able content, only follow changes if onlineSegments list (of ideal-state) is changed.
  private final Map _segmentInfoMap = new HashMap<>();

  // computed value based on status change.
  private transient TablePartitionInfo _tablePartitionInfo;

  public SegmentPartitionMetadataManager(String tableNameWithType, String partitionColumn, String partitionFunctionName,
      int numPartitions) {
    _tableNameWithType = tableNameWithType;
    _partitionColumn = partitionColumn;
    _partitionFunctionName = partitionFunctionName;
    _numPartitions = numPartitions;
  }

  @Override
  public void init(IdealState idealState, ExternalView externalView, List onlineSegments,
      List znRecords) {
    int numSegments = onlineSegments.size();
    for (int i = 0; i < numSegments; i++) {
      String segment = onlineSegments.get(i);
      SegmentPartitionInfo partitionInfo =
          SegmentPartitionUtils.extractPartitionInfo(_tableNameWithType, _partitionColumn, segment, znRecords.get(i));
      SegmentInfo segmentInfo = new SegmentInfo(getPartitionId(partitionInfo), getOnlineServers(externalView, segment));
      _segmentInfoMap.put(segment, segmentInfo);
    }
    computeTablePartitionInfo();
  }

  private int getPartitionId(@Nullable SegmentPartitionInfo segmentPartitionInfo) {
    if (segmentPartitionInfo == null || segmentPartitionInfo == SegmentPartitionUtils.INVALID_PARTITION_INFO) {
      return INVALID_PARTITION_ID;
    }
    if (!_partitionColumn.equals(segmentPartitionInfo.getPartitionColumn())) {
      return INVALID_PARTITION_ID;
    }
    PartitionFunction partitionFunction = segmentPartitionInfo.getPartitionFunction();
    if (!_partitionFunctionName.equalsIgnoreCase(partitionFunction.getName())) {
      return INVALID_PARTITION_ID;
    }
    if (_numPartitions != partitionFunction.getNumPartitions()) {
      return INVALID_PARTITION_ID;
    }
    Set partitions = segmentPartitionInfo.getPartitions();
    if (partitions.size() != 1) {
      return INVALID_PARTITION_ID;
    }
    return partitions.iterator().next();
  }

  private List getOnlineServers(ExternalView externalView, String segment) {
    Map instanceStateMap = externalView.getStateMap(segment);
    if (instanceStateMap == null) {
      return Collections.emptyList();
    }
    List onlineServers = new ArrayList<>(instanceStateMap.size());
    for (Map.Entry entry : instanceStateMap.entrySet()) {
      String instanceState = entry.getValue();
      if (instanceState.equals(SegmentStateModel.ONLINE) || instanceState.equals(SegmentStateModel.CONSUMING)) {
        onlineServers.add(entry.getKey());
      }
    }
    return onlineServers;
  }

  private void computeTablePartitionInfo() {
    PartitionInfo[] partitionInfoMap = new PartitionInfo[_numPartitions];
    Set segmentsWithInvalidPartition = new HashSet<>();
    for (Map.Entry entry : _segmentInfoMap.entrySet()) {
      String segment = entry.getKey();
      SegmentInfo segmentInfo = entry.getValue();
      int partitionId = segmentInfo._partitionId;
      List onlineServers = segmentInfo._onlineServers;
      if (partitionId == INVALID_PARTITION_ID) {
        segmentsWithInvalidPartition.add(segment);
        continue;
      }
      PartitionInfo partitionInfo = partitionInfoMap[partitionId];
      if (partitionInfo == null) {
        Set fullyReplicatedServers = new HashSet<>(onlineServers);
        List segments = new ArrayList<>();
        segments.add(segment);
        partitionInfo = new PartitionInfo(fullyReplicatedServers, segments);
        partitionInfoMap[partitionId] = partitionInfo;
      } else {
        partitionInfo._fullyReplicatedServers.retainAll(onlineServers);
        partitionInfo._segments.add(segment);
      }
    }
    if (!segmentsWithInvalidPartition.isEmpty()) {
      int numSegmentsWithInvalidPartition = segmentsWithInvalidPartition.size();
      if (numSegmentsWithInvalidPartition <= 10) {
        LOGGER.warn("Found {} segments: {} with invalid partition from table: {}", numSegmentsWithInvalidPartition,
            segmentsWithInvalidPartition, _tableNameWithType);
      } else {
        LOGGER.warn("Found {} segments: {} with invalid partition from table: {}", numSegmentsWithInvalidPartition,
            segmentsWithInvalidPartition, _tableNameWithType);
      }
    }
    _tablePartitionInfo =
        new TablePartitionInfo(_tableNameWithType, _partitionColumn, _partitionFunctionName, _numPartitions,
            partitionInfoMap, segmentsWithInvalidPartition);
  }

  @Override
  public synchronized void onAssignmentChange(IdealState idealState, ExternalView externalView,
      Set onlineSegments, List pulledSegments, List znRecords) {
    // Update segment partition id for the pulled segments
    int numSegments = pulledSegments.size();
    for (int i = 0; i < numSegments; i++) {
      String segment = pulledSegments.get(i);
      SegmentPartitionInfo partitionInfo =
          SegmentPartitionUtils.extractPartitionInfo(_tableNameWithType, _partitionColumn, segment, znRecords.get(i));
      SegmentInfo segmentInfo = new SegmentInfo(getPartitionId(partitionInfo), getOnlineServers(externalView, segment));
      _segmentInfoMap.put(segment, segmentInfo);
    }
    // Update online servers for all online segments
    for (String segment : onlineSegments) {
      SegmentInfo segmentInfo = _segmentInfoMap.get(segment);
      if (segmentInfo == null) {
        segmentInfo = new SegmentInfo(INVALID_PARTITION_ID, getOnlineServers(externalView, segment));
        _segmentInfoMap.put(segment, segmentInfo);
      } else {
        segmentInfo._onlineServers = getOnlineServers(externalView, segment);
      }
    }
    _segmentInfoMap.keySet().retainAll(onlineSegments);
    computeTablePartitionInfo();
  }

  @Override
  public synchronized void refreshSegment(String segment, @Nullable ZNRecord znRecord) {
    SegmentPartitionInfo partitionInfo =
        SegmentPartitionUtils.extractPartitionInfo(_tableNameWithType, _partitionColumn, segment, znRecord);
    int partitionId = getPartitionId(partitionInfo);
    SegmentInfo segmentInfo = _segmentInfoMap.get(segment);
    if (segmentInfo == null) {
      segmentInfo = new SegmentInfo(partitionId, Collections.emptyList());
      _segmentInfoMap.put(segment, segmentInfo);
    } else {
      segmentInfo._partitionId = partitionId;
    }
    computeTablePartitionInfo();
  }

  public TablePartitionInfo getTablePartitionInfo() {
    return _tablePartitionInfo;
  }

  private static class SegmentInfo {
    int _partitionId;
    List _onlineServers;

    SegmentInfo(int partitionId, List onlineServers) {
      _partitionId = partitionId;
      _onlineServers = onlineServers;
    }
  }
}