com.metamx.druid.master.SegmentReplicantLookup.java Source code

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Here is the source code for com.metamx.druid.master.SegmentReplicantLookup.java

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/*
 * Druid - a distributed column store.
 * Copyright (C) 2012  Metamarkets Group Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package com.metamx.druid.master;

import com.google.common.collect.HashBasedTable;
import com.google.common.collect.Maps;
import com.google.common.collect.MinMaxPriorityQueue;
import com.google.common.collect.Table;
import com.metamx.druid.client.DataSegment;
import com.metamx.druid.client.DruidServer;

import java.util.Map;

/**
 * A lookup for the number of replicants of a given segment for a certain tier.
 */
public class SegmentReplicantLookup {
    public static SegmentReplicantLookup make(DruidCluster cluster) {
        final Table<String, String, Integer> segmentsInCluster = HashBasedTable.create();
        final Table<String, String, Integer> loadingSegments = HashBasedTable.create();

        for (MinMaxPriorityQueue<ServerHolder> serversByType : cluster.getSortedServersByTier()) {
            for (ServerHolder serverHolder : serversByType) {
                DruidServer server = serverHolder.getServer();

                for (DataSegment segment : server.getSegments().values()) {
                    Integer numReplicants = segmentsInCluster.get(segment.getIdentifier(), server.getTier());
                    if (numReplicants == null) {
                        numReplicants = 0;
                    }
                    segmentsInCluster.put(segment.getIdentifier(), server.getTier(), ++numReplicants);
                }

                // Also account for queued segments
                for (DataSegment segment : serverHolder.getPeon().getSegmentsToLoad()) {
                    Integer numReplicants = loadingSegments.get(segment.getIdentifier(), server.getTier());
                    if (numReplicants == null) {
                        numReplicants = 0;
                    }
                    loadingSegments.put(segment.getIdentifier(), server.getTier(), ++numReplicants);
                }
            }
        }

        return new SegmentReplicantLookup(segmentsInCluster, loadingSegments);
    }

    private final Table<String, String, Integer> segmentsInCluster;
    private final Table<String, String, Integer> loadingSegments;

    private SegmentReplicantLookup(Table<String, String, Integer> segmentsInCluster,
            Table<String, String, Integer> loadingSegments) {
        this.segmentsInCluster = segmentsInCluster;
        this.loadingSegments = loadingSegments;
    }

    public Map<String, Integer> getClusterTiers(String segmentId) {
        Map<String, Integer> retVal = segmentsInCluster.row(segmentId);
        return (retVal == null) ? Maps.<String, Integer>newHashMap() : retVal;
    }

    public Map<String, Integer> getLoadingTiers(String segmentId) {
        Map<String, Integer> retVal = loadingSegments.row(segmentId);
        return (retVal == null) ? Maps.<String, Integer>newHashMap() : retVal;
    }

    public int getClusterReplicants(String segmentId, String tier) {
        Integer retVal = segmentsInCluster.get(segmentId, tier);
        return (retVal == null) ? 0 : retVal;
    }

    public int getLoadingReplicants(String segmentId, String tier) {
        Integer retVal = loadingSegments.get(segmentId, tier);
        return (retVal == null) ? 0 : retVal;
    }

    public int getTotalReplicants(String segmentId, String tier) {
        return getClusterReplicants(segmentId, tier) + getLoadingReplicants(segmentId, tier);
    }
}