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Posted to commits@accumulo.apache.org by el...@apache.org on 2014/06/05 06:42:56 UTC

[14/35] ACCUMULO-2041 extract tablet classes to new files, move tablet-related code to o.a.a.tserver.tablet, make member variables private

http://git-wip-us.apache.org/repos/asf/accumulo/blob/7db2abf1/server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java
----------------------------------------------------------------------
diff --git a/server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java b/server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java
deleted file mode 100644
index fadf4ed..0000000
--- a/server/tserver/src/main/java/org/apache/accumulo/tserver/Tablet.java
+++ /dev/null
@@ -1,3810 +0,0 @@
-/*
- * 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.accumulo.tserver;
-
-import java.io.ByteArrayInputStream;
-import java.io.DataInputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.PriorityQueue;
-import java.util.Set;
-import java.util.SortedMap;
-import java.util.TreeMap;
-import java.util.TreeSet;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicLong;
-import java.util.concurrent.atomic.AtomicReference;
-import java.util.concurrent.locks.ReentrantLock;
-
-import org.apache.accumulo.core.Constants;
-import org.apache.accumulo.core.client.Connector;
-import org.apache.accumulo.core.client.IteratorSetting;
-import org.apache.accumulo.core.client.impl.ScannerImpl;
-import org.apache.accumulo.core.conf.AccumuloConfiguration;
-import org.apache.accumulo.core.conf.ConfigurationCopy;
-import org.apache.accumulo.core.conf.ConfigurationObserver;
-import org.apache.accumulo.core.conf.Property;
-import org.apache.accumulo.core.constraints.Violations;
-import org.apache.accumulo.core.data.ByteSequence;
-import org.apache.accumulo.core.data.Column;
-import org.apache.accumulo.core.data.ColumnUpdate;
-import org.apache.accumulo.core.data.Key;
-import org.apache.accumulo.core.data.KeyExtent;
-import org.apache.accumulo.core.data.KeyValue;
-import org.apache.accumulo.core.data.Mutation;
-import org.apache.accumulo.core.data.Range;
-import org.apache.accumulo.core.data.Value;
-import org.apache.accumulo.core.data.thrift.IterInfo;
-import org.apache.accumulo.core.data.thrift.MapFileInfo;
-import org.apache.accumulo.core.file.FileOperations;
-import org.apache.accumulo.core.file.FileSKVIterator;
-import org.apache.accumulo.core.iterators.IterationInterruptedException;
-import org.apache.accumulo.core.iterators.IteratorEnvironment;
-import org.apache.accumulo.core.iterators.IteratorUtil;
-import org.apache.accumulo.core.iterators.IteratorUtil.IteratorScope;
-import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
-import org.apache.accumulo.core.iterators.system.ColumnFamilySkippingIterator;
-import org.apache.accumulo.core.iterators.system.ColumnQualifierFilter;
-import org.apache.accumulo.core.iterators.system.DeletingIterator;
-import org.apache.accumulo.core.iterators.system.InterruptibleIterator;
-import org.apache.accumulo.core.iterators.system.MultiIterator;
-import org.apache.accumulo.core.iterators.system.SourceSwitchingIterator;
-import org.apache.accumulo.core.iterators.system.SourceSwitchingIterator.DataSource;
-import org.apache.accumulo.core.iterators.system.StatsIterator;
-import org.apache.accumulo.core.iterators.system.VisibilityFilter;
-import org.apache.accumulo.core.master.thrift.TabletLoadState;
-import org.apache.accumulo.core.metadata.MetadataTable;
-import org.apache.accumulo.core.metadata.RootTable;
-import org.apache.accumulo.core.metadata.schema.DataFileValue;
-import org.apache.accumulo.core.metadata.schema.MetadataSchema.TabletsSection;
-import org.apache.accumulo.core.metadata.schema.MetadataSchema.TabletsSection.DataFileColumnFamily;
-import org.apache.accumulo.core.metadata.schema.MetadataSchema.TabletsSection.LogColumnFamily;
-import org.apache.accumulo.core.metadata.schema.MetadataSchema.TabletsSection.ScanFileColumnFamily;
-import org.apache.accumulo.core.security.Authorizations;
-import org.apache.accumulo.core.security.ColumnVisibility;
-import org.apache.accumulo.core.security.Credentials;
-import org.apache.accumulo.core.tabletserver.log.LogEntry;
-import org.apache.accumulo.core.util.CachedConfiguration;
-import org.apache.accumulo.core.util.LocalityGroupUtil;
-import org.apache.accumulo.core.util.LocalityGroupUtil.LocalityGroupConfigurationError;
-import org.apache.accumulo.core.util.MapCounter;
-import org.apache.accumulo.core.util.Pair;
-import org.apache.accumulo.core.util.UtilWaitThread;
-import org.apache.accumulo.fate.zookeeper.IZooReaderWriter;
-import org.apache.accumulo.server.ServerConstants;
-import org.apache.accumulo.server.client.HdfsZooInstance;
-import org.apache.accumulo.server.conf.TableConfiguration;
-import org.apache.accumulo.server.fs.FileRef;
-import org.apache.accumulo.server.fs.VolumeManager;
-import org.apache.accumulo.server.fs.VolumeManager.FileType;
-import org.apache.accumulo.server.fs.VolumeManagerImpl;
-import org.apache.accumulo.server.fs.VolumeUtil;
-import org.apache.accumulo.server.fs.VolumeUtil.TabletFiles;
-import org.apache.accumulo.server.master.state.TServerInstance;
-import org.apache.accumulo.server.master.tableOps.CompactionIterators;
-import org.apache.accumulo.server.problems.ProblemReport;
-import org.apache.accumulo.server.problems.ProblemReports;
-import org.apache.accumulo.server.problems.ProblemType;
-import org.apache.accumulo.server.security.SystemCredentials;
-import org.apache.accumulo.server.tablets.TabletTime;
-import org.apache.accumulo.server.tablets.UniqueNameAllocator;
-import org.apache.accumulo.server.util.FileUtil;
-import org.apache.accumulo.server.util.MasterMetadataUtil;
-import org.apache.accumulo.server.util.MetadataTableUtil;
-import org.apache.accumulo.server.util.TabletOperations;
-import org.apache.accumulo.server.zookeeper.ZooReaderWriter;
-import org.apache.accumulo.start.classloader.vfs.AccumuloVFSClassLoader;
-import org.apache.accumulo.trace.instrument.Span;
-import org.apache.accumulo.trace.instrument.Trace;
-import org.apache.accumulo.tserver.Compactor.CompactionCanceledException;
-import org.apache.accumulo.tserver.Compactor.CompactionEnv;
-import org.apache.accumulo.tserver.FileManager.ScanFileManager;
-import org.apache.accumulo.tserver.InMemoryMap.MemoryIterator;
-import org.apache.accumulo.tserver.TabletServer.TservConstraintEnv;
-import org.apache.accumulo.tserver.TabletServerResourceManager.TabletResourceManager;
-import org.apache.accumulo.tserver.TabletStatsKeeper.Operation;
-import org.apache.accumulo.tserver.compaction.CompactionPlan;
-import org.apache.accumulo.tserver.compaction.CompactionStrategy;
-import org.apache.accumulo.tserver.compaction.DefaultCompactionStrategy;
-import org.apache.accumulo.tserver.compaction.MajorCompactionReason;
-import org.apache.accumulo.tserver.compaction.MajorCompactionRequest;
-import org.apache.accumulo.tserver.compaction.WriteParameters;
-import org.apache.accumulo.tserver.constraints.ConstraintChecker;
-import org.apache.accumulo.tserver.log.DfsLogger;
-import org.apache.accumulo.tserver.log.MutationReceiver;
-import org.apache.accumulo.tserver.mastermessage.TabletStatusMessage;
-import org.apache.accumulo.tserver.metrics.TabletServerMinCMetrics;
-import org.apache.commons.codec.DecoderException;
-import org.apache.commons.codec.binary.Hex;
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FileStatus;
-import org.apache.hadoop.fs.FileSystem;
-import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.io.Text;
-import org.apache.log4j.Logger;
-import org.apache.zookeeper.KeeperException;
-import org.apache.zookeeper.KeeperException.NoNodeException;
-
-/*
- * We need to be able to have the master tell a tabletServer to
- * close this file, and the tablet server to handle all pending client reads
- * before closing
- * 
- */
-
-/**
- * 
- * this class just provides an interface to read from a MapFile mostly takes care of reporting start and end keys
- * 
- * need this because a single row extent can have multiple columns this manages all the columns (each handled by a store) for a single row-extent
- * 
- * 
- */
-
-public class Tablet {
-
-  enum MinorCompactionReason {
-    USER, SYSTEM, CLOSE
-  }
-
-  public class CommitSession {
-
-    private int seq;
-    private InMemoryMap memTable;
-    private int commitsInProgress;
-    private long maxCommittedTime = Long.MIN_VALUE;
-
-    private CommitSession(int seq, InMemoryMap imm) {
-      this.seq = seq;
-      this.memTable = imm;
-      commitsInProgress = 0;
-    }
-
-    public int getWALogSeq() {
-      return seq;
-    }
-
-    private void decrementCommitsInProgress() {
-      if (commitsInProgress < 1)
-        throw new IllegalStateException("commitsInProgress = " + commitsInProgress);
-
-      commitsInProgress--;
-      if (commitsInProgress == 0)
-        Tablet.this.notifyAll();
-    }
-
-    private void incrementCommitsInProgress() {
-      if (commitsInProgress < 0)
-        throw new IllegalStateException("commitsInProgress = " + commitsInProgress);
-
-      commitsInProgress++;
-    }
-
-    private void waitForCommitsToFinish() {
-      while (commitsInProgress > 0) {
-        try {
-          Tablet.this.wait(50);
-        } catch (InterruptedException e) {
-          log.warn(e, e);
-        }
-      }
-    }
-
-    public void abortCommit(List<Mutation> value) {
-      Tablet.this.abortCommit(this, value);
-    }
-
-    public void commit(List<Mutation> mutations) {
-      Tablet.this.commit(this, mutations);
-    }
-
-    public Tablet getTablet() {
-      return Tablet.this;
-    }
-
-    public boolean beginUpdatingLogsUsed(ArrayList<DfsLogger> copy, boolean mincFinish) {
-      return Tablet.this.beginUpdatingLogsUsed(memTable, copy, mincFinish);
-    }
-
-    public void finishUpdatingLogsUsed() {
-      Tablet.this.finishUpdatingLogsUsed();
-    }
-
-    public int getLogId() {
-      return logId;
-    }
-
-    public KeyExtent getExtent() {
-      return extent;
-    }
-
-    private void updateMaxCommittedTime(long time) {
-      maxCommittedTime = Math.max(time, maxCommittedTime);
-    }
-
-    private long getMaxCommittedTime() {
-      if (maxCommittedTime == Long.MIN_VALUE)
-        throw new IllegalStateException("Tried to read max committed time when it was never set");
-      return maxCommittedTime;
-    }
-
-  }
-
-  private class TabletMemory {
-    private InMemoryMap memTable;
-    private InMemoryMap otherMemTable;
-    private InMemoryMap deletingMemTable;
-    private int nextSeq = 1;
-    private CommitSession commitSession;
-
-    TabletMemory() {
-      try {
-        memTable = new InMemoryMap(acuTableConf);
-      } catch (LocalityGroupConfigurationError e) {
-        throw new RuntimeException(e);
-      }
-      commitSession = new CommitSession(nextSeq, memTable);
-      nextSeq += 2;
-    }
-
-    InMemoryMap getMemTable() {
-      return memTable;
-    }
-
-    InMemoryMap getMinCMemTable() {
-      return otherMemTable;
-    }
-
-    CommitSession prepareForMinC() {
-      if (otherMemTable != null) {
-        throw new IllegalStateException();
-      }
-
-      if (deletingMemTable != null) {
-        throw new IllegalStateException();
-      }
-
-      otherMemTable = memTable;
-      try {
-        memTable = new InMemoryMap(acuTableConf);
-      } catch (LocalityGroupConfigurationError e) {
-        throw new RuntimeException(e);
-      }
-
-      CommitSession oldCommitSession = commitSession;
-      commitSession = new CommitSession(nextSeq, memTable);
-      nextSeq += 2;
-
-      tabletResources.updateMemoryUsageStats(Tablet.this, memTable.estimatedSizeInBytes(), otherMemTable.estimatedSizeInBytes());
-
-      return oldCommitSession;
-    }
-
-    void finishedMinC() {
-
-      if (otherMemTable == null) {
-        throw new IllegalStateException();
-      }
-
-      if (deletingMemTable != null) {
-        throw new IllegalStateException();
-      }
-
-      deletingMemTable = otherMemTable;
-
-      otherMemTable = null;
-      Tablet.this.notifyAll();
-    }
-
-    void finalizeMinC() {
-      try {
-        deletingMemTable.delete(15000);
-      } finally {
-        synchronized (Tablet.this) {
-          if (otherMemTable != null) {
-            throw new IllegalStateException();
-          }
-
-          if (deletingMemTable == null) {
-            throw new IllegalStateException();
-          }
-
-          deletingMemTable = null;
-
-          tabletResources.updateMemoryUsageStats(Tablet.this, memTable.estimatedSizeInBytes(), 0);
-        }
-      }
-    }
-
-    boolean memoryReservedForMinC() {
-      return otherMemTable != null || deletingMemTable != null;
-    }
-
-    void waitForMinC() {
-      while (otherMemTable != null || deletingMemTable != null) {
-        try {
-          Tablet.this.wait(50);
-        } catch (InterruptedException e) {
-          log.warn(e, e);
-        }
-      }
-    }
-
-    void mutate(CommitSession cm, List<Mutation> mutations) {
-      cm.memTable.mutate(mutations);
-    }
-
-    void updateMemoryUsageStats() {
-      long other = 0;
-      if (otherMemTable != null)
-        other = otherMemTable.estimatedSizeInBytes();
-      else if (deletingMemTable != null)
-        other = deletingMemTable.estimatedSizeInBytes();
-
-      tabletResources.updateMemoryUsageStats(Tablet.this, memTable.estimatedSizeInBytes(), other);
-    }
-
-    List<MemoryIterator> getIterators() {
-      List<MemoryIterator> toReturn = new ArrayList<MemoryIterator>(2);
-      toReturn.add(memTable.skvIterator());
-      if (otherMemTable != null)
-        toReturn.add(otherMemTable.skvIterator());
-      return toReturn;
-    }
-
-    void returnIterators(List<MemoryIterator> iters) {
-      for (MemoryIterator iter : iters) {
-        iter.close();
-      }
-    }
-
-    public long getNumEntries() {
-      if (otherMemTable != null)
-        return memTable.getNumEntries() + otherMemTable.getNumEntries();
-      return memTable.getNumEntries();
-    }
-
-    CommitSession getCommitSession() {
-      return commitSession;
-    }
-  }
-
-  private TabletMemory tabletMemory;
-
-  private final TabletTime tabletTime;
-  private long persistedTime;
-  private final Object timeLock = new Object();
-
-  private final Path location; // absolute path of this tablets dir
-  private TServerInstance lastLocation;
-
-  private Configuration conf;
-  private VolumeManager fs;
-
-  private final TableConfiguration acuTableConf;
-
-  private volatile boolean tableDirChecked = false;
-
-  private AtomicLong dataSourceDeletions = new AtomicLong(0);
-  private Set<ScanDataSource> activeScans = new HashSet<ScanDataSource>();
-
-  private volatile boolean closing = false;
-  private boolean closed = false;
-  private boolean closeComplete = false;
-
-  private long lastFlushID = -1;
-  private long lastCompactID = -1;
-
-  private KeyExtent extent;
-
-  private TabletResourceManager tabletResources;
-  final private DatafileManager datafileManager;
-  private volatile boolean majorCompactionInProgress = false;
-  private volatile boolean majorCompactionWaitingToStart = false;
-  private Set<MajorCompactionReason> majorCompactionQueued = Collections.synchronizedSet(EnumSet.noneOf(MajorCompactionReason.class));
-  private volatile boolean minorCompactionInProgress = false;
-  private volatile boolean minorCompactionWaitingToStart = false;
-
-  private boolean updatingFlushID = false;
-
-  private AtomicReference<ConstraintChecker> constraintChecker = new AtomicReference<ConstraintChecker>();
-
-  private final String tabletDirectory;
-
-  private int writesInProgress = 0;
-
-  private static final Logger log = Logger.getLogger(Tablet.class);
-  public TabletStatsKeeper timer;
-
-  private Rate queryRate = new Rate(0.2);
-  private long queryCount = 0;
-
-  private Rate queryByteRate = new Rate(0.2);
-  private long queryBytes = 0;
-
-  private Rate ingestRate = new Rate(0.2);
-  private long ingestCount = 0;
-
-  private Rate ingestByteRate = new Rate(0.2);
-  private long ingestBytes = 0;
-
-  private byte[] defaultSecurityLabel = new byte[0];
-
-  private long lastMinorCompactionFinishTime;
-  private long lastMapFileImportTime;
-
-  private volatile long numEntries;
-  private volatile long numEntriesInMemory;
-
-  // a count of the amount of data read by the iterators
-  private AtomicLong scannedCount = new AtomicLong(0);
-  private Rate scannedRate = new Rate(0.2);
-
-  private ConfigurationObserver configObserver;
-
-  private TabletServer tabletServer;
-
-  private final int logId;
-  // ensure we only have one reader/writer of our bulk file notes at at time
-  public final Object bulkFileImportLock = new Object();
-
-  public int getLogId() {
-    return logId;
-  }
-
-  public static class TabletClosedException extends RuntimeException {
-    public TabletClosedException(Exception e) {
-      super(e);
-    }
-
-    public TabletClosedException() {
-      super();
-    }
-
-    private static final long serialVersionUID = 1L;
-  }
-
-  FileRef getNextMapFilename(String prefix) throws IOException {
-    String extension = FileOperations.getNewFileExtension(tabletServer.getTableConfiguration(extent));
-    checkTabletDir();
-    return new FileRef(location.toString() + "/" + prefix + UniqueNameAllocator.getInstance().getNextName() + "." + extension);
-  }
-
-  private void checkTabletDir() throws IOException {
-    if (!tableDirChecked) {
-      checkTabletDir(this.location);
-      tableDirChecked = true;
-    }
-  }
-
-  private void checkTabletDir(Path tabletDir) throws IOException {
-
-    FileStatus[] files = null;
-    try {
-      files = fs.listStatus(tabletDir);
-    } catch (FileNotFoundException ex) {
-      // ignored
-    }
-
-    if (files == null) {
-      if (tabletDir.getName().startsWith("c-"))
-        log.debug("Tablet " + extent + " had no dir, creating " + tabletDir); // its a clone dir...
-      else
-        log.warn("Tablet " + extent + " had no dir, creating " + tabletDir);
-
-      fs.mkdirs(tabletDir);
-    }
-  }
-
-  class DatafileManager {
-    // access to datafilesizes needs to be synchronized: see CompactionRunner#getNumFiles
-    final private Map<FileRef,DataFileValue> datafileSizes = Collections.synchronizedMap(new TreeMap<FileRef,DataFileValue>());
-
-    DatafileManager(SortedMap<FileRef,DataFileValue> datafileSizes) {
-      for (Entry<FileRef,DataFileValue> datafiles : datafileSizes.entrySet())
-        this.datafileSizes.put(datafiles.getKey(), datafiles.getValue());
-    }
-
-    FileRef mergingMinorCompactionFile = null;
-    Set<FileRef> filesToDeleteAfterScan = new HashSet<FileRef>();
-    Map<Long,Set<FileRef>> scanFileReservations = new HashMap<Long,Set<FileRef>>();
-    MapCounter<FileRef> fileScanReferenceCounts = new MapCounter<FileRef>();
-    long nextScanReservationId = 0;
-    boolean reservationsBlocked = false;
-
-    Set<FileRef> majorCompactingFiles = new HashSet<FileRef>();
-
-    Pair<Long,Map<FileRef,DataFileValue>> reserveFilesForScan() {
-      synchronized (Tablet.this) {
-
-        while (reservationsBlocked) {
-          try {
-            Tablet.this.wait(50);
-          } catch (InterruptedException e) {
-            log.warn(e, e);
-          }
-        }
-
-        Set<FileRef> absFilePaths = new HashSet<FileRef>(datafileSizes.keySet());
-
-        long rid = nextScanReservationId++;
-
-        scanFileReservations.put(rid, absFilePaths);
-
-        Map<FileRef,DataFileValue> ret = new HashMap<FileRef,DataFileValue>();
-
-        for (FileRef path : absFilePaths) {
-          fileScanReferenceCounts.increment(path, 1);
-          ret.put(path, datafileSizes.get(path));
-        }
-
-        return new Pair<Long,Map<FileRef,DataFileValue>>(rid, ret);
-      }
-    }
-
-    void returnFilesForScan(Long reservationId) {
-
-      final Set<FileRef> filesToDelete = new HashSet<FileRef>();
-
-      synchronized (Tablet.this) {
-        Set<FileRef> absFilePaths = scanFileReservations.remove(reservationId);
-
-        if (absFilePaths == null)
-          throw new IllegalArgumentException("Unknown scan reservation id " + reservationId);
-
-        boolean notify = false;
-        for (FileRef path : absFilePaths) {
-          long refCount = fileScanReferenceCounts.decrement(path, 1);
-          if (refCount == 0) {
-            if (filesToDeleteAfterScan.remove(path))
-              filesToDelete.add(path);
-            notify = true;
-          } else if (refCount < 0)
-            throw new IllegalStateException("Scan ref count for " + path + " is " + refCount);
-        }
-
-        if (notify)
-          Tablet.this.notifyAll();
-      }
-
-      if (filesToDelete.size() > 0) {
-        log.debug("Removing scan refs from metadata " + extent + " " + filesToDelete);
-        MetadataTableUtil.removeScanFiles(extent, filesToDelete, SystemCredentials.get(), tabletServer.getLock());
-      }
-    }
-
-    private void removeFilesAfterScan(Set<FileRef> scanFiles) {
-      if (scanFiles.size() == 0)
-        return;
-
-      Set<FileRef> filesToDelete = new HashSet<FileRef>();
-
-      synchronized (Tablet.this) {
-        for (FileRef path : scanFiles) {
-          if (fileScanReferenceCounts.get(path) == 0)
-            filesToDelete.add(path);
-          else
-            filesToDeleteAfterScan.add(path);
-        }
-      }
-
-      if (filesToDelete.size() > 0) {
-        log.debug("Removing scan refs from metadata " + extent + " " + filesToDelete);
-        MetadataTableUtil.removeScanFiles(extent, filesToDelete, SystemCredentials.get(), tabletServer.getLock());
-      }
-    }
-
-    private TreeSet<FileRef> waitForScansToFinish(Set<FileRef> pathsToWaitFor, boolean blockNewScans, long maxWaitTime) {
-      long startTime = System.currentTimeMillis();
-      TreeSet<FileRef> inUse = new TreeSet<FileRef>();
-
-      Span waitForScans = Trace.start("waitForScans");
-      try {
-        synchronized (Tablet.this) {
-          if (blockNewScans) {
-            if (reservationsBlocked)
-              throw new IllegalStateException();
-
-            reservationsBlocked = true;
-          }
-
-          for (FileRef path : pathsToWaitFor) {
-            while (fileScanReferenceCounts.get(path) > 0 && System.currentTimeMillis() - startTime < maxWaitTime) {
-              try {
-                Tablet.this.wait(100);
-              } catch (InterruptedException e) {
-                log.warn(e, e);
-              }
-            }
-          }
-
-          for (FileRef path : pathsToWaitFor) {
-            if (fileScanReferenceCounts.get(path) > 0)
-              inUse.add(path);
-          }
-
-          if (blockNewScans) {
-            reservationsBlocked = false;
-            Tablet.this.notifyAll();
-          }
-
-        }
-      } finally {
-        waitForScans.stop();
-      }
-      return inUse;
-    }
-
-    public void importMapFiles(long tid, Map<FileRef,DataFileValue> pathsString, boolean setTime) throws IOException {
-
-      String bulkDir = null;
-
-      Map<FileRef,DataFileValue> paths = new HashMap<FileRef,DataFileValue>();
-      for (Entry<FileRef,DataFileValue> entry : pathsString.entrySet())
-        paths.put(entry.getKey(), entry.getValue());
-
-      for (FileRef tpath : paths.keySet()) {
-
-        boolean inTheRightDirectory = false;
-        Path parent = tpath.path().getParent().getParent();
-        for (String tablesDir : ServerConstants.getTablesDirs()) {
-          if (parent.equals(new Path(tablesDir, extent.getTableId().toString()))) {
-            inTheRightDirectory = true;
-            break;
-          }
-        }
-        if (!inTheRightDirectory) {
-          throw new IOException("Data file " + tpath + " not in table dirs");
-        }
-
-        if (bulkDir == null)
-          bulkDir = tpath.path().getParent().toString();
-        else if (!bulkDir.equals(tpath.path().getParent().toString()))
-          throw new IllegalArgumentException("bulk files in different dirs " + bulkDir + " " + tpath);
-
-      }
-
-      if (extent.isRootTablet()) {
-        throw new IllegalArgumentException("Can not import files to root tablet");
-      }
-
-      synchronized (bulkFileImportLock) {
-        Credentials creds = SystemCredentials.get();
-        Connector conn;
-        try {
-          conn = HdfsZooInstance.getInstance().getConnector(creds.getPrincipal(), creds.getToken());
-        } catch (Exception ex) {
-          throw new IOException(ex);
-        }
-        // Remove any bulk files we've previously loaded and compacted away
-        List<FileRef> files = MetadataTableUtil.getBulkFilesLoaded(conn, extent, tid);
-
-        for (FileRef file : files)
-          if (paths.keySet().remove(file))
-            log.debug("Ignoring request to re-import a file already imported: " + extent + ": " + file);
-
-        if (paths.size() > 0) {
-          long bulkTime = Long.MIN_VALUE;
-          if (setTime) {
-            for (DataFileValue dfv : paths.values()) {
-              long nextTime = tabletTime.getAndUpdateTime();
-              if (nextTime < bulkTime)
-                throw new IllegalStateException("Time went backwards unexpectedly " + nextTime + " " + bulkTime);
-              bulkTime = nextTime;
-              dfv.setTime(bulkTime);
-            }
-          }
-
-          synchronized (timeLock) {
-            if (bulkTime > persistedTime)
-              persistedTime = bulkTime;
-
-            MetadataTableUtil.updateTabletDataFile(tid, extent, paths, tabletTime.getMetadataValue(persistedTime), creds, tabletServer.getLock());
-          }
-        }
-      }
-
-      synchronized (Tablet.this) {
-        for (Entry<FileRef,DataFileValue> tpath : paths.entrySet()) {
-          if (datafileSizes.containsKey(tpath.getKey())) {
-            log.error("Adding file that is already in set " + tpath.getKey());
-          }
-          datafileSizes.put(tpath.getKey(), tpath.getValue());
-
-        }
-
-        tabletResources.importedMapFiles();
-
-        computeNumEntries();
-      }
-
-      for (Entry<FileRef,DataFileValue> entry : paths.entrySet()) {
-        log.log(TLevel.TABLET_HIST, extent + " import " + entry.getKey() + " " + entry.getValue());
-      }
-    }
-
-    FileRef reserveMergingMinorCompactionFile() {
-      if (mergingMinorCompactionFile != null)
-        throw new IllegalStateException("Tried to reserve merging minor compaction file when already reserved  : " + mergingMinorCompactionFile);
-
-      if (extent.isRootTablet())
-        return null;
-
-      int maxFiles = acuTableConf.getMaxFilesPerTablet();
-
-      // when a major compaction is running and we are at max files, write out
-      // one extra file... want to avoid the case where major compaction is
-      // compacting everything except for the largest file, and therefore the
-      // largest file is returned for merging.. the following check mostly
-      // avoids this case, except for the case where major compactions fail or
-      // are canceled
-      if (majorCompactingFiles.size() > 0 && datafileSizes.size() == maxFiles)
-        return null;
-
-      if (datafileSizes.size() >= maxFiles) {
-        // find the smallest file
-
-        long min = Long.MAX_VALUE;
-        FileRef minName = null;
-
-        for (Entry<FileRef,DataFileValue> entry : datafileSizes.entrySet()) {
-          if (entry.getValue().getSize() < min && !majorCompactingFiles.contains(entry.getKey())) {
-            min = entry.getValue().getSize();
-            minName = entry.getKey();
-          }
-        }
-
-        if (minName == null)
-          return null;
-
-        mergingMinorCompactionFile = minName;
-        return minName;
-      }
-
-      return null;
-    }
-
-    void unreserveMergingMinorCompactionFile(FileRef file) {
-      if ((file == null && mergingMinorCompactionFile != null) || (file != null && mergingMinorCompactionFile == null)
-          || (file != null && mergingMinorCompactionFile != null && !file.equals(mergingMinorCompactionFile)))
-        throw new IllegalStateException("Disagreement " + file + " " + mergingMinorCompactionFile);
-
-      mergingMinorCompactionFile = null;
-    }
-
-    void bringMinorCompactionOnline(FileRef tmpDatafile, FileRef newDatafile, FileRef absMergeFile, DataFileValue dfv, CommitSession commitSession, long flushId)
-        throws IOException {
-
-      IZooReaderWriter zoo = ZooReaderWriter.getRetryingInstance();
-      if (extent.isRootTablet()) {
-        try {
-          if (!zoo.isLockHeld(tabletServer.getLock().getLockID())) {
-            throw new IllegalStateException();
-          }
-        } catch (Exception e) {
-          throw new IllegalStateException("Can not bring major compaction online, lock not held", e);
-        }
-      }
-
-      // rename before putting in metadata table, so files in metadata table should
-      // always exist
-      do {
-        try {
-          if (dfv.getNumEntries() == 0) {
-            fs.deleteRecursively(tmpDatafile.path());
-          } else {
-            if (fs.exists(newDatafile.path())) {
-              log.warn("Target map file already exist " + newDatafile);
-              fs.deleteRecursively(newDatafile.path());
-            }
-
-            rename(fs, tmpDatafile.path(), newDatafile.path());
-          }
-          break;
-        } catch (IOException ioe) {
-          log.warn("Tablet " + extent + " failed to rename " + newDatafile + " after MinC, will retry in 60 secs...", ioe);
-          UtilWaitThread.sleep(60 * 1000);
-        }
-      } while (true);
-
-      long t1, t2;
-
-      // the code below always assumes merged files are in use by scans... this must be done
-      // because the in memory list of files is not updated until after the metadata table
-      // therefore the file is available to scans until memory is updated, but want to ensure
-      // the file is not available for garbage collection... if memory were updated
-      // before this point (like major compactions do), then the following code could wait
-      // for scans to finish like major compactions do.... used to wait for scans to finish
-      // here, but that was incorrect because a scan could start after waiting but before
-      // memory was updated... assuming the file is always in use by scans leads to
-      // one uneeded metadata update when it was not actually in use
-      Set<FileRef> filesInUseByScans = Collections.emptySet();
-      if (absMergeFile != null)
-        filesInUseByScans = Collections.singleton(absMergeFile);
-
-      // very important to write delete entries outside of log lock, because
-      // this metadata write does not go up... it goes sideways or to itself
-      if (absMergeFile != null)
-        MetadataTableUtil.addDeleteEntries(extent, Collections.singleton(absMergeFile), SystemCredentials.get());
-
-      Set<String> unusedWalLogs = beginClearingUnusedLogs();
-      try {
-        // the order of writing to metadata and walog is important in the face of machine/process failures
-        // need to write to metadata before writing to walog, when things are done in the reverse order
-        // data could be lost... the minor compaction start even should be written before the following metadata
-        // write is made
-
-        synchronized (timeLock) {
-          if (commitSession.getMaxCommittedTime() > persistedTime)
-            persistedTime = commitSession.getMaxCommittedTime();
-
-          String time = tabletTime.getMetadataValue(persistedTime);
-          MasterMetadataUtil.updateTabletDataFile(extent, newDatafile, absMergeFile, dfv, time, SystemCredentials.get(), filesInUseByScans,
-              tabletServer.getClientAddressString(), tabletServer.getLock(), unusedWalLogs, lastLocation, flushId);
-        }
-
-      } finally {
-        finishClearingUnusedLogs();
-      }
-
-      do {
-        try {
-          // the purpose of making this update use the new commit session, instead of the old one passed in,
-          // is because the new one will reference the logs used by current memory...
-
-          tabletServer.minorCompactionFinished(tabletMemory.getCommitSession(), newDatafile.toString(), commitSession.getWALogSeq() + 2);
-          break;
-        } catch (IOException e) {
-          log.error("Failed to write to write-ahead log " + e.getMessage() + " will retry", e);
-          UtilWaitThread.sleep(1 * 1000);
-        }
-      } while (true);
-
-      synchronized (Tablet.this) {
-        lastLocation = null;
-
-        t1 = System.currentTimeMillis();
-        if (datafileSizes.containsKey(newDatafile)) {
-          log.error("Adding file that is already in set " + newDatafile);
-        }
-
-        if (dfv.getNumEntries() > 0) {
-          datafileSizes.put(newDatafile, dfv);
-        }
-
-        if (absMergeFile != null) {
-          datafileSizes.remove(absMergeFile);
-        }
-
-        unreserveMergingMinorCompactionFile(absMergeFile);
-
-        dataSourceDeletions.incrementAndGet();
-        tabletMemory.finishedMinC();
-
-        lastFlushID = flushId;
-
-        computeNumEntries();
-        t2 = System.currentTimeMillis();
-      }
-
-      // must do this after list of files in memory is updated above
-      removeFilesAfterScan(filesInUseByScans);
-
-      if (absMergeFile != null)
-        log.log(TLevel.TABLET_HIST, extent + " MinC [" + absMergeFile + ",memory] -> " + newDatafile);
-      else
-        log.log(TLevel.TABLET_HIST, extent + " MinC [memory] -> " + newDatafile);
-      log.debug(String.format("MinC finish lock %.2f secs %s", (t2 - t1) / 1000.0, getExtent().toString()));
-      if (dfv.getSize() > acuTableConf.getMemoryInBytes(Property.TABLE_SPLIT_THRESHOLD)) {
-        log.debug(String.format("Minor Compaction wrote out file larger than split threshold.  split threshold = %,d  file size = %,d",
-            acuTableConf.getMemoryInBytes(Property.TABLE_SPLIT_THRESHOLD), dfv.getSize()));
-      }
-
-    }
-
-    public void reserveMajorCompactingFiles(Collection<FileRef> files) {
-      if (majorCompactingFiles.size() != 0)
-        throw new IllegalStateException("Major compacting files not empty " + majorCompactingFiles);
-
-      if (mergingMinorCompactionFile != null && files.contains(mergingMinorCompactionFile))
-        throw new IllegalStateException("Major compaction tried to resrve file in use by minor compaction " + mergingMinorCompactionFile);
-
-      majorCompactingFiles.addAll(files);
-    }
-
-    public void clearMajorCompactingFile() {
-      majorCompactingFiles.clear();
-    }
-
-    void bringMajorCompactionOnline(Set<FileRef> oldDatafiles, FileRef tmpDatafile, FileRef newDatafile, Long compactionId, DataFileValue dfv)
-        throws IOException {
-      long t1, t2;
-
-      if (!extent.isRootTablet()) {
-
-        if (fs.exists(newDatafile.path())) {
-          log.error("Target map file already exist " + newDatafile, new Exception());
-          throw new IllegalStateException("Target map file already exist " + newDatafile);
-        }
-
-        // rename before putting in metadata table, so files in metadata table should
-        // always exist
-        rename(fs, tmpDatafile.path(), newDatafile.path());
-
-        if (dfv.getNumEntries() == 0) {
-          fs.deleteRecursively(newDatafile.path());
-        }
-      }
-
-      TServerInstance lastLocation = null;
-      synchronized (Tablet.this) {
-
-        t1 = System.currentTimeMillis();
-
-        IZooReaderWriter zoo = ZooReaderWriter.getRetryingInstance();
-
-        dataSourceDeletions.incrementAndGet();
-
-        if (extent.isRootTablet()) {
-
-          waitForScansToFinish(oldDatafiles, true, Long.MAX_VALUE);
-
-          try {
-            if (!zoo.isLockHeld(tabletServer.getLock().getLockID())) {
-              throw new IllegalStateException();
-            }
-          } catch (Exception e) {
-            throw new IllegalStateException("Can not bring major compaction online, lock not held", e);
-          }
-
-          // mark files as ready for deletion, but
-          // do not delete them until we successfully
-          // rename the compacted map file, in case
-          // the system goes down
-
-          RootFiles.replaceFiles(acuTableConf, fs, location, oldDatafiles, tmpDatafile, newDatafile);
-        }
-
-        // atomically remove old files and add new file
-        for (FileRef oldDatafile : oldDatafiles) {
-          if (!datafileSizes.containsKey(oldDatafile)) {
-            log.error("file does not exist in set " + oldDatafile);
-          }
-          datafileSizes.remove(oldDatafile);
-          majorCompactingFiles.remove(oldDatafile);
-        }
-
-        if (datafileSizes.containsKey(newDatafile)) {
-          log.error("Adding file that is already in set " + newDatafile);
-        }
-
-        if (dfv.getNumEntries() > 0) {
-          datafileSizes.put(newDatafile, dfv);
-        }
-
-        // could be used by a follow on compaction in a multipass compaction
-        majorCompactingFiles.add(newDatafile);
-
-        computeNumEntries();
-
-        lastLocation = Tablet.this.lastLocation;
-        Tablet.this.lastLocation = null;
-
-        if (compactionId != null)
-          lastCompactID = compactionId;
-
-        t2 = System.currentTimeMillis();
-      }
-
-      if (!extent.isRootTablet()) {
-        Set<FileRef> filesInUseByScans = waitForScansToFinish(oldDatafiles, false, 10000);
-        if (filesInUseByScans.size() > 0)
-          log.debug("Adding scan refs to metadata " + extent + " " + filesInUseByScans);
-        MasterMetadataUtil.replaceDatafiles(extent, oldDatafiles, filesInUseByScans, newDatafile, compactionId, dfv, SystemCredentials.get(),
-            tabletServer.getClientAddressString(), lastLocation, tabletServer.getLock());
-        removeFilesAfterScan(filesInUseByScans);
-      }
-
-      log.debug(String.format("MajC finish lock %.2f secs", (t2 - t1) / 1000.0));
-      log.log(TLevel.TABLET_HIST, extent + " MajC " + oldDatafiles + " --> " + newDatafile);
-    }
-
-    public SortedMap<FileRef,DataFileValue> getDatafileSizes() {
-      synchronized (Tablet.this) {
-        TreeMap<FileRef,DataFileValue> copy = new TreeMap<FileRef,DataFileValue>(datafileSizes);
-        return Collections.unmodifiableSortedMap(copy);
-      }
-    }
-
-    public Set<FileRef> getFiles() {
-      synchronized (Tablet.this) {
-        HashSet<FileRef> files = new HashSet<FileRef>(datafileSizes.keySet());
-        return Collections.unmodifiableSet(files);
-      }
-    }
-
-  }
-
-  public Tablet(TabletServer tabletServer, Text location, KeyExtent extent, TabletResourceManager trm, SortedMap<Key,Value> tabletsKeyValues)
-      throws IOException {
-    this(tabletServer, location, extent, trm, CachedConfiguration.getInstance(), tabletsKeyValues);
-    splitCreationTime = 0;
-  }
-
-  public Tablet(KeyExtent extent, TabletServer tabletServer, TabletResourceManager trm, SplitInfo info) throws IOException {
-    this(tabletServer, new Text(info.dir), extent, trm, CachedConfiguration.getInstance(), info.datafiles, info.time, info.initFlushID, info.initCompactID,
-        info.lastLocation);
-    splitCreationTime = System.currentTimeMillis();
-  }
-
-  private Tablet(TabletServer tabletServer, Text location, KeyExtent extent, TabletResourceManager trm, Configuration conf,
-      SortedMap<Key,Value> tabletsKeyValues) throws IOException {
-    this(tabletServer, location, extent, trm, conf, VolumeManagerImpl.get(), tabletsKeyValues);
-  }
-
-  static private final List<LogEntry> EMPTY = Collections.emptyList();
-
-  private Tablet(TabletServer tabletServer, Text location, KeyExtent extent, TabletResourceManager trm, Configuration conf,
-      SortedMap<FileRef,DataFileValue> datafiles, String time, long initFlushID, long initCompactID, TServerInstance lastLocation) throws IOException {
-    this(tabletServer, location, extent, trm, conf, VolumeManagerImpl.get(), EMPTY, datafiles, time, lastLocation, new HashSet<FileRef>(), initFlushID,
-        initCompactID);
-  }
-
-  private static String lookupTime(AccumuloConfiguration conf, KeyExtent extent, SortedMap<Key,Value> tabletsKeyValues) {
-    SortedMap<Key,Value> entries;
-
-    if (extent.isRootTablet()) {
-      return null;
-    } else {
-      entries = new TreeMap<Key,Value>();
-      Text rowName = extent.getMetadataEntry();
-      for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-        if (entry.getKey().compareRow(rowName) == 0 && TabletsSection.ServerColumnFamily.TIME_COLUMN.hasColumns(entry.getKey())) {
-          entries.put(new Key(entry.getKey()), new Value(entry.getValue()));
-        }
-      }
-    }
-
-    // log.debug("extent : "+extent+"   entries : "+entries);
-
-    if (entries.size() == 1)
-      return entries.values().iterator().next().toString();
-    return null;
-  }
-
-  private static SortedMap<FileRef,DataFileValue> lookupDatafiles(AccumuloConfiguration conf, VolumeManager fs, KeyExtent extent,
-      SortedMap<Key,Value> tabletsKeyValues) throws IOException {
-
-    TreeMap<FileRef,DataFileValue> datafiles = new TreeMap<FileRef,DataFileValue>();
-
-    if (extent.isRootTablet()) { // the meta0 tablet
-      Path location = new Path(MetadataTableUtil.getRootTabletDir());
-
-      // cleanUpFiles() has special handling for delete. files
-      FileStatus[] files = fs.listStatus(location);
-      Collection<String> goodPaths = RootFiles.cleanupReplacement(fs, files, true);
-      for (String good : goodPaths) {
-        Path path = new Path(good);
-        String filename = path.getName();
-        FileRef ref = new FileRef(location.toString() + "/" + filename, path);
-        DataFileValue dfv = new DataFileValue(0, 0);
-        datafiles.put(ref, dfv);
-      }
-    } else {
-
-      Text rowName = extent.getMetadataEntry();
-
-      String tableId = extent.isMeta() ? RootTable.ID : MetadataTable.ID;
-      ScannerImpl mdScanner = new ScannerImpl(HdfsZooInstance.getInstance(), SystemCredentials.get(), tableId, Authorizations.EMPTY);
-
-      // Commented out because when no data file is present, each tablet will scan through metadata table and return nothing
-      // reduced batch size to improve performance
-      // changed here after endKeys were implemented from 10 to 1000
-      mdScanner.setBatchSize(1000);
-
-      // leave these in, again, now using endKey for safety
-      mdScanner.fetchColumnFamily(DataFileColumnFamily.NAME);
-
-      mdScanner.setRange(new Range(rowName));
-
-      for (Entry<Key,Value> entry : mdScanner) {
-
-        if (entry.getKey().compareRow(rowName) != 0) {
-          break;
-        }
-
-        FileRef ref = new FileRef(fs, entry.getKey());
-        datafiles.put(ref, new DataFileValue(entry.getValue().get()));
-      }
-    }
-    return datafiles;
-  }
-
-  private static List<LogEntry> lookupLogEntries(KeyExtent ke, SortedMap<Key,Value> tabletsKeyValues) {
-    List<LogEntry> logEntries = new ArrayList<LogEntry>();
-
-    if (ke.isMeta()) {
-      try {
-        logEntries = MetadataTableUtil.getLogEntries(SystemCredentials.get(), ke);
-      } catch (Exception ex) {
-        throw new RuntimeException("Unable to read tablet log entries", ex);
-      }
-    } else {
-      log.debug("Looking at metadata " + tabletsKeyValues);
-      Text row = ke.getMetadataEntry();
-      for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-        Key key = entry.getKey();
-        if (key.getRow().equals(row)) {
-          if (key.getColumnFamily().equals(LogColumnFamily.NAME)) {
-            logEntries.add(LogEntry.fromKeyValue(key, entry.getValue()));
-          }
-        }
-      }
-    }
-
-    log.debug("got " + logEntries + " for logs for " + ke);
-    return logEntries;
-  }
-
-  private static Set<FileRef> lookupScanFiles(KeyExtent extent, SortedMap<Key,Value> tabletsKeyValues, VolumeManager fs) throws IOException {
-    HashSet<FileRef> scanFiles = new HashSet<FileRef>();
-
-    Text row = extent.getMetadataEntry();
-    for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-      Key key = entry.getKey();
-      if (key.getRow().equals(row) && key.getColumnFamily().equals(ScanFileColumnFamily.NAME)) {
-        scanFiles.add(new FileRef(fs, key));
-      }
-    }
-
-    return scanFiles;
-  }
-
-  private static long lookupFlushID(KeyExtent extent, SortedMap<Key,Value> tabletsKeyValues) {
-    Text row = extent.getMetadataEntry();
-    for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-      Key key = entry.getKey();
-      if (key.getRow().equals(row) && TabletsSection.ServerColumnFamily.FLUSH_COLUMN.equals(key.getColumnFamily(), key.getColumnQualifier()))
-        return Long.parseLong(entry.getValue().toString());
-    }
-
-    return -1;
-  }
-
-  private static long lookupCompactID(KeyExtent extent, SortedMap<Key,Value> tabletsKeyValues) {
-    Text row = extent.getMetadataEntry();
-    for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-      Key key = entry.getKey();
-      if (key.getRow().equals(row) && TabletsSection.ServerColumnFamily.COMPACT_COLUMN.equals(key.getColumnFamily(), key.getColumnQualifier()))
-        return Long.parseLong(entry.getValue().toString());
-    }
-
-    return -1;
-  }
-
-  private Tablet(TabletServer tabletServer, Text location, KeyExtent extent, TabletResourceManager trm, Configuration conf, VolumeManager fs,
-      SortedMap<Key,Value> tabletsKeyValues) throws IOException {
-    this(tabletServer, location, extent, trm, conf, fs, lookupLogEntries(extent, tabletsKeyValues), lookupDatafiles(tabletServer.getSystemConfiguration(), fs,
-        extent, tabletsKeyValues), lookupTime(tabletServer.getSystemConfiguration(), extent, tabletsKeyValues), lookupLastServer(extent, tabletsKeyValues),
-        lookupScanFiles(extent, tabletsKeyValues, fs), lookupFlushID(extent, tabletsKeyValues), lookupCompactID(extent, tabletsKeyValues));
-  }
-
-  private static TServerInstance lookupLastServer(KeyExtent extent, SortedMap<Key,Value> tabletsKeyValues) {
-    for (Entry<Key,Value> entry : tabletsKeyValues.entrySet()) {
-      if (entry.getKey().getColumnFamily().compareTo(TabletsSection.LastLocationColumnFamily.NAME) == 0) {
-        return new TServerInstance(entry.getValue(), entry.getKey().getColumnQualifier());
-      }
-    }
-    return null;
-  }
-
-  /**
-   * yet another constructor - this one allows us to avoid costly lookups into the Metadata table if we already know the files we need - as at split time
-   */
-  private Tablet(final TabletServer tabletServer, final Text location, final KeyExtent extent, final TabletResourceManager trm, final Configuration conf,
-      final VolumeManager fs, final List<LogEntry> rawLogEntries, final SortedMap<FileRef,DataFileValue> rawDatafiles, String time,
-      final TServerInstance lastLocation, Set<FileRef> scanFiles, long initFlushID, long initCompactID) throws IOException {
-
-    TabletFiles tabletPaths = VolumeUtil.updateTabletVolumes(tabletServer.getLock(), fs, extent, new TabletFiles(location.toString(), rawLogEntries,
-        rawDatafiles));
-
-    Path locationPath;
-
-    if (tabletPaths.dir.contains(":")) {
-      locationPath = new Path(tabletPaths.dir.toString());
-    } else {
-      locationPath = fs.getFullPath(FileType.TABLE, extent.getTableId().toString() + tabletPaths.dir.toString());
-    }
-
-    final List<LogEntry> logEntries = tabletPaths.logEntries;
-    final SortedMap<FileRef,DataFileValue> datafiles = tabletPaths.datafiles;
-
-    this.location = locationPath;
-    this.lastLocation = lastLocation;
-    this.tabletDirectory = tabletPaths.dir;
-    this.conf = conf;
-    this.acuTableConf = tabletServer.getTableConfiguration(extent);
-
-    this.fs = fs;
-    this.extent = extent;
-    this.tabletResources = trm;
-
-    this.lastFlushID = initFlushID;
-    this.lastCompactID = initCompactID;
-
-    if (extent.isRootTablet()) {
-      long rtime = Long.MIN_VALUE;
-      for (FileRef ref : datafiles.keySet()) {
-        Path path = ref.path();
-        FileSystem ns = fs.getVolumeByPath(path).getFileSystem();
-        FileSKVIterator reader = FileOperations.getInstance().openReader(path.toString(), true, ns, ns.getConf(), tabletServer.getTableConfiguration(extent));
-        long maxTime = -1;
-        try {
-
-          while (reader.hasTop()) {
-            maxTime = Math.max(maxTime, reader.getTopKey().getTimestamp());
-            reader.next();
-          }
-
-        } finally {
-          reader.close();
-        }
-
-        if (maxTime > rtime) {
-          time = TabletTime.LOGICAL_TIME_ID + "" + maxTime;
-          rtime = maxTime;
-        }
-      }
-    }
-    if (time == null && datafiles.isEmpty() && extent.equals(RootTable.OLD_EXTENT)) {
-      // recovery... old root tablet has no data, so time doesn't matter:
-      time = TabletTime.LOGICAL_TIME_ID + "" + Long.MIN_VALUE;
-    }
-
-    this.tabletServer = tabletServer;
-    this.logId = tabletServer.createLogId(extent);
-
-    this.timer = new TabletStatsKeeper();
-
-    setupDefaultSecurityLabels(extent);
-
-    tabletMemory = new TabletMemory();
-    tabletTime = TabletTime.getInstance(time);
-    persistedTime = tabletTime.getTime();
-
-    acuTableConf.addObserver(configObserver = new ConfigurationObserver() {
-
-      private void reloadConstraints() {
-        constraintChecker.set(new ConstraintChecker(acuTableConf));
-      }
-
-      @Override
-      public void propertiesChanged() {
-        reloadConstraints();
-
-        try {
-          setupDefaultSecurityLabels(extent);
-        } catch (Exception e) {
-          log.error("Failed to reload default security labels for extent: " + extent.toString());
-        }
-      }
-
-      @Override
-      public void propertyChanged(String prop) {
-        if (prop.startsWith(Property.TABLE_CONSTRAINT_PREFIX.getKey()))
-          reloadConstraints();
-        else if (prop.equals(Property.TABLE_DEFAULT_SCANTIME_VISIBILITY.getKey())) {
-          try {
-            log.info("Default security labels changed for extent: " + extent.toString());
-            setupDefaultSecurityLabels(extent);
-          } catch (Exception e) {
-            log.error("Failed to reload default security labels for extent: " + extent.toString());
-          }
-        }
-
-      }
-
-      @Override
-      public void sessionExpired() {
-        log.debug("Session expired, no longer updating per table props...");
-      }
-
-    });
-
-    acuTableConf.getNamespaceConfiguration().addObserver(configObserver);
-
-    // Force a load of any per-table properties
-    configObserver.propertiesChanged();
-
-    if (!logEntries.isEmpty()) {
-      log.info("Starting Write-Ahead Log recovery for " + this.extent);
-      final long[] count = new long[2];
-      final CommitSession commitSession = tabletMemory.getCommitSession();
-      count[1] = Long.MIN_VALUE;
-      try {
-        Set<String> absPaths = new HashSet<String>();
-        for (FileRef ref : datafiles.keySet())
-          absPaths.add(ref.path().toString());
-
-        tabletServer.recover(this.tabletServer.getFileSystem(), extent, acuTableConf, logEntries, absPaths, new MutationReceiver() {
-          @Override
-          public void receive(Mutation m) {
-            // LogReader.printMutation(m);
-            Collection<ColumnUpdate> muts = m.getUpdates();
-            for (ColumnUpdate columnUpdate : muts) {
-              if (!columnUpdate.hasTimestamp()) {
-                // if it is not a user set timestamp, it must have been set
-                // by the system
-                count[1] = Math.max(count[1], columnUpdate.getTimestamp());
-              }
-            }
-            tabletMemory.mutate(commitSession, Collections.singletonList(m));
-            count[0]++;
-          }
-        });
-
-        if (count[1] != Long.MIN_VALUE) {
-          tabletTime.useMaxTimeFromWALog(count[1]);
-        }
-        commitSession.updateMaxCommittedTime(tabletTime.getTime());
-
-        if (count[0] == 0) {
-          MetadataTableUtil.removeUnusedWALEntries(extent, logEntries, tabletServer.getLock());
-          logEntries.clear();
-        }
-
-      } catch (Throwable t) {
-        if (acuTableConf.getBoolean(Property.TABLE_FAILURES_IGNORE)) {
-          log.warn("Error recovering from log files: ", t);
-        } else {
-          throw new RuntimeException(t);
-        }
-      }
-      // make some closed references that represent the recovered logs
-      currentLogs = new HashSet<DfsLogger>();
-      for (LogEntry logEntry : logEntries) {
-        for (String log : logEntry.logSet) {
-          currentLogs.add(new DfsLogger(tabletServer.getServerConfig(), log));
-        }
-      }
-
-      log.info("Write-Ahead Log recovery complete for " + this.extent + " (" + count[0] + " mutations applied, " + tabletMemory.getNumEntries()
-          + " entries created)");
-    }
-
-    String contextName = acuTableConf.get(Property.TABLE_CLASSPATH);
-    if (contextName != null && !contextName.equals("")) {
-      // initialize context classloader, instead of possibly waiting for it to initialize for a scan
-      // TODO this could hang, causing other tablets to fail to load - ACCUMULO-1292
-      AccumuloVFSClassLoader.getContextManager().getClassLoader(contextName);
-    }
-
-    // do this last after tablet is completely setup because it
-    // could cause major compaction to start
-    datafileManager = new DatafileManager(datafiles);
-
-    computeNumEntries();
-
-    datafileManager.removeFilesAfterScan(scanFiles);
-
-    // look for hints of a failure on the previous tablet server
-    if (!logEntries.isEmpty() || needsMajorCompaction(MajorCompactionReason.NORMAL)) {
-      // look for any temp files hanging around
-      removeOldTemporaryFiles();
-    }
-
-    log.log(TLevel.TABLET_HIST, extent + " opened");
-  }
-
-  private void removeOldTemporaryFiles() {
-    // remove any temporary files created by a previous tablet server
-    try {
-      for (FileStatus tmp : fs.globStatus(new Path(location, "*_tmp"))) {
-        try {
-          log.debug("Removing old temp file " + tmp.getPath());
-          fs.delete(tmp.getPath());
-        } catch (IOException ex) {
-          log.error("Unable to remove old temp file " + tmp.getPath() + ": " + ex);
-        }
-      }
-    } catch (IOException ex) {
-      log.error("Error scanning for old temp files in " + location);
-    }
-  }
-
-  private void setupDefaultSecurityLabels(KeyExtent extent) {
-    if (extent.isMeta()) {
-      defaultSecurityLabel = new byte[0];
-    } else {
-      try {
-        ColumnVisibility cv = new ColumnVisibility(acuTableConf.get(Property.TABLE_DEFAULT_SCANTIME_VISIBILITY));
-        this.defaultSecurityLabel = cv.getExpression();
-      } catch (Exception e) {
-        log.error(e, e);
-        this.defaultSecurityLabel = new byte[0];
-      }
-    }
-  }
-
-  public static class KVEntry extends KeyValue {
-    private static final long serialVersionUID = 1L;
-
-    public KVEntry(Key k, Value v) {
-      super(new Key(k), Arrays.copyOf(v.get(), v.get().length));
-    }
-
-    int numBytes() {
-      return getKey().getSize() + getValue().get().length;
-    }
-
-    int estimateMemoryUsed() {
-      return getKey().getSize() + getValue().get().length + (9 * 32); // overhead is 32 per object
-    }
-  }
-
-  private LookupResult lookup(SortedKeyValueIterator<Key,Value> mmfi, List<Range> ranges, HashSet<Column> columnSet, ArrayList<KVEntry> results,
-      long maxResultsSize) throws IOException {
-
-    LookupResult lookupResult = new LookupResult();
-
-    boolean exceededMemoryUsage = false;
-    boolean tabletClosed = false;
-
-    Set<ByteSequence> cfset = null;
-    if (columnSet.size() > 0)
-      cfset = LocalityGroupUtil.families(columnSet);
-
-    for (Range range : ranges) {
-
-      if (exceededMemoryUsage || tabletClosed) {
-        lookupResult.unfinishedRanges.add(range);
-        continue;
-      }
-
-      int entriesAdded = 0;
-
-      try {
-        if (cfset != null)
-          mmfi.seek(range, cfset, true);
-        else
-          mmfi.seek(range, LocalityGroupUtil.EMPTY_CF_SET, false);
-
-        while (mmfi.hasTop()) {
-          Key key = mmfi.getTopKey();
-
-          KVEntry kve = new KVEntry(key, mmfi.getTopValue());
-          results.add(kve);
-          entriesAdded++;
-          lookupResult.bytesAdded += kve.estimateMemoryUsed();
-          lookupResult.dataSize += kve.numBytes();
-
-          exceededMemoryUsage = lookupResult.bytesAdded > maxResultsSize;
-
-          if (exceededMemoryUsage) {
-            addUnfinishedRange(lookupResult, range, key, false);
-            break;
-          }
-
-          mmfi.next();
-        }
-
-      } catch (TooManyFilesException tmfe) {
-        // treat this as a closed tablet, and let the client retry
-        log.warn("Tablet " + getExtent() + " has too many files, batch lookup can not run");
-        handleTabletClosedDuringScan(results, lookupResult, exceededMemoryUsage, range, entriesAdded);
-        tabletClosed = true;
-      } catch (IOException ioe) {
-        if (shutdownInProgress()) {
-          // assume HDFS shutdown hook caused this exception
-          log.debug("IOException while shutdown in progress ", ioe);
-          handleTabletClosedDuringScan(results, lookupResult, exceededMemoryUsage, range, entriesAdded);
-          tabletClosed = true;
-        } else {
-          throw ioe;
-        }
-      } catch (IterationInterruptedException iie) {
-        if (isClosed()) {
-          handleTabletClosedDuringScan(results, lookupResult, exceededMemoryUsage, range, entriesAdded);
-          tabletClosed = true;
-        } else {
-          throw iie;
-        }
-      } catch (TabletClosedException tce) {
-        handleTabletClosedDuringScan(results, lookupResult, exceededMemoryUsage, range, entriesAdded);
-        tabletClosed = true;
-      }
-
-    }
-
-    return lookupResult;
-  }
-
-  private void handleTabletClosedDuringScan(ArrayList<KVEntry> results, LookupResult lookupResult, boolean exceededMemoryUsage, Range range, int entriesAdded) {
-    if (exceededMemoryUsage)
-      throw new IllegalStateException("tablet should not exceed memory usage or close, not both");
-
-    if (entriesAdded > 0)
-      addUnfinishedRange(lookupResult, range, results.get(results.size() - 1).getKey(), false);
-    else
-      lookupResult.unfinishedRanges.add(range);
-
-    lookupResult.closed = true;
-  }
-
-  private void addUnfinishedRange(LookupResult lookupResult, Range range, Key key, boolean inclusiveStartKey) {
-    if (range.getEndKey() == null || key.compareTo(range.getEndKey()) < 0) {
-      Range nlur = new Range(new Key(key), inclusiveStartKey, range.getEndKey(), range.isEndKeyInclusive());
-      lookupResult.unfinishedRanges.add(nlur);
-    }
-  }
-
-  public static interface KVReceiver {
-    void receive(List<KVEntry> matches) throws IOException;
-  }
-
-  class LookupResult {
-    List<Range> unfinishedRanges = new ArrayList<Range>();
-    long bytesAdded = 0;
-    long dataSize = 0;
-    boolean closed = false;
-  }
-
-  public LookupResult lookup(List<Range> ranges, HashSet<Column> columns, Authorizations authorizations, ArrayList<KVEntry> results, long maxResultSize,
-      List<IterInfo> ssiList, Map<String,Map<String,String>> ssio, AtomicBoolean interruptFlag) throws IOException {
-
-    if (ranges.size() == 0) {
-      return new LookupResult();
-    }
-
-    ranges = Range.mergeOverlapping(ranges);
-    Collections.sort(ranges);
-
-    Range tabletRange = extent.toDataRange();
-    for (Range range : ranges) {
-      // do a test to see if this range falls within the tablet, if it does not
-      // then clip will throw an exception
-      tabletRange.clip(range);
-    }
-
-    ScanDataSource dataSource = new ScanDataSource(authorizations, this.defaultSecurityLabel, columns, ssiList, ssio, interruptFlag);
-
-    LookupResult result = null;
-
-    try {
-      SortedKeyValueIterator<Key,Value> iter = new SourceSwitchingIterator(dataSource);
-      result = lookup(iter, ranges, columns, results, maxResultSize);
-      return result;
-    } catch (IOException ioe) {
-      dataSource.close(true);
-      throw ioe;
-    } finally {
-      // code in finally block because always want
-      // to return mapfiles, even when exception is thrown
-      dataSource.close(false);
-
-      synchronized (this) {
-        queryCount += results.size();
-        if (result != null)
-          queryBytes += result.dataSize;
-      }
-    }
-  }
-
-  private Batch nextBatch(SortedKeyValueIterator<Key,Value> iter, Range range, int num, Set<Column> columns) throws IOException {
-
-    // log.info("In nextBatch..");
-
-    List<KVEntry> results = new ArrayList<KVEntry>();
-    Key key = null;
-
-    Value value;
-    long resultSize = 0L;
-    long resultBytes = 0L;
-
-    long maxResultsSize = acuTableConf.getMemoryInBytes(Property.TABLE_SCAN_MAXMEM);
-
-    if (columns.size() == 0) {
-      iter.seek(range, LocalityGroupUtil.EMPTY_CF_SET, false);
-    } else {
-      iter.seek(range, LocalityGroupUtil.families(columns), true);
-    }
-
-    Key continueKey = null;
-    boolean skipContinueKey = false;
-
-    boolean endOfTabletReached = false;
-    while (iter.hasTop()) {
-
-      value = iter.getTopValue();
-      key = iter.getTopKey();
-
-      KVEntry kvEntry = new KVEntry(key, value); // copies key and value
-      results.add(kvEntry);
-      resultSize += kvEntry.estimateMemoryUsed();
-      resultBytes += kvEntry.numBytes();
-
-      if (resultSize >= maxResultsSize || results.size() >= num) {
-        continueKey = new Key(key);
-        skipContinueKey = true;
-        break;
-      }
-
-      iter.next();
-    }
-
-    if (iter.hasTop() == false) {
-      endOfTabletReached = true;
-    }
-
-    Batch retBatch = new Batch();
-    retBatch.numBytes = resultBytes;
-
-    if (!endOfTabletReached) {
-      retBatch.continueKey = continueKey;
-      retBatch.skipContinueKey = skipContinueKey;
-    } else {
-      retBatch.continueKey = null;
-    }
-
-    if (endOfTabletReached && results.size() == 0)
-      retBatch.results = null;
-    else
-      retBatch.results = results;
-
-    return retBatch;
-  }
-
-  /**
-   * Determine if a JVM shutdown is in progress.
-   * 
-   */
-  private boolean shutdownInProgress() {
-    try {
-      Runtime.getRuntime().removeShutdownHook(new Thread(new Runnable() {
-        @Override
-        public void run() {}
-      }));
-    } catch (IllegalStateException ise) {
-      return true;
-    }
-
-    return false;
-  }
-
-  private class Batch {
-    public boolean skipContinueKey;
-    public List<KVEntry> results;
-    public Key continueKey;
-    public long numBytes;
-  }
-
-  Scanner createScanner(Range range, int num, Set<Column> columns, Authorizations authorizations, List<IterInfo> ssiList, Map<String,Map<String,String>> ssio,
-      boolean isolated, AtomicBoolean interruptFlag) {
-    // do a test to see if this range falls within the tablet, if it does not
-    // then clip will throw an exception
-    extent.toDataRange().clip(range);
-
-    ScanOptions opts = new ScanOptions(num, authorizations, this.defaultSecurityLabel, columns, ssiList, ssio, interruptFlag, isolated);
-    return new Scanner(range, opts);
-  }
-
-  class ScanBatch {
-    boolean more;
-    List<KVEntry> results;
-
-    ScanBatch(List<KVEntry> results, boolean more) {
-      this.results = results;
-      this.more = more;
-    }
-  }
-
-  class Scanner {
-
-    private ScanOptions options;
-    private Range range;
-    private SortedKeyValueIterator<Key,Value> isolatedIter;
-    private ScanDataSource isolatedDataSource;
-    private boolean sawException = false;
-    private boolean scanClosed = false;
-
-    Scanner(Range range, ScanOptions options) {
-      this.range = range;
-      this.options = options;
-    }
-
-    synchronized ScanBatch read() throws IOException, TabletClosedException {
-
-      if (sawException)
-        throw new IllegalStateException("Tried to use scanner after exception occurred.");
-
-      if (scanClosed)
-        throw new IllegalStateException("Tried to use scanner after it was closed.");
-
-      Batch results = null;
-
-      ScanDataSource dataSource;
-
-      if (options.isolated) {
-        if (isolatedDataSource == null)
-          isolatedDataSource = new ScanDataSource(options);
-        dataSource = isolatedDataSource;
-      } else {
-        dataSource = new ScanDataSource(options);
-      }
-
-      try {
-
-        SortedKeyValueIterator<Key,Value> iter;
-
-        if (options.isolated) {
-          if (isolatedIter == null)
-            isolatedIter = new SourceSwitchingIterator(dataSource, true);
-          else
-            isolatedDataSource.fileManager.reattach();
-          iter = isolatedIter;
-        } else {
-          iter = new SourceSwitchingIterator(dataSource, false);
-        }
-
-        results = nextBatch(iter, range, options.num, options.columnSet);
-
-        if (results.results == null) {
-          range = null;
-          return new ScanBatch(new ArrayList<Tablet.KVEntry>(), false);
-        } else if (results.continueKey == null) {
-          return new ScanBatch(results.results, false);
-        } else {
-          range = new Range(results.continueKey, !results.skipContinueKey, range.getEndKey(), range.isEndKeyInclusive());
-          return new ScanBatch(results.results, true);
-        }
-
-      } catch (IterationInterruptedException iie) {
-        sawException = true;
-        if (isClosed())
-          throw new TabletClosedException(iie);
-        else
-          throw iie;
-      } catch (IOException ioe) {
-        if (shutdownInProgress()) {
-          log.debug("IOException while shutdown in progress ", ioe);
-          throw new TabletClosedException(ioe); // assume IOException was caused by execution of HDFS shutdown hook
-        }
-
-        sawException = true;
-        dataSource.close(true);
-        throw ioe;
-      } catch (RuntimeException re) {
-        sawException = true;
-        throw re;
-      } finally {
-        // code in finally block because always want
-        // to return mapfiles, even when exception is thrown
-        if (!options.isolated)
-          dataSource.close(false);
-        else if (dataSource.fileManager != null)
-          dataSource.fileManager.detach();
-
-        synchronized (Tablet.this) {
-          if (results != null && results.results != null) {
-            long more = results.results.size();
-            queryCount += more;
-            queryBytes += results.numBytes;
-          }
-        }
-      }
-    }
-
-    // close and read are synchronized because can not call close on the data source while it is in use
-    // this cloud lead to the case where file iterators that are in use by a thread are returned
-    // to the pool... this would be bad
-    void close() {
-      options.interruptFlag.set(true);
-      synchronized (this) {
-        scanClosed = true;
-        if (isolatedDataSource != null)
-          isolatedDataSource.close(false);
-      }
-    }
-  }
-
-  static class ScanOptions {
-
-    // scan options
-    Authorizations authorizations;
-    byte[] defaultLabels;
-    Set<Column> columnSet;
-    List<IterInfo> ssiList;
-    Map<String,Map<String,String>> ssio;
-    AtomicBoolean interruptFlag;
-    int num;
-    boolean isolated;
-
-    ScanOptions(int num, Authorizations authorizations, byte[] defaultLabels, Set<Column> columnSet, List<IterInfo> ssiList,
-        Map<String,Map<String,String>> ssio, AtomicBoolean interruptFlag, boolean isolated) {
-      this.num = num;
-      this.authorizations = authorizations;
-      this.defaultLabels = defaultLabels;
-      this.columnSet = columnSet;
-      this.ssiList = ssiList;
-      this.ssio = ssio;
-      this.interruptFlag = interruptFlag;
-      this.isolated = isolated;
-    }
-
-  }
-
-  class ScanDataSource implements DataSource {
-
-    // data source state
-    private ScanFileManager fileManager;
-    private SortedKeyValueIterator<Key,Value> iter;
-    private long expectedDeletionCount;
-    private List<MemoryIterator> memIters = null;
-    private long fileReservationId;
-    private AtomicBoolean interruptFlag;
-    private StatsIterator statsIterator;
-
-    ScanOptions options;
-
-    ScanDataSource(Authorizations authorizations, byte[] defaultLabels, HashSet<Column> columnSet, List<IterInfo> ssiList, Map<String,Map<String,String>> ssio,
-        AtomicBoolean interruptFlag) {
-      expectedDeletionCount = dataSourceDeletions.get();
-      this.options = new ScanOptions(-1, authorizations, defaultLabels, columnSet, ssiList, ssio, interruptFlag, false);
-      this.interruptFlag = interruptFlag;
-    }
-
-    ScanDataSource(ScanOptions options) {
-      expectedDeletionCount = dataSourceDeletions.get();
-      this.options = options;
-      this.interruptFlag = options.interruptFlag;
-    }
-
-    @Override
-    public DataSource getNewDataSource() {
-      if (!isCurrent()) {
-        // log.debug("Switching data sources during a scan");
-        if (memIters != null) {
-          tabletMemory.returnIterators(memIters);
-          memIters = null;
-          datafileManager.returnFilesForScan(fileReservationId);
-          fileReservationId = -1;
-        }
-
-        if (fileManager != null)
-          fileManager.releaseOpenFiles(false);
-
-        expectedDeletionCount = dataSourceDeletions.get();
-        iter = null;
-
-        return this;
-      } else
-        return this;
-    }
-
-    @Override
-    public boolean isCurrent() {
-      return expectedDeletionCount == dataSourceDeletions.get();
-    }
-
-    @Override
-    public SortedKeyValueIterator<Key,Value> iterator() throws IOException {
-      if (iter == null)
-        iter = createIterator();
-      return iter;
-    }
-
-    private SortedKeyValueIterator<Key,Value> createIterator() throws IOException {
-
-      Map<FileRef,DataFileValue> files;
-
-      synchronized (Tablet.this) {
-
-        if (memIters != null)
-          throw new IllegalStateException("Tried to create new scan iterator w/o releasing memory");
-
-        if (Tablet.this.closed)
-          throw new TabletClosedException();
-
-        if (interruptFlag.get())
-          throw new IterationInterruptedException(extent.toString() + " " + interruptFlag.hashCode());
-
-        // only acquire the file manager when we know the tablet is open
-        if (fileManager == null) {
-          fileManager = tabletResources.newScanFileManager();
-          activeScans.add(this);
-        }
-
-        if (fileManager.getNumOpenFiles() != 0)
-          throw new IllegalStateException("Tried to create new scan iterator w/o releasing files");
-
-        // set this before trying to get iterators in case
-        // getIterators() throws an exception
-        expectedDeletionCount = dataSourceDeletions.get();
-
-        memIters = tabletMemory.getIterators();
-        Pair<Long,Map<FileRef,DataFileValue>> reservation = datafileManager.reserveFilesForScan();
-        fileReservationId = reservation.getFirst();
-        files = reservation.getSecond();
-      }
-
-      Collection<InterruptibleIterator> mapfiles = fileManager.openFiles(files, options.isolated);
-
-      List<SortedKeyValueIterator<Key,Value>> iters = new ArrayList<SortedKeyValueIterator<Key,Value>>(mapfiles.size() + memIters.size());
-
-      iters.addAll(mapfiles);
-      iters.addAll(memIters);
-
-      for (SortedKeyValueIterator<Key,Value> skvi : iters)
-        ((InterruptibleIterator) skvi).setInterruptFlag(interruptFlag);
-
-      MultiIterator multiIter = new MultiIterator(iters, extent);
-
-      TabletIteratorEnvironment iterEnv = new TabletIteratorEnvironment(IteratorScope.scan, acuTableConf, fileManager, files);
-
-      statsIterator = new StatsIterator(multiIter, TabletServer.seekCount, scannedCount);
-
-      DeletingIterator delIter = new DeletingIterator(statsIterator, false);
-
-      ColumnFamilySkippingIterator cfsi = new ColumnFamilySkippingIterator(delIter);
-
-      ColumnQualifierFilter colFilter = new ColumnQualifierFilter(cfsi, options.columnSet);
-
-      VisibilityFilter visFilter = new VisibilityFilter(colFilter, options.authorizations, options.defaultLabels);
-
-      return iterEnv.getTopLevelIterator(IteratorUtil
-          .loadIterators(IteratorScope.scan, visFilter, extent, acuTableConf, options.ssiList, options.ssio, iterEnv));
-    }
-
-    private void close(boolean sawErrors) {
-
-      if (memIters != null) {
-        tabletMemory.returnIterators(memIters);
-        memIters = null;
-        datafileManager.returnFilesForScan(fileReservationId);
-        fileReservationId = -1;
-      }
-
-      synchronized (Tablet.this) {
-        activeScans.remove(this);
-        if (activeScans.size() == 0)
-          Tablet.this.notifyAll();
-      }
-
-      if (fileManager != null) {
-        fileManager.releaseOpenFiles(sawErrors);
-        fileManager = null;
-      }
-
-      if (statsIterator != null) {
-        statsIterator.report();
-      }
-
-    }
-
-    public void interrupt() {
-      interruptFlag.set(true);
-    }
-
-    @Override
-    public DataSource getDeepCopyDataSource(IteratorEnvironment env) {
-      throw new UnsupportedOperationException();
-    }
-
-  }
-
-  private DataFileValue minorCompact(Configuration conf, VolumeManager fs, InMemoryMap memTable, FileRef tmpDatafile, FileRef newDatafile, FileRef mergeFile,
-      boolean hasQueueTime, long queued, CommitSession commitSession, long flushId, MinorCompactionReason mincReason) {
-    boolean failed = false;
-    long start = System.currentTimeMillis();
-    timer.incrementStatusMinor();
-
-    long count = 0;
-
-    try {
-      Span span = Trace.start("write");
-      CompactionStats stats;
-      try {
-        count = memTable.getNumEntries();
-
-        DataFileValue dfv = null;
-        if (mergeFile != null)
-          dfv = datafileManager.getDatafileSizes().get(mergeFile);
-
-        MinorCompactor compactor = new MinorCompactor(conf, fs, memTable, mergeFile, dfv, tmpDatafile, acuTableConf, extent, mincReason);
-        stats = compactor.call();
-      } finally {
-        span.stop();
-      }
-      span = Trace.start("bringOnline");
-      try {
-        datafileManager.bringMinorCompactionOnline(tmpDatafile, newDatafile, mergeFile, new DataFileValue(stats.getFileSize(), stats.getEntriesWritten()),
-            commitSession, flushId);
-      } finally {
-        span.stop();
-      }
-      return new DataFileValue(stats.getFileSize(), stats.getEntriesWritten());
-    } catch (Exception E) {
-      failed = true;
-      throw new RuntimeException(E);
-    } catch (Error E) {
-      // Weird errors like "OutOfMemoryError" when trying to create the thread for the compaction
-      failed = true;
-      throw new RuntimeException(E);
-    } finally {
-      try {
-        tabletMemory.finalizeMinC();
-      } catch (Throwable t) {
-        log.error("Failed to free tablet memory", t);
-      }
-
-      if (!failed) {
-        lastMinorCompactionFinishTime = System.currentTimeMillis();
-      }
-      if (tabletServer.mincMetrics.isEnabled())
-        tabletServer.mincMetrics.add(TabletServerMinCMetrics.minc, (lastMinorCompactionFinishTime - start));
-      if (hasQueueTime) {
-        timer.updateTime(Operation.MINOR, queued, start, count, failed);
-        if (tabletServer.mincMetrics.isEnabled())
-          tabletServer.mincMetrics.add(TabletServerMinCMetrics.queue, (start - queued));
-      } else
-        timer.updateTime(Operation.MINOR, start, count, failed);
-    }
-  }
-
-  private class MinorCompactionTask implements Runnable {
-
-    private long queued;
-    private CommitSession commitSession;
-    private DataFileValue stats;
-    private FileRef mergeFile;
-    private long flushId;
-    private MinorCompactionReason mincReason;
-
-    MinorCompactionTask(FileRef mergeFile, CommitSession commitSession, long flushId, MinorCompactionReason mincReason) {
-      queued = System.currentTimeMillis();
-      minorCompactionWaitingToStart = true;
-      this.commitSession = commitSession;
-      this.mergeFile = mergeFile;
-      this.flushId = flushId;
-      this.mincReason = mincReason;
-    }
-
-    @Override
-    public void run() {
-      minorCompactionWaitingToStart = false;
-      minorCompactionInProgress = true;
-      Span minorCompaction = Trace.on("minorCompaction");
-      try {
-        FileRef newMapfileLocation = getNextMapFilename(mergeFile == null ? "F" : "M");
-        FileRef tmpFileRef = new FileRef(newMapfileLocation.path() + "_tmp");
-        Span span = Trace.start("waitForCommits");
-        synchronized (Tablet.this) {
-          commitSession.waitForCommitsToFinish();
-        }
-        span.stop();
-        span = Trace.start("start");
-        while (true) {
-          try {
-            // the purpose of the minor compaction start event is to keep track of the filename... in the case
-            // where the metadata table write for the minor compaction finishes and the process dies before
-            // writing the minor compaction finish event, then the start event+filename in metadata table will
-            // prevent recovery of duplicate data... the minor compaction start event could be written at any time
-            // before the metadata write for the minor compaction
-            tabletServer.minorCompactionStarted(commitSession, commitSession.getWALogSeq() + 1, newMapfileLocation.path().toString());
-            break;
-          } catch (IOException e) {
-            log.warn("Failed to write to write ahead log " + e.getMessage(), e);
-          }
-        }
-        span.stop();
-        span = Trace.start("compact");
-        this.stats = minorCompact(conf, fs, tabletMemory.getMinCMemTable(), tmpFileRef, newMapfileLocation, mergeFile, true, queued, commitSession, flushId,
-            mincReason);
-        span.stop();
-
-        if (needsSplit()) {
-          tabletServer.executeSplit(Tablet.this);
-        } else {
-          initiateMajorCompaction(MajorCompactionReason.NORMAL);
-        }
-      } catch (Throwable t) {
-        log.error("Unknown error during minor compaction for extent: " + getExtent(), t);
-        throw new RuntimeException(t);
-      } finally {
-        minorCompactionInProgress = false;
-        minorCompaction.data("extent", extent.toString());
-        minorCompaction.data("numEntries", Long.toString(this.stats.getNumEntries()));
-        minorCompaction.data("size", Long.toString(this.stats.getSize()));
-        minorCompaction.stop();
-      }
-    }
-  }
-
-  private synchronized MinorCompactionTask prepareForMinC(long flushId, MinorCompactionReason mincReason) {
-    CommitSession oldCommitSession = tabletMemory.prepareForMinC();
-    otherLogs = currentLogs;
-    currentLogs = new HashSet<DfsLogger>();
-
-    FileRef mergeFile = datafileManager.reserveMergingMinorCompactionFile();
-
-    return new MinorCompactionTask(mergeFile, oldCommitSession, flushId, mincReason);
-
-  }
-
-  void flush(long tableFlushID) {
-    boolean updateMetadata = false;
-    boolean initiateMinor = false;
-
-    try {
-
-      synchronized (this) {
-
-        // only want one thing at a time to update flush ID to ensure that metadata table and tablet in memory state are consistent
-        if (updatingFlushID)
-          return;
-
-        if (lastFlushID >= tableFlushID)
-          return;
-
-        if (closing || closed || tabletMemory.memoryReservedForMinC())
-          return;
-
-        if (tabletMemory.getMemTable().getNumEntries() == 0) {
-          lastFlushID = tableFlushID;
-          updatingFlushID = true;
-          updateMetadata = true;
-        } else
-          initiateMinor = true;
-      }
-
-      if (updateMetadata) {
-        Credentials creds = SystemCredentials.get();
-        // if multiple threads were allowed to update this outside of a sync block, then it would be
-        // a race condition
-        MetadataTableUtil.updateTabletFlushID(extent, tableFlushID, creds, tabletServer.getLock());
-      } else if (initiateMinor)
-        initiateMinorCompaction(tableFlushID, MinorCompactionReason.USER);
-
-    } finally {
-      if (updateMetadata) {
-        synchronized (this) {
-          updatingFlushID = false;
-          this.notifyAll();
-        }
-      }
-    }
-
-  }
-
-  boolean initiateMinorCompaction(MinorCompactionReason mincReason) {
-    if (isClosed()) {
-      // don't bother trying to get flush id if closed... could be closed after this check but that is ok... just trying to cut down on uneeded log messages....
-      return false;
-    }
-
-    // get the flush id before the new memmap is made available for write
-    long flushId;
-    try {
-      flushId = getFlushID();
-    } catch (NoNodeException e) {
-      log.info("Asked to initiate MinC when there was no flush id " + getExtent() + " " + e.getMessage());
-      return false;
-    }
-    return initiateMinorCompaction(flushId, mincReason);
-  }
-
-  boolean minorCompactNow(MinorCompactionReason mincReason) {
-    long flushId;
-    try {
-      flushId = getFlushID();
-    } catch (NoNodeException e) {
-      log.info("Asked to initiate MinC when there was no flush id " + getExtent() + " " + e.getMessage());
-      return false;
-    }
-    MinorCompactionTask mct = createMinorCompactionTask(flushId, mincReason);
-    if (mct == null)
-      return false;
-    mct.run();
-    return true;
-  }
-
-  boolean initiateMinorCompaction(long flushId, MinorCompactionReason mincReason) {
-    MinorCompactionTask mct = createMinorCompactionTask(flushId, mincReason);
-    if (mct == null)
-      return false;
-    tabletResources.executeMinorCompaction(mct);
-    return true;
-  }
-
-  private MinorCompactionTask createMinorCompactionTask(long flushId, MinorCompactionReason mincReason) {
-    MinorCompactionTask mct;
-    long t1, t2;
-
-    StringBuilder logMessage = null;
-
-    try {
-      synchronized (this) {
-        t1 = System.currentTimeMillis();
-
-        if (closing || closed || majorCompactionWaitingToStart || tabletMemory.memoryReservedForMinC() || tabletMemory.getMemTable().getNumEntries() == 0
-            || updatingFlushID) {
-
-          logMessage = new StringBuilder();
-
-          logMessage.append(extent.toString());
-          logMessage.append(" closing " + closing);
-          logMessage.append(" closed " + closed);
-          logMessage.append(" majorCompactionWaitingToStart " + majorCompactionWaitingToStart);
-          if (tabletMemory != null)
-            logMessage.append(" tabletMemory.memoryReservedForMinC() " + tabletMemory.memoryReservedForMinC());
-          if (tabletMemory != null && tabletMemory.getMemTable() != null)
-            logMessage.append(" tabletMemory.getMemTable().getNumEntries() " + tabletMemory.getMemTable().getNumEntries());
-          logMessage.append(" updatingFlushID " + updatingFlushID);
-
-          return null;
-        }
-        // We're still recovering log entries
-        if (datafileManager == null) {
-          logMessage = new StringBuilder();
-          logMessage.append(extent.toString());
-          logMessage.append(" datafileManager " + datafileManager);
-          return null;
-        }
-
-        mct = prepareForMinC(flushId, mincReason);
-        t2 = System.currentTimeMillis();
-      }
-    } finally {
-      // log outside of sync block
-      if (logMessage != null && log.isDebugEnabled())
-        log.debug(logMessage);
-    }
-
-    log.debug(String.format("MinC initiate lock %.2f secs", (t2 - t1) / 1000.0));
-    return mct;
-  }
-
-  long getFlushID() throws NoNodeException {
-    try {
-      String zTablePath = Constants.ZROOT + "/" + HdfsZooInstance.getInstance().getInstanceID() + Constants.ZTABLES + "/" + extent.getTableId()
-          + Constants.ZTABLE_FLUSH_ID;
-      return Long.parseLong(new String(ZooReaderWriter.getRetryingInstance().getData(zTablePath, null), StandardCharsets.UTF_8));
-    } catch (InterruptedException e) {
-      throw new RuntimeException(e);
-    } catch (NumberFormatException nfe) {
-      throw new RuntimeException(nfe);
-    } catch (KeeperException ke) {
-      if (ke instanceof NoNodeException) {
-        throw (NoNodeException) ke;
-      } else {
-        throw new RuntimeException(ke);
-      }
-    }
-  }
-
-  long getCompactionCancelID() {
-    String zTablePath = Constants.ZROOT + "/" + HdfsZooInstance.getInstance().getInstanceID() + Constants.ZTABLES + "/" + extent.getTableId()
-        + Constants.ZTABLE_COMPACT_CANCEL_ID;
-
-    try {
-      return Long.parseLong(new String(ZooReaderWriter.getRetryingInstance().getData(zTablePath, null), StandardCharsets.UTF_8));
-    } catch (KeeperException e) {
-      throw new RuntimeException(e);
-    } catch (InterruptedException e) {
-      throw new RuntimeException(e);
-    }
-  }
-
-  Pair<Long,List<IteratorSetting>> getCompactionID() throws NoNodeException {
-    try {
-      String zTablePath = Constants.ZROOT + "/" + HdfsZooInstance.getInstance().getInstanceID() + Constants.ZTABLES + "/" + extent.getTableId()
-          + Constants.ZTABLE_COMPACT_ID;
-
-      String[] tokens = new String(ZooReaderWriter.getRetryingInstance().getData(zTablePath, null), StandardCharsets.UTF_8).split(",");
-      long compactID = Long.parseLong(tokens[0]);
-
-      CompactionIterators iters = new CompactionIterators();
-
-      if (tokens.length > 1) {
-        Hex hex = new Hex();
-        ByteArrayInputStream bais = new ByteArrayInputStream(hex.decode(tokens[1].split("=")[1].getBytes(StandardCharsets.UTF_8)));
-        DataInputStream dis = new DataInputStream(bais);
-
-        try {
-          iters.readFields(dis);
-        } catch (IOException e) {
-          throw new RuntimeException(e);
-        }
-
-        KeyExtent ke = new KeyExtent(extent.getTableId(), iters.getEndRow(), iters.getStartRow());
-
-        if (!ke.overlaps(extent)) {
-          // only use iterators if compaction range overlaps
-          iters = new CompactionIterators();
-        }
-      }
-
-      return new Pair<Long,List<IteratorSetting>>(compactID, iters.getIterators());
-    } catch (InterruptedException e) {
-      throw new RuntimeException(e);
-    } catch (NumberFormatException nfe) {
-      throw new RuntimeException(nfe);
-    } catch (KeeperException ke) {
-      if (ke instanceof NoNodeException) {
-        throw (NoNodeException) ke;
-      } else {
-        throw new RuntimeException(ke);
-      }
-    } catch (DecoderException e) {
-      throw new RuntimeException(e);
-    }
-  }
-
-  public synchronized void waitForMinC() {
-    tabletMemory.waitForMinC();
-  }
-
-  static class TConstraintViolationException extends Exception {
-    private static final long serialVersionUID = 1L;
-    private Violations violations;
-    private List<Mutation> violators;
-    private List<Mutation> nonViolators;
-    private CommitSession commitSession;
-
-    TConstraintViolationException(Violations violations, List<Mutation> violators, List<Mutation> nonViolators, CommitSession commitSession) {
-      this.violations = violations;
-      this.violators = violators;
-      this.nonViolators = nonViolators;
-      this.commitSession = commitSession;
-    }
-
-    Violations getViolations() {
-      return violations;
-    }
-
-    List<Mutation> getViolators() {
-      return violators;
-    }
-
-    List<Mutation> getNonViolators() {
-      return nonViolators;
-    }
-
-    CommitSession getCommitSession() {
-      return commitSession;
-    }
-  }
-
-  private synchronized CommitSession finishPreparingMutations(long time) {
-    if (writesInProgress < 0) {
-      throw new IllegalStateException("waitingForLogs < 0 " + writesInProgress);
-    }
-
-    if (closed || tabletMemory == null) {
-      // log.debug("tablet closed, can't commit");
-      return null;
-    }
-
-    writesInProgress++;
-    CommitSession commitSession = tabletMemory.getCommitSession();
-    commitSession.incrementCommitsInProgress();
-    commitSession.updateMaxCommittedTime(time);
-    return commitSession;


<TRUNCATED>