MobConstants.java example

Explorer
hbase-master
/**
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase.mob;

import org.apache.hadoop.hbase.ArrayBackedTag;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.Tag;
import org.apache.hadoop.hbase.TagType;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.util.Bytes;

/**
 * The constants used in mob.
 */
@InterfaceAudience.Public
public final class MobConstants {

  public static final String MOB_SCAN_RAW = "hbase.mob.scan.raw";
  public static final String MOB_CACHE_BLOCKS = "hbase.mob.cache.blocks";
  public static final String MOB_SCAN_REF_ONLY = "hbase.mob.scan.ref.only";
  public static final String EMPTY_VALUE_ON_MOBCELL_MISS = "empty.value.on.mobcell.miss";

  public static final String MOB_FILE_CACHE_SIZE_KEY = "hbase.mob.file.cache.size";
  public static final int DEFAULT_MOB_FILE_CACHE_SIZE = 1000;

  public static final String MOB_DIR_NAME = "mobdir";
  public static final String MOB_REGION_NAME = ".mob";
  public static final byte[] MOB_REGION_NAME_BYTES = Bytes.toBytes(MOB_REGION_NAME);

  public static final String MOB_CLEANER_PERIOD = "hbase.master.mob.ttl.cleaner.period";
  public static final int DEFAULT_MOB_CLEANER_PERIOD = 24 * 60 * 60; // one day

  public static final String MOB_CACHE_EVICT_PERIOD = "hbase.mob.cache.evict.period";
  public static final String MOB_CACHE_EVICT_REMAIN_RATIO = "hbase.mob.cache.evict.remain.ratio";
  public static final Tag MOB_REF_TAG = new ArrayBackedTag(TagType.MOB_REFERENCE_TAG_TYPE,
      HConstants.EMPTY_BYTE_ARRAY);

  public static final float DEFAULT_EVICT_REMAIN_RATIO = 0.5f;
  public static final long DEFAULT_MOB_CACHE_EVICT_PERIOD = 3600L;

  public final static String TEMP_DIR_NAME = ".tmp";
  public final static String BULKLOAD_DIR_NAME = ".bulkload";
  public final static byte[] MOB_TABLE_LOCK_SUFFIX = Bytes.toBytes(".mobLock");
  public final static String EMPTY_STRING = "";
  /**
   * If the size of a mob file is less than this value, it's regarded as a small file and needs to
   * be merged in mob compaction. The default value is 1280MB.
   */
  public static final String MOB_COMPACTION_MERGEABLE_THRESHOLD =
    "hbase.mob.compaction.mergeable.threshold";
  public static final long DEFAULT_MOB_COMPACTION_MERGEABLE_THRESHOLD = 10 * 128 * 1024 * 1024;
  /**
   * The max number of del files that is allowed in the mob file compaction. In the mob
   * compaction, when the number of existing del files is larger than this value, they are merged
   * until number of del files is not larger this value. The default value is 3.
   */
  public static final String MOB_DELFILE_MAX_COUNT = "hbase.mob.delfile.max.count";
  public static final int DEFAULT_MOB_DELFILE_MAX_COUNT = 3;
  /**
   * The max number of the mob files that is allowed in a batch of the mob compaction.
   * The mob compaction merges the small mob files to bigger ones. If the number of the
   * small files is very large, it could lead to a "too many opened file handlers" in the merge.
   * And the merge has to be split into batches. This value limits the number of mob files
   * that are selected in a batch of the mob compaction. The default value is 100.
   */
  public static final String MOB_COMPACTION_BATCH_SIZE =
    "hbase.mob.compaction.batch.size";
  public static final int DEFAULT_MOB_COMPACTION_BATCH_SIZE = 100;
  /**
   * The period that MobCompactionChore runs. The unit is second.
   * The default value is one week.
   */
  public static final String MOB_COMPACTION_CHORE_PERIOD =
    "hbase.mob.compaction.chore.period";
  public static final int DEFAULT_MOB_COMPACTION_CHORE_PERIOD =
    24 * 60 * 60 * 7; // a week
  public static final String MOB_COMPACTOR_CLASS_KEY = "hbase.mob.compactor.class";
  /**
   * The max number of threads used in MobCompactor.
   */
  public static final String MOB_COMPACTION_THREADS_MAX =
    "hbase.mob.compaction.threads.max";
  public static final int DEFAULT_MOB_COMPACTION_THREADS_MAX = 1;
  private MobConstants() {

  }
}