001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase;
019
020import static org.apache.hadoop.hbase.io.hfile.BlockType.MAGIC_LENGTH;
021
022import java.nio.ByteBuffer;
023import java.nio.charset.Charset;
024import java.util.Arrays;
025import java.util.Collections;
026import java.util.List;
027import java.util.UUID;
028import java.util.regex.Pattern;
029import org.apache.commons.lang3.ArrayUtils;
030import org.apache.hadoop.hbase.util.Bytes;
031import org.apache.yetus.audience.InterfaceAudience;
032
033/**
034 * HConstants holds a bunch of HBase-related constants
035 */
036@InterfaceAudience.Public
037public final class HConstants {
038  // NOTICE!!!! Please do not add a constants here, unless they are referenced by a lot of classes.
039
040  //Bytes.UTF8_ENCODING should be updated if this changed
041  /** When we encode strings, we always specify UTF8 encoding */
042  public static final String UTF8_ENCODING = "UTF-8";
043
044  //Bytes.UTF8_CHARSET should be updated if this changed
045  /** When we encode strings, we always specify UTF8 encoding */
046  public static final Charset UTF8_CHARSET = Charset.forName(UTF8_ENCODING);
047  /**
048   * Default block size for an HFile.
049   */
050  public final static int DEFAULT_BLOCKSIZE = 64 * 1024;
051
052  /** Used as a magic return value while optimized index key feature enabled(HBASE-7845) */
053  public final static int INDEX_KEY_MAGIC = -2;
054  /*
055     * Name of directory that holds recovered edits written by the wal log
056     * splitting code, one per region
057     */
058  public static final String RECOVERED_EDITS_DIR = "recovered.edits";
059  /**
060   * The first four bytes of Hadoop RPC connections
061   */
062  public static final byte[] RPC_HEADER = new byte[] { 'H', 'B', 'a', 's' };
063  public static final byte RPC_CURRENT_VERSION = 0;
064
065  // HFileBlock constants. TODO!!!! THESE DEFINES BELONG IN HFILEBLOCK, NOT UP HERE.
066  // Needed down in hbase-common though by encoders but these encoders should not be dealing
067  // in the internals of hfileblocks. Fix encapsulation.
068
069  /** The size data structures with minor version is 0 */
070  public static final int HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM = MAGIC_LENGTH + 2 * Bytes.SIZEOF_INT
071      + Bytes.SIZEOF_LONG;
072  /** The size of a version 2 HFile block header, minor version 1.
073   * There is a 1 byte checksum type, followed by a 4 byte bytesPerChecksum
074   * followed by another 4 byte value to store sizeofDataOnDisk.
075   */
076  public static final int HFILEBLOCK_HEADER_SIZE = HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM +
077    Bytes.SIZEOF_BYTE + 2 * Bytes.SIZEOF_INT;
078  /** Just an array of bytes of the right size. */
079  public static final byte[] HFILEBLOCK_DUMMY_HEADER = new byte[HFILEBLOCK_HEADER_SIZE];
080
081  //End HFileBlockConstants.
082
083  /**
084   * Status codes used for return values of bulk operations.
085   */
086  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
087  public enum OperationStatusCode {
088    NOT_RUN,
089    SUCCESS,
090    BAD_FAMILY,
091    STORE_TOO_BUSY,
092    SANITY_CHECK_FAILURE,
093    FAILURE
094  }
095
096  /** long constant for zero */
097  public static final Long ZERO_L = Long.valueOf(0L);
098  public static final String NINES = "99999999999999";
099  public static final String ZEROES = "00000000000000";
100
101  // For migration
102
103  /** name of version file */
104  public static final String VERSION_FILE_NAME = "hbase.version";
105
106  /**
107   * Current version of file system.
108   * Version 4 supports only one kind of bloom filter.
109   * Version 5 changes versions in catalog table regions.
110   * Version 6 enables blockcaching on catalog tables.
111   * Version 7 introduces hfile -- hbase 0.19 to 0.20..
112   * Version 8 introduces namespace
113   */
114  // public static final String FILE_SYSTEM_VERSION = "6";
115  public static final String FILE_SYSTEM_VERSION = "8";
116
117  // Configuration parameters
118
119  //TODO: Is having HBase homed on port 60k OK?
120
121  /** Cluster is in distributed mode or not */
122  public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
123
124  /** Config for pluggable load balancers */
125  public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
126
127  /** Config for balancing the cluster by table */
128  public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
129
130  /** Config for the max percent of regions in transition */
131  public static final String HBASE_MASTER_BALANCER_MAX_RIT_PERCENT =
132      "hbase.master.balancer.maxRitPercent";
133
134  /** Default value for the max percent of regions in transition */
135  public static final double DEFAULT_HBASE_MASTER_BALANCER_MAX_RIT_PERCENT = 1.0;
136
137  /** Config for the max balancing time */
138  public static final String HBASE_BALANCER_MAX_BALANCING = "hbase.balancer.max.balancing";
139
140  /** Config for the balancer period */
141  public static final String HBASE_BALANCER_PERIOD = "hbase.balancer.period";
142
143  /** Default value for the balancer period */
144  public static final int DEFAULT_HBASE_BALANCER_PERIOD = 300000;
145
146  /** The name of the ensemble table */
147  public static final TableName ENSEMBLE_TABLE_NAME = TableName.valueOf("hbase:ensemble");
148
149  /** Config for pluggable region normalizer */
150  public static final String HBASE_MASTER_NORMALIZER_CLASS =
151    "hbase.master.normalizer.class";
152
153  /** Cluster is standalone or pseudo-distributed */
154  public static final boolean CLUSTER_IS_LOCAL = false;
155
156  /** Default value for cluster distributed mode */
157  public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
158
159  /** default host address */
160  public static final String DEFAULT_HOST = "0.0.0.0";
161
162  /** Parameter name for port master listens on. */
163  public static final String MASTER_PORT = "hbase.master.port";
164
165  /** default port that the master listens on */
166  public static final int DEFAULT_MASTER_PORT = 16000;
167
168  /** default port for master web api */
169  public static final int DEFAULT_MASTER_INFOPORT = 16010;
170
171  /** Configuration key for master web API port */
172  public static final String MASTER_INFO_PORT = "hbase.master.info.port";
173
174  /** Parameter name for the master type being backup (waits for primary to go inactive). */
175  public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
176
177  /**
178   * by default every master is a possible primary master unless the conf explicitly overrides it
179   */
180  public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
181
182  /** Name of ZooKeeper quorum configuration parameter. */
183  public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
184
185  /** Name of ZooKeeper quorum configuration parameter for client to locate meta. */
186  public static final String CLIENT_ZOOKEEPER_QUORUM = "hbase.client.zookeeper.quorum";
187
188  /** Client port of ZooKeeper for client to locate meta */
189  public static final String CLIENT_ZOOKEEPER_CLIENT_PORT =
190      "hbase.client.zookeeper.property.clientPort";
191
192  /** Indicate whether the client ZK are observer nodes of the server ZK */
193  public static final String CLIENT_ZOOKEEPER_OBSERVER_MODE =
194      "hbase.client.zookeeper.observer.mode";
195  /** Assuming client zk not in observer mode and master need to synchronize information */
196  public static final boolean DEFAULT_CLIENT_ZOOKEEPER_OBSERVER_MODE = false;
197
198  /** Common prefix of ZooKeeper configuration properties */
199  public static final String ZK_CFG_PROPERTY_PREFIX =
200      "hbase.zookeeper.property.";
201
202  public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
203      ZK_CFG_PROPERTY_PREFIX.length();
204
205  /**
206   * The ZK client port key in the ZK properties map. The name reflects the
207   * fact that this is not an HBase configuration key.
208   */
209  public static final String CLIENT_PORT_STR = "clientPort";
210
211  /** Parameter name for the client port that the zookeeper listens on */
212  public static final String ZOOKEEPER_CLIENT_PORT =
213      ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
214
215  /** Default client port that the zookeeper listens on */
216  public static final int DEFAULT_ZOOKEEPER_CLIENT_PORT = 2181;
217
218  /** Parameter name for the root dir in ZK for this cluster */
219  public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
220
221  public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
222
223  /**
224   * Parameter name for the limit on concurrent client-side zookeeper
225   * connections
226   */
227  public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
228      ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
229
230  /** Parameter name for the ZK data directory */
231  public static final String ZOOKEEPER_DATA_DIR =
232      ZK_CFG_PROPERTY_PREFIX + "dataDir";
233
234  /** Parameter name for the ZK tick time */
235  public static final String ZOOKEEPER_TICK_TIME =
236      ZK_CFG_PROPERTY_PREFIX + "tickTime";
237
238  /** Default limit on concurrent client-side zookeeper connections */
239  public static final int DEFAULT_ZOOKEEPER_MAX_CLIENT_CNXNS = 300;
240
241  /** Configuration key for ZooKeeper session timeout */
242  public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
243
244  /** Default value for ZooKeeper session timeout */
245  public static final int DEFAULT_ZK_SESSION_TIMEOUT = 90 * 1000;
246
247  /** Parameter name for port region server listens on. */
248  public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
249
250  /** Default port region server listens on. */
251  public static final int DEFAULT_REGIONSERVER_PORT = 16020;
252
253  /** default port for region server web api */
254  public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
255
256  /** A configuration key for regionserver info port */
257  public static final String REGIONSERVER_INFO_PORT =
258    "hbase.regionserver.info.port";
259
260  /** A flag that enables automatic selection of regionserver info port */
261  public static final String REGIONSERVER_INFO_PORT_AUTO =
262      REGIONSERVER_INFO_PORT + ".auto";
263
264  /** Parameter name for what region server implementation to use. */
265  public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
266
267  /** Parameter name for what master implementation to use. */
268  public static final String MASTER_IMPL= "hbase.master.impl";
269
270  /** Parameter name for how often threads should wake up */
271  public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
272
273  /** Default value for thread wake frequency */
274  public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
275
276  /** Parameter name for how often we should try to write a version file, before failing */
277  public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
278
279  /** Parameter name for how often we should try to write a version file, before failing */
280  public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
281
282  /** Parameter name and default value for how often a region should perform a major compaction */
283  public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
284  public static final long   DEFAULT_MAJOR_COMPACTION_PERIOD = 1000 * 60 * 60 * 24 * 7; // 7 days
285
286  /**
287   * Parameter name and default value for major compaction jitter.
288   * Used as a multiplier applied to {@link HConstants#MAJOR_COMPACTION_PERIOD}
289   * to cause compaction to occur a given amount of time either side of
290   * {@link HConstants#MAJOR_COMPACTION_PERIOD}.
291   * Default to 0.5 so jitter has us fall evenly either side of when the compaction should run.
292   */
293  public static final String MAJOR_COMPACTION_JITTER = "hbase.hregion.majorcompaction.jitter";
294  public static final float  DEFAULT_MAJOR_COMPACTION_JITTER = 0.50F;
295
296  /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
297  public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
298  public static final int COMPACTION_KV_MAX_DEFAULT = 10;
299
300  /** Parameter name for HBase instance root directory */
301  public static final String HBASE_DIR = "hbase.rootdir";
302
303  /** Parameter name for HBase client IPC pool type */
304  public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
305
306  /** Parameter name for HBase client IPC pool size */
307  public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
308
309  /** Parameter name for HBase client operation timeout. */
310  public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
311
312  /** Parameter name for HBase client meta operation timeout. */
313  public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
314    "hbase.client.meta.operation.timeout";
315
316  /** Default HBase client operation timeout, which is tantamount to a blocking call */
317  public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
318
319  /** Parameter name for HBase client meta replica scan call timeout. */
320  public static final String HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT =
321      "hbase.client.meta.replica.scan.timeout";
322
323  /** Default HBase client meta replica scan call timeout, 1 second */
324  public static final int HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT_DEFAULT = 1000000;
325
326  /** Used to construct the name of the log directory for a region server */
327  public static final String HREGION_LOGDIR_NAME = "WALs";
328
329  /** Used to construct the name of the splitlog directory for a region server */
330  public static final String SPLIT_LOGDIR_NAME = "splitWAL";
331
332  /** Like the previous, but for old logs that are about to be deleted */
333  public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
334
335  /** Staging dir used by bulk load */
336  public static final String BULKLOAD_STAGING_DIR_NAME = "staging";
337
338  public static final String CORRUPT_DIR_NAME = "corrupt";
339
340  /** Used by HBCK to sideline backup data */
341  public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
342
343  /** Any artifacts left from migration can be moved here */
344  public static final String MIGRATION_NAME = ".migration";
345
346  /** Used to construct the name of the compaction directory during compaction */
347  public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
348
349  /** Conf key for the max file size after which we split the region */
350  public static final String HREGION_MAX_FILESIZE =
351      "hbase.hregion.max.filesize";
352
353  /** Default maximum file size */
354  public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
355
356  /**
357   * Max size of single row for Get's or Scan's without in-row scanning flag set.
358   */
359  public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
360
361  /**
362   * Default max row size (1 Gb).
363   */
364  public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
365
366  /**
367   * The max number of threads used for opening and closing stores or store
368   * files in parallel
369   */
370  public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
371    "hbase.hstore.open.and.close.threads.max";
372
373  /**
374   * The default number for the max number of threads used for opening and
375   * closing stores or store files in parallel
376   */
377  public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
378
379  /**
380   * Block updates if memstore has hbase.hregion.memstore.block.multiplier
381   * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
382   * runaway memstore during spikes in update traffic.
383   */
384  public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
385          "hbase.hregion.memstore.block.multiplier";
386
387  /**
388   * Default value for hbase.hregion.memstore.block.multiplier
389   */
390  public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
391
392  /** Conf key for the memstore size at which we flush the memstore */
393  public static final String HREGION_MEMSTORE_FLUSH_SIZE =
394      "hbase.hregion.memstore.flush.size";
395
396  public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
397      "hbase.hregion.edits.replay.skip.errors";
398
399  public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
400      false;
401
402  /** Maximum value length, enforced on KeyValue construction */
403  public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
404
405  /** name of the file for unique cluster ID */
406  public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
407
408  /** Default value for cluster ID */
409  public static final String CLUSTER_ID_DEFAULT = "default-cluster";
410
411  /** Parameter name for # days to keep MVCC values during a major compaction */
412  public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
413  /** At least to keep MVCC values in hfiles for 5 days */
414  public static final int MIN_KEEP_SEQID_PERIOD = 5;
415
416  // Always store the location of the root table's HRegion.
417  // This HRegion is never split.
418
419  // region name = table + startkey + regionid. This is the row key.
420  // each row in the root and meta tables describes exactly 1 region
421  // Do we ever need to know all the information that we are storing?
422
423  // Note that the name of the root table starts with "-" and the name of the
424  // meta table starts with "." Why? it's a trick. It turns out that when we
425  // store region names in memory, we use a SortedMap. Since "-" sorts before
426  // "." (and since no other table name can start with either of these
427  // characters, the root region will always be the first entry in such a Map,
428  // followed by all the meta regions (which will be ordered by their starting
429  // row key as well), followed by all user tables. So when the Master is
430  // choosing regions to assign, it will always choose the root region first,
431  // followed by the meta regions, followed by user regions. Since the root
432  // and meta regions always need to be on-line, this ensures that they will
433  // be the first to be reassigned if the server(s) they are being served by
434  // should go down.
435
436  public static final String BASE_NAMESPACE_DIR = "data";
437
438  /** delimiter used between portions of a region name */
439  public static final int META_ROW_DELIMITER = ',';
440
441  /** The catalog family as a string*/
442  public static final String CATALOG_FAMILY_STR = "info";
443
444  /** The catalog family */
445  public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
446
447  /** The RegionInfo qualifier as a string */
448  public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
449
450  /** The regioninfo column qualifier */
451  public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
452
453  /** The server column qualifier */
454  public static final String SERVER_QUALIFIER_STR = "server";
455  /** The server column qualifier */
456  public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
457
458  /** The startcode column qualifier */
459  public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
460  /** The startcode column qualifier */
461  public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
462
463  /** The open seqnum column qualifier */
464  public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
465  /** The open seqnum column qualifier */
466  public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
467
468  /** The state column qualifier */
469  public static final String STATE_QUALIFIER_STR = "state";
470
471  public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
472
473  /**
474   * The serverName column qualifier. Its the server where the region is
475   * transitioning on, while column server is the server where the region is
476   * opened on. They are the same when the region is in state OPEN.
477   */
478  public static final String SERVERNAME_QUALIFIER_STR = "sn";
479
480  public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
481
482  /** The lower-half split region column qualifier */
483  public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
484
485  /** The upper-half split region column qualifier */
486  public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
487
488  /**
489   * Merge qualifier prefix.
490   * We used to only allow two regions merge; mergeA and mergeB.
491   * Now we allow many to merge. Each region to merge will be referenced
492   * in a column whose qualifier starts with this define.
493   */
494  public static final String MERGE_QUALIFIER_PREFIX_STR = "merge";
495  public static final byte [] MERGE_QUALIFIER_PREFIX =
496      Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR);
497
498  /**
499   * The lower-half merge region column qualifier
500   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for
501   *   the {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
502   */
503  @Deprecated
504  public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "A");
505
506  /**
507   * The upper-half merge region column qualifier
508   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for
509   *   the {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
510   */
511  @Deprecated
512  public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "B");
513
514  /** The catalog family as a string*/
515  public static final String TABLE_FAMILY_STR = "table";
516
517  /** The catalog family */
518  public static final byte [] TABLE_FAMILY = Bytes.toBytes(TABLE_FAMILY_STR);
519
520  /** The serialized table state qualifier */
521  public static final byte[] TABLE_STATE_QUALIFIER = Bytes.toBytes("state");
522
523  /** The replication barrier family as a string*/
524  public static final String REPLICATION_BARRIER_FAMILY_STR = "rep_barrier";
525
526  /** The replication barrier family */
527  public static final byte[] REPLICATION_BARRIER_FAMILY =
528      Bytes.toBytes(REPLICATION_BARRIER_FAMILY_STR);
529
530  /** The namespace family as a string */
531  public static final String NAMESPACE_FAMILY_STR = "ns";
532
533  /** The namespace family */
534  public static final byte[] NAMESPACE_FAMILY = Bytes.toBytes(NAMESPACE_FAMILY_STR);
535
536  public static final byte[] NAMESPACE_COL_DESC_QUALIFIER = Bytes.toBytes("d");
537  /**
538   * The meta table version column qualifier.
539   * We keep current version of the meta table in this column in <code>-ROOT-</code>
540   * table: i.e. in the 'info:v' column.
541   */
542  public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
543
544  /**
545   * The current version of the meta table.
546   * - pre-hbase 0.92.  There is no META_VERSION column in the root table
547   * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
548   * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
549   * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
550   * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
551   * byte[] serialization from Writables to Protobuf.
552   * See HRegionInfo.VERSION
553   */
554  public static final short META_VERSION = 1;
555
556  // Other constants
557
558  /**
559   * An empty byte array instance.
560   */
561  public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
562
563  /**
564   * An empty string instance.
565   */
566  public static final String EMPTY_STRING = "";
567
568  public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
569
570  /**
571   * Used by scanners, etc when they want to start at the beginning of a region
572   */
573  public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
574
575  /**
576   * Last row in a table.
577   */
578  public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
579
580  /**
581    * Used by scanners and others when they're trying to detect the end of a
582    * table
583    */
584  public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
585
586  /**
587   * Max length a row can have because of the limitation in TFile.
588   */
589  public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
590
591  /**
592   * Timestamp to use when we want to refer to the latest cell.
593   *
594   * On client side, this is the timestamp set by default when no timestamp is specified,
595   * to refer to the latest.
596   * On server side, this acts as a notation.
597   * (1) For a cell of Put, which has this notation,
598   *     its timestamp will be replaced with server's current time.
599   * (2) For a cell of Delete, which has this notation,
600   *     A. If the cell is of {@link KeyValue.Type#Delete}, HBase issues a Get operation firstly.
601   *        a. When the count of cell it gets is less than the count of cell to delete,
602   *           the timestamp of Delete cell will be replaced with server's current time.
603   *        b. When the count of cell it gets is equal to the count of cell to delete,
604   *           the timestamp of Delete cell will be replaced with the latest timestamp of cell it
605   *           gets.
606   *       (c. It is invalid and an exception will be thrown,
607   *           if the count of cell it gets is greater than the count of cell to delete,
608   *           as the max version of Get is set to the count of cell to delete.)
609   *     B. If the cell is of other Delete types, like {@link KeyValue.Type#DeleteFamilyVersion},
610   *        {@link KeyValue.Type#DeleteColumn}, or {@link KeyValue.Type#DeleteFamily},
611   *        the timestamp of Delete cell will be replaced with server's current time.
612   *
613   * So that is why it is named as "latest" but assigned as the max value of Long.
614   */
615  public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
616
617  /**
618   * Timestamp to use when we want to refer to the oldest cell.
619   * Special! Used in fake Cells only. Should never be the timestamp on an actual Cell returned to
620   * a client.
621   * @deprecated Should not be public since hbase-1.3.0. For internal use only. Move internal to
622   *   Scanners flagged as special timestamp value never to be returned as timestamp on a Cell.
623   */
624  @Deprecated
625  public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
626
627  /**
628   * LATEST_TIMESTAMP in bytes form
629   */
630  public static final byte [] LATEST_TIMESTAMP_BYTES = {
631    // big-endian
632    (byte) (LATEST_TIMESTAMP >>> 56),
633    (byte) (LATEST_TIMESTAMP >>> 48),
634    (byte) (LATEST_TIMESTAMP >>> 40),
635    (byte) (LATEST_TIMESTAMP >>> 32),
636    (byte) (LATEST_TIMESTAMP >>> 24),
637    (byte) (LATEST_TIMESTAMP >>> 16),
638    (byte) (LATEST_TIMESTAMP >>> 8),
639    (byte) LATEST_TIMESTAMP,
640  };
641
642  /**
643   * Define for 'return-all-versions'.
644   */
645  public static final int ALL_VERSIONS = Integer.MAX_VALUE;
646
647  /**
648   * Unlimited time-to-live.
649   */
650//  public static final int FOREVER = -1;
651  public static final int FOREVER = Integer.MAX_VALUE;
652
653  /**
654   * Seconds in a day, hour and minute
655   */
656  public static final int DAY_IN_SECONDS = 24 * 60 * 60;
657  public static final int HOUR_IN_SECONDS = 60 * 60;
658  public static final int MINUTE_IN_SECONDS = 60;
659
660  //TODO: although the following are referenced widely to format strings for
661  //      the shell. They really aren't a part of the public API. It would be
662  //      nice if we could put them somewhere where they did not need to be
663  //      public. They could have package visibility
664  public static final String NAME = "NAME";
665  public static final String VERSIONS = "VERSIONS";
666  public static final String IN_MEMORY = "IN_MEMORY";
667  public static final String METADATA = "METADATA";
668  public static final String CONFIGURATION = "CONFIGURATION";
669
670  /**
671   * Retrying we multiply hbase.client.pause setting by what we have in this array until we
672   * run out of array items.  Retries beyond this use the last number in the array.  So, for
673   * example, if hbase.client.pause is 1 second, and maximum retries count
674   * hbase.client.retries.number is 10, we will retry at the following intervals:
675   * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
676   * With 100ms, a back-off of 200 means 20s
677   */
678  public static final int [] RETRY_BACKOFF = {1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200};
679
680  public static final String REGION_IMPL = "hbase.hregion.impl";
681
682  /**
683   * Scope tag for locally scoped data.
684   * This data will not be replicated.
685   */
686  public static final int REPLICATION_SCOPE_LOCAL = 0;
687
688  /**
689   * Scope tag for globally scoped data.
690   * This data will be replicated to all peers.
691   */
692  public static final int REPLICATION_SCOPE_GLOBAL = 1;
693
694  /**
695   * Default cluster ID, cannot be used to identify a cluster so a key with
696   * this value means it wasn't meant for replication.
697   */
698  public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
699
700  /**
701   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
702   * Controlled by the client.
703   */
704  public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
705      "hbase.client.scanner.max.result.size";
706
707  /**
708   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
709   * Controlled by the server.
710   */
711  public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
712      "hbase.server.scanner.max.result.size";
713
714  /**
715   * Maximum number of bytes returned when calling a scanner's next method.
716   * Note that when a single row is larger than this limit the row is still
717   * returned completely.
718   *
719   * The default value is 2MB.
720   */
721  public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
722
723  /**
724   * Maximum number of bytes returned when calling a scanner's next method.
725   * Note that when a single row is larger than this limit the row is still
726   * returned completely.
727   * Safety setting to protect the region server.
728   *
729   * The default value is 100MB. (a client would rarely request larger chunks on purpose)
730   */
731  public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
732
733  /**
734   * Parameter name for client pause value, used mostly as value to wait
735   * before running a retry of a failed get, region lookup, etc.
736   */
737  public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
738
739  /**
740   * Default value of {@link #HBASE_CLIENT_PAUSE}.
741   */
742  public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
743
744  /**
745   * Parameter name for client pause value for special case such as call queue too big, etc.
746   */
747  public static final String HBASE_CLIENT_PAUSE_FOR_CQTBE = "hbase.client.pause.cqtbe";
748
749  /**
750   * The maximum number of concurrent connections the client will maintain.
751   */
752  public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
753
754  /**
755   * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
756   */
757  public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
758
759  /**
760   * The maximum number of concurrent connections the client will maintain to a single
761   * RegionServer.
762   */
763  public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
764
765  /**
766   * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
767   */
768  public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
769
770  /**
771   * The maximum number of concurrent connections the client will maintain to a single
772   * Region.
773   */
774  public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
775
776  /**
777   * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
778   */
779  public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
780
781  /**
782   * The maximum number of concurrent pending RPC requests for one server in process level.
783   */
784  public static final String HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD =
785      "hbase.client.perserver.requests.threshold";
786
787  /**
788   * Default value of {@link #HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD}.
789   */
790  public static final int DEFAULT_HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD = Integer.MAX_VALUE;
791
792
793  /**
794   * Parameter name for server pause value, used mostly as value to wait before
795   * running a retry of a failed operation.
796   */
797  public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
798
799  /**
800   * Default value of {@link #HBASE_SERVER_PAUSE}.
801   */
802  public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
803
804  /**
805   * Parameter name for maximum retries, used as maximum for all retryable
806   * operations such as fetching of the root region from root region server,
807   * getting a cell's value, starting a row update, etc.
808   */
809  public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
810
811  /**
812   * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
813   */
814  public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 15;
815
816  public static final String HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER =
817      "hbase.client.serverside.retries.multiplier";
818
819  public static final int DEFAULT_HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER = 3;
820
821  /**
822   * Parameter name to set the default scanner caching for all clients.
823   */
824  public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
825
826  /**
827   * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
828   */
829  public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
830
831  /**
832   * Parameter name for number of rows that will be fetched when calling next on
833   * a scanner if it is not served from memory. Higher caching values will
834   * enable faster scanners but will eat up more memory and some calls of next
835   * may take longer and longer times when the cache is empty.
836   */
837  public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
838
839  /**
840   * Default value of {@link #HBASE_META_SCANNER_CACHING}.
841   */
842  public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
843
844  /**
845   * Parameter name for number of versions, kept by meta table.
846   */
847  public static final String HBASE_META_VERSIONS = "hbase.meta.versions";
848
849  /**
850   * Default value of {@link #HBASE_META_VERSIONS}.
851   */
852  public static final int DEFAULT_HBASE_META_VERSIONS = 3;
853
854  /**
855   * Parameter name for number of versions, kept by meta table.
856   */
857  public static final String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
858
859  /**
860   * Default value of {@link #HBASE_META_BLOCK_SIZE}.
861   */
862  public static final int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
863
864  /**
865   * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
866   * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
867   * for all intents and purposes, are the same except for their instance ids, then they will not be
868   * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
869   * even if the instance ids are the same, it could result in non-shared
870   * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
871   * differ.
872   */
873  public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
874
875  /**
876   * The client scanner timeout period in milliseconds.
877   */
878  public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD =
879      "hbase.client.scanner.timeout.period";
880
881  /**
882   * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
883   * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
884   */
885  @Deprecated
886  public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
887      "hbase.regionserver.lease.period";
888
889  /**
890   * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
891   */
892  public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
893
894  /**
895   * timeout for each RPC
896   */
897  public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
898
899  /**
900   * timeout for each read RPC
901   */
902  public static final String HBASE_RPC_READ_TIMEOUT_KEY = "hbase.rpc.read.timeout";
903
904  /**
905   * timeout for each write RPC
906   */
907  public static final String HBASE_RPC_WRITE_TIMEOUT_KEY = "hbase.rpc.write.timeout";
908
909  /**
910   * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
911   */
912  public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
913
914  /**
915   * timeout for short operation RPC
916   */
917  public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
918      "hbase.rpc.shortoperation.timeout";
919
920  /**
921   * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
922   */
923  public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
924
925  /**
926   * Value indicating the server name was saved with no sequence number.
927   */
928  public static final long NO_SEQNUM = -1;
929
930
931  /*
932   * cluster replication constants.
933   */
934  public static final String
935      REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
936  public static final String
937      REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
938  public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
939    "org.apache.hadoop.hbase.replication.regionserver.Replication";
940  public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
941  public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
942  /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
943  public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
944  /**
945   * Max total size of buffered entries in all replication peers. It will prevent server getting
946   * OOM if there are many peers. Default value is 256MB which is four times to default
947   * replication.source.size.capacity.
948   */
949  public static final String REPLICATION_SOURCE_TOTAL_BUFFER_KEY = "replication.total.buffer.quota";
950
951  public static final int REPLICATION_SOURCE_TOTAL_BUFFER_DFAULT = 256 * 1024 * 1024;
952
953
954  /**
955   * Directory where the source cluster file system client configuration are placed which is used by
956   * sink cluster to copy HFiles from source cluster file system
957   */
958  public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
959
960  /** Maximum time to retry for a failed bulk load request */
961  public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
962
963  public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
964    "hbase.regionserver.hostname.seen.by.master";
965
966  public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
967      "hbase.master.logcleaner.plugins";
968
969  public static final String HBASE_REGION_SPLIT_POLICY_KEY =
970    "hbase.regionserver.region.split.policy";
971
972  /** Whether nonces are enabled; default is true. */
973  public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
974
975  /**
976   * Configuration key for the size of the block cache
977   */
978  public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
979    "hfile.block.cache.size";
980
981  public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
982
983  /*
984    * Minimum percentage of free heap necessary for a successful cluster startup.
985    */
986  public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
987
988  /**
989   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
990   */
991  @Deprecated
992  public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
993      Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
994
995  /**
996   * <pre>
997   * Pattern that matches a coprocessor specification. Form is:
998   * {@code <coprocessor jar file location> '|' <class name> ['|' <priority> ['|' <arguments>]]}
999   * where arguments are {@code <KEY> '=' <VALUE> [,...]}
1000   * For example: {@code hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2}
1001   * </pre>
1002   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1003   */
1004  @Deprecated
1005  public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
1006      Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
1007  /**
1008   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1009   */
1010  @Deprecated
1011  public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
1012  /**
1013   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1014   */
1015  @Deprecated
1016  public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
1017  /**
1018   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1019   */
1020  @Deprecated
1021  public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
1022      "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
1023      CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
1024  public static final String CP_HTD_ATTR_INCLUSION_KEY =
1025      "hbase.coprocessor.classloader.included.classes";
1026
1027  /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
1028  public static final int SOCKET_RETRY_WAIT_MS = 200;
1029
1030  /** Host name of the local machine */
1031  public static final String LOCALHOST = "localhost";
1032
1033  /**
1034   * If this parameter is set to true, then hbase will read
1035   * data and then verify checksums. Checksum verification
1036   * inside hdfs will be switched off.  However, if the hbase-checksum
1037   * verification fails, then it will switch back to using
1038   * hdfs checksums for verifiying data that is being read from storage.
1039   *
1040   * If this parameter is set to false, then hbase will not
1041   * verify any checksums, instead it will depend on checksum verification
1042   * being done in the hdfs client.
1043   */
1044  public static final String HBASE_CHECKSUM_VERIFICATION =
1045      "hbase.regionserver.checksum.verify";
1046
1047  public static final String LOCALHOST_IP = "127.0.0.1";
1048
1049  public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
1050  public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
1051
1052  /*
1053   * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT:
1054   * -1  => Disable aborting
1055   * 0   => Abort if even a single handler has died
1056   * 0.x => Abort only when this percent of handlers have died
1057   * 1   => Abort only all of the handers have died
1058   */
1059  public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
1060      "hbase.regionserver.handler.abort.on.error.percent";
1061  public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
1062
1063  //High priority handlers to deal with admin requests and system table operation requests
1064  public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
1065      "hbase.regionserver.metahandler.count";
1066  public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
1067
1068  public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
1069      "hbase.regionserver.replication.handler.count";
1070  public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
1071  // Meta Transition handlers to deal with meta ReportRegionStateTransitionRequest. Meta transition
1072  // should be dealt with in a separate handler in case blocking other region's transition.
1073  public static final String MASTER_META_TRANSITION_HANDLER_COUNT =
1074      "hbase.master.meta.transition.handler.count";
1075  public static final int MASTER__META_TRANSITION_HANDLER_COUNT_DEFAULT = 1;
1076
1077  /** Conf key for enabling meta replication */
1078  public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
1079  public static final boolean DEFAULT_USE_META_REPLICAS = false;
1080  public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
1081  public static final int DEFAULT_META_REPLICA_NUM = 1;
1082
1083  /**
1084   * The name of the configuration parameter that specifies
1085   * the number of bytes in a newly created checksum chunk.
1086   */
1087  public static final String BYTES_PER_CHECKSUM =
1088      "hbase.hstore.bytes.per.checksum";
1089
1090  /**
1091   * The name of the configuration parameter that specifies
1092   * the name of an algorithm that is used to compute checksums
1093   * for newly created blocks.
1094   */
1095  public static final String CHECKSUM_TYPE_NAME =
1096      "hbase.hstore.checksum.algorithm";
1097
1098  /** Enable file permission modification from standard hbase */
1099  public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
1100  /** File permission umask to use when creating hbase data files */
1101  public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
1102
1103  /** Configuration name of WAL Compression */
1104  public static final String ENABLE_WAL_COMPRESSION =
1105    "hbase.regionserver.wal.enablecompression";
1106
1107  /** Configuration name of WAL storage policy
1108   * Valid values are: HOT, COLD, WARM, ALL_SSD, ONE_SSD, LAZY_PERSIST
1109   * See http://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html*/
1110  public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
1111  /**
1112   * "NONE" is not a valid storage policy and means we defer the policy to HDFS. @see
1113   * <a href="https://issues.apache.org/jira/browse/HBASE-20691">HBASE-20691</a>
1114   */
1115  public static final String DEFER_TO_HDFS_STORAGE_POLICY = "NONE";
1116  /** By default we defer the WAL storage policy to HDFS */
1117  public static final String DEFAULT_WAL_STORAGE_POLICY = DEFER_TO_HDFS_STORAGE_POLICY;
1118
1119  /** Region in Transition metrics threshold time */
1120  public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1121      "hbase.metrics.rit.stuck.warning.threshold";
1122
1123  public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1124
1125  /** delimiter used between portions of a region name */
1126  public static final int DELIMITER = ',';
1127
1128  /**
1129   * QOS attributes: these attributes are used to demarcate RPC call processing
1130   * by different set of handlers. For example, HIGH_QOS tagged methods are
1131   * handled by high priority handlers.
1132   */
1133  // normal_QOS < replication_QOS < replay_QOS < QOS_threshold < admin_QOS < high_QOS < meta_QOS
1134  public static final int PRIORITY_UNSET = -1;
1135  public static final int NORMAL_QOS = 0;
1136  public static final int REPLICATION_QOS = 5;
1137  public static final int REPLAY_QOS = 6;
1138  public static final int QOS_THRESHOLD = 10;
1139  public static final int ADMIN_QOS = 100;
1140  public static final int HIGH_QOS = 200;
1141  public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1142  /**
1143   * @deprecated the name "META_QOS" is a bit ambiguous, actually only meta region transition can
1144   *             use this priority, and you should not use this directly. Will be removed in 3.0.0.
1145   */
1146  @Deprecated
1147  public static final int META_QOS = 300;
1148
1149  /** Directory under /hbase where archived hfiles are stored */
1150  public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1151
1152  /**
1153   * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
1154   * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
1155   * uni-directional.
1156   */
1157  public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1158
1159  /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1160  public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1161
1162  /** Temporary directory used for table creation and deletion */
1163  public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1164  /**
1165   * The period (in milliseconds) between computing region server point in time metrics
1166   */
1167  public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1168  public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1169  /** Directories that are not HBase table directories */
1170  public static final List<String> HBASE_NON_TABLE_DIRS =
1171    Collections.unmodifiableList(Arrays.asList(new String[] {
1172      HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
1173    }));
1174
1175  /** Directories that are not HBase user table directories */
1176  public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1177    Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
1178      new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1179      HBASE_NON_TABLE_DIRS.toArray())));
1180
1181  /** Health script related settings. */
1182  public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1183  public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1184  public static final String HEALTH_CHORE_WAKE_FREQ =
1185      "hbase.node.health.script.frequency";
1186  public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1187  /**
1188   * The maximum number of health check failures a server can encounter consecutively.
1189   */
1190  public static final String HEALTH_FAILURE_THRESHOLD =
1191      "hbase.node.health.failure.threshold";
1192  public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1193
1194
1195  /**
1196   * Setting to activate, or not, the publication of the status by the master. Default
1197   *  notification is by a multicast message.
1198   */
1199  public static final String STATUS_PUBLISHED = "hbase.status.published";
1200  public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1201
1202  /**
1203   * IP to use for the multicast status messages between the master and the clients.
1204   * The default address is chosen as one among others within the ones suitable for multicast
1205   * messages.
1206   */
1207  public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1208  public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1209
1210  /**
1211   * The address to use for binding the local socket for receiving multicast. Defaults to
1212   * 0.0.0.0.
1213   * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1214   */
1215  public static final String STATUS_MULTICAST_BIND_ADDRESS =
1216      "hbase.status.multicast.bind.address.ip";
1217  public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1218
1219  /**
1220   * The port to use for the multicast messages.
1221   */
1222  public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1223  public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1224
1225  /**
1226   * The network interface name to use for the multicast messages.
1227   */
1228  public static final String STATUS_MULTICAST_NI_NAME = "hbase.status.multicast.ni.name";
1229
1230  /**
1231   * The address to use for binding the local socket for sending multicast. Defaults to 0.0.0.0.
1232   */
1233  public static final String STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS =
1234    "hbase.status.multicast.publisher.bind.address.ip";
1235  public static final String DEFAULT_STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS = "0.0.0.0";
1236
1237  public static final long NO_NONCE = 0;
1238
1239  /** Default cipher for encryption */
1240  public static final String CIPHER_AES = "AES";
1241
1242  /** Configuration key for the crypto algorithm provider, a class name */
1243  public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1244
1245  /** Configuration key for the crypto key provider, a class name */
1246  public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1247
1248  /** Configuration key for the crypto key provider parameters */
1249  public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1250      "hbase.crypto.keyprovider.parameters";
1251
1252  /** Configuration key for the name of the master key for the cluster, a string */
1253  public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1254
1255  /** Configuration key for the name of the alternate master key for the cluster, a string */
1256  public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1257    "hbase.crypto.master.alternate.key.name";
1258
1259  /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1260  public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1261
1262  /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1263  public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1264
1265  /** Configuration key for the algorithm used for creating jks key, a string */
1266  public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1267
1268  /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1269  public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1270      "hbase.crypto.alternate.key.algorithm";
1271
1272  /** Configuration key for enabling WAL encryption, a boolean */
1273  public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1274
1275  /** Configuration key for setting RPC codec class name */
1276  public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1277
1278  /** Configuration key for setting replication codec class name */
1279  public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1280
1281  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1282  public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1283      "hbase.replication.source.maxthreads";
1284
1285  /** Drop edits for tables that been deleted from the replication source and target */
1286  public static final String REPLICATION_DROP_ON_DELETED_TABLE_KEY =
1287      "hbase.replication.drop.on.deleted.table";
1288
1289  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1290  public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1291
1292  /** Configuration key for SplitLog manager timeout */
1293  public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1294
1295  /**
1296   * Configuration keys for Bucket cache
1297   */
1298  // TODO moving these bucket cache implementation specific configs to this level is violation of
1299  // encapsulation. But as these has to be referred from hbase-common and bucket cache
1300  // sits in hbase-server, there were no other go! Can we move the cache implementation to
1301  // hbase-common?
1302
1303  /**
1304   * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1305   * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1306   * list of supported ioengine options.
1307   * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1308   */
1309  public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1310
1311  /**
1312   * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1313   * memory size to give to the cache (if &lt; 1.0) OR, it is the capacity in
1314   * megabytes of the cache.
1315   */
1316  public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1317
1318  /**
1319   * HConstants for fast fail on the client side follow
1320   */
1321  /**
1322   * Config for enabling/disabling the fast fail mode.
1323   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1324   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1325   */
1326  @Deprecated
1327  public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1328    "hbase.client.fast.fail.mode.enabled";
1329
1330  /**
1331   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1332   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1333   */
1334  @Deprecated
1335  public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT = false;
1336
1337  /**
1338   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1339   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1340   */
1341  @Deprecated
1342  public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1343    "hbase.client.fastfail.threshold";
1344
1345  /**
1346   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1347   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1348   */
1349  @Deprecated
1350  public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT = 60000;
1351
1352  /**
1353   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1354   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1355   */
1356  @Deprecated
1357  public static final String HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS =
1358    "hbase.client.failure.map.cleanup.interval";
1359
1360  /**
1361   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1362   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1363   */
1364  @Deprecated
1365  public static final long HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS_DEFAULT = 600000;
1366
1367  /**
1368   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1369   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1370   */
1371  @Deprecated
1372  public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1373    "hbase.client.fast.fail.cleanup.duration";
1374
1375  /**
1376   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1377   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1378   */
1379  @Deprecated
1380  public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT = 600000;
1381
1382  /**
1383   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1384   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1385   */
1386  @Deprecated
1387  public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1388    "hbase.client.fast.fail.interceptor.impl";
1389
1390  public static final String HBASE_SPLIT_WAL_COORDINATED_BY_ZK = "hbase.split.wal.zk.coordinated";
1391
1392  public static final boolean DEFAULT_HBASE_SPLIT_COORDINATED_BY_ZK = true;
1393
1394  public static final String HBASE_SPLIT_WAL_MAX_SPLITTER = "hbase.regionserver.wal.max.splitters";
1395
1396  public static final int DEFAULT_HBASE_SPLIT_WAL_MAX_SPLITTER = 2;
1397
1398  /** Config key for if the server should send backpressure and if the client should listen to
1399   * that backpressure from the server */
1400  public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1401  public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1402
1403  public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1404      "hbase.heap.occupancy.low_water_mark";
1405  public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1406  public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1407      "hbase.heap.occupancy.high_water_mark";
1408  public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1409
1410  /**
1411   * The max number of threads used for splitting storefiles in parallel during
1412   * the region split process.
1413   */
1414  public static final String REGION_SPLIT_THREADS_MAX =
1415    "hbase.regionserver.region.split.threads.max";
1416
1417  /** Canary config keys */
1418  // TODO: Move these defines to Canary Class
1419  public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1420
1421  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1422      "hbase.canary.write.perserver.regions.lowerLimit";
1423
1424  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1425      "hbase.canary.write.perserver.regions.upperLimit";
1426
1427  public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1428
1429  public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1430      "hbase.canary.write.table.check.period";
1431
1432  public static final String HBASE_CANARY_READ_RAW_SCAN_KEY = "hbase.canary.read.raw.enabled";
1433
1434  /**
1435   * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1436   */
1437  public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1438  public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1439      "hbase.zookeeper.client.kerberos.principal";
1440  public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1441  public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1442      "hbase.zookeeper.server.kerberos.principal";
1443
1444  /** Config key for hbase temporary directory in hdfs */
1445  public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1446
1447  /**
1448   * Don't use it! This'll get you the wrong path in a secure cluster.
1449   * Use FileSystem.getHomeDirectory() or
1450   * "/user/" + UserGroupInformation.getCurrentUser().getShortUserName()
1451   */
1452  public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY = "/user/"
1453      + System.getProperty("user.name") + "/hbase-staging";
1454
1455  public static final String SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT =
1456      "hbase.snapshot.restore.take.failsafe.snapshot";
1457  public static final boolean DEFAULT_SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT = true;
1458
1459  public static final String SNAPSHOT_RESTORE_FAILSAFE_NAME =
1460      "hbase.snapshot.restore.failsafe.name";
1461  public static final String DEFAULT_SNAPSHOT_RESTORE_FAILSAFE_NAME =
1462      "hbase-failsafe-{snapshot.name}-{restore.timestamp}";
1463
1464  public static final String DEFAULT_LOSSY_COUNTING_ERROR_RATE =
1465      "hbase.util.default.lossycounting.errorrate";
1466  public static final String NOT_IMPLEMENTED = "Not implemented";
1467
1468  // Default TTL - FOREVER
1469  public static final long DEFAULT_SNAPSHOT_TTL = 0;
1470
1471  // User defined Default TTL config key
1472  public static final String DEFAULT_SNAPSHOT_TTL_CONFIG_KEY = "hbase.master.snapshot.ttl";
1473
1474  public static final String SNAPSHOT_CLEANER_DISABLE = "hbase.master.cleaner.snapshot.disable";
1475
1476  /**
1477   * Configurations for master executor services.
1478   */
1479  public static final String MASTER_OPEN_REGION_THREADS =
1480      "hbase.master.executor.openregion.threads";
1481  public static final int MASTER_OPEN_REGION_THREADS_DEFAULT = 5;
1482
1483  public static final String MASTER_CLOSE_REGION_THREADS =
1484      "hbase.master.executor.closeregion.threads";
1485  public static final int MASTER_CLOSE_REGION_THREADS_DEFAULT = 5;
1486
1487  public static final String MASTER_SERVER_OPERATIONS_THREADS =
1488      "hbase.master.executor.serverops.threads";
1489  public static final int MASTER_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1490
1491  public static final String MASTER_META_SERVER_OPERATIONS_THREADS =
1492      "hbase.master.executor.meta.serverops.threads";
1493  public static final int MASTER_META_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1494
1495  public static final String MASTER_LOG_REPLAY_OPS_THREADS =
1496      "hbase.master.executor.logreplayops.threads";
1497  public static final int MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT = 10;
1498
1499  public static final String MASTER_SNAPSHOT_OPERATIONS_THREADS =
1500      "hbase.master.executor.snapshot.threads";
1501  public static final int MASTER_SNAPSHOT_OPERATIONS_THREADS_DEFAULT = 3;
1502
1503
1504  private HConstants() {
1505    // Can't be instantiated with this ctor.
1506  }
1507}