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.conf.ConfigKey;
031import org.apache.hadoop.hbase.util.Bytes;
032import org.apache.yetus.audience.InterfaceAudience;
033
034/**
035 * HConstants holds a bunch of HBase-related constants
036 */
037@InterfaceAudience.Public
038public final class HConstants {
039  // NOTICE!!!! Please do not add a constants here, unless they are referenced by a lot of classes.
040
041  // Bytes.UTF8_ENCODING should be updated if this changed
042  /** When we encode strings, we always specify UTF8 encoding */
043  public static final String UTF8_ENCODING = "UTF-8";
044
045  // Bytes.UTF8_CHARSET should be updated if this changed
046  /** When we encode strings, we always specify UTF8 encoding */
047  public static final Charset UTF8_CHARSET = Charset.forName(UTF8_ENCODING);
048  /**
049   * Default block size for an HFile.
050   */
051  public final static int DEFAULT_BLOCKSIZE = 64 * 1024;
052
053  /** Used as a magic return value while optimized index key feature enabled(HBASE-7845) */
054  public final static int INDEX_KEY_MAGIC = -2;
055
056  /*
057   * Name of directory that holds recovered edits written by the wal log splitting code, one per
058   * region
059   */
060  public static final String RECOVERED_EDITS_DIR = "recovered.edits";
061
062  /*
063   * Name of directory that holds recovered hfiles written by the wal log splitting code, one per
064   * region
065   */
066  public static final String RECOVERED_HFILES_DIR = "recovered.hfiles";
067
068  /**
069   * Date Tiered Compaction tmp dir prefix name if use storage policy
070   */
071  public static final String STORAGE_POLICY_PREFIX = "storage_policy_";
072
073  /**
074   * The first four bytes of Hadoop RPC connections
075   */
076  public static final byte[] RPC_HEADER = new byte[] { 'H', 'B', 'a', 's' };
077  public static final byte RPC_CURRENT_VERSION = 0;
078
079  // HFileBlock constants. TODO!!!! THESE DEFINES BELONG IN HFILEBLOCK, NOT UP HERE.
080  // Needed down in hbase-common though by encoders but these encoders should not be dealing
081  // in the internals of hfileblocks. Fix encapsulation.
082
083  /** The size data structures with minor version is 0 */
084  public static final int HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM =
085    MAGIC_LENGTH + 2 * Bytes.SIZEOF_INT + Bytes.SIZEOF_LONG;
086  /**
087   * The size of a version 2 HFile block header, minor version 1. There is a 1 byte checksum type,
088   * followed by a 4 byte bytesPerChecksum followed by another 4 byte value to store
089   * sizeofDataOnDisk.
090   */
091  public static final int HFILEBLOCK_HEADER_SIZE =
092    HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM + Bytes.SIZEOF_BYTE + 2 * Bytes.SIZEOF_INT;
093  /** Just an array of bytes of the right size. */
094  public static final byte[] HFILEBLOCK_DUMMY_HEADER = new byte[HFILEBLOCK_HEADER_SIZE];
095
096  // End HFileBlockConstants.
097
098  /**
099   * Status codes used for return values of bulk operations.
100   */
101  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
102  public enum OperationStatusCode {
103    NOT_RUN,
104    SUCCESS,
105    BAD_FAMILY,
106    STORE_TOO_BUSY,
107    SANITY_CHECK_FAILURE,
108    FAILURE
109  }
110
111  /** long constant for zero */
112  public static final Long ZERO_L = Long.valueOf(0L);
113  public static final String NINES = "99999999999999";
114  public static final String ZEROES = "00000000000000";
115
116  // For migration
117
118  /** name of version file */
119  public static final String VERSION_FILE_NAME = "hbase.version";
120
121  /**
122   * Current version of file system. Version 4 supports only one kind of bloom filter. Version 5
123   * changes versions in catalog table regions. Version 6 enables blockcaching on catalog tables.
124   * Version 7 introduces hfile -- hbase 0.19 to 0.20.. Version 8 introduces namespace
125   */
126  // public static final String FILE_SYSTEM_VERSION = "6";
127  public static final String FILE_SYSTEM_VERSION = "8";
128
129  // Configuration parameters
130
131  // TODO: Is having HBase homed on port 60k OK?
132
133  /** Cluster is in distributed mode or not */
134  public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
135
136  /** Config for pluggable load balancers */
137  public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
138
139  /** Config for balancing the cluster by table */
140  public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
141
142  /** Config for the max percent of regions in transition */
143  public static final String HBASE_MASTER_BALANCER_MAX_RIT_PERCENT =
144    "hbase.master.balancer.maxRitPercent";
145
146  /** Default value for the max percent of regions in transition */
147  public static final double DEFAULT_HBASE_MASTER_BALANCER_MAX_RIT_PERCENT = 1.0;
148
149  /** Config for the max balancing time */
150  public static final String HBASE_BALANCER_MAX_BALANCING = "hbase.balancer.max.balancing";
151
152  /** Config for the balancer period */
153  public static final String HBASE_BALANCER_PERIOD = "hbase.balancer.period";
154
155  /** Default value for the balancer period */
156  public static final int DEFAULT_HBASE_BALANCER_PERIOD = 300000;
157
158  /** Config for the oldWALs directory size updater period */
159  public static final String HBASE_OLDWAL_DIR_SIZE_UPDATER_PERIOD =
160    "hbase.master.oldwals.dir.updater.period";
161
162  /** Default value for the oldWALs directory size updater period */
163  public static final int DEFAULT_HBASE_OLDWAL_DIR_SIZE_UPDATER_PERIOD = 300000;
164
165  /**
166   * Config key for enable/disable automatically separate child regions to different region servers
167   * in the procedure of split regions. One child will be kept to the server where parent region is
168   * on, and the other child will be assigned to a random server. See HBASE-25518.
169   */
170  public static final String HBASE_ENABLE_SEPARATE_CHILD_REGIONS =
171    "hbase.master.auto.separate.child.regions.after.split.enabled";
172
173  /**
174   * Default value for automatically separate child regions to different region servers (set to
175   * "false" to keep all child regions to the server where parent region is on)
176   */
177  public static final boolean DEFAULT_HBASE_ENABLE_SEPARATE_CHILD_REGIONS = false;
178
179  /** The name of the ensemble table */
180  public static final TableName ENSEMBLE_TABLE_NAME = TableName.valueOf("hbase:ensemble");
181
182  /** Config for pluggable region normalizer */
183  public static final String HBASE_MASTER_NORMALIZER_CLASS = "hbase.master.normalizer.class";
184
185  /** Cluster is standalone or pseudo-distributed */
186  public static final boolean CLUSTER_IS_LOCAL = false;
187
188  /** Cluster is fully-distributed */
189  @Deprecated // unused. see HBASE-13636. remove this in 3.0
190  public static final boolean CLUSTER_IS_DISTRIBUTED = true;
191
192  /** Default value for cluster distributed mode */
193  public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
194
195  /** default host address */
196  public static final String DEFAULT_HOST = "0.0.0.0";
197
198  /** Parameter name for port master listens on. */
199  public static final String MASTER_PORT = "hbase.master.port";
200
201  /** default port that the master listens on */
202  public static final int DEFAULT_MASTER_PORT = 16000;
203
204  /** default port for master web api */
205  public static final int DEFAULT_MASTER_INFOPORT = 16010;
206
207  /** Configuration key for master web API port */
208  public static final String MASTER_INFO_PORT = "hbase.master.info.port";
209
210  /** Configuration key for the list of master host:ports **/
211  public static final String MASTER_ADDRS_KEY = "hbase.masters";
212
213  /** Full class name of the Zookeeper based connection registry implementation */
214  public static final String ZK_CONNECTION_REGISTRY_CLASS =
215    "org.apache.hadoop.hbase.client.ZKConnectionRegistry";
216
217  /** Parameter name for the master type being backup (waits for primary to go inactive). */
218  public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
219
220  /**
221   * by default every master is a possible primary master unless the conf explicitly overrides it
222   */
223  public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
224
225  /** Name of ZooKeeper quorum configuration parameter. */
226  public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
227
228  /** Name of ZooKeeper quorum configuration parameter for client to locate meta. */
229  public static final String CLIENT_ZOOKEEPER_QUORUM = "hbase.client.zookeeper.quorum";
230
231  /** Client port of ZooKeeper for client to locate meta */
232  public static final String CLIENT_ZOOKEEPER_CLIENT_PORT =
233    "hbase.client.zookeeper.property.clientPort";
234
235  /** Indicate whether the client ZK are observer nodes of the server ZK */
236  public static final String CLIENT_ZOOKEEPER_OBSERVER_MODE =
237    "hbase.client.zookeeper.observer.mode";
238  /** Assuming client zk not in observer mode and master need to synchronize information */
239  public static final boolean DEFAULT_CLIENT_ZOOKEEPER_OBSERVER_MODE = false;
240
241  /** Common prefix of ZooKeeper configuration properties */
242  public static final String ZK_CFG_PROPERTY_PREFIX = "hbase.zookeeper.property.";
243
244  public static final int ZK_CFG_PROPERTY_PREFIX_LEN = ZK_CFG_PROPERTY_PREFIX.length();
245
246  /**
247   * The ZK client port key in the ZK properties map. The name reflects the fact that this is not an
248   * HBase configuration key.
249   */
250  public static final String CLIENT_PORT_STR = "clientPort";
251
252  /** Parameter name for the client port that the zookeeper listens on */
253  public static final String ZOOKEEPER_CLIENT_PORT = ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
254
255  /**
256   * Will be removed in hbase 3.0
257   * @deprecated use {@link #DEFAULT_ZOOKEEPER_CLIENT_PORT} instead
258   */
259  @Deprecated
260  public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
261
262  /** Default client port that the zookeeper listens on */
263  public static final int DEFAULT_ZOOKEEPER_CLIENT_PORT = 2181;
264
265  /**
266   * Parameter name for the wait time for the recoverable zookeeper
267   */
268  @Deprecated // unused. see HBASE-3065. remove this in 3.0
269  public static final String ZOOKEEPER_RECOVERABLE_WAITTIME =
270    "hbase.zookeeper.recoverable.waittime";
271
272  /** Default wait time for the recoverable zookeeper */
273  @Deprecated // unused. see HBASE-3065. remove this in 3.0
274  public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
275
276  /** Parameter name for the root dir in ZK for this cluster */
277  public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
278
279  public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
280
281  /**
282   * Parameter name for the limit on concurrent client-side zookeeper connections
283   */
284  public static final String ZOOKEEPER_MAX_CLIENT_CNXNS = ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
285
286  /** Parameter name for the ZK data directory */
287  public static final String ZOOKEEPER_DATA_DIR = ZK_CFG_PROPERTY_PREFIX + "dataDir";
288
289  /** Parameter name for the ZK tick time */
290  public static final String ZOOKEEPER_TICK_TIME = ZK_CFG_PROPERTY_PREFIX + "tickTime";
291
292  /**
293   * Will be removed in hbase 3.0
294   * @deprecated use {@link #DEFAULT_ZOOKEEPER_MAX_CLIENT_CNXNS} instead
295   */
296  @Deprecated
297  public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
298
299  /** Default limit on concurrent client-side zookeeper connections */
300  public static final int DEFAULT_ZOOKEEPER_MAX_CLIENT_CNXNS = 300;
301
302  /** Configuration key for ZooKeeper session timeout */
303  public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
304
305  /** Timeout for the ZK sync() call */
306  public static final String ZK_SYNC_BLOCKING_TIMEOUT_MS = "hbase.zookeeper.sync.timeout.millis";
307  // Choice of the default value is based on the following ZK recommendation (from docs). Keeping it
308  // lower lets the callers fail fast in case of any issues.
309  // "The clients view of the system is guaranteed to be up-to-date within a certain time bound.
310  // (On the order of tens of seconds.) Either system changes will be seen by a client within this
311  // bound, or the client will detect a service outage."
312  public static final long ZK_SYNC_BLOCKING_TIMEOUT_DEFAULT_MS = 30 * 1000;
313
314  /** Default value for ZooKeeper session timeout */
315  public static final int DEFAULT_ZK_SESSION_TIMEOUT = 90 * 1000;
316
317  /** Parameter name for port region server listens on. */
318  public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
319
320  /** Default port region server listens on. */
321  public static final int DEFAULT_REGIONSERVER_PORT = 16020;
322
323  /** default port for region server web api */
324  public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
325
326  /** A configuration key for regionserver info port */
327  public static final String REGIONSERVER_INFO_PORT = "hbase.regionserver.info.port";
328
329  /** A flag that enables automatic selection of regionserver info port */
330  public static final String REGIONSERVER_INFO_PORT_AUTO = REGIONSERVER_INFO_PORT + ".auto";
331
332  /** Parameter name for what region server implementation to use. */
333  public static final String REGION_SERVER_IMPL = "hbase.regionserver.impl";
334
335  /** Parameter name for what master implementation to use. */
336  public static final String MASTER_IMPL = "hbase.master.impl";
337
338  /** Parameter name for what hbase client implementation to use. */
339  @Deprecated // unused. see HBASE-7460. remove this in 3.0
340  public static final String HBASECLIENT_IMPL = "hbase.hbaseclient.impl";
341
342  /** Parameter name for how often threads should wake up */
343  public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
344
345  /** Default value for thread wake frequency */
346  public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
347
348  /** Parameter name for how often we should try to write a version file, before failing */
349  public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
350
351  /** Parameter name for how often we should try to write a version file, before failing */
352  public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
353
354  /** Parameter name and default value for how often a region should perform a major compaction */
355  public static final String MAJOR_COMPACTION_PERIOD =
356    ConfigKey.LONG("hbase.hregion.majorcompaction");
357  public static final long DEFAULT_MAJOR_COMPACTION_PERIOD = 1000 * 60 * 60 * 24 * 7; // 7 days
358
359  /**
360   * Parameter name and default value for major compaction jitter. Used as a multiplier applied to
361   * {@link HConstants#MAJOR_COMPACTION_PERIOD} to cause compaction to occur a given amount of time
362   * either side of {@link HConstants#MAJOR_COMPACTION_PERIOD}. Default to 0.5 so jitter has us fall
363   * evenly either side of when the compaction should run.
364   */
365  public static final String MAJOR_COMPACTION_JITTER =
366    ConfigKey.FLOAT("hbase.hregion.majorcompaction.jitter");
367  public static final float DEFAULT_MAJOR_COMPACTION_JITTER = 0.50F;
368
369  /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
370  public static final String COMPACTION_KV_MAX = ConfigKey.INT("hbase.hstore.compaction.kv.max");
371  public static final int COMPACTION_KV_MAX_DEFAULT = 10;
372
373  /** Parameter name for the scanner size limit to be used in compactions */
374  public static final String COMPACTION_SCANNER_SIZE_MAX =
375    ConfigKey.LONG("hbase.hstore.compaction.scanner.size.limit");
376  public static final long COMPACTION_SCANNER_SIZE_MAX_DEFAULT = 10 * 1024 * 1024L; // 10MB
377
378  /** Parameter name for HBase instance root directory */
379  public static final String HBASE_DIR = "hbase.rootdir";
380
381  /** Parameter name for HBase client IPC pool type */
382  public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
383
384  /** Parameter name for HBase client IPC pool size */
385  public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
386
387  /** Parameter name for HBase client operation timeout. */
388  public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
389
390  /** Parameter name for HBase client meta operation timeout. */
391  public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
392    "hbase.client.meta.operation.timeout";
393
394  /** Default HBase client operation timeout, which is tantamount to a blocking call */
395  public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
396
397  /** Parameter name for HBase client meta replica scan call timeout. */
398  public static final String HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT =
399    "hbase.client.meta.replica.scan.timeout";
400
401  /** Default HBase client meta replica scan call timeout, 1 second */
402  public static final int HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT_DEFAULT = 1000000;
403
404  /** Used to construct the name of the log directory for a region server */
405  public static final String HREGION_LOGDIR_NAME = "WALs";
406
407  /** Used to construct the name of the splitlog directory for a region server */
408  public static final String SPLIT_LOGDIR_NAME = "splitWAL";
409
410  /** Like the previous, but for old logs that are about to be deleted */
411  public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
412
413  /** Staging dir used by bulk load */
414  public static final String BULKLOAD_STAGING_DIR_NAME = "staging";
415
416  public static final String CORRUPT_DIR_NAME = "corrupt";
417
418  /** Used by HBCK to sideline backup data */
419  public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
420
421  /** Any artifacts left from migration can be moved here */
422  public static final String MIGRATION_NAME = ".migration";
423
424  /**
425   * The directory from which co-processor/custom filter jars can be loaded dynamically by the
426   * region servers. This value can be overridden by the hbase.dynamic.jars.dir config.
427   */
428  @Deprecated // unused. see HBASE-12054. remove this in 3.0
429  public static final String LIB_DIR = "lib";
430
431  /** Used to construct the name of the compaction directory during compaction */
432  public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
433
434  /** Conf key for the max file size after which we split the region */
435  public static final String HREGION_MAX_FILESIZE = ConfigKey.LONG("hbase.hregion.max.filesize");
436
437  /** Default maximum file size */
438  public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
439
440  /** Conf key for if we should sum overall region files size when check to split */
441  public static final String OVERALL_HREGION_FILES = "hbase.hregion.split.overallfiles";
442
443  /** Default overall region files */
444  public static final boolean DEFAULT_OVERALL_HREGION_FILES = false;
445
446  /**
447   * Max size of single row for Get's or Scan's without in-row scanning flag set.
448   */
449  public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
450
451  /**
452   * Default max row size (1 Gb).
453   */
454  public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
455
456  /**
457   * The max number of threads used for opening and closing stores or store files in parallel
458   */
459  public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
460    ConfigKey.INT("hbase.hstore.open.and.close.threads.max");
461
462  /**
463   * The default number for the max number of threads used for opening and closing stores or store
464   * files in parallel
465   */
466  public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
467
468  /**
469   * Block updates if memstore has hbase.hregion.memstore.block.multiplier times
470   * hbase.hregion.memstore.flush.size bytes. Useful preventing runaway memstore during spikes in
471   * update traffic.
472   */
473  public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
474    ConfigKey.INT("hbase.hregion.memstore.block.multiplier", v -> v > 0);
475
476  /**
477   * Default value for hbase.hregion.memstore.block.multiplier
478   */
479  public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
480
481  /** Conf key for the memstore size at which we flush the memstore */
482  public static final String HREGION_MEMSTORE_FLUSH_SIZE =
483    ConfigKey.LONG("hbase.hregion.memstore.flush.size", v -> v > 0);
484
485  public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
486    "hbase.hregion.edits.replay.skip.errors";
487
488  public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS = false;
489
490  /** Maximum value length, enforced on KeyValue construction */
491  public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
492
493  /** name of the file for unique cluster ID */
494  public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
495
496  /** Default value for cluster ID */
497  public static final String CLUSTER_ID_DEFAULT = "default-cluster";
498
499  /** Parameter name for # days to keep MVCC values during a major compaction */
500  public static final String KEEP_SEQID_PERIOD =
501    ConfigKey.INT("hbase.hstore.compaction.keep.seqId.period");
502  /** At least to keep MVCC values in hfiles for 5 days */
503  public static final int MIN_KEEP_SEQID_PERIOD = 5;
504
505  // Always store the location of the root table's HRegion.
506  // This HRegion is never split.
507
508  // region name = table + startkey + regionid. This is the row key.
509  // each row in the root and meta tables describes exactly 1 region
510  // Do we ever need to know all the information that we are storing?
511
512  // Note that the name of the root table starts with "-" and the name of the
513  // meta table starts with "." Why? it's a trick. It turns out that when we
514  // store region names in memory, we use a SortedMap. Since "-" sorts before
515  // "." (and since no other table name can start with either of these
516  // characters, the root region will always be the first entry in such a Map,
517  // followed by all the meta regions (which will be ordered by their starting
518  // row key as well), followed by all user tables. So when the Master is
519  // choosing regions to assign, it will always choose the root region first,
520  // followed by the meta regions, followed by user regions. Since the root
521  // and meta regions always need to be on-line, this ensures that they will
522  // be the first to be reassigned if the server(s) they are being served by
523  // should go down.
524
525  public static final String BASE_NAMESPACE_DIR = "data";
526
527  /** delimiter used between portions of a region name */
528  public static final int META_ROW_DELIMITER = ',';
529
530  /** The catalog family as a string */
531  public static final String CATALOG_FAMILY_STR = "info";
532
533  /** The catalog family */
534  public static final byte[] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
535
536  /** The RegionInfo qualifier as a string */
537  public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
538
539  /** The regioninfo column qualifier */
540  public static final byte[] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
541
542  /** The server column qualifier */
543  public static final String SERVER_QUALIFIER_STR = "server";
544  /** The server column qualifier */
545  public static final byte[] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
546
547  /** The startcode column qualifier */
548  public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
549  /** The startcode column qualifier */
550  public static final byte[] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
551
552  /** The open seqnum column qualifier */
553  public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
554  /** The open seqnum column qualifier */
555  public static final byte[] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
556
557  /** The state column qualifier */
558  public static final String STATE_QUALIFIER_STR = "state";
559
560  public static final byte[] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
561
562  /**
563   * The serverName column qualifier. Its the server where the region is transitioning on, while
564   * column server is the server where the region is opened on. They are the same when the region is
565   * in state OPEN.
566   */
567  public static final String SERVERNAME_QUALIFIER_STR = "sn";
568
569  public static final byte[] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
570
571  /** The lower-half split region column qualifier string. */
572  public static final String SPLITA_QUALIFIER_STR = "splitA";
573  /** The lower-half split region column qualifier */
574  public static final byte[] SPLITA_QUALIFIER = Bytes.toBytes(SPLITA_QUALIFIER_STR);
575
576  /** The upper-half split region column qualifier String. */
577  public static final String SPLITB_QUALIFIER_STR = "splitB";
578  /** The upper-half split region column qualifier */
579  public static final byte[] SPLITB_QUALIFIER = Bytes.toBytes(SPLITB_QUALIFIER_STR);
580
581  /**
582   * Merge qualifier prefix. We used to only allow two regions merge; mergeA and mergeB. Now we
583   * allow many to merge. Each region to merge will be referenced in a column whose qualifier starts
584   * with this define.
585   */
586  public static final String MERGE_QUALIFIER_PREFIX_STR = "merge";
587  public static final byte[] MERGE_QUALIFIER_PREFIX = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR);
588
589  /**
590   * The lower-half merge region column qualifier
591   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for the
592   *             {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
593   */
594  @Deprecated
595  public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "A");
596
597  /**
598   * The upper-half merge region column qualifier
599   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for the
600   *             {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
601   */
602  @Deprecated
603  public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "B");
604
605  /** The catalog family as a string */
606  public static final String TABLE_FAMILY_STR = "table";
607
608  /** The catalog family */
609  public static final byte[] TABLE_FAMILY = Bytes.toBytes(TABLE_FAMILY_STR);
610
611  /** The serialized table state qualifier */
612  public static final byte[] TABLE_STATE_QUALIFIER = Bytes.toBytes("state");
613
614  /** The replication barrier family as a string */
615  public static final String REPLICATION_BARRIER_FAMILY_STR = "rep_barrier";
616
617  /** The replication barrier family */
618  public static final byte[] REPLICATION_BARRIER_FAMILY =
619    Bytes.toBytes(REPLICATION_BARRIER_FAMILY_STR);
620
621  /**
622   * The meta table version column qualifier. We keep current version of the meta table in this
623   * column in <code>-ROOT-</code> table: i.e. in the 'info:v' column.
624   */
625  public static final byte[] META_VERSION_QUALIFIER = Bytes.toBytes("v");
626
627  /** The family str as a key in map */
628  public static final String FAMILY_KEY_STR = "family";
629
630  /**
631   * The current version of the meta table. - pre-hbase 0.92. There is no META_VERSION column in the
632   * root table in this case. The meta has HTableDescriptor serialized into the HRegionInfo; -
633   * version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using Writable
634   * serialization, and HRegionInfo's does not contain HTableDescriptors. - version 1 for 0.96+
635   * keeps HRegionInfo data structures, but changes the byte[] serialization from Writables to
636   * Protobuf. See HRegionInfo.VERSION
637   */
638  public static final short META_VERSION = 1;
639
640  // Other constants
641
642  /**
643   * An empty byte array instance.
644   */
645  public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
646
647  /**
648   * An empty string instance.
649   */
650  public static final String EMPTY_STRING = "";
651
652  public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
653
654  /**
655   * Used by scanners, etc when they want to start at the beginning of a region
656   */
657  public static final byte[] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
658
659  /**
660   * Last row in a table.
661   */
662  public static final byte[] EMPTY_END_ROW = EMPTY_BYTE_ARRAY;
663
664  /**
665   * Used by scanners and others when they're trying to detect the end of a table
666   */
667  public static final byte[] LAST_ROW = EMPTY_BYTE_ARRAY;
668
669  /**
670   * Max length a row can have because of the limitation in TFile.
671   */
672  public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
673
674  /**
675   * Timestamp to use when we want to refer to the latest cell. This is the timestamp sent by
676   * clients when no timestamp is specified on commit.
677   */
678  public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
679
680  /**
681   * Timestamp to use when we want to refer to the oldest cell. Special! Used in fake Cells only.
682   * Should never be the timestamp on an actual Cell returned to a client.
683   * @deprecated Should not be public since hbase-1.3.0. For internal use only. Move internal to
684   *             Scanners flagged as special timestamp value never to be returned as timestamp on a
685   *             Cell.
686   */
687  @Deprecated
688  public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
689
690  /**
691   * LATEST_TIMESTAMP in bytes form
692   */
693  public static final byte[] LATEST_TIMESTAMP_BYTES = {
694    // big-endian
695    (byte) (LATEST_TIMESTAMP >>> 56), (byte) (LATEST_TIMESTAMP >>> 48),
696    (byte) (LATEST_TIMESTAMP >>> 40), (byte) (LATEST_TIMESTAMP >>> 32),
697    (byte) (LATEST_TIMESTAMP >>> 24), (byte) (LATEST_TIMESTAMP >>> 16),
698    (byte) (LATEST_TIMESTAMP >>> 8), (byte) LATEST_TIMESTAMP, };
699
700  /**
701   * Define for 'return-all-versions'.
702   */
703  public static final int ALL_VERSIONS = Integer.MAX_VALUE;
704
705  /**
706   * Unlimited time-to-live.
707   */
708  // public static final int FOREVER = -1;
709  public static final int FOREVER = Integer.MAX_VALUE;
710
711  /**
712   * Seconds in a week
713   */
714  @Deprecated // unused. see HBASE-2692. remove this in 3.0
715  public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
716
717  /**
718   * Seconds in a day, hour and minute
719   */
720  public static final int DAY_IN_SECONDS = 24 * 60 * 60;
721  public static final int HOUR_IN_SECONDS = 60 * 60;
722  public static final int MINUTE_IN_SECONDS = 60;
723
724  /**
725   * KB, MB, GB, TB equivalent to how many bytes
726   */
727  public static final long KB_IN_BYTES = 1024;
728  public static final long MB_IN_BYTES = 1024 * KB_IN_BYTES;
729  public static final long GB_IN_BYTES = 1024 * MB_IN_BYTES;
730  public static final long TB_IN_BYTES = 1024 * GB_IN_BYTES;
731
732  // TODO: although the following are referenced widely to format strings for
733  // the shell. They really aren't a part of the public API. It would be
734  // nice if we could put them somewhere where they did not need to be
735  // public. They could have package visibility
736  public static final String NAME = "NAME";
737  public static final String VERSIONS = "VERSIONS";
738  public static final String IN_MEMORY = "IN_MEMORY";
739  public static final String METADATA = "METADATA";
740  public static final String CONFIGURATION = "CONFIGURATION";
741
742  /**
743   * Retrying we multiply hbase.client.pause setting by what we have in this array until we run out
744   * of array items. Retries beyond this use the last number in the array. So, for example, if
745   * hbase.client.pause is 1 second, and maximum retries count hbase.client.retries.number is 10, we
746   * will retry at the following intervals: 1, 2, 3, 5, 10, 20, 40, 100, 100, 100. With 100ms, a
747   * back-off of 200 means 20s
748   */
749  public static final int[] RETRY_BACKOFF =
750    { 1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200 };
751
752  public static final String REGION_IMPL = "hbase.hregion.impl";
753
754  /**
755   * Scope tag for locally scoped data. This data will not be replicated.
756   */
757  public static final int REPLICATION_SCOPE_LOCAL = 0;
758
759  /**
760   * Scope tag for globally scoped data. This data will be replicated to all peers.
761   */
762  public static final int REPLICATION_SCOPE_GLOBAL = 1;
763
764  /**
765   * Default cluster ID, cannot be used to identify a cluster so a key with this value means it
766   * wasn't meant for replication.
767   */
768  public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L, 0L);
769
770  /**
771   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
772   * Controlled by the client.
773   */
774  public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
775    "hbase.client.scanner.max.result.size";
776
777  /**
778   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
779   * Controlled by the server.
780   */
781  public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
782    "hbase.server.scanner.max.result.size";
783
784  /**
785   * Maximum number of bytes returned when calling a scanner's next method. Note that when a single
786   * row is larger than this limit the row is still returned completely. The default value is 2MB.
787   */
788  public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
789
790  /**
791   * Maximum number of bytes returned when calling a scanner's next method. Note that when a single
792   * row is larger than this limit the row is still returned completely. Safety setting to protect
793   * the region server. The default value is 100MB. (a client would rarely request larger chunks on
794   * purpose)
795   */
796  public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
797
798  /**
799   * Parameter name for client pause value, used mostly as value to wait before running a retry of a
800   * failed get, region lookup, etc.
801   */
802  public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
803
804  /**
805   * Default value of {@link #HBASE_CLIENT_PAUSE}.
806   */
807  public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
808
809  /**
810   * Parameter name for client pause value for special case such as call queue too big, etc.
811   * @deprecated Since 2.5.0, will be removed in 4.0.0. Please use
812   *             hbase.client.pause.server.overloaded instead.
813   */
814  @Deprecated
815  public static final String HBASE_CLIENT_PAUSE_FOR_CQTBE = "hbase.client.pause.cqtbe";
816
817  /**
818   * The maximum number of concurrent connections the client will maintain.
819   */
820  public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
821
822  /**
823   * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
824   */
825  public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
826
827  /**
828   * The maximum number of concurrent connections the client will maintain to a single RegionServer.
829   */
830  public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
831
832  /**
833   * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
834   */
835  public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
836
837  /**
838   * The maximum number of concurrent connections the client will maintain to a single Region.
839   */
840  public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
841
842  /**
843   * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
844   */
845  public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
846
847  /**
848   * The maximum number of concurrent pending RPC requests for one server in process level.
849   */
850  public static final String HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD =
851    "hbase.client.perserver.requests.threshold";
852
853  /**
854   * Default value of {@link #HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD}.
855   */
856  public static final int DEFAULT_HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD = Integer.MAX_VALUE;
857
858  /**
859   * Parameter name for server pause value, used mostly as value to wait before running a retry of a
860   * failed operation.
861   */
862  public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
863
864  /**
865   * Default value of {@link #HBASE_SERVER_PAUSE}.
866   */
867  public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
868
869  /**
870   * Parameter name for maximum retries, used as maximum for all retryable operations such as
871   * fetching of the root region from root region server, getting a cell's value, starting a row
872   * update, etc.
873   */
874  public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
875
876  /**
877   * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
878   */
879  public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 15;
880
881  public static final String HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER =
882    "hbase.client.serverside.retries.multiplier";
883
884  public static final int DEFAULT_HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER = 3;
885
886  /**
887   * Parameter name to set the default scanner caching for all clients.
888   */
889  public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
890
891  /**
892   * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
893   */
894  public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
895
896  /**
897   * Parameter name for number of rows that will be fetched when calling next on a scanner if it is
898   * not served from memory. Higher caching values will enable faster scanners but will eat up more
899   * memory and some calls of next may take longer and longer times when the cache is empty.
900   */
901  public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
902
903  /**
904   * Default value of {@link #HBASE_META_SCANNER_CACHING}.
905   */
906  public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
907
908  /**
909   * Parameter name for number of versions, kept by meta table.
910   */
911  public static final String HBASE_META_VERSIONS = "hbase.meta.versions";
912
913  /**
914   * Default value of {@link #HBASE_META_VERSIONS}.
915   */
916  public static final int DEFAULT_HBASE_META_VERSIONS = 3;
917
918  /**
919   * Parameter name for number of versions, kept by meta table.
920   */
921  public static final String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
922
923  /**
924   * Default value of {@link #HBASE_META_BLOCK_SIZE}.
925   */
926  public static final int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
927
928  /**
929   * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
930   * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
931   * for all intents and purposes, are the same except for their instance ids, then they will not be
932   * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
933   * even if the instance ids are the same, it could result in non-shared
934   * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
935   * differ.
936   */
937  public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
938
939  /**
940   * The client scanner timeout period in milliseconds.
941   */
942  public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD =
943    "hbase.client.scanner.timeout.period";
944
945  /**
946   * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
947   * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
948   */
949  @Deprecated
950  public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
951    "hbase.regionserver.lease.period";
952
953  /**
954   * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
955   */
956  public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
957
958  /**
959   * timeout for each RPC
960   */
961  public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
962
963  /**
964   * timeout for each read RPC
965   */
966  public static final String HBASE_RPC_READ_TIMEOUT_KEY = "hbase.rpc.read.timeout";
967
968  /**
969   * timeout for each write RPC
970   */
971  public static final String HBASE_RPC_WRITE_TIMEOUT_KEY = "hbase.rpc.write.timeout";
972
973  /**
974   * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
975   */
976  public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
977
978  /**
979   * timeout for short operation RPC
980   */
981  public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
982    "hbase.rpc.shortoperation.timeout";
983
984  /**
985   * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
986   */
987  public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
988
989  /**
990   * Retry pause time for short operation RPC
991   */
992  public static final String HBASE_RPC_SHORTOPERATION_RETRY_PAUSE_TIME =
993    "hbase.rpc.shortoperation.retry.pause.time";
994
995  /**
996   * Default value of {@link #HBASE_RPC_SHORTOPERATION_RETRY_PAUSE_TIME}
997   */
998  public static final long DEFAULT_HBASE_RPC_SHORTOPERATION_RETRY_PAUSE_TIME = 1000;
999
1000  /**
1001   * Value indicating the server name was saved with no sequence number.
1002   */
1003  public static final long NO_SEQNUM = -1;
1004
1005  /**
1006   * Registry implementation to be used on the client side.
1007   */
1008  public static final String CLIENT_CONNECTION_REGISTRY_IMPL_CONF_KEY =
1009    "hbase.client.registry.impl";
1010
1011  /*
1012   * cluster replication constants.
1013   */
1014  public static final String REPLICATION_SOURCE_SERVICE_CLASSNAME =
1015    "hbase.replication.source.service";
1016  public static final String REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
1017  public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
1018    "org.apache.hadoop.hbase.replication.regionserver.Replication";
1019  public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
1020  public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
1021  /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
1022  public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
1023  /**
1024   * Max total size of buffered entries in all replication peers. It will prevent server getting OOM
1025   * if there are many peers. Default value is 256MB which is four times to default
1026   * replication.source.size.capacity.
1027   */
1028  public static final String REPLICATION_SOURCE_TOTAL_BUFFER_KEY = "replication.total.buffer.quota";
1029
1030  public static final int REPLICATION_SOURCE_TOTAL_BUFFER_DFAULT = 256 * 1024 * 1024;
1031
1032  /** Configuration key for ReplicationSource shipeEdits timeout */
1033  public static final String REPLICATION_SOURCE_SHIPEDITS_TIMEOUT =
1034    "replication.source.shipedits.timeout";
1035  public static final int REPLICATION_SOURCE_SHIPEDITS_TIMEOUT_DFAULT = 60000;
1036
1037  /**
1038   * Directory where the source cluster file system client configuration are placed which is used by
1039   * sink cluster to copy HFiles from source cluster file system
1040   */
1041  public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
1042
1043  /** Maximum time to retry for a failed bulk load request */
1044  public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
1045
1046  /** HBCK special code name used as server name when manipulating ZK nodes */
1047  @Deprecated // unused. see HBASE-3789. remove this in 3.0
1048  public static final String HBCK_CODE_NAME = "HBCKServerName";
1049
1050  public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
1051    "hbase.regionserver.hostname.seen.by.master";
1052
1053  public static final String HBASE_MASTER_LOGCLEANER_PLUGINS = "hbase.master.logcleaner.plugins";
1054
1055  public static final String HBASE_REGION_SPLIT_POLICY_KEY =
1056    "hbase.regionserver.region.split.policy";
1057
1058  /** Whether nonces are enabled; default is true. */
1059  public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
1060
1061  /**
1062   * Configuration key for the size of the block cache
1063   */
1064  public static final String HFILE_BLOCK_CACHE_SIZE_KEY = "hfile.block.cache.size";
1065
1066  public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
1067
1068  /**
1069   * Configuration key for the memory size of the block cache
1070   */
1071  public static final String HFILE_BLOCK_CACHE_MEMORY_SIZE_KEY = "hfile.block.cache.memory.size";
1072
1073  /**
1074   * Configuration key for setting the fix size of the block size, default do nothing and it should
1075   * be explicitly set by user or only used within ClientSideRegionScanner. if it's set less than
1076   * current max on heap size, it overrides the max size of block cache
1077   */
1078  public static final String HFILE_ONHEAP_BLOCK_CACHE_FIXED_SIZE_KEY =
1079    "hfile.onheap.block.cache.fixed.size";
1080  public static final long HFILE_ONHEAP_BLOCK_CACHE_FIXED_SIZE_DEFAULT = 0L;
1081  public static final long HBASE_CLIENT_SCANNER_ONHEAP_BLOCK_CACHE_FIXED_SIZE_DEFAULT =
1082    32 * 1024 * 1024L;
1083
1084  /**
1085   * Configuration key for setting pread must read both necessaryLen and extraLen, default is
1086   * disabled. This is an optimized flag for reading HFile from blob storage.
1087   */
1088  public static final String HFILE_PREAD_ALL_BYTES_ENABLED_KEY = "hfile.pread.all.bytes.enabled";
1089  public static final boolean HFILE_PREAD_ALL_BYTES_ENABLED_DEFAULT = false;
1090
1091  /*
1092   * Default minimum fraction (20%) of free heap required for RegionServer startup, used only when
1093   * 'hbase.regionserver.free.heap.min.memory.size' is not explicitly set.
1094   */
1095  public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
1096
1097  /**
1098   * @deprecated It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1099   */
1100  @Deprecated
1101  public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
1102    Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
1103
1104  /**
1105   * <pre>
1106   * Pattern that matches a coprocessor specification. Form is:
1107   * {@code <coprocessor jar file location> '|' <class name> ['|' <priority> ['|' <arguments>]]}
1108   * where arguments are {@code <KEY> '=' <VALUE> [,...]}
1109   * For example: {@code hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2}
1110   * </pre>
1111   *
1112   * @deprecated It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1113   */
1114  @Deprecated
1115  public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
1116    Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
1117  /**
1118   * @deprecated It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1119   */
1120  @Deprecated
1121  public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
1122  /**
1123   * @deprecated It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1124   */
1125  @Deprecated
1126  public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
1127  /**
1128   * @deprecated It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1129   */
1130  @Deprecated
1131  public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile("("
1132    + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" + CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
1133  public static final String CP_HTD_ATTR_INCLUSION_KEY =
1134    "hbase.coprocessor.classloader.included.classes";
1135
1136  /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
1137  public static final int SOCKET_RETRY_WAIT_MS = 200;
1138
1139  /** Host name of the local machine */
1140  public static final String LOCALHOST = "localhost";
1141
1142  /**
1143   * If this parameter is set to true, then hbase will read data and then verify checksums. Checksum
1144   * verification inside hdfs will be switched off. However, if the hbase-checksum verification
1145   * fails, then it will switch back to using hdfs checksums for verifiying data that is being read
1146   * from storage. If this parameter is set to false, then hbase will not verify any checksums,
1147   * instead it will depend on checksum verification being done in the hdfs client.
1148   */
1149  public static final String HBASE_CHECKSUM_VERIFICATION = "hbase.regionserver.checksum.verify";
1150
1151  public static final String LOCALHOST_IP = "127.0.0.1";
1152
1153  public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
1154  public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
1155
1156  /*
1157   * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT: -1 => Disable aborting 0 => Abort if even a
1158   * single handler has died 0.x => Abort only when this percent of handlers have died 1 => Abort
1159   * only all of the handers have died
1160   */
1161  public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
1162    "hbase.regionserver.handler.abort.on.error.percent";
1163  public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
1164
1165  // High priority handlers to deal with admin requests and system table operation requests
1166  public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
1167    "hbase.regionserver.metahandler.count";
1168  public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
1169
1170  public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
1171    "hbase.regionserver.replication.handler.count";
1172  public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
1173  public static final String REGION_SERVER_BULKLOAD_HANDLER_COUNT =
1174    "hbase.regionserver.bulkload.handler.count";
1175  public static final int DEFAULT_REGION_SERVER_BULKLOAD_HANDLER_COUNT = 0;
1176  // Meta Transition handlers to deal with meta ReportRegionStateTransitionRequest. Meta transition
1177  // should be dealt with in a separate handler in case blocking other region's transition.
1178  public static final String MASTER_META_TRANSITION_HANDLER_COUNT =
1179    "hbase.master.meta.transition.handler.count";
1180  public static final int MASTER__META_TRANSITION_HANDLER_COUNT_DEFAULT = 1;
1181
1182  @Deprecated // unused. see HBASE-10569. remove this in 3.0
1183  public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
1184  @Deprecated // unused. see HBASE-10569. remove this in 3.0
1185  public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
1186
1187  /** Conf key that specifies timeout value to wait for a region ready */
1188  @Deprecated // unused. see HBASE-13616. remove this in 3.0
1189  public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
1190    "hbase.master.log.replay.wait.region.timeout";
1191
1192  /** Conf key for enabling meta replication */
1193  public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
1194  public static final boolean DEFAULT_USE_META_REPLICAS = false;
1195
1196  /**
1197   * @deprecated Since 2.4.0, will be removed in 4.0.0. Please change the meta replicas number by
1198   *             altering meta table, i.e, set a new 'region replication' number and call
1199   *             modifyTable.
1200   */
1201  @Deprecated
1202  public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
1203  /**
1204   * @deprecated Since 2.4.0, will be removed in 4.0.0. Please change the meta replicas number by
1205   *             altering meta table, i.e, set a new 'region replication' number and call
1206   *             modifyTable.
1207   */
1208  @Deprecated
1209  public static final int DEFAULT_META_REPLICA_NUM = 1;
1210
1211  /**
1212   * The name of the configuration parameter that specifies the number of bytes in a newly created
1213   * checksum chunk.
1214   */
1215  public static final String BYTES_PER_CHECKSUM = "hbase.hstore.bytes.per.checksum";
1216
1217  /**
1218   * The name of the configuration parameter that specifies the name of an algorithm that is used to
1219   * compute checksums for newly created blocks.
1220   */
1221  public static final String CHECKSUM_TYPE_NAME = "hbase.hstore.checksum.algorithm";
1222
1223  /** Enable file permission modification from standard hbase */
1224  public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
1225  /** File permission umask to use when creating hbase data files */
1226  public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
1227
1228  /** Configuration name of WAL Compression */
1229  public static final String ENABLE_WAL_COMPRESSION = "hbase.regionserver.wal.enablecompression";
1230
1231  /**
1232   * Configuration name of WAL storage policy Valid values are: HOT, COLD, WARM, ALL_SSD, ONE_SSD,
1233   * LAZY_PERSIST See
1234   * http://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html
1235   */
1236  public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
1237  /**
1238   * "NONE" is not a valid storage policy and means we defer the policy to HDFS. @see
1239   * <a href="https://issues.apache.org/jira/browse/HBASE-20691">HBASE-20691</a>
1240   */
1241  public static final String DEFER_TO_HDFS_STORAGE_POLICY = "NONE";
1242  /** By default we defer the WAL storage policy to HDFS */
1243  public static final String DEFAULT_WAL_STORAGE_POLICY = DEFER_TO_HDFS_STORAGE_POLICY;
1244
1245  /** Region in Transition metrics threshold time */
1246  public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1247    "hbase.metrics.rit.stuck.warning.threshold";
1248
1249  public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1250
1251  /** delimiter used between portions of a region name */
1252  public static final int DELIMITER = ',';
1253
1254  /**
1255   * QOS attributes: these attributes are used to demarcate RPC call processing by different set of
1256   * handlers. For example, HIGH_QOS tagged methods are handled by high priority handlers.
1257   */
1258  // normal_QOS < replication_QOS < replay_QOS < QOS_threshold < admin_QOS < high_QOS < meta_QOS
1259  public static final int PRIORITY_UNSET = -1;
1260  public static final int NORMAL_QOS = 0;
1261  public static final int REPLICATION_QOS = 5;
1262  public static final int BULKLOAD_QOS = 4;
1263  /**
1264   * @deprecated since 3.0.0, will be removed in 4.0.0. DLR has been purged for a long time and
1265   *             region replication has its own 'replay' method.
1266   */
1267  @Deprecated
1268  public static final int REPLAY_QOS = 6;
1269  public static final int QOS_THRESHOLD = 10;
1270  public static final int ADMIN_QOS = 100;
1271  public static final int HIGH_QOS = 200;
1272  public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1273  /**
1274   * @deprecated the name "META_QOS" is a bit ambiguous, actually only meta region transition can
1275   *             use this priority, and you should not use this directly. Will be removed in 3.0.0.
1276   */
1277  @Deprecated
1278  public static final int META_QOS = 300;
1279
1280  /** Directory under /hbase where archived hfiles are stored */
1281  public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1282
1283  /**
1284   * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for remaining
1285   * snapshot constants; this is here to keep HConstants dependencies at a minimum and
1286   * uni-directional.
1287   */
1288  public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1289
1290  /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1291  public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1292
1293  /** Temporary directory used for table creation and deletion */
1294  public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1295  /**
1296   * The period (in milliseconds) between computing region server point in time metrics
1297   */
1298  public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1299  public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1300  /** Directories that are not HBase table directories */
1301  public static final List<String> HBASE_NON_TABLE_DIRS = Collections.unmodifiableList(
1302    Arrays.asList(new String[] { HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME }));
1303
1304  /**
1305   * Directories that are not HBase user table directories.
1306   * @deprecated Since hbase-2.3.0; no replacement as not used any more (internally at least)
1307   */
1308  @Deprecated
1309  public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1310    Collections.unmodifiableList(Arrays.asList(
1311      (String[]) ArrayUtils.addAll(new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1312        HBASE_NON_TABLE_DIRS.toArray())));
1313
1314  /** Health script related settings. */
1315  public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1316  public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1317  public static final String HEALTH_CHORE_WAKE_FREQ = "hbase.node.health.script.frequency";
1318  public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1319  /**
1320   * The maximum number of health check failures a server can encounter consecutively.
1321   */
1322  public static final String HEALTH_FAILURE_THRESHOLD = "hbase.node.health.failure.threshold";
1323  public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1324
1325  /**
1326   * Setting to activate, or not, the publication of the status by the master. Default notification
1327   * is by a multicast message.
1328   */
1329  public static final String STATUS_PUBLISHED = "hbase.status.published";
1330  public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1331
1332  /**
1333   * IP to use for the multicast status messages between the master and the clients. The default
1334   * address is chosen as one among others within the ones suitable for multicast messages.
1335   */
1336  public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1337  public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1338
1339  /**
1340   * The address to use for binding the local socket for receiving multicast. Defaults to 0.0.0.0.
1341   * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1342   */
1343  public static final String STATUS_MULTICAST_BIND_ADDRESS =
1344    "hbase.status.multicast.bind.address.ip";
1345  public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1346
1347  /**
1348   * The port to use for the multicast messages.
1349   */
1350  public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1351  public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1352
1353  /**
1354   * The network interface name to use for the multicast messages.
1355   */
1356  public static final String STATUS_MULTICAST_NI_NAME = "hbase.status.multicast.ni.name";
1357
1358  /**
1359   * The address to use for binding the local socket for sending multicast. Defaults to 0.0.0.0.
1360   */
1361  public static final String STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS =
1362    "hbase.status.multicast.publisher.bind.address.ip";
1363  public static final String DEFAULT_STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS = "0.0.0.0";
1364
1365  public static final long NO_NONCE = 0;
1366
1367  /** Default cipher for encryption */
1368  public static final String CIPHER_AES = "AES";
1369
1370  /** Configuration key for the crypto algorithm provider, a class name */
1371  public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1372
1373  /** Configuration key for the crypto key provider, a class name */
1374  public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1375
1376  /** Configuration key for the crypto key provider parameters */
1377  public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1378    "hbase.crypto.keyprovider.parameters";
1379
1380  /** Configuration key for the name of the master key for the cluster, a string */
1381  public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1382
1383  /** Configuration key for the name of the alternate master key for the cluster, a string */
1384  public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1385    "hbase.crypto.master.alternate.key.name";
1386
1387  /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1388  public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1389
1390  /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1391  public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1392
1393  /** Configuration key for the algorithm used for creating jks key, a string */
1394  public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1395
1396  /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1397  public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1398    "hbase.crypto.alternate.key.algorithm";
1399
1400  /** Configuration key for enabling WAL encryption, a boolean */
1401  public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1402
1403  /** Configuration key for setting RPC codec class name */
1404  public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1405
1406  /** Configuration key for setting replication codec class name */
1407  public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1408
1409  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1410  public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1411    "hbase.replication.source.maxthreads";
1412
1413  /**
1414   * Drop edits for tables that been deleted from the replication source and target
1415   * @deprecated moved it into HBaseInterClusterReplicationEndpoint
1416   */
1417  @Deprecated
1418  public static final String REPLICATION_DROP_ON_DELETED_TABLE_KEY =
1419    "hbase.replication.drop.on.deleted.table";
1420
1421  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1422  public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1423
1424  /** Configuration key for SplitLog manager timeout */
1425  public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1426
1427  /**
1428   * Configuration keys for Bucket cache
1429   */
1430  // TODO moving these bucket cache implementation specific configs to this level is violation of
1431  // encapsulation. But as these has to be referred from hbase-common and bucket cache
1432  // sits in hbase-server, there were no other go! Can we move the cache implementation to
1433  // hbase-common?
1434
1435  /**
1436   * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path to the
1437   * file that will host the file-based cache. See BucketCache#getIOEngineFromName() for list of
1438   * supported ioengine options.
1439   * <p>
1440   * Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1441   */
1442  public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1443
1444  /**
1445   * When using bucket cache, it is the capacity in megabytes of the cache.
1446   */
1447  public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1448
1449  /**
1450   * If the chosen ioengine can persist its state across restarts, the path to the file to persist
1451   * to. This file is NOT the data file. It is a file into which we will serialize the map of what
1452   * is in the data file. For example, if you pass the following argument as
1453   * BUCKET_CACHE_IOENGINE_KEY ("hbase.bucketcache.ioengine"),
1454   * <code>file:/tmp/bucketcache.data </code>, then we will write the bucketcache data to the file
1455   * <code>/tmp/bucketcache.data</code> but the metadata on where the data is in the supplied file
1456   * is an in-memory map that needs to be persisted across restarts. Where to store this in-memory
1457   * state is what you supply here: e.g. <code>/tmp/bucketcache.map</code>.
1458   */
1459  public static final String BUCKET_CACHE_PERSISTENT_PATH_KEY = "hbase.bucketcache.persistent.path";
1460
1461  /**
1462   * HConstants for fast fail on the client side follow
1463   */
1464  /**
1465   * Config for enabling/disabling the fast fail mode.
1466   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1467   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1468   */
1469  @Deprecated
1470  public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1471    "hbase.client.fast.fail.mode.enabled";
1472
1473  /**
1474   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1475   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1476   */
1477  @Deprecated
1478  public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT = false;
1479
1480  /**
1481   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1482   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1483   */
1484  @Deprecated
1485  public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1486    "hbase.client.fastfail.threshold";
1487
1488  /**
1489   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1490   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1491   */
1492  @Deprecated
1493  public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT = 60000;
1494
1495  /**
1496   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1497   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1498   */
1499  @Deprecated
1500  public static final String HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS =
1501    "hbase.client.failure.map.cleanup.interval";
1502
1503  /**
1504   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1505   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1506   */
1507  @Deprecated
1508  public static final long HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS_DEFAULT = 600000;
1509
1510  /**
1511   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1512   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1513   */
1514  @Deprecated
1515  public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1516    "hbase.client.fast.fail.cleanup.duration";
1517
1518  /**
1519   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1520   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1521   */
1522  @Deprecated
1523  public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT = 600000;
1524
1525  /**
1526   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1527   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1528   */
1529  @Deprecated
1530  public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1531    "hbase.client.fast.fail.interceptor.impl";
1532
1533  /**
1534   * @deprecated since 2.4.0 and in 3.0.0, to be removed in 4.0.0, replaced by procedure-based
1535   *             distributed WAL splitter; see SplitWALManager.
1536   */
1537  @Deprecated
1538  public static final String HBASE_SPLIT_WAL_COORDINATED_BY_ZK = "hbase.split.wal.zk.coordinated";
1539
1540  /**
1541   * @deprecated since 2.4.0 and in 3.0.0, to be removed in 4.0.0.
1542   */
1543  @Deprecated
1544  public static final boolean DEFAULT_HBASE_SPLIT_COORDINATED_BY_ZK = false;
1545
1546  public static final String HBASE_SPLIT_WAL_MAX_SPLITTER = "hbase.regionserver.wal.max.splitters";
1547
1548  public static final int DEFAULT_HBASE_SPLIT_WAL_MAX_SPLITTER = 2;
1549
1550  /**
1551   * Config key for if the server should send backpressure and if the client should listen to that
1552   * backpressure from the server
1553   */
1554  public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1555  public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1556
1557  public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1558    "hbase.heap.occupancy.low_water_mark";
1559  public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1560  public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1561    "hbase.heap.occupancy.high_water_mark";
1562  public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1563
1564  /**
1565   * The max number of threads used for splitting storefiles in parallel during the region split
1566   * process.
1567   */
1568  public static final String REGION_SPLIT_THREADS_MAX =
1569    "hbase.regionserver.region.split.threads.max";
1570
1571  /** Canary config keys */
1572  // TODO: Move these defines to Canary Class
1573  public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1574
1575  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1576    "hbase.canary.write.perserver.regions.lowerLimit";
1577
1578  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1579    "hbase.canary.write.perserver.regions.upperLimit";
1580
1581  public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1582
1583  public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1584    "hbase.canary.write.table.check.period";
1585
1586  public static final String HBASE_CANARY_READ_RAW_SCAN_KEY = "hbase.canary.read.raw.enabled";
1587
1588  public static final String HBASE_CANARY_READ_ALL_CF = "hbase.canary.read.all.column.famliy";
1589  /**
1590   * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1591   */
1592  public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1593  public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1594    "hbase.zookeeper.client.kerberos.principal";
1595  public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1596  public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1597    "hbase.zookeeper.server.kerberos.principal";
1598
1599  /** Config key for hbase temporary directory in hdfs */
1600  public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1601  public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY =
1602    "/user/" + System.getProperty("user.name") + "/hbase-staging";
1603
1604  public static final String SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT =
1605    "hbase.snapshot.restore.take.failsafe.snapshot";
1606  public static final boolean DEFAULT_SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT = true;
1607
1608  public static final String SNAPSHOT_RESTORE_FAILSAFE_NAME =
1609    "hbase.snapshot.restore.failsafe.name";
1610  public static final String DEFAULT_SNAPSHOT_RESTORE_FAILSAFE_NAME =
1611    "hbase-failsafe-{snapshot.name}-{restore.timestamp}";
1612
1613  public static final String DEFAULT_LOSSY_COUNTING_ERROR_RATE =
1614    "hbase.util.default.lossycounting.errorrate";
1615  public static final String NOT_IMPLEMENTED = "Not implemented";
1616
1617  // Default TTL - FOREVER
1618  public static final long DEFAULT_SNAPSHOT_TTL = 0;
1619
1620  // User defined Default TTL config key
1621  public static final String DEFAULT_SNAPSHOT_TTL_CONFIG_KEY = "hbase.master.snapshot.ttl";
1622
1623  // Soft drop for destructive table actions configuration
1624  public static final String SNAPSHOT_BEFORE_DESTRUCTIVE_ACTION_ENABLED_KEY =
1625    "hbase.snapshot.before.destructive.action.enabled";
1626  public static final boolean DEFAULT_SNAPSHOT_BEFORE_DESTRUCTIVE_ACTION_ENABLED = false;
1627
1628  public static final String SNAPSHOT_BEFORE_DESTRUCTIVE_ACTION_TTL_KEY =
1629    "hbase.snapshot.before.destructive.action.ttl";
1630  public static final long DEFAULT_SNAPSHOT_BEFORE_DESTRUCTIVE_ACTION_TTL = 86400; // 1 day
1631
1632  // Table-level attribute name for recovery snapshot TTL override
1633  public static final String TABLE_RECOVERY_SNAPSHOT_TTL_KEY = "RECOVERY_SNAPSHOT_TTL";
1634
1635  // Regions Recovery based on high storeFileRefCount threshold value
1636  public static final String STORE_FILE_REF_COUNT_THRESHOLD =
1637    "hbase.regions.recovery.store.file.ref.count";
1638
1639  // default -1 indicates there is no threshold on high storeRefCount
1640  public static final int DEFAULT_STORE_FILE_REF_COUNT_THRESHOLD = -1;
1641
1642  public static final String REGIONS_RECOVERY_INTERVAL =
1643    "hbase.master.regions.recovery.check.interval";
1644
1645  public static final int DEFAULT_REGIONS_RECOVERY_INTERVAL = 1200 * 1000; // Default 20 min
1646
1647  /**
1648   * Configurations for master executor services.
1649   */
1650  public static final String MASTER_OPEN_REGION_THREADS =
1651    "hbase.master.executor.openregion.threads";
1652  public static final int MASTER_OPEN_REGION_THREADS_DEFAULT = 5;
1653
1654  public static final String MASTER_CLOSE_REGION_THREADS =
1655    "hbase.master.executor.closeregion.threads";
1656  public static final int MASTER_CLOSE_REGION_THREADS_DEFAULT = 5;
1657
1658  public static final String MASTER_SERVER_OPERATIONS_THREADS =
1659    "hbase.master.executor.serverops.threads";
1660  public static final int MASTER_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1661
1662  /**
1663   * Number of threads used to dispatch merge operations to the regionservers.
1664   */
1665  public static final String MASTER_MERGE_DISPATCH_THREADS =
1666    "hbase.master.executor.merge.dispatch.threads";
1667  public static final int MASTER_MERGE_DISPATCH_THREADS_DEFAULT = 2;
1668
1669  public static final String MASTER_META_SERVER_OPERATIONS_THREADS =
1670    "hbase.master.executor.meta.serverops.threads";
1671  public static final int MASTER_META_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1672
1673  public static final String MASTER_LOG_REPLAY_OPS_THREADS =
1674    "hbase.master.executor.logreplayops.threads";
1675  public static final int MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT = 10;
1676
1677  public static final int DEFAULT_SLOW_LOG_RING_BUFFER_SIZE = 256;
1678
1679  public static final String SLOW_LOG_BUFFER_ENABLED_KEY =
1680    "hbase.regionserver.slowlog.buffer.enabled";
1681  public static final boolean DEFAULT_ONLINE_LOG_PROVIDER_ENABLED = false;
1682
1683  /** The slowlog info family as a string */
1684  private static final String SLOWLOG_INFO_FAMILY_STR = "info";
1685
1686  /** The slowlog info family */
1687  public static final byte[] SLOWLOG_INFO_FAMILY = Bytes.toBytes(SLOWLOG_INFO_FAMILY_STR);
1688
1689  public static final String SLOW_LOG_SYS_TABLE_ENABLED_KEY =
1690    "hbase.regionserver.slowlog.systable.enabled";
1691  public static final boolean DEFAULT_SLOW_LOG_SYS_TABLE_ENABLED_KEY = false;
1692
1693  @Deprecated
1694  // since <need to know the version number> and will be removed in <version number>
1695  // Instead use hbase.regionserver.named.queue.chore.duration config property
1696  public static final String SLOW_LOG_SYS_TABLE_CHORE_DURATION_KEY =
1697    "hbase.slowlog.systable.chore.duration";
1698  // Default 10 mins.
1699  public static final int DEFAULT_SLOW_LOG_SYS_TABLE_CHORE_DURATION = 10 * 60 * 1000;
1700
1701  public static final String SLOW_LOG_SCAN_PAYLOAD_ENABLED = "hbase.slowlog.scan.payload.enabled";
1702  public static final boolean SLOW_LOG_SCAN_PAYLOAD_ENABLED_DEFAULT = false;
1703
1704  public static final String SHELL_TIMESTAMP_FORMAT_EPOCH_KEY =
1705    "hbase.shell.timestamp.format.epoch";
1706
1707  public static final boolean DEFAULT_SHELL_TIMESTAMP_FORMAT_EPOCH = false;
1708
1709  /**
1710   * Number of rows in a batch operation above which a warning will be logged.
1711   */
1712  public static final String BATCH_ROWS_THRESHOLD_NAME = "hbase.rpc.rows.warning.threshold";
1713
1714  /**
1715   * Default value of {@link #BATCH_ROWS_THRESHOLD_NAME}
1716   */
1717  public static final int BATCH_ROWS_THRESHOLD_DEFAULT = 5000;
1718
1719  /**
1720   * In some scenarios, such as the elastic scaling scenario on the cloud, the HBase client may not
1721   * be able to resolve the hostname of the newly added node. If the network is interconnected, the
1722   * client can actually access the HBase cluster nodes through ip. However, since the HBase client
1723   * obtains the Master/RS address info from or the ZK or the meta table, so the Master/RS of the
1724   * HBase cluster needs to expose the service with ip instead of the hostname. Therefore, We can
1725   * use hostname by default, but at the same time, we can also provide a config to support whether
1726   * to use ip for Master/RS service. See HBASE-27304 for details.
1727   */
1728  public final static String HBASE_SERVER_USEIP_ENABLED_KEY = "hbase.server.useip.enabled";
1729
1730  /**
1731   * Default value of {@link #HBASE_SERVER_USEIP_ENABLED_KEY}
1732   */
1733  public final static boolean HBASE_SERVER_USEIP_ENABLED_DEFAULT = false;
1734
1735  /**
1736   * Should the HMaster reject hosts of decommissioned RegionServers, bypass matching their port and
1737   * startcode parts of their ServerName or not? When True, the HMaster will reject a RegionServer's
1738   * request to `reportForDuty` if it's hostname exists in the list of decommissioned RegionServers
1739   * it maintains internally. Added in HBASE-28342.
1740   */
1741  public final static String REJECT_DECOMMISSIONED_HOSTS_KEY =
1742    "hbase.master.reject.decommissioned.hosts";
1743
1744  /**
1745   * Default value of {@link #REJECT_DECOMMISSIONED_HOSTS_KEY}
1746   */
1747  public final static boolean REJECT_DECOMMISSIONED_HOSTS_DEFAULT = false;
1748
1749  private HConstants() {
1750    // Can't be instantiated with this ctor.
1751  }
1752}