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;
029
030import org.apache.commons.lang3.ArrayUtils;
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
058   * splitting code, one per 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
064   * splitting code, one per region
065   */
066  public static final String RECOVERED_HFILES_DIR = "recovered.hfiles";
067
068  /**
069   * The first four bytes of Hadoop RPC connections
070   */
071  public static final byte[] RPC_HEADER = new byte[] { 'H', 'B', 'a', 's' };
072  public static final byte RPC_CURRENT_VERSION = 0;
073
074  // HFileBlock constants. TODO!!!! THESE DEFINES BELONG IN HFILEBLOCK, NOT UP HERE.
075  // Needed down in hbase-common though by encoders but these encoders should not be dealing
076  // in the internals of hfileblocks. Fix encapsulation.
077
078  /** The size data structures with minor version is 0 */
079  public static final int HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM = MAGIC_LENGTH + 2 * Bytes.SIZEOF_INT
080      + Bytes.SIZEOF_LONG;
081  /** The size of a version 2 HFile block header, minor version 1.
082   * There is a 1 byte checksum type, followed by a 4 byte bytesPerChecksum
083   * followed by another 4 byte value to store sizeofDataOnDisk.
084   */
085  public static final int HFILEBLOCK_HEADER_SIZE = HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM +
086    Bytes.SIZEOF_BYTE + 2 * Bytes.SIZEOF_INT;
087  /** Just an array of bytes of the right size. */
088  public static final byte[] HFILEBLOCK_DUMMY_HEADER = new byte[HFILEBLOCK_HEADER_SIZE];
089
090  //End HFileBlockConstants.
091
092  /**
093   * Status codes used for return values of bulk operations.
094   */
095  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
096  public enum OperationStatusCode {
097    NOT_RUN,
098    SUCCESS,
099    BAD_FAMILY,
100    STORE_TOO_BUSY,
101    SANITY_CHECK_FAILURE,
102    FAILURE
103  }
104
105  /** long constant for zero */
106  public static final Long ZERO_L = Long.valueOf(0L);
107  public static final String NINES = "99999999999999";
108  public static final String ZEROES = "00000000000000";
109
110  // For migration
111
112  /** name of version file */
113  public static final String VERSION_FILE_NAME = "hbase.version";
114
115  /**
116   * Current version of file system.
117   * Version 4 supports only one kind of bloom filter.
118   * Version 5 changes versions in catalog table regions.
119   * Version 6 enables blockcaching on catalog tables.
120   * Version 7 introduces hfile -- hbase 0.19 to 0.20..
121   * Version 8 introduces namespace
122   */
123  // public static final String FILE_SYSTEM_VERSION = "6";
124  public static final String FILE_SYSTEM_VERSION = "8";
125
126  // Configuration parameters
127
128  //TODO: Is having HBase homed on port 60k OK?
129
130  /** Cluster is in distributed mode or not */
131  public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
132
133  /** Config for pluggable load balancers */
134  public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
135
136  /** Config for balancing the cluster by table */
137  public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
138
139  /** Config for the max percent of regions in transition */
140  public static final String HBASE_MASTER_BALANCER_MAX_RIT_PERCENT =
141      "hbase.master.balancer.maxRitPercent";
142
143  /** Default value for the max percent of regions in transition */
144  public static final double DEFAULT_HBASE_MASTER_BALANCER_MAX_RIT_PERCENT = 1.0;
145
146  /** Config for the max balancing time */
147  public static final String HBASE_BALANCER_MAX_BALANCING = "hbase.balancer.max.balancing";
148
149  /** Config for the balancer period */
150  public static final String HBASE_BALANCER_PERIOD = "hbase.balancer.period";
151
152  /** Default value for the balancer period */
153  public static final int DEFAULT_HBASE_BALANCER_PERIOD = 300000;
154
155  /** The name of the ensemble table */
156  public static final TableName ENSEMBLE_TABLE_NAME = TableName.valueOf("hbase:ensemble");
157
158  /** Config for pluggable region normalizer */
159  public static final String HBASE_MASTER_NORMALIZER_CLASS =
160    "hbase.master.normalizer.class";
161
162  /** Cluster is standalone or pseudo-distributed */
163  public static final boolean CLUSTER_IS_LOCAL = false;
164
165  /** Cluster is fully-distributed */
166  @Deprecated // unused. see HBASE-13636. remove this in 3.0
167  public static final boolean CLUSTER_IS_DISTRIBUTED = true;
168
169  /** Default value for cluster distributed mode */
170  public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
171
172  /** default host address */
173  public static final String DEFAULT_HOST = "0.0.0.0";
174
175  /** Parameter name for port master listens on. */
176  public static final String MASTER_PORT = "hbase.master.port";
177
178  /** default port that the master listens on */
179  public static final int DEFAULT_MASTER_PORT = 16000;
180
181  /** default port for master web api */
182  public static final int DEFAULT_MASTER_INFOPORT = 16010;
183
184  /** Configuration key for master web API port */
185  public static final String MASTER_INFO_PORT = "hbase.master.info.port";
186
187  /** Configuration key for the list of master host:ports **/
188  public static final String MASTER_ADDRS_KEY = "hbase.masters";
189
190  /** Full class name of the Zookeeper based connection registry implementation */
191  public static final String ZK_CONNECTION_REGISTRY_CLASS =
192      "org.apache.hadoop.hbase.client.ZKConnectionRegistry";
193
194  /** Parameter name for the master type being backup (waits for primary to go inactive). */
195  public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
196
197  /**
198   * by default every master is a possible primary master unless the conf explicitly overrides it
199   */
200  public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
201
202  /** Name of ZooKeeper quorum configuration parameter. */
203  public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
204
205  /** Name of ZooKeeper quorum configuration parameter for client to locate meta. */
206  public static final String CLIENT_ZOOKEEPER_QUORUM = "hbase.client.zookeeper.quorum";
207
208  /** Client port of ZooKeeper for client to locate meta */
209  public static final String CLIENT_ZOOKEEPER_CLIENT_PORT =
210      "hbase.client.zookeeper.property.clientPort";
211
212  /** Indicate whether the client ZK are observer nodes of the server ZK */
213  public static final String CLIENT_ZOOKEEPER_OBSERVER_MODE =
214      "hbase.client.zookeeper.observer.mode";
215  /** Assuming client zk not in observer mode and master need to synchronize information */
216  public static final boolean DEFAULT_CLIENT_ZOOKEEPER_OBSERVER_MODE = false;
217
218  /** Common prefix of ZooKeeper configuration properties */
219  public static final String ZK_CFG_PROPERTY_PREFIX =
220      "hbase.zookeeper.property.";
221
222  public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
223      ZK_CFG_PROPERTY_PREFIX.length();
224
225  /**
226   * The ZK client port key in the ZK properties map. The name reflects the
227   * fact that this is not an HBase configuration key.
228   */
229  public static final String CLIENT_PORT_STR = "clientPort";
230
231  /** Parameter name for the client port that the zookeeper listens on */
232  public static final String ZOOKEEPER_CLIENT_PORT =
233      ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
234
235  /**
236   * Will be removed in hbase 3.0
237   * @deprecated use {@link #DEFAULT_ZOOKEEPER_CLIENT_PORT} instead
238   */
239  @Deprecated
240  public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
241
242  /** Default client port that the zookeeper listens on */
243  public static final int DEFAULT_ZOOKEEPER_CLIENT_PORT = 2181;
244
245  /**
246   * Parameter name for the wait time for the recoverable zookeeper
247   */
248  @Deprecated // unused. see HBASE-3065. remove this in 3.0
249  public static final String ZOOKEEPER_RECOVERABLE_WAITTIME =
250      "hbase.zookeeper.recoverable.waittime";
251
252  /** Default wait time for the recoverable zookeeper */
253  @Deprecated // unused. see HBASE-3065. remove this in 3.0
254  public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
255
256  /** Parameter name for the root dir in ZK for this cluster */
257  public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
258
259  public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
260
261  /**
262   * Parameter name for the limit on concurrent client-side zookeeper
263   * connections
264   */
265  public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
266      ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
267
268  /** Parameter name for the ZK data directory */
269  public static final String ZOOKEEPER_DATA_DIR =
270      ZK_CFG_PROPERTY_PREFIX + "dataDir";
271
272  /** Parameter name for the ZK tick time */
273  public static final String ZOOKEEPER_TICK_TIME =
274      ZK_CFG_PROPERTY_PREFIX + "tickTime";
275
276  /**
277   * Will be removed in hbase 3.0
278   * @deprecated use {@link #DEFAULT_ZOOKEEPER_MAX_CLIENT_CNXNS} instead
279   */
280  @Deprecated
281  public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
282
283  /** Default limit on concurrent client-side zookeeper connections */
284  public static final int DEFAULT_ZOOKEEPER_MAX_CLIENT_CNXNS = 300;
285
286  /** Configuration key for ZooKeeper session timeout */
287  public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
288
289  /** Timeout for the ZK sync() call */
290  public static final String ZK_SYNC_BLOCKING_TIMEOUT_MS = "hbase.zookeeper.sync.timeout.millis";
291  // Choice of the default value is based on the following ZK recommendation (from docs). Keeping it
292  // lower lets the callers fail fast in case of any issues.
293  // "The clients view of the system is guaranteed to be up-to-date within a certain time bound.
294  // (On the order of tens of seconds.) Either system changes will be seen by a client within this
295  // bound, or the client will detect a service outage."
296  public static final long ZK_SYNC_BLOCKING_TIMEOUT_DEFAULT_MS = 30 * 1000;
297
298  /** Default value for ZooKeeper session timeout */
299  public static final int DEFAULT_ZK_SESSION_TIMEOUT = 90 * 1000;
300
301  /** Parameter name for port region server listens on. */
302  public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
303
304  /** Default port region server listens on. */
305  public static final int DEFAULT_REGIONSERVER_PORT = 16020;
306
307  /** default port for region server web api */
308  public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
309
310  /** A configuration key for regionserver info port */
311  public static final String REGIONSERVER_INFO_PORT =
312    "hbase.regionserver.info.port";
313
314  /** A flag that enables automatic selection of regionserver info port */
315  public static final String REGIONSERVER_INFO_PORT_AUTO =
316      REGIONSERVER_INFO_PORT + ".auto";
317
318  /** Parameter name for what region server implementation to use. */
319  public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
320
321  /** Parameter name for what master implementation to use. */
322  public static final String MASTER_IMPL= "hbase.master.impl";
323
324  /** Parameter name for what hbase client implementation to use. */
325  @Deprecated // unused. see HBASE-7460. remove this in 3.0
326  public static final String HBASECLIENT_IMPL= "hbase.hbaseclient.impl";
327
328  /** Parameter name for how often threads should wake up */
329  public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
330
331  /** Default value for thread wake frequency */
332  public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
333
334  /** Parameter name for how often we should try to write a version file, before failing */
335  public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
336
337  /** Parameter name for how often we should try to write a version file, before failing */
338  public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
339
340  /** Parameter name and default value for how often a region should perform a major compaction */
341  public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
342  public static final long   DEFAULT_MAJOR_COMPACTION_PERIOD = 1000 * 60 * 60 * 24 * 7; // 7 days
343
344  /**
345   * Parameter name and default value for major compaction jitter.
346   * Used as a multiplier applied to {@link HConstants#MAJOR_COMPACTION_PERIOD}
347   * to cause compaction to occur a given amount of time either side of
348   * {@link HConstants#MAJOR_COMPACTION_PERIOD}.
349   * Default to 0.5 so jitter has us fall evenly either side of when the compaction should run.
350   */
351  public static final String MAJOR_COMPACTION_JITTER = "hbase.hregion.majorcompaction.jitter";
352  public static final float  DEFAULT_MAJOR_COMPACTION_JITTER = 0.50F;
353
354  /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
355  public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
356  public static final int COMPACTION_KV_MAX_DEFAULT = 10;
357
358  /** Parameter name for HBase instance root directory */
359  public static final String HBASE_DIR = "hbase.rootdir";
360
361  /** Parameter name for HBase client IPC pool type */
362  public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
363
364  /** Parameter name for HBase client IPC pool size */
365  public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
366
367  /** Parameter name for HBase client operation timeout. */
368  public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
369
370  /** Parameter name for HBase client meta operation timeout. */
371  public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
372    "hbase.client.meta.operation.timeout";
373
374  /** Default HBase client operation timeout, which is tantamount to a blocking call */
375  public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
376
377  /** Parameter name for HBase client meta replica scan call timeout. */
378  public static final String HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT =
379      "hbase.client.meta.replica.scan.timeout";
380
381  /** Default HBase client meta replica scan call timeout, 1 second */
382  public static final int HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT_DEFAULT = 1000000;
383
384  /** Used to construct the name of the log directory for a region server */
385  public static final String HREGION_LOGDIR_NAME = "WALs";
386
387  /** Used to construct the name of the splitlog directory for a region server */
388  public static final String SPLIT_LOGDIR_NAME = "splitWAL";
389
390  /** Like the previous, but for old logs that are about to be deleted */
391  public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
392
393  /** Staging dir used by bulk load */
394  public static final String BULKLOAD_STAGING_DIR_NAME = "staging";
395
396  public static final String CORRUPT_DIR_NAME = "corrupt";
397
398  /** Used by HBCK to sideline backup data */
399  public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
400
401  /** Any artifacts left from migration can be moved here */
402  public static final String MIGRATION_NAME = ".migration";
403
404  /**
405   * The directory from which co-processor/custom filter jars can be loaded
406   * dynamically by the region servers. This value can be overridden by the
407   * hbase.dynamic.jars.dir config.
408   */
409  @Deprecated // unused. see HBASE-12054. remove this in 3.0
410  public static final String LIB_DIR = "lib";
411
412  /** Used to construct the name of the compaction directory during compaction */
413  public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
414
415  /** Conf key for the max file size after which we split the region */
416  public static final String HREGION_MAX_FILESIZE =
417      "hbase.hregion.max.filesize";
418
419  /** Default maximum file size */
420  public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
421
422  /**
423   * Max size of single row for Get's or Scan's without in-row scanning flag set.
424   */
425  public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
426
427  /**
428   * Default max row size (1 Gb).
429   */
430  public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
431
432  /**
433   * The max number of threads used for opening and closing stores or store
434   * files in parallel
435   */
436  public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
437    "hbase.hstore.open.and.close.threads.max";
438
439  /**
440   * The default number for the max number of threads used for opening and
441   * closing stores or store files in parallel
442   */
443  public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
444
445  /**
446   * Block updates if memstore has hbase.hregion.memstore.block.multiplier
447   * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
448   * runaway memstore during spikes in update traffic.
449   */
450  public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
451          "hbase.hregion.memstore.block.multiplier";
452
453  /**
454   * Default value for hbase.hregion.memstore.block.multiplier
455   */
456  public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
457
458  /** Conf key for the memstore size at which we flush the memstore */
459  public static final String HREGION_MEMSTORE_FLUSH_SIZE =
460      "hbase.hregion.memstore.flush.size";
461
462  public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
463      "hbase.hregion.edits.replay.skip.errors";
464
465  public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
466      false;
467
468  /** Maximum value length, enforced on KeyValue construction */
469  public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
470
471  /** name of the file for unique cluster ID */
472  public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
473
474  /** Default value for cluster ID */
475  public static final String CLUSTER_ID_DEFAULT = "default-cluster";
476
477  /** Parameter name for # days to keep MVCC values during a major compaction */
478  public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
479  /** At least to keep MVCC values in hfiles for 5 days */
480  public static final int MIN_KEEP_SEQID_PERIOD = 5;
481
482  // Always store the location of the root table's HRegion.
483  // This HRegion is never split.
484
485  // region name = table + startkey + regionid. This is the row key.
486  // each row in the root and meta tables describes exactly 1 region
487  // Do we ever need to know all the information that we are storing?
488
489  // Note that the name of the root table starts with "-" and the name of the
490  // meta table starts with "." Why? it's a trick. It turns out that when we
491  // store region names in memory, we use a SortedMap. Since "-" sorts before
492  // "." (and since no other table name can start with either of these
493  // characters, the root region will always be the first entry in such a Map,
494  // followed by all the meta regions (which will be ordered by their starting
495  // row key as well), followed by all user tables. So when the Master is
496  // choosing regions to assign, it will always choose the root region first,
497  // followed by the meta regions, followed by user regions. Since the root
498  // and meta regions always need to be on-line, this ensures that they will
499  // be the first to be reassigned if the server(s) they are being served by
500  // should go down.
501
502  public static final String BASE_NAMESPACE_DIR = "data";
503
504  /** delimiter used between portions of a region name */
505  public static final int META_ROW_DELIMITER = ',';
506
507  /** The catalog family as a string*/
508  public static final String CATALOG_FAMILY_STR = "info";
509
510  /** The catalog family */
511  public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
512
513  /** The RegionInfo qualifier as a string */
514  public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
515
516  /** The regioninfo column qualifier */
517  public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
518
519  /** The server column qualifier */
520  public static final String SERVER_QUALIFIER_STR = "server";
521  /** The server column qualifier */
522  public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
523
524  /** The startcode column qualifier */
525  public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
526  /** The startcode column qualifier */
527  public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
528
529  /** The open seqnum column qualifier */
530  public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
531  /** The open seqnum column qualifier */
532  public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
533
534  /** The state column qualifier */
535  public static final String STATE_QUALIFIER_STR = "state";
536
537  public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
538
539  /**
540   * The serverName column qualifier. Its the server where the region is
541   * transitioning on, while column server is the server where the region is
542   * opened on. They are the same when the region is in state OPEN.
543   */
544  public static final String SERVERNAME_QUALIFIER_STR = "sn";
545
546  public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
547
548  /** The lower-half split region column qualifier string. */
549  public static final String SPLITA_QUALIFIER_STR = "splitA";
550  /** The lower-half split region column qualifier */
551  public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes(SPLITA_QUALIFIER_STR);
552
553  /** The upper-half split region column qualifier String. */
554  public static final String SPLITB_QUALIFIER_STR = "splitB";
555  /** The upper-half split region column qualifier */
556  public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes(SPLITB_QUALIFIER_STR);
557
558  /**
559   * Merge qualifier prefix.
560   * We used to only allow two regions merge; mergeA and mergeB.
561   * Now we allow many to merge. Each region to merge will be referenced
562   * in a column whose qualifier starts with this define.
563   */
564  public static final String MERGE_QUALIFIER_PREFIX_STR = "merge";
565  public static final byte [] MERGE_QUALIFIER_PREFIX =
566      Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR);
567
568  /**
569   * The lower-half merge region column qualifier
570   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for
571   *   the {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
572   */
573  @Deprecated
574  public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "A");
575
576  /**
577   * The upper-half merge region column qualifier
578   * @deprecated Since 2.3.0 and 2.2.1. Not used anymore. Instead we look for
579   *   the {@link #MERGE_QUALIFIER_PREFIX_STR} prefix.
580   */
581  @Deprecated
582  public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes(MERGE_QUALIFIER_PREFIX_STR + "B");
583
584  /** The catalog family as a string*/
585  public static final String TABLE_FAMILY_STR = "table";
586
587  /** The catalog family */
588  public static final byte [] TABLE_FAMILY = Bytes.toBytes(TABLE_FAMILY_STR);
589
590  /** The serialized table state qualifier */
591  public static final byte[] TABLE_STATE_QUALIFIER = Bytes.toBytes("state");
592
593  /** The replication barrier family as a string*/
594  public static final String REPLICATION_BARRIER_FAMILY_STR = "rep_barrier";
595
596  /** The replication barrier family */
597  public static final byte[] REPLICATION_BARRIER_FAMILY =
598      Bytes.toBytes(REPLICATION_BARRIER_FAMILY_STR);
599
600  /**
601   * The meta table version column qualifier.
602   * We keep current version of the meta table in this column in <code>-ROOT-</code>
603   * table: i.e. in the 'info:v' column.
604   */
605  public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
606
607  /**
608   * The current version of the meta table.
609   * - pre-hbase 0.92.  There is no META_VERSION column in the root table
610   * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
611   * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
612   * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
613   * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
614   * byte[] serialization from Writables to Protobuf.
615   * See HRegionInfo.VERSION
616   */
617  public static final short META_VERSION = 1;
618
619  // Other constants
620
621  /**
622   * An empty byte array instance.
623   */
624  public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
625
626  /**
627   * An empty string instance.
628   */
629  public static final String EMPTY_STRING = "";
630
631  public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
632
633  /**
634   * Used by scanners, etc when they want to start at the beginning of a region
635   */
636  public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
637
638  /**
639   * Last row in a table.
640   */
641  public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
642
643  /**
644    * Used by scanners and others when they're trying to detect the end of a
645    * table
646    */
647  public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
648
649  /**
650   * Max length a row can have because of the limitation in TFile.
651   */
652  public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
653
654  /**
655   * Timestamp to use when we want to refer to the latest cell.
656   * This is the timestamp sent by clients when no timestamp is specified on
657   * commit.
658   */
659  public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
660
661  /**
662   * Timestamp to use when we want to refer to the oldest cell.
663   * Special! Used in fake Cells only. Should never be the timestamp on an actual Cell returned to
664   * a client.
665   * @deprecated Should not be public since hbase-1.3.0. For internal use only. Move internal to
666   *   Scanners flagged as special timestamp value never to be returned as timestamp on a Cell.
667   */
668  @Deprecated
669  public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
670
671  /**
672   * LATEST_TIMESTAMP in bytes form
673   */
674  public static final byte [] LATEST_TIMESTAMP_BYTES = {
675    // big-endian
676    (byte) (LATEST_TIMESTAMP >>> 56),
677    (byte) (LATEST_TIMESTAMP >>> 48),
678    (byte) (LATEST_TIMESTAMP >>> 40),
679    (byte) (LATEST_TIMESTAMP >>> 32),
680    (byte) (LATEST_TIMESTAMP >>> 24),
681    (byte) (LATEST_TIMESTAMP >>> 16),
682    (byte) (LATEST_TIMESTAMP >>> 8),
683    (byte) LATEST_TIMESTAMP,
684  };
685
686  /**
687   * Define for 'return-all-versions'.
688   */
689  public static final int ALL_VERSIONS = Integer.MAX_VALUE;
690
691  /**
692   * Unlimited time-to-live.
693   */
694//  public static final int FOREVER = -1;
695  public static final int FOREVER = Integer.MAX_VALUE;
696
697  /**
698   * Seconds in a week
699   */
700  @Deprecated // unused. see HBASE-2692. remove this in 3.0
701  public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
702
703  /**
704   * Seconds in a day, hour and minute
705   */
706  public static final int DAY_IN_SECONDS = 24 * 60 * 60;
707  public static final int HOUR_IN_SECONDS = 60 * 60;
708  public static final int MINUTE_IN_SECONDS = 60;
709
710  //TODO: although the following are referenced widely to format strings for
711  //      the shell. They really aren't a part of the public API. It would be
712  //      nice if we could put them somewhere where they did not need to be
713  //      public. They could have package visibility
714  public static final String NAME = "NAME";
715  public static final String VERSIONS = "VERSIONS";
716  public static final String IN_MEMORY = "IN_MEMORY";
717  public static final String METADATA = "METADATA";
718  public static final String CONFIGURATION = "CONFIGURATION";
719
720  /**
721   * Retrying we multiply hbase.client.pause setting by what we have in this array until we
722   * run out of array items.  Retries beyond this use the last number in the array.  So, for
723   * example, if hbase.client.pause is 1 second, and maximum retries count
724   * hbase.client.retries.number is 10, we will retry at the following intervals:
725   * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
726   * With 100ms, a back-off of 200 means 20s
727   */
728  public static final int [] RETRY_BACKOFF = {1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200};
729
730  public static final String REGION_IMPL = "hbase.hregion.impl";
731
732  /**
733   * Scope tag for locally scoped data.
734   * This data will not be replicated.
735   */
736  public static final int REPLICATION_SCOPE_LOCAL = 0;
737
738  /**
739   * Scope tag for globally scoped data.
740   * This data will be replicated to all peers.
741   */
742  public static final int REPLICATION_SCOPE_GLOBAL = 1;
743
744  /**
745   * Default cluster ID, cannot be used to identify a cluster so a key with
746   * this value means it wasn't meant for replication.
747   */
748  public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
749
750  /**
751   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
752   * Controlled by the client.
753   */
754  public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
755      "hbase.client.scanner.max.result.size";
756
757  /**
758   * Parameter name for maximum number of bytes returned when calling a scanner's next method.
759   * Controlled by the server.
760   */
761  public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
762      "hbase.server.scanner.max.result.size";
763
764  /**
765   * Maximum number of bytes returned when calling a scanner's next method.
766   * Note that when a single row is larger than this limit the row is still
767   * returned completely.
768   *
769   * The default value is 2MB.
770   */
771  public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
772
773  /**
774   * Maximum number of bytes returned when calling a scanner's next method.
775   * Note that when a single row is larger than this limit the row is still
776   * returned completely.
777   * Safety setting to protect the region server.
778   *
779   * The default value is 100MB. (a client would rarely request larger chunks on purpose)
780   */
781  public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
782
783  /**
784   * Parameter name for client pause value, used mostly as value to wait
785   * before running a retry of a failed get, region lookup, etc.
786   */
787  public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
788
789  /**
790   * Default value of {@link #HBASE_CLIENT_PAUSE}.
791   */
792  public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
793
794  /**
795   * Parameter name for client pause value for special case such as call queue too big, etc.
796   */
797  public static final String HBASE_CLIENT_PAUSE_FOR_CQTBE = "hbase.client.pause.cqtbe";
798
799  /**
800   * The maximum number of concurrent connections the client will maintain.
801   */
802  public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
803
804  /**
805   * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
806   */
807  public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
808
809  /**
810   * The maximum number of concurrent connections the client will maintain to a single
811   * RegionServer.
812   */
813  public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
814
815  /**
816   * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
817   */
818  public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
819
820  /**
821   * The maximum number of concurrent connections the client will maintain to a single
822   * Region.
823   */
824  public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
825
826  /**
827   * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
828   */
829  public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
830
831  /**
832   * The maximum number of concurrent pending RPC requests for one server in process level.
833   */
834  public static final String HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD =
835      "hbase.client.perserver.requests.threshold";
836
837  /**
838   * Default value of {@link #HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD}.
839   */
840  public static final int DEFAULT_HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD = Integer.MAX_VALUE;
841
842
843  /**
844   * Parameter name for server pause value, used mostly as value to wait before
845   * running a retry of a failed operation.
846   */
847  public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
848
849  /**
850   * Default value of {@link #HBASE_SERVER_PAUSE}.
851   */
852  public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
853
854  /**
855   * Parameter name for maximum retries, used as maximum for all retryable
856   * operations such as fetching of the root region from root region server,
857   * getting a cell's value, starting a row update, etc.
858   */
859  public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
860
861  /**
862   * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
863   */
864  public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 15;
865
866  public static final String HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER =
867      "hbase.client.serverside.retries.multiplier";
868
869  public static final int DEFAULT_HBASE_CLIENT_SERVERSIDE_RETRIES_MULTIPLIER = 3;
870
871  /**
872   * Parameter name to set the default scanner caching for all clients.
873   */
874  public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
875
876  /**
877   * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
878   */
879  public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
880
881  /**
882   * Parameter name for number of rows that will be fetched when calling next on
883   * a scanner if it is not served from memory. Higher caching values will
884   * enable faster scanners but will eat up more memory and some calls of next
885   * may take longer and longer times when the cache is empty.
886   */
887  public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
888
889  /**
890   * Default value of {@link #HBASE_META_SCANNER_CACHING}.
891   */
892  public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
893
894  /**
895   * Parameter name for number of versions, kept by meta table.
896   */
897  public static final String HBASE_META_VERSIONS = "hbase.meta.versions";
898
899  /**
900   * Default value of {@link #HBASE_META_VERSIONS}.
901   */
902  public static final int DEFAULT_HBASE_META_VERSIONS = 3;
903
904  /**
905   * Parameter name for number of versions, kept by meta table.
906   */
907  public static final String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
908
909  /**
910   * Default value of {@link #HBASE_META_BLOCK_SIZE}.
911   */
912  public static final int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
913
914  /**
915   * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
916   * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
917   * for all intents and purposes, are the same except for their instance ids, then they will not be
918   * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
919   * even if the instance ids are the same, it could result in non-shared
920   * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
921   * differ.
922   */
923  public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
924
925  /**
926   * The client scanner timeout period in milliseconds.
927   */
928  public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD =
929      "hbase.client.scanner.timeout.period";
930
931  /**
932   * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
933   * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
934   */
935  @Deprecated
936  public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
937      "hbase.regionserver.lease.period";
938
939  /**
940   * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
941   */
942  public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
943
944  /**
945   * timeout for each RPC
946   */
947  public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
948
949  /**
950   * timeout for each read RPC
951   */
952  public static final String HBASE_RPC_READ_TIMEOUT_KEY = "hbase.rpc.read.timeout";
953
954  /**
955   * timeout for each write RPC
956   */
957  public static final String HBASE_RPC_WRITE_TIMEOUT_KEY = "hbase.rpc.write.timeout";
958
959  /**
960   * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
961   */
962  public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
963
964  /**
965   * timeout for short operation RPC
966   */
967  public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
968      "hbase.rpc.shortoperation.timeout";
969
970  /**
971   * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
972   */
973  public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
974
975  /**
976   * Value indicating the server name was saved with no sequence number.
977   */
978  public static final long NO_SEQNUM = -1;
979
980  /**
981   * Registry implementation to be used on the client side.
982   */
983  public static final String CLIENT_CONNECTION_REGISTRY_IMPL_CONF_KEY =
984      "hbase.client.registry.impl";
985
986  /*
987   * cluster replication constants.
988   */
989  public static final String
990      REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
991  public static final String
992      REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
993  public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
994    "org.apache.hadoop.hbase.replication.regionserver.Replication";
995  public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
996  public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
997  /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
998  public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
999  /**
1000   * Max total size of buffered entries in all replication peers. It will prevent server getting
1001   * OOM if there are many peers. Default value is 256MB which is four times to default
1002   * replication.source.size.capacity.
1003   */
1004  public static final String REPLICATION_SOURCE_TOTAL_BUFFER_KEY = "replication.total.buffer.quota";
1005
1006  public static final int REPLICATION_SOURCE_TOTAL_BUFFER_DFAULT = 256 * 1024 * 1024;
1007
1008  /** Configuration key for ReplicationSource shipeEdits timeout */
1009  public static final String REPLICATION_SOURCE_SHIPEDITS_TIMEOUT =
1010      "replication.source.shipedits.timeout";
1011  public static final int REPLICATION_SOURCE_SHIPEDITS_TIMEOUT_DFAULT = 60000;
1012
1013  /**
1014   * Directory where the source cluster file system client configuration are placed which is used by
1015   * sink cluster to copy HFiles from source cluster file system
1016   */
1017  public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
1018
1019  /** Maximum time to retry for a failed bulk load request */
1020  public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
1021
1022  /** HBCK special code name used as server name when manipulating ZK nodes */
1023  @Deprecated // unused. see HBASE-3789. remove this in 3.0
1024  public static final String HBCK_CODE_NAME = "HBCKServerName";
1025
1026  public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
1027    "hbase.regionserver.hostname.seen.by.master";
1028
1029  public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
1030      "hbase.master.logcleaner.plugins";
1031
1032  public static final String HBASE_REGION_SPLIT_POLICY_KEY =
1033    "hbase.regionserver.region.split.policy";
1034
1035  /** Whether nonces are enabled; default is true. */
1036  public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
1037
1038  /**
1039   * Configuration key for the size of the block cache
1040   */
1041  public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
1042    "hfile.block.cache.size";
1043
1044  public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
1045
1046  /*
1047    * Minimum percentage of free heap necessary for a successful cluster startup.
1048    */
1049  public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
1050
1051  /**
1052   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1053   */
1054  @Deprecated
1055  public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
1056      Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
1057
1058  /**
1059   * <pre>
1060   * Pattern that matches a coprocessor specification. Form is:
1061   * {@code <coprocessor jar file location> '|' <class name> ['|' <priority> ['|' <arguments>]]}
1062   * where arguments are {@code <KEY> '=' <VALUE> [,...]}
1063   * For example: {@code hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2}
1064   * </pre>
1065   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1066   */
1067  @Deprecated
1068  public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
1069      Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
1070  /**
1071   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1072   */
1073  @Deprecated
1074  public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
1075  /**
1076   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1077   */
1078  @Deprecated
1079  public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
1080  /**
1081   * @deprecated  It is used internally. As of release 2.0.0, this will be removed in HBase 3.0.0.
1082   */
1083  @Deprecated
1084  public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
1085      "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
1086      CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
1087  public static final String CP_HTD_ATTR_INCLUSION_KEY =
1088      "hbase.coprocessor.classloader.included.classes";
1089
1090  /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
1091  public static final int SOCKET_RETRY_WAIT_MS = 200;
1092
1093  /** Host name of the local machine */
1094  public static final String LOCALHOST = "localhost";
1095
1096  /**
1097   * If this parameter is set to true, then hbase will read
1098   * data and then verify checksums. Checksum verification
1099   * inside hdfs will be switched off.  However, if the hbase-checksum
1100   * verification fails, then it will switch back to using
1101   * hdfs checksums for verifiying data that is being read from storage.
1102   *
1103   * If this parameter is set to false, then hbase will not
1104   * verify any checksums, instead it will depend on checksum verification
1105   * being done in the hdfs client.
1106   */
1107  public static final String HBASE_CHECKSUM_VERIFICATION =
1108      "hbase.regionserver.checksum.verify";
1109
1110  public static final String LOCALHOST_IP = "127.0.0.1";
1111
1112  public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
1113  public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
1114
1115  /*
1116   * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT:
1117   * -1  => Disable aborting
1118   * 0   => Abort if even a single handler has died
1119   * 0.x => Abort only when this percent of handlers have died
1120   * 1   => Abort only all of the handers have died
1121   */
1122  public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
1123      "hbase.regionserver.handler.abort.on.error.percent";
1124  public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
1125
1126  //High priority handlers to deal with admin requests and system table operation requests
1127  public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
1128      "hbase.regionserver.metahandler.count";
1129  public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
1130
1131  public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
1132      "hbase.regionserver.replication.handler.count";
1133  public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
1134  // Meta Transition handlers to deal with meta ReportRegionStateTransitionRequest. Meta transition
1135  // should be dealt with in a separate handler in case blocking other region's transition.
1136  public static final String MASTER_META_TRANSITION_HANDLER_COUNT =
1137      "hbase.master.meta.transition.handler.count";
1138  public static final int MASTER__META_TRANSITION_HANDLER_COUNT_DEFAULT = 1;
1139
1140  @Deprecated // unused. see HBASE-10569. remove this in 3.0
1141  public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
1142  @Deprecated // unused. see HBASE-10569. remove this in 3.0
1143  public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
1144
1145  /** Conf key that specifies timeout value to wait for a region ready */
1146  @Deprecated // unused. see HBASE-13616. remove this in 3.0
1147  public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
1148      "hbase.master.log.replay.wait.region.timeout";
1149
1150  /** Conf key for enabling meta replication */
1151  public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
1152  public static final boolean DEFAULT_USE_META_REPLICAS = false;
1153  public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
1154  public static final int DEFAULT_META_REPLICA_NUM = 1;
1155
1156  /**
1157   * The name of the configuration parameter that specifies
1158   * the number of bytes in a newly created checksum chunk.
1159   */
1160  public static final String BYTES_PER_CHECKSUM =
1161      "hbase.hstore.bytes.per.checksum";
1162
1163  /**
1164   * The name of the configuration parameter that specifies
1165   * the name of an algorithm that is used to compute checksums
1166   * for newly created blocks.
1167   */
1168  public static final String CHECKSUM_TYPE_NAME =
1169      "hbase.hstore.checksum.algorithm";
1170
1171  /** Enable file permission modification from standard hbase */
1172  public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
1173  /** File permission umask to use when creating hbase data files */
1174  public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
1175
1176  /** Configuration name of WAL Compression */
1177  public static final String ENABLE_WAL_COMPRESSION =
1178    "hbase.regionserver.wal.enablecompression";
1179
1180  /** Configuration name of WAL storage policy
1181   * Valid values are: HOT, COLD, WARM, ALL_SSD, ONE_SSD, LAZY_PERSIST
1182   * See http://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html*/
1183  public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
1184  /**
1185   * "NONE" is not a valid storage policy and means we defer the policy to HDFS. @see
1186   * <a href="https://issues.apache.org/jira/browse/HBASE-20691">HBASE-20691</a>
1187   */
1188  public static final String DEFER_TO_HDFS_STORAGE_POLICY = "NONE";
1189  /** By default we defer the WAL storage policy to HDFS */
1190  public static final String DEFAULT_WAL_STORAGE_POLICY = DEFER_TO_HDFS_STORAGE_POLICY;
1191
1192  /** Region in Transition metrics threshold time */
1193  public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1194      "hbase.metrics.rit.stuck.warning.threshold";
1195
1196  public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1197
1198  /** delimiter used between portions of a region name */
1199  public static final int DELIMITER = ',';
1200
1201  /**
1202   * QOS attributes: these attributes are used to demarcate RPC call processing
1203   * by different set of handlers. For example, HIGH_QOS tagged methods are
1204   * handled by high priority handlers.
1205   */
1206  // normal_QOS < replication_QOS < replay_QOS < QOS_threshold < admin_QOS < high_QOS < meta_QOS
1207  public static final int PRIORITY_UNSET = -1;
1208  public static final int NORMAL_QOS = 0;
1209  public static final int REPLICATION_QOS = 5;
1210  public static final int REPLAY_QOS = 6;
1211  public static final int QOS_THRESHOLD = 10;
1212  public static final int ADMIN_QOS = 100;
1213  public static final int HIGH_QOS = 200;
1214  public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1215  /**
1216   * @deprecated the name "META_QOS" is a bit ambiguous, actually only meta region transition can
1217   *             use this priority, and you should not use this directly. Will be removed in 3.0.0.
1218   */
1219  @Deprecated
1220  public static final int META_QOS = 300;
1221
1222  /** Directory under /hbase where archived hfiles are stored */
1223  public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1224
1225  /**
1226   * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
1227   * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
1228   * uni-directional.
1229   */
1230  public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1231
1232  /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1233  public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1234
1235  /** Temporary directory used for table creation and deletion */
1236  public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1237  /**
1238   * The period (in milliseconds) between computing region server point in time metrics
1239   */
1240  public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1241  public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1242  /** Directories that are not HBase table directories */
1243  public static final List<String> HBASE_NON_TABLE_DIRS =
1244    Collections.unmodifiableList(Arrays.asList(new String[] {
1245      HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
1246    }));
1247
1248  /**
1249   * Directories that are not HBase user table directories.
1250   * @deprecated Since hbase-2.3.0; no replacement as not used any more (internally at least)
1251   */
1252  @Deprecated
1253  public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1254    Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
1255      new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1256      HBASE_NON_TABLE_DIRS.toArray())));
1257
1258  /** Health script related settings. */
1259  public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1260  public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1261  public static final String HEALTH_CHORE_WAKE_FREQ =
1262      "hbase.node.health.script.frequency";
1263  public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1264  /**
1265   * The maximum number of health check failures a server can encounter consecutively.
1266   */
1267  public static final String HEALTH_FAILURE_THRESHOLD =
1268      "hbase.node.health.failure.threshold";
1269  public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1270
1271
1272  /**
1273   * Setting to activate, or not, the publication of the status by the master. Default
1274   *  notification is by a multicast message.
1275   */
1276  public static final String STATUS_PUBLISHED = "hbase.status.published";
1277  public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1278
1279  /**
1280   * IP to use for the multicast status messages between the master and the clients.
1281   * The default address is chosen as one among others within the ones suitable for multicast
1282   * messages.
1283   */
1284  public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1285  public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1286
1287  /**
1288   * The address to use for binding the local socket for receiving multicast. Defaults to
1289   * 0.0.0.0.
1290   * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1291   */
1292  public static final String STATUS_MULTICAST_BIND_ADDRESS =
1293      "hbase.status.multicast.bind.address.ip";
1294  public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1295
1296  /**
1297   * The port to use for the multicast messages.
1298   */
1299  public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1300  public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1301
1302  /**
1303   * The network interface name to use for the multicast messages.
1304   */
1305  public static final String STATUS_MULTICAST_NI_NAME = "hbase.status.multicast.ni.name";
1306
1307  /**
1308   * The address to use for binding the local socket for sending multicast. Defaults to 0.0.0.0.
1309   */
1310  public static final String STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS =
1311    "hbase.status.multicast.publisher.bind.address.ip";
1312  public static final String DEFAULT_STATUS_MULTICAST_PUBLISHER_BIND_ADDRESS = "0.0.0.0";
1313
1314  public static final long NO_NONCE = 0;
1315
1316  /** Default cipher for encryption */
1317  public static final String CIPHER_AES = "AES";
1318
1319  /** Configuration key for the crypto algorithm provider, a class name */
1320  public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1321
1322  /** Configuration key for the crypto key provider, a class name */
1323  public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1324
1325  /** Configuration key for the crypto key provider parameters */
1326  public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1327      "hbase.crypto.keyprovider.parameters";
1328
1329  /** Configuration key for the name of the master key for the cluster, a string */
1330  public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1331
1332  /** Configuration key for the name of the alternate master key for the cluster, a string */
1333  public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1334    "hbase.crypto.master.alternate.key.name";
1335
1336  /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1337  public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1338
1339  /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1340  public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1341
1342  /** Configuration key for the algorithm used for creating jks key, a string */
1343  public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1344
1345  /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1346  public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1347      "hbase.crypto.alternate.key.algorithm";
1348
1349  /** Configuration key for enabling WAL encryption, a boolean */
1350  public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1351
1352  /** Configuration key for setting RPC codec class name */
1353  public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1354
1355  /** Configuration key for setting replication codec class name */
1356  public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1357
1358  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1359  public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1360      "hbase.replication.source.maxthreads";
1361
1362  /**
1363   * Drop edits for tables that been deleted from the replication source and target
1364   * @deprecated moved it into HBaseInterClusterReplicationEndpoint
1365   */
1366  @Deprecated
1367  public static final String REPLICATION_DROP_ON_DELETED_TABLE_KEY =
1368      "hbase.replication.drop.on.deleted.table";
1369
1370  /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1371  public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1372
1373  /** Configuration key for SplitLog manager timeout */
1374  public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1375
1376  /**
1377   * Configuration keys for Bucket cache
1378   */
1379  // TODO moving these bucket cache implementation specific configs to this level is violation of
1380  // encapsulation. But as these has to be referred from hbase-common and bucket cache
1381  // sits in hbase-server, there were no other go! Can we move the cache implementation to
1382  // hbase-common?
1383
1384  /**
1385   * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1386   * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1387   * list of supported ioengine options.
1388   * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1389   */
1390  public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1391
1392  /**
1393   * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1394   * memory size to give to the cache (if &lt; 1.0) OR, it is the capacity in
1395   * megabytes of the cache.
1396   */
1397  public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1398
1399  /**
1400   * HConstants for fast fail on the client side follow
1401   */
1402  /**
1403   * Config for enabling/disabling the fast fail mode.
1404   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1405   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1406   */
1407  @Deprecated
1408  public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1409    "hbase.client.fast.fail.mode.enabled";
1410
1411  /**
1412   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1413   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1414   */
1415  @Deprecated
1416  public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT = false;
1417
1418  /**
1419   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1420   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1421   */
1422  @Deprecated
1423  public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1424    "hbase.client.fastfail.threshold";
1425
1426  /**
1427   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1428   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1429   */
1430  @Deprecated
1431  public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT = 60000;
1432
1433  /**
1434   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1435   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1436   */
1437  @Deprecated
1438  public static final String HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS =
1439    "hbase.client.failure.map.cleanup.interval";
1440
1441  /**
1442   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1443   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1444   */
1445  @Deprecated
1446  public static final long HBASE_CLIENT_FAILURE_MAP_CLEANUP_INTERVAL_MS_DEFAULT = 600000;
1447
1448  /**
1449   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1450   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1451   */
1452  @Deprecated
1453  public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1454    "hbase.client.fast.fail.cleanup.duration";
1455
1456  /**
1457   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1458   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1459   */
1460  @Deprecated
1461  public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT = 600000;
1462
1463  /**
1464   * @deprecated since 2.3.0, and in 3.0.0 the actually implementation will be removed so config
1465   *             this value will have no effect. The constants itself will be removed in 4.0.0.
1466   */
1467  @Deprecated
1468  public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1469    "hbase.client.fast.fail.interceptor.impl";
1470
1471  public static final String HBASE_SPLIT_WAL_COORDINATED_BY_ZK = "hbase.split.wal.zk.coordinated";
1472
1473  public static final boolean DEFAULT_HBASE_SPLIT_COORDINATED_BY_ZK = true;
1474
1475  public static final String HBASE_SPLIT_WAL_MAX_SPLITTER = "hbase.regionserver.wal.max.splitters";
1476
1477  public static final int DEFAULT_HBASE_SPLIT_WAL_MAX_SPLITTER = 2;
1478
1479  /** Config key for if the server should send backpressure and if the client should listen to
1480   * that backpressure from the server */
1481  public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1482  public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1483
1484  public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1485      "hbase.heap.occupancy.low_water_mark";
1486  public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1487  public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1488      "hbase.heap.occupancy.high_water_mark";
1489  public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1490
1491  /**
1492   * The max number of threads used for splitting storefiles in parallel during
1493   * the region split process.
1494   */
1495  public static final String REGION_SPLIT_THREADS_MAX =
1496    "hbase.regionserver.region.split.threads.max";
1497
1498  /** Canary config keys */
1499  // TODO: Move these defines to Canary Class
1500  public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1501
1502  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1503      "hbase.canary.write.perserver.regions.lowerLimit";
1504
1505  public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1506      "hbase.canary.write.perserver.regions.upperLimit";
1507
1508  public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1509
1510  public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1511      "hbase.canary.write.table.check.period";
1512
1513  public static final String HBASE_CANARY_READ_RAW_SCAN_KEY = "hbase.canary.read.raw.enabled";
1514
1515  public static final String HBASE_CANARY_READ_ALL_CF = "hbase.canary.read.all.column.famliy";
1516  /**
1517   * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1518   */
1519  public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1520  public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1521      "hbase.zookeeper.client.kerberos.principal";
1522  public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1523  public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1524      "hbase.zookeeper.server.kerberos.principal";
1525
1526  /** Config key for hbase temporary directory in hdfs */
1527  public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1528  public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY = "/user/"
1529      + System.getProperty("user.name") + "/hbase-staging";
1530
1531  public static final String SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT =
1532      "hbase.snapshot.restore.take.failsafe.snapshot";
1533  public static final boolean DEFAULT_SNAPSHOT_RESTORE_TAKE_FAILSAFE_SNAPSHOT = true;
1534
1535  public static final String SNAPSHOT_RESTORE_FAILSAFE_NAME =
1536      "hbase.snapshot.restore.failsafe.name";
1537  public static final String DEFAULT_SNAPSHOT_RESTORE_FAILSAFE_NAME =
1538      "hbase-failsafe-{snapshot.name}-{restore.timestamp}";
1539
1540  public static final String DEFAULT_LOSSY_COUNTING_ERROR_RATE =
1541      "hbase.util.default.lossycounting.errorrate";
1542  public static final String NOT_IMPLEMENTED = "Not implemented";
1543
1544  // Default TTL - FOREVER
1545  public static final long DEFAULT_SNAPSHOT_TTL = 0;
1546
1547  // User defined Default TTL config key
1548  public static final String DEFAULT_SNAPSHOT_TTL_CONFIG_KEY = "hbase.master.snapshot.ttl";
1549
1550  // Regions Recovery based on high storeFileRefCount threshold value
1551  public static final String STORE_FILE_REF_COUNT_THRESHOLD =
1552    "hbase.regions.recovery.store.file.ref.count";
1553
1554  // default -1 indicates there is no threshold on high storeRefCount
1555  public static final int DEFAULT_STORE_FILE_REF_COUNT_THRESHOLD = -1;
1556
1557  public static final String REGIONS_RECOVERY_INTERVAL =
1558    "hbase.master.regions.recovery.check.interval";
1559
1560  public static final int DEFAULT_REGIONS_RECOVERY_INTERVAL = 1200 * 1000; // Default 20 min
1561
1562  /**
1563   * Configurations for master executor services.
1564   */
1565  public static final String MASTER_OPEN_REGION_THREADS =
1566      "hbase.master.executor.openregion.threads";
1567  public static final int MASTER_OPEN_REGION_THREADS_DEFAULT = 5;
1568
1569  public static final String MASTER_CLOSE_REGION_THREADS =
1570      "hbase.master.executor.closeregion.threads";
1571  public static final int MASTER_CLOSE_REGION_THREADS_DEFAULT = 5;
1572
1573  public static final String MASTER_SERVER_OPERATIONS_THREADS =
1574      "hbase.master.executor.serverops.threads";
1575  public static final int MASTER_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1576
1577  public static final String MASTER_META_SERVER_OPERATIONS_THREADS =
1578      "hbase.master.executor.meta.serverops.threads";
1579  public static final int MASTER_META_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1580
1581  public static final String MASTER_LOG_REPLAY_OPS_THREADS =
1582      "hbase.master.executor.logreplayops.threads";
1583  public static final int MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT = 10;
1584
1585  public static final int DEFAULT_SLOW_LOG_RING_BUFFER_SIZE = 256;
1586
1587  public static final String SLOW_LOG_BUFFER_ENABLED_KEY =
1588    "hbase.regionserver.slowlog.buffer.enabled";
1589  public static final boolean DEFAULT_ONLINE_LOG_PROVIDER_ENABLED = false;
1590
1591  /** The slowlog info family as a string*/
1592  private static final String SLOWLOG_INFO_FAMILY_STR = "info";
1593
1594  /** The slowlog info family */
1595  public static final byte [] SLOWLOG_INFO_FAMILY = Bytes.toBytes(SLOWLOG_INFO_FAMILY_STR);
1596
1597  public static final String SLOW_LOG_SYS_TABLE_ENABLED_KEY =
1598    "hbase.regionserver.slowlog.systable.enabled";
1599  public static final boolean DEFAULT_SLOW_LOG_SYS_TABLE_ENABLED_KEY = false;
1600
1601  private HConstants() {
1602    // Can't be instantiated with this ctor.
1603  }
1604}