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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase;
19  
20  import static org.apache.hadoop.hbase.io.hfile.BlockType.MAGIC_LENGTH;
21  
22  import java.nio.charset.Charset;
23  import java.util.Arrays;
24  import java.util.Collections;
25  import java.util.List;
26  import java.util.UUID;
27  import java.util.regex.Pattern;
28  
29  import org.apache.commons.lang.ArrayUtils;
30  import org.apache.hadoop.hbase.classification.InterfaceAudience;
31  import org.apache.hadoop.hbase.classification.InterfaceStability;
32  import org.apache.hadoop.hbase.util.Bytes;
33  
34  /**
35   * HConstants holds a bunch of HBase-related constants
36   */
37  @InterfaceAudience.Public
38  @InterfaceStability.Stable
39  public final class HConstants {
40    // NOTICE!!!! Please do not add a constants here, unless they are referenced by a lot of classes.
41  
42    //Bytes.UTF8_ENCODING should be updated if this changed
43    /** When we encode strings, we always specify UTF8 encoding */
44    public static final String UTF8_ENCODING = "UTF-8";
45  
46    //Bytes.UTF8_CHARSET should be updated if this changed
47    /** When we encode strings, we always specify UTF8 encoding */
48    public static final Charset UTF8_CHARSET = Charset.forName(UTF8_ENCODING);
49    /**
50     * Default block size for an HFile.
51     */
52    public final static int DEFAULT_BLOCKSIZE = 64 * 1024;
53  
54    /** Used as a magic return value while optimized index key feature enabled(HBASE-7845) */
55    public final static int INDEX_KEY_MAGIC = -2;
56    /*
57       * Name of directory that holds recovered edits written by the wal log
58       * splitting code, one per region
59       */
60    public static final String RECOVERED_EDITS_DIR = "recovered.edits";
61    /**
62     * The first four bytes of Hadoop RPC connections
63     */
64    public static final byte[] RPC_HEADER = new byte[] { 'H', 'B', 'a', 's' };
65    public static final byte RPC_CURRENT_VERSION = 0;
66  
67    // HFileBlock constants. TODO!!!! THESE DEFINES BELONG IN HFILEBLOCK, NOT UP HERE.
68    // Needed down in hbase-common though by encoders but these encoders should not be dealing
69    // in the internals of hfileblocks. Fix encapsulation.
70  
71    /** The size data structures with minor version is 0 */
72    public static final int HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM = MAGIC_LENGTH + 2 * Bytes.SIZEOF_INT
73        + Bytes.SIZEOF_LONG;
74    /** The size of a version 2 HFile block header, minor version 1.
75     * There is a 1 byte checksum type, followed by a 4 byte bytesPerChecksum
76     * followed by another 4 byte value to store sizeofDataOnDisk.
77     */
78    public static final int HFILEBLOCK_HEADER_SIZE = HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM +
79      Bytes.SIZEOF_BYTE + 2 * Bytes.SIZEOF_INT;
80    /** Just an array of bytes of the right size. */
81    public static final byte[] HFILEBLOCK_DUMMY_HEADER = new byte[HFILEBLOCK_HEADER_SIZE];
82    public static final String REGISTRY_IMPL_CONF_KEY = "hbase.client.registry.impl";
83  
84    //End HFileBlockConstants.
85  
86    /**
87     * Status codes used for return values of bulk operations.
88     */
89    @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
90    public enum OperationStatusCode {
91      NOT_RUN,
92      SUCCESS,
93      BAD_FAMILY,
94      SANITY_CHECK_FAILURE,
95      FAILURE;
96    }
97  
98    /** long constant for zero */
99    public static final Long ZERO_L = Long.valueOf(0L);
100   public static final String NINES = "99999999999999";
101   public static final String ZEROES = "00000000000000";
102 
103   // For migration
104 
105   /** name of version file */
106   public static final String VERSION_FILE_NAME = "hbase.version";
107 
108   /**
109    * Current version of file system.
110    * Version 4 supports only one kind of bloom filter.
111    * Version 5 changes versions in catalog table regions.
112    * Version 6 enables blockcaching on catalog tables.
113    * Version 7 introduces hfile -- hbase 0.19 to 0.20..
114    * Version 8 introduces namespace
115    */
116   // public static final String FILE_SYSTEM_VERSION = "6";
117   public static final String FILE_SYSTEM_VERSION = "8";
118 
119   // Configuration parameters
120 
121   //TODO: Is having HBase homed on port 60k OK?
122 
123   /** Cluster is in distributed mode or not */
124   public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
125 
126   /** Config for pluggable load balancers */
127   public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
128 
129   /** Config for balancing the cluster by table */
130   public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
131 
132   /** Config for the max percent of regions in transition */
133   public static final String HBASE_MASTER_BALANCER_MAX_RIT_PERCENT =
134       "hbase.master.balancer.maxRitPercent";
135 
136   /** Default value for the max percent of regions in transition */
137   public static final double DEFAULT_HBASE_MASTER_BALANCER_MAX_RIT_PERCENT = 1.0;
138 
139   /** Time in milliseconds to wait meta region assignment, when moving non-meta regions. */
140   public static final String HBASE_MASTER_WAITING_META_ASSIGNMENT_TIMEOUT =
141     "hbase.master.waiting.meta.assignment.timeout";
142 
143   public static final long HBASE_MASTER_WAITING_META_ASSIGNMENT_TIMEOUT_DEFAULT = 10000;
144 
145   /** Config for the max balancing time */
146   public static final String HBASE_BALANCER_MAX_BALANCING = "hbase.balancer.max.balancing";
147 
148   /** Config for the balancer period */
149   public static final String HBASE_BALANCER_PERIOD = "hbase.balancer.period";
150 
151   /** Default value for the balancer period */
152   public static final int DEFAULT_HBASE_BALANCER_PERIOD = 300000;
153 
154   /** The name of the ensemble table */
155   public static final String ENSEMBLE_TABLE_NAME = "hbase:ensemble";
156 
157   /** Config for pluggable region normalizer */
158   public static final String HBASE_MASTER_NORMALIZER_CLASS =
159     "hbase.master.normalizer.class";
160 
161   /** Cluster is standalone or pseudo-distributed */
162   public static final boolean CLUSTER_IS_LOCAL = false;
163 
164   /** Cluster is fully-distributed */
165   public static final boolean CLUSTER_IS_DISTRIBUTED = true;
166 
167   /** Default value for cluster distributed mode */
168   public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
169 
170   /** default host address */
171   public static final String DEFAULT_HOST = "0.0.0.0";
172 
173   /** Parameter name for port master listens on. */
174   public static final String MASTER_PORT = "hbase.master.port";
175 
176   /** default port that the master listens on */
177   public static final int DEFAULT_MASTER_PORT = 16000;
178 
179   /** default port for master web api */
180   public static final int DEFAULT_MASTER_INFOPORT = 16010;
181 
182   /** Configuration key for master web API port */
183   public static final String MASTER_INFO_PORT = "hbase.master.info.port";
184 
185   /** Configuration key for the list of master host:ports **/
186   public static final String MASTER_ADDRS_KEY = "hbase.masters";
187 
188   public static final String MASTER_ADDRS_DEFAULT =  "localhost:" + DEFAULT_MASTER_PORT;
189 
190   /** Parameter name for the master type being backup (waits for primary to go inactive). */
191   public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
192 
193   /** by default every master is a possible primary master unless the conf explicitly overrides it */
194   public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
195 
196   /** Name of ZooKeeper quorum configuration parameter. */
197   public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
198 
199   /** Name of ZooKeeper config file in conf/ directory. */
200   public static final String ZOOKEEPER_CONFIG_NAME = "zoo.cfg";
201 
202   /** Common prefix of ZooKeeper configuration properties */
203   public static final String ZK_CFG_PROPERTY_PREFIX =
204       "hbase.zookeeper.property.";
205 
206   public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
207       ZK_CFG_PROPERTY_PREFIX.length();
208 
209   /**
210    * The ZK client port key in the ZK properties map. The name reflects the
211    * fact that this is not an HBase configuration key.
212    */
213   public static final String CLIENT_PORT_STR = "clientPort";
214 
215   /** Parameter name for the client port that the zookeeper listens on */
216   public static final String ZOOKEEPER_CLIENT_PORT =
217       ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
218 
219   /** Default client port that the zookeeper listens on */
220   public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
221 
222   /** Parameter name for the wait time for the recoverable zookeeper */
223   public static final String ZOOKEEPER_RECOVERABLE_WAITTIME = "hbase.zookeeper.recoverable.waittime";
224 
225   /** Default wait time for the recoverable zookeeper */
226   public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
227 
228   /** Parameter name for the root dir in ZK for this cluster */
229   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
230 
231   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
232 
233   /**
234    * Parameter name for the limit on concurrent client-side zookeeper
235    * connections
236    */
237   public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
238       ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
239 
240   /** Parameter name for the ZK data directory */
241   public static final String ZOOKEEPER_DATA_DIR =
242       ZK_CFG_PROPERTY_PREFIX + "dataDir";
243 
244   /** Parameter name for the ZK tick time */
245   public static final String ZOOKEEPER_TICK_TIME =
246       ZK_CFG_PROPERTY_PREFIX + "tickTime";
247 
248   /** Default limit on concurrent client-side zookeeper connections */
249   public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
250 
251   /** Configuration key for ZooKeeper session timeout */
252   public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
253 
254   /** Timeout for the ZK sync() call */
255   public static final String ZK_SYNC_BLOCKING_TIMEOUT_MS = "hbase.zookeeper.sync.timeout.millis";
256   // Choice of the default value is based on the following ZK recommendation (from docs). Keeping it
257   // lower lets the callers fail fast in case of any issues.
258   // "The clients view of the system is guaranteed to be up-to-date within a certain time bound.
259   // (On the order of tens of seconds.) Either system changes will be seen by a client within this
260   // bound, or the client will detect a service outage."
261   public static final long ZK_SYNC_BLOCKING_TIMEOUT_DEFAULT_MS = 30 * 1000;
262 
263   /** Default value for ZooKeeper session timeout */
264   public static final int DEFAULT_ZK_SESSION_TIMEOUT = 180 * 1000;
265 
266   /** Configuration key for whether to use ZK.multi */
267   public static final String ZOOKEEPER_USEMULTI = "hbase.zookeeper.useMulti";
268 
269   /** Parameter name for port region server listens on. */
270   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
271 
272   /** Default port region server listens on. */
273   public static final int DEFAULT_REGIONSERVER_PORT = 16020;
274 
275   /** default port for region server web api */
276   public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
277 
278   /** A configuration key for regionserver info port */
279   public static final String REGIONSERVER_INFO_PORT =
280     "hbase.regionserver.info.port";
281 
282   /** A flag that enables automatic selection of regionserver info port */
283   public static final String REGIONSERVER_INFO_PORT_AUTO =
284       REGIONSERVER_INFO_PORT + ".auto";
285 
286   /** Parameter name for what region server implementation to use. */
287   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
288 
289   /** Parameter name for what master implementation to use. */
290   public static final String MASTER_IMPL= "hbase.master.impl";
291 
292   /** Parameter name for what hbase client implementation to use. */
293   public static final String HBASECLIENT_IMPL= "hbase.hbaseclient.impl";
294 
295   /** Parameter name for how often threads should wake up */
296   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
297 
298   /** Default value for thread wake frequency */
299   public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
300 
301   /** Parameter name for how often we should try to write a version file, before failing */
302   public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
303 
304   /** Parameter name for how often we should try to write a version file, before failing */
305   public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
306 
307   /** Parameter name for how often a region should should perform a major compaction */
308   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
309 
310   /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
311   public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
312   public static final int COMPACTION_KV_MAX_DEFAULT = 10;
313 
314   /** Parameter name for HBase instance root directory */
315   public static final String HBASE_DIR = "hbase.rootdir";
316 
317   /** Parameter name for HBase client IPC pool type */
318   public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
319 
320   /** Parameter name for HBase client IPC pool size */
321   public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
322 
323   /** Parameter name for HBase client operation timeout. */
324   public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
325 
326   /** Parameter name for HBase client meta operation timeout. */
327   public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
328     "hbase.client.meta.operation.timeout";
329 
330   /** Parameter name for HBase client max backoff across SASL relogin failure retries */
331   public static final String HBASE_RELOGIN_MAXBACKOFF = "hbase.security.relogin.maxbackoff";
332 
333   /** Parameter name for HBase client minimum time between forceful relogin attempts */
334   public static final String HBASE_MINTIME_BEFORE_FORCE_RELOGIN =
335       "hbase.mintime.before.force.relogin";
336 
337   /**
338    * Whether forceful relogin (explicit clearing of kerberos tickets) is enabled on SASL
339    * Authentication failure
340    */
341   public static final String HBASE_FORCE_RELOGIN_ENABLED = "hbase.security.force.relogin.enabled";
342 
343   /** Default HBase client operation timeout, which is tantamount to a blocking call */
344   public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
345 
346   /** Parameter name for HBase client meta replica scan call timeout. */
347   public static final String HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT =
348       "hbase.client.meta.replica.scan.timeout";
349 
350   /** Default HBase client meta replica scan call timeout, 1 second */
351   public static final int HBASE_CLIENT_META_REPLICA_SCAN_TIMEOUT_DEFAULT = 1000000;
352 
353 
354   /** Used to construct the name of the log directory for a region server */
355   public static final String HREGION_LOGDIR_NAME = "WALs";
356 
357   /** Used to construct the name of the splitlog directory for a region server */
358   public static final String SPLIT_LOGDIR_NAME = "splitWAL";
359 
360   /** Like the previous, but for old logs that are about to be deleted */
361   public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
362 
363   public static final String CORRUPT_DIR_NAME = "corrupt";
364 
365   /** Used by HBCK to sideline backup data */
366   public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
367 
368   /** Any artifacts left from migration can be moved here */
369   public static final String MIGRATION_NAME = ".migration";
370 
371   /**
372    * The directory from which co-processor/custom filter jars can be loaded
373    * dynamically by the region servers. This value can be overridden by the
374    * hbase.dynamic.jars.dir config.
375    */
376   public static final String LIB_DIR = "lib";
377 
378   /** Used to construct the name of the compaction directory during compaction */
379   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
380 
381   /** Conf key for the max file size after which we split the region */
382   public static final String HREGION_MAX_FILESIZE =
383       "hbase.hregion.max.filesize";
384 
385   /** Default maximum file size */
386   public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
387 
388   /**
389    * Max size of single row for Get's or Scan's without in-row scanning flag set.
390    */
391   public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
392 
393   /**
394    * Default max row size (1 Gb).
395    */
396   public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
397 
398   /**
399    * The max number of threads used for opening and closing stores or store
400    * files in parallel
401    */
402   public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
403     "hbase.hstore.open.and.close.threads.max";
404 
405   /**
406    * The default number for the max number of threads used for opening and
407    * closing stores or store files in parallel
408    */
409   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
410 
411   /**
412    * Block updates if memstore has hbase.hregion.memstore.block.multiplier
413    * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
414    * runaway memstore during spikes in update traffic.
415    */
416   public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
417           "hbase.hregion.memstore.block.multiplier";
418 
419   /**
420    * Default value for hbase.hregion.memstore.block.multiplier
421    */
422   public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
423 
424   /** Conf key for the memstore size at which we flush the memstore */
425   public static final String HREGION_MEMSTORE_FLUSH_SIZE =
426       "hbase.hregion.memstore.flush.size";
427 
428   public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
429       "hbase.hregion.edits.replay.skip.errors";
430 
431   public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
432       false;
433 
434   /** Maximum value length, enforced on KeyValue construction */
435   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
436 
437   /** name of the file for unique cluster ID */
438   public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
439 
440   /** Default value for cluster ID */
441   public static final String CLUSTER_ID_DEFAULT = "default-cluster";
442 
443   /** Parameter name for # days to keep MVCC values during a major compaction */
444   public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
445   /** At least to keep MVCC values in hfiles for 5 days */
446   public static final int MIN_KEEP_SEQID_PERIOD = 5;
447 
448   // Always store the location of the root table's HRegion.
449   // This HRegion is never split.
450 
451   // region name = table + startkey + regionid. This is the row key.
452   // each row in the root and meta tables describes exactly 1 region
453   // Do we ever need to know all the information that we are storing?
454 
455   // Note that the name of the root table starts with "-" and the name of the
456   // meta table starts with "." Why? it's a trick. It turns out that when we
457   // store region names in memory, we use a SortedMap. Since "-" sorts before
458   // "." (and since no other table name can start with either of these
459   // characters, the root region will always be the first entry in such a Map,
460   // followed by all the meta regions (which will be ordered by their starting
461   // row key as well), followed by all user tables. So when the Master is
462   // choosing regions to assign, it will always choose the root region first,
463   // followed by the meta regions, followed by user regions. Since the root
464   // and meta regions always need to be on-line, this ensures that they will
465   // be the first to be reassigned if the server(s) they are being served by
466   // should go down.
467 
468 
469   /**
470    * The hbase:meta table's name.
471    * @deprecated For upgrades of 0.94 to 0.96
472    */
473   @Deprecated  // for compat from 0.94 -> 0.96.
474   public static final byte[] META_TABLE_NAME = TableName.META_TABLE_NAME.getName();
475 
476   public static final String BASE_NAMESPACE_DIR = "data";
477 
478   /** delimiter used between portions of a region name */
479   public static final int META_ROW_DELIMITER = ',';
480 
481   /** The catalog family as a string*/
482   public static final String CATALOG_FAMILY_STR = "info";
483 
484   /** The catalog family */
485   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
486 
487   /** The RegionInfo qualifier as a string */
488   public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
489 
490   /** The regioninfo column qualifier */
491   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
492 
493   /** The server column qualifier */
494   public static final String SERVER_QUALIFIER_STR = "server";
495   /** The server column qualifier */
496   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
497 
498   /** The startcode column qualifier */
499   public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
500   /** The startcode column qualifier */
501   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
502 
503   /** The open seqnum column qualifier */
504   public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
505   /** The open seqnum column qualifier */
506   public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
507 
508   /** The state column qualifier */
509   public static final String STATE_QUALIFIER_STR = "state";
510 
511   public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
512 
513   /**
514    * The serverName column qualifier. Its the server where the region is
515    * transitioning on, while column server is the server where the region is
516    * opened on. They are the same when the region is in state OPEN.
517    */
518   public static final String SERVERNAME_QUALIFIER_STR = "sn";
519 
520   public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
521 
522   /** The lower-half split region column qualifier */
523   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
524 
525   /** The upper-half split region column qualifier */
526   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
527 
528   /** The lower-half merge region column qualifier */
529   public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes("mergeA");
530 
531   /** The upper-half merge region column qualifier */
532   public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes("mergeB");
533 
534   /**
535    * The meta table version column qualifier.
536    * We keep current version of the meta table in this column in <code>-ROOT-</code>
537    * table: i.e. in the 'info:v' column.
538    */
539   public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
540 
541   /**
542    * The current version of the meta table.
543    * - pre-hbase 0.92.  There is no META_VERSION column in the root table
544    * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
545    * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
546    * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
547    * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
548    * byte[] serialization from Writables to Protobuf.
549    * See HRegionInfo.VERSION
550    */
551   public static final short META_VERSION = 1;
552 
553   // Other constants
554 
555   /**
556    * An empty instance.
557    */
558   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
559 
560   /**
561    * Used by scanners, etc when they want to start at the beginning of a region
562    */
563   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
564 
565   /**
566    * Last row in a table.
567    */
568   public static final byte [] EMPTY_END_ROW = EMPTY_BYTE_ARRAY;
569 
570   /**
571     * Used by scanners and others when they're trying to detect the end of a
572     * table
573     */
574   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
575 
576   /**
577    * Max length a row can have because of the limitation in TFile.
578    */
579   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
580 
581   /**
582    * Timestamp to use when we want to refer to the latest cell.
583    * This is the timestamp sent by clients when no timestamp is specified on
584    * commit.
585    */
586   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
587 
588   /**
589    * Timestamp to use when we want to refer to the oldest cell.
590    * Special! Used in fake Cells only. Should never be the timestamp on an actual Cell returned to
591    * a client.
592    * @deprecated Should not be public since hbase-1.3.0. For internal use only. Move internal to
593    * Scanners flagged as special timestamp value never to be returned as timestamp on a Cell.
594    */
595   @Deprecated
596   public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
597 
598   /**
599    * LATEST_TIMESTAMP in bytes form
600    */
601   public static final byte [] LATEST_TIMESTAMP_BYTES = {
602     // big-endian
603     (byte) (LATEST_TIMESTAMP >>> 56),
604     (byte) (LATEST_TIMESTAMP >>> 48),
605     (byte) (LATEST_TIMESTAMP >>> 40),
606     (byte) (LATEST_TIMESTAMP >>> 32),
607     (byte) (LATEST_TIMESTAMP >>> 24),
608     (byte) (LATEST_TIMESTAMP >>> 16),
609     (byte) (LATEST_TIMESTAMP >>> 8),
610     (byte) LATEST_TIMESTAMP,
611   };
612 
613   /**
614    * Define for 'return-all-versions'.
615    */
616   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
617 
618   /**
619    * Unlimited time-to-live.
620    */
621 //  public static final int FOREVER = -1;
622   public static final int FOREVER = Integer.MAX_VALUE;
623 
624   /**
625    * Seconds in a week
626    */
627   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
628 
629   /**
630    * Seconds in a day, hour and minute
631    */
632   public static final int DAY_IN_SECONDS = 24 * 60 * 60;
633   public static final int HOUR_IN_SECONDS = 60 * 60;
634   public static final int MINUTE_IN_SECONDS = 60;
635 
636   //TODO: although the following are referenced widely to format strings for
637   //      the shell. They really aren't a part of the public API. It would be
638   //      nice if we could put them somewhere where they did not need to be
639   //      public. They could have package visibility
640   public static final String NAME = "NAME";
641   public static final String VERSIONS = "VERSIONS";
642   public static final String IN_MEMORY = "IN_MEMORY";
643   public static final String METADATA = "METADATA";
644   public static final String CONFIGURATION = "CONFIGURATION";
645 
646   /**
647    * Retrying we multiply hbase.client.pause setting by what we have in this array until we
648    * run out of array items.  Retries beyond this use the last number in the array.  So, for
649    * example, if hbase.client.pause is 1 second, and maximum retries count
650    * hbase.client.retries.number is 10, we will retry at the following intervals:
651    * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
652    * With 100ms, a back-off of 200 means 20s
653    */
654   public static final int [] RETRY_BACKOFF = {1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200};
655 
656   public static final String REGION_IMPL = "hbase.hregion.impl";
657 
658   /** modifyTable op for replacing the table descriptor */
659   @InterfaceAudience.Private
660   public static enum Modify {
661     CLOSE_REGION,
662     TABLE_COMPACT,
663     TABLE_FLUSH,
664     TABLE_MAJOR_COMPACT,
665     TABLE_SET_HTD,
666     TABLE_SPLIT
667   }
668 
669   /**
670    * Scope tag for locally scoped data.
671    * This data will not be replicated.
672    */
673   public static final int REPLICATION_SCOPE_LOCAL = 0;
674 
675   /**
676    * Scope tag for globally scoped data.
677    * This data will be replicated to all peers.
678    */
679   public static final int REPLICATION_SCOPE_GLOBAL = 1;
680 
681   /**
682    * Default cluster ID, cannot be used to identify a cluster so a key with
683    * this value means it wasn't meant for replication.
684    */
685   public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
686 
687   /**
688    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
689    * Controlled by the client.
690    */
691   public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
692       "hbase.client.scanner.max.result.size";
693 
694   /**
695    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
696    * Controlled by the server.
697    */
698   public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
699       "hbase.server.scanner.max.result.size";
700 
701   /**
702    * Maximum number of bytes returned when calling a scanner's next method.
703    * Note that when a single row is larger than this limit the row is still
704    * returned completely.
705    *
706    * The default value is 2MB.
707    */
708   public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
709 
710   /**
711    * Maximum number of bytes returned when calling a scanner's next method.
712    * Note that when a single row is larger than this limit the row is still
713    * returned completely.
714    * Safety setting to protect the region server.
715    *
716    * The default value is 100MB. (a client would rarely request larger chunks on purpose)
717    */
718   public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
719 
720   /**
721    * Parameter name for client pause value, used mostly as value to wait
722    * before running a retry of a failed get, region lookup, etc.
723    */
724   public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
725 
726   /**
727    * Default value of {@link #HBASE_CLIENT_PAUSE}.
728    */
729   public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
730 
731   /*
732    * Parameter name for client pause value for special case such as call queue too big, etc.
733    */
734   public static final String HBASE_CLIENT_PAUSE_FOR_CQTBE = "hbase.client.pause.cqtbe";
735 
736   /**
737    * The maximum number of concurrent connections the client will maintain.
738    */
739   public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
740 
741   /**
742    * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
743    */
744   public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
745 
746   /**
747    * The maximum number of concurrent connections the client will maintain to a single
748    * RegionServer.
749    */
750   public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
751 
752   /**
753    * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
754    */
755   public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
756 
757   /**
758    * The maximum number of concurrent connections the client will maintain to a single
759    * Region.
760    */
761   public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
762 
763   /**
764    * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
765    */
766   public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
767 
768   /**
769    * The maximum number of concurrent pending RPC requests for one server in process level.
770    */
771   public static final String HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD =
772       "hbase.client.perserver.requests.threshold";
773 
774   /**
775    * Default value of {@link #HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD}.
776    */
777   public static final int DEFAULT_HBASE_CLIENT_PERSERVER_REQUESTS_THRESHOLD = Integer.MAX_VALUE;
778 
779 
780   /**
781    * Parameter name for server pause value, used mostly as value to wait before
782    * running a retry of a failed operation.
783    */
784   public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
785 
786   /**
787    * Default value of {@link #HBASE_SERVER_PAUSE}.
788    */
789   public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
790 
791   /**
792    * Parameter name for maximum retries, used as maximum for all retryable
793    * operations such as fetching of the root region from root region server,
794    * getting a cell's value, starting a row update, etc.
795    */
796   public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
797 
798   /**
799    * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
800    */
801   public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 31;
802 
803   /**
804    * Parameter name to set the default scanner caching for all clients.
805    */
806   public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
807 
808   /**
809    * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
810    */
811   public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
812 
813   /**
814    * Parameter name for number of versions, kept by meta table.
815    */
816   public static String HBASE_META_VERSIONS = "hbase.meta.versions";
817 
818   /**
819    * Default value of {@link #HBASE_META_VERSIONS}.
820    */
821   public static int DEFAULT_HBASE_META_VERSIONS = 3;
822 
823   /**
824    * Parameter name for number of versions, kept by meta table.
825    */
826   public static String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
827 
828   /**
829    * Default value of {@link #HBASE_META_BLOCK_SIZE}.
830    */
831   public static int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
832 
833   /**
834    * Parameter name for number of rows that will be fetched when calling next on
835    * a scanner if it is not served from memory. Higher caching values will
836    * enable faster scanners but will eat up more memory and some calls of next
837    * may take longer and longer times when the cache is empty.
838    */
839   public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
840 
841   /**
842    * Default value of {@link #HBASE_META_SCANNER_CACHING}.
843    */
844   public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
845 
846   /**
847    * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
848    * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
849    * for all intents and purposes, are the same except for their instance ids, then they will not be
850    * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
851    * even if the instance ids are the same, it could result in non-shared
852    * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
853    * differ.
854    */
855   public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
856 
857   /**
858    * The client scanner timeout period in milliseconds.
859    */
860   public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = "hbase.client.scanner.timeout.period";
861 
862   /**
863    * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
864    * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
865    */
866   @Deprecated
867   public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
868       "hbase.regionserver.lease.period";
869 
870   /**
871    * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
872    */
873   public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
874 
875   /**
876    * timeout for each RPC
877    * @deprecated Use {@link #HBASE_RPC_READ_TIMEOUT_KEY} or {@link #HBASE_RPC_WRITE_TIMEOUT_KEY}
878    * instead.
879    */
880   @Deprecated
881   public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
882 
883   /**
884    * timeout for each read RPC
885    */
886   public static final String HBASE_RPC_READ_TIMEOUT_KEY = "hbase.rpc.read.timeout";
887 
888   /**
889    * timeout for each write RPC
890    */
891   public static final String HBASE_RPC_WRITE_TIMEOUT_KEY = "hbase.rpc.write.timeout";
892 
893   /**
894    * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
895    */
896   public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
897 
898   /**
899    * timeout for short operation RPC
900    */
901   public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
902       "hbase.rpc.shortoperation.timeout";
903 
904   /**
905    * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
906    */
907   public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
908 
909   /**
910    * Value indicating the server name was saved with no sequence number.
911    */
912   public static final long NO_SEQNUM = -1;
913 
914 
915   /*
916    * cluster replication constants.
917    */
918   public static final String
919       REPLICATION_ENABLE_KEY = "hbase.replication";
920   public static final boolean
921       REPLICATION_ENABLE_DEFAULT = true;
922   public static final String
923       REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
924   public static final String
925       REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
926   public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
927     "org.apache.hadoop.hbase.replication.regionserver.Replication";
928   public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
929   public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
930   /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
931   public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
932   /**
933    * Max total size of buffered entries in all replication peers. It will prevent server getting
934    * OOM if there are many peers. Default value is 256MB which is four times to default
935    * replication.source.size.capacity.
936    */
937   public static final String REPLICATION_SOURCE_TOTAL_BUFFER_KEY = "replication.total.buffer.quota";
938   public static final int REPLICATION_SOURCE_TOTAL_BUFFER_DFAULT = 256 * 1024 * 1024;
939 
940 
941   /**
942    * Directory where the source cluster file system client configuration are placed which is used by
943    * sink cluster to copy HFiles from source cluster file system
944    */
945   public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
946 
947   /** Maximum time to retry for a failed bulk load request */
948   public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
949 
950   /** HBCK special code name used as server name when manipulating ZK nodes */
951   public static final String HBCK_CODE_NAME = "HBCKServerName";
952 
953   public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
954     "hbase.regionserver.hostname.seen.by.master";
955 
956   public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
957       "hbase.master.logcleaner.plugins";
958 
959   public static final String HBASE_REGION_SPLIT_POLICY_KEY =
960     "hbase.regionserver.region.split.policy";
961 
962   /** Whether nonces are enabled; default is true. */
963   public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
964 
965   /**
966    * Configuration key for the size of the block cache
967    */
968   public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
969     "hfile.block.cache.size";
970 
971   public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
972 
973   /*
974     * Minimum percentage of free heap necessary for a successful cluster startup.
975     */
976   public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
977 
978   public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
979       Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
980 
981   /**
982    * Pattern that matches a coprocessor specification. Form is:
983    * <code>
984    *&lt;coprocessor jar file location> '|' &lt;class name> ['|' &lt;priority> ['|' &lt;arguments>]]
985    * </code>
986    * ...where arguments are <code>&lt;KEY> '=' &lt;VALUE> [,...]</code>
987    * <p>For example: <code>hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2</code>
988    */
989   public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
990       Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
991 
992   public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
993   public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
994   public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
995       "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
996       CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
997   public static final String CP_HTD_ATTR_INCLUSION_KEY =
998       "hbase.coprocessor.classloader.included.classes";
999 
1000   /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
1001   public static final int SOCKET_RETRY_WAIT_MS = 200;
1002 
1003   /** Host name of the local machine */
1004   public static final String LOCALHOST = "localhost";
1005 
1006   /**
1007    * If this parameter is set to true, then hbase will read
1008    * data and then verify checksums. Checksum verification
1009    * inside hdfs will be switched off.  However, if the hbase-checksum
1010    * verification fails, then it will switch back to using
1011    * hdfs checksums for verifiying data that is being read from storage.
1012    *
1013    * If this parameter is set to false, then hbase will not
1014    * verify any checksums, instead it will depend on checksum verification
1015    * being done in the hdfs client.
1016    */
1017   public static final String HBASE_CHECKSUM_VERIFICATION =
1018       "hbase.regionserver.checksum.verify";
1019 
1020   public static final String LOCALHOST_IP = "127.0.0.1";
1021 
1022   /** Conf key that enables unflushed WAL edits directly being replayed to region servers
1023    */
1024   public static final String DISTRIBUTED_LOG_REPLAY_KEY = "hbase.master.distributed.log.replay";
1025   public static final boolean DEFAULT_DISTRIBUTED_LOG_REPLAY_CONFIG = false;
1026   public static final String DISALLOW_WRITES_IN_RECOVERING =
1027       "hbase.regionserver.disallow.writes.when.recovering";
1028   public static final boolean DEFAULT_DISALLOW_WRITES_IN_RECOVERING_CONFIG = false;
1029 
1030   public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
1031   public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
1032 
1033   /*
1034    * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT:
1035    * -1  => Disable aborting
1036    * 0   => Abort if even a single handler has died
1037    * 0.x => Abort only when this percent of handlers have died
1038    * 1   => Abort only all of the handers have died
1039    */
1040   public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
1041       "hbase.regionserver.handler.abort.on.error.percent";
1042   public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
1043 
1044   //High priority handlers to deal with admin requests and system table operation requests
1045   public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
1046       "hbase.regionserver.metahandler.count";
1047   public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
1048 
1049   public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
1050       "hbase.regionserver.replication.handler.count";
1051   public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
1052 
1053   public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
1054   public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
1055 
1056   /** Conf key that specifies timeout value to wait for a region ready */
1057   public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
1058       "hbase.master.log.replay.wait.region.timeout";
1059 
1060   /** Conf key for enabling meta replication */
1061   public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
1062   public static final boolean DEFAULT_USE_META_REPLICAS = false;
1063   public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
1064   public static final int DEFAULT_META_REPLICA_NUM = 1;
1065 
1066   /**
1067    * The name of the configuration parameter that specifies
1068    * the number of bytes in a newly created checksum chunk.
1069    */
1070   public static final String BYTES_PER_CHECKSUM =
1071       "hbase.hstore.bytes.per.checksum";
1072 
1073   /**
1074    * The name of the configuration parameter that specifies
1075    * the name of an algorithm that is used to compute checksums
1076    * for newly created blocks.
1077    */
1078   public static final String CHECKSUM_TYPE_NAME =
1079       "hbase.hstore.checksum.algorithm";
1080 
1081   /** Enable file permission modification from standard hbase */
1082   public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
1083   /** File permission umask to use when creating hbase data files */
1084   public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
1085 
1086   /** Configuration name of WAL Compression */
1087   public static final String ENABLE_WAL_COMPRESSION =
1088     "hbase.regionserver.wal.enablecompression";
1089 
1090   /** Configuration name of WAL storage policy
1091    * Valid values are: HOT, COLD, WARM, ALL_SSD, ONE_SSD, LAZY_PERSIST
1092    * See http://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html*/
1093   public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
1094   /**
1095    * "NONE" is not a valid storage policy and means we defer the policy to HDFS. @see
1096    * <a href="https://issues.apache.org/jira/browse/HBASE-20691">HBASE-20691</a>
1097    */
1098   public static final String DEFER_TO_HDFS_STORAGE_POLICY = "NONE";
1099   /** By default we defer the WAL storage policy to HDFS */
1100   public static final String DEFAULT_WAL_STORAGE_POLICY = DEFER_TO_HDFS_STORAGE_POLICY;
1101 
1102   /** Region in Transition metrics threshold time */
1103   public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1104       "hbase.metrics.rit.stuck.warning.threshold";
1105 
1106   public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1107 
1108   /** delimiter used between portions of a region name */
1109   public static final int DELIMITER = ',';
1110   public static final String HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
1111       "hbase.config.read.zookeeper.config";
1112   public static final boolean DEFAULT_HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
1113       false;
1114 
1115   /**
1116    * QOS attributes: these attributes are used to demarcate RPC call processing
1117    * by different set of handlers. For example, HIGH_QOS tagged methods are
1118    * handled by high priority handlers.
1119    */
1120   // normal_QOS < QOS_threshold < replication_QOS < replay_QOS < admin_QOS < high_QOS
1121   public static final int PRIORITY_UNSET = -1;
1122   public static final int NORMAL_QOS = 0;
1123   public static final int QOS_THRESHOLD = 10;
1124   public static final int HIGH_QOS = 200;
1125   public static final int REPLICATION_QOS = 5;
1126   public static final int REPLAY_QOS = 6;
1127   public static final int ADMIN_QOS = 100;
1128   public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1129 
1130   /** Directory under /hbase where archived hfiles are stored */
1131   public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1132 
1133   /**
1134    * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
1135    * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
1136    * uni-directional.
1137    */
1138   public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1139 
1140   /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1141   public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1142 
1143   /** Temporary directory used for table creation and deletion */
1144   public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1145   /**
1146    * The period (in milliseconds) between computing region server point in time metrics
1147    */
1148   public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1149   public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1150   /** Directories that are not HBase table directories */
1151   public static final List<String> HBASE_NON_TABLE_DIRS =
1152     Collections.unmodifiableList(Arrays.asList(new String[] {
1153       HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
1154     }));
1155 
1156   /** Directories that are not HBase user table directories */
1157   public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1158     Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
1159       new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1160       HBASE_NON_TABLE_DIRS.toArray())));
1161 
1162   /** Health script related settings. */
1163   public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1164   public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1165   public static final String HEALTH_CHORE_WAKE_FREQ =
1166       "hbase.node.health.script.frequency";
1167   public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1168   /**
1169    * The maximum number of health check failures a server can encounter consecutively.
1170    */
1171   public static final String HEALTH_FAILURE_THRESHOLD =
1172       "hbase.node.health.failure.threshold";
1173   public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1174 
1175   public static final String EXECUTOR_STATUS_COLLECT_ENABLED =
1176       "hbase.executors.status.collect.enabled";
1177   public static final boolean DEFAULT_EXECUTOR_STATUS_COLLECT_ENABLED = true;
1178 
1179   /**
1180    * Setting to activate, or not, the publication of the status by the master. Default
1181    *  notification is by a multicast message.
1182    */
1183   public static final String STATUS_PUBLISHED = "hbase.status.published";
1184   public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1185 
1186   /**
1187    * IP to use for the multicast status messages between the master and the clients.
1188    * The default address is chosen as one among others within the ones suitable for multicast
1189    * messages.
1190    */
1191   public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1192   public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1193 
1194   /**
1195    * The address to use for binding the local socket for receiving multicast. Defaults to
1196    * 0.0.0.0.
1197    * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1198    */
1199   public static final String STATUS_MULTICAST_BIND_ADDRESS =
1200       "hbase.status.multicast.bind.address.ip";
1201   public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1202 
1203   /**
1204    * The port to use for the multicast messages.
1205    */
1206   public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1207   public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1208 
1209   public static final long NO_NONCE = 0;
1210 
1211   /** Default cipher for encryption */
1212   public static final String CIPHER_AES = "AES";
1213 
1214   /** Configuration key for the crypto algorithm provider, a class name */
1215   public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1216 
1217   /** Configuration key for the crypto key provider, a class name */
1218   public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1219 
1220   /** Configuration key for the crypto key provider parameters */
1221   public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1222       "hbase.crypto.keyprovider.parameters";
1223 
1224   /** Configuration key for the name of the master key for the cluster, a string */
1225   public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1226 
1227   /** Configuration key for the name of the alternate master key for the cluster, a string */
1228   public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1229     "hbase.crypto.master.alternate.key.name";
1230 
1231   /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1232   public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1233 
1234   /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1235   public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1236 
1237   /** Configuration key for the algorithm used for creating jks key, a string */
1238   public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1239 
1240   /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1241   public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1242       "hbase.crypto.alternate.key.algorithm";
1243 
1244   /** Configuration key for enabling WAL encryption, a boolean */
1245   public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1246 
1247   /** Configuration key for setting RPC codec class name */
1248   public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1249 
1250   /** Configuration key for setting replication codec class name */
1251   public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1252 
1253   /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1254   public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1255       "hbase.replication.source.maxthreads";
1256 
1257   /** Drop edits for tables that been deleted from the replication source and target */
1258   public static final String REPLICATION_DROP_ON_DELETED_TABLE_KEY =
1259       "hbase.replication.drop.on.deleted.table";
1260 
1261   /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1262   public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1263 
1264   /** Config for pluggable consensus provider */
1265   public static final String HBASE_COORDINATED_STATE_MANAGER_CLASS =
1266     "hbase.coordinated.state.manager.class";
1267 
1268   /** Configuration key for SplitLog manager timeout */
1269   public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1270 
1271   /**
1272    * Configuration keys for Bucket cache
1273    */
1274   // TODO moving these bucket cache implementation specific configs to this level is violation of
1275   // encapsulation. But as these has to be referred from hbase-common and bucket cache
1276   // sits in hbase-server, there were no other go! Can we move the cache implementation to
1277   // hbase-common?
1278 
1279   /**
1280    * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1281    * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1282    * list of supported ioengine options.
1283    * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1284    */
1285   public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1286 
1287   /**
1288    * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1289    * memory size to give to the cache (if &lt; 1.0) OR, it is the capacity in
1290    * megabytes of the cache.
1291    */
1292   public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1293 
1294   /**
1295    * HConstants for fast fail on the client side follow
1296    */
1297   /**
1298    * Config for enabling/disabling the fast fail mode.
1299    */
1300   public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1301       "hbase.client.fast.fail.mode.enabled";
1302 
1303   public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT =
1304       false;
1305 
1306   public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1307       "hbase.client.fastfail.threshold";
1308 
1309   public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT =
1310       60000;
1311 
1312   public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1313       "hbase.client.fast.fail.cleanup.duration";
1314 
1315   public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT =
1316       600000;
1317 
1318   public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1319       "hbase.client.fast.fail.interceptor.impl";
1320 
1321   /** Config key for if the server should send backpressure and if the client should listen to
1322    * that backpressure from the server */
1323   public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1324   public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1325 
1326   public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1327       "hbase.heap.occupancy.low_water_mark";
1328   public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1329   public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1330       "hbase.heap.occupancy.high_water_mark";
1331   public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1332 
1333   /**
1334    * The max number of threads used for splitting storefiles in parallel during
1335    * the region split process.
1336    */
1337   public static final String REGION_SPLIT_THREADS_MAX =
1338     "hbase.regionserver.region.split.threads.max";
1339 
1340   /** Canary config keys */
1341   public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1342 
1343   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1344       "hbase.canary.write.perserver.regions.lowerLimit";
1345 
1346   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1347       "hbase.canary.write.perserver.regions.upperLimit";
1348 
1349   public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1350 
1351   public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1352       "hbase.canary.write.table.check.period";
1353   
1354   public static final String HBASE_CANARY_READ_RAW_SCAN_KEY = "hbase.canary.read.raw.enabled";
1355 
1356   /**
1357    * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1358    */
1359   public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1360   public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1361       "hbase.zookeeper.client.kerberos.principal";
1362   public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1363   public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1364       "hbase.zookeeper.server.kerberos.principal";
1365 
1366   /** Config key for hbase temporary directory in hdfs */
1367   public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1368   public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY = "/user/"
1369       + System.getProperty("user.name") + "/hbase-staging";
1370   public static final String DEFAULT_LOSSY_COUNTING_ERROR_RATE =
1371       "hbase.util.default.lossycounting.errorrate";
1372 
1373   // Default TTL - FOREVER
1374   public static final long DEFAULT_SNAPSHOT_TTL = 0;
1375 
1376   // User defined Default TTL config key
1377   public static final String DEFAULT_SNAPSHOT_TTL_CONFIG_KEY = "hbase.master.snapshot.ttl";
1378 
1379   // Regions Recovery based on high storeFileRefCount threshold value
1380   public static final String STORE_FILE_REF_COUNT_THRESHOLD =
1381     "hbase.regions.recovery.store.file.ref.count";
1382 
1383   // default -1 indicates there is no threshold on high storeRefCount
1384   public static final int DEFAULT_STORE_FILE_REF_COUNT_THRESHOLD = -1;
1385 
1386   public static final String REGIONS_RECOVERY_INTERVAL =
1387     "hbase.master.regions.recovery.check.interval";
1388 
1389   public static final int DEFAULT_REGIONS_RECOVERY_INTERVAL = 1200 * 1000; // Default 20 min
1390 
1391   /**
1392    * Configurations for master executor services.
1393    */
1394   public static final String MASTER_OPEN_REGION_THREADS =
1395       "hbase.master.executor.openregion.threads";
1396   public static final int MASTER_OPEN_REGION_THREADS_DEFAULT = 5;
1397 
1398   public static final String MASTER_CLOSE_REGION_THREADS =
1399       "hbase.master.executor.closeregion.threads";
1400   public static final int MASTER_CLOSE_REGION_THREADS_DEFAULT = 5;
1401 
1402   public static final String MASTER_SERVER_OPERATIONS_THREADS =
1403       "hbase.master.executor.serverops.threads";
1404   public static final int MASTER_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1405 
1406   /**
1407    * Number of threads used to dispatch merge operations to the regionservers.
1408    */
1409   public static final String MASTER_MERGE_DISPATCH_THREADS =
1410       "hbase.master.executor.merge.dispatch.threads";
1411   public static final int MASTER_MERGE_DISPATCH_THREADS_DEFAULT = 2;
1412 
1413   public static final String MASTER_META_SERVER_OPERATIONS_THREADS =
1414       "hbase.master.executor.meta.serverops.threads";
1415   public static final int MASTER_META_SERVER_OPERATIONS_THREADS_DEFAULT = 5;
1416 
1417   public static final String MASTER_LOG_REPLAY_OPS_THREADS =
1418       "hbase.master.executor.logreplayops.threads";
1419   public static final int MASTER_LOG_REPLAY_OPS_THREADS_DEFAULT = 10;
1420 
1421   /**
1422    * Number of rows in a batch operation above which a warning will be logged.
1423    */
1424   public static final String BATCH_ROWS_THRESHOLD_NAME = "hbase.rpc.rows.warning.threshold";
1425 
1426   /**
1427    * Default value of {@link #BATCH_ROWS_THRESHOLD_NAME}
1428    */
1429   public static final int BATCH_ROWS_THRESHOLD_DEFAULT = 5000;
1430 
1431   public static final int DEFAULT_SLOW_LOG_RING_BUFFER_SIZE = 256;
1432 
1433   public static final String SLOW_LOG_BUFFER_ENABLED_KEY =
1434     "hbase.regionserver.slowlog.buffer.enabled";
1435   public static final boolean DEFAULT_ONLINE_LOG_PROVIDER_ENABLED = false;
1436 
1437   /** The slowlog info family as a string*/
1438   private static final String SLOWLOG_INFO_FAMILY_STR = "info";
1439 
1440   /** The slowlog info family */
1441   public static final byte [] SLOWLOG_INFO_FAMILY = Bytes.toBytes(SLOWLOG_INFO_FAMILY_STR);
1442 
1443   public static final String SLOW_LOG_SYS_TABLE_ENABLED_KEY =
1444     "hbase.regionserver.slowlog.systable.enabled";
1445   public static final boolean DEFAULT_SLOW_LOG_SYS_TABLE_ENABLED_KEY = false;
1446 
1447   /**
1448    * This config is for experts: don't set its value unless you really know what you are doing.
1449    * When set to true, HBase client using SASL Kerberos will skip reverse DNS lookup and use
1450    * provided hostname of the destination for the principal instead.
1451    * See https://issues.apache.org/jira/browse/HBASE-25665 for more details.
1452    */
1453   @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
1454   public static final String UNSAFE_HBASE_CLIENT_KERBEROS_HOSTNAME_DISABLE_REVERSEDNS =
1455     "hbase.unsafe.client.kerberos.hostname.disable.reversedns";
1456   public static final boolean DEFAULT_UNSAFE_HBASE_CLIENT_KERBEROS_HOSTNAME_DISABLE_REVERSEDNS =
1457     false;
1458 
1459   private HConstants() {
1460     // Can't be instantiated with this ctor.
1461   }
1462 }