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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  
83    //End HFileBlockConstants.
84  
85    /**
86     * Status codes used for return values of bulk operations.
87     */
88    @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
89    public enum OperationStatusCode {
90      NOT_RUN,
91      SUCCESS,
92      BAD_FAMILY,
93      SANITY_CHECK_FAILURE,
94      FAILURE;
95    }
96  
97    /** long constant for zero */
98    public static final Long ZERO_L = Long.valueOf(0L);
99    public static final String NINES = "99999999999999";
100   public static final String ZEROES = "00000000000000";
101 
102   // For migration
103 
104   /** name of version file */
105   public static final String VERSION_FILE_NAME = "hbase.version";
106 
107   /**
108    * Current version of file system.
109    * Version 4 supports only one kind of bloom filter.
110    * Version 5 changes versions in catalog table regions.
111    * Version 6 enables blockcaching on catalog tables.
112    * Version 7 introduces hfile -- hbase 0.19 to 0.20..
113    * Version 8 introduces namespace
114    */
115   // public static final String FILE_SYSTEM_VERSION = "6";
116   public static final String FILE_SYSTEM_VERSION = "8";
117 
118   // Configuration parameters
119 
120   //TODO: Is having HBase homed on port 60k OK?
121 
122   /** Cluster is in distributed mode or not */
123   public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
124 
125   /** Config for pluggable load balancers */
126   public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
127 
128   /** Config for balancing the cluster by table */
129   public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
130 
131   /** The name of the ensemble table */
132   public static final String ENSEMBLE_TABLE_NAME = "hbase:ensemble";
133 
134   /** Config for pluggable region normalizer */
135   public static final String HBASE_MASTER_NORMALIZER_CLASS =
136     "hbase.master.normalizer.class";
137 
138   /** Cluster is standalone or pseudo-distributed */
139   public static final boolean CLUSTER_IS_LOCAL = false;
140 
141   /** Cluster is fully-distributed */
142   public static final boolean CLUSTER_IS_DISTRIBUTED = true;
143 
144   /** Default value for cluster distributed mode */
145   public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
146 
147   /** default host address */
148   public static final String DEFAULT_HOST = "0.0.0.0";
149 
150   /** Parameter name for port master listens on. */
151   public static final String MASTER_PORT = "hbase.master.port";
152 
153   /** default port that the master listens on */
154   public static final int DEFAULT_MASTER_PORT = 16000;
155 
156   /** default port for master web api */
157   public static final int DEFAULT_MASTER_INFOPORT = 16010;
158 
159   /** Configuration key for master web API port */
160   public static final String MASTER_INFO_PORT = "hbase.master.info.port";
161 
162   /** Parameter name for the master type being backup (waits for primary to go inactive). */
163   public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
164 
165   /** by default every master is a possible primary master unless the conf explicitly overrides it */
166   public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
167 
168   /** Name of ZooKeeper quorum configuration parameter. */
169   public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
170 
171   /** Name of ZooKeeper config file in conf/ directory. */
172   public static final String ZOOKEEPER_CONFIG_NAME = "zoo.cfg";
173 
174   /** Common prefix of ZooKeeper configuration properties */
175   public static final String ZK_CFG_PROPERTY_PREFIX =
176       "hbase.zookeeper.property.";
177 
178   public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
179       ZK_CFG_PROPERTY_PREFIX.length();
180 
181   /**
182    * The ZK client port key in the ZK properties map. The name reflects the
183    * fact that this is not an HBase configuration key.
184    */
185   public static final String CLIENT_PORT_STR = "clientPort";
186 
187   /** Parameter name for the client port that the zookeeper listens on */
188   public static final String ZOOKEEPER_CLIENT_PORT =
189       ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
190 
191   /** Default client port that the zookeeper listens on */
192   public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
193 
194   /** Parameter name for the wait time for the recoverable zookeeper */
195   public static final String ZOOKEEPER_RECOVERABLE_WAITTIME = "hbase.zookeeper.recoverable.waittime";
196 
197   /** Default wait time for the recoverable zookeeper */
198   public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
199 
200   /** Parameter name for the root dir in ZK for this cluster */
201   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
202 
203   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
204 
205   /**
206    * Parameter name for the limit on concurrent client-side zookeeper
207    * connections
208    */
209   public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
210       ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
211 
212   /** Parameter name for the ZK data directory */
213   public static final String ZOOKEEPER_DATA_DIR =
214       ZK_CFG_PROPERTY_PREFIX + "dataDir";
215 
216   /** Parameter name for the ZK tick time */
217   public static final String ZOOKEEPER_TICK_TIME =
218       ZK_CFG_PROPERTY_PREFIX + "tickTime";
219 
220   /** Default limit on concurrent client-side zookeeper connections */
221   public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
222 
223   /** Configuration key for ZooKeeper session timeout */
224   public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
225 
226   /** Default value for ZooKeeper session timeout */
227   public static final int DEFAULT_ZK_SESSION_TIMEOUT = 180 * 1000;
228 
229   /** Configuration key for whether to use ZK.multi */
230   public static final String ZOOKEEPER_USEMULTI = "hbase.zookeeper.useMulti";
231 
232   /** Parameter name for port region server listens on. */
233   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
234 
235   /** Default port region server listens on. */
236   public static final int DEFAULT_REGIONSERVER_PORT = 16020;
237 
238   /** default port for region server web api */
239   public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
240 
241   /** A configuration key for regionserver info port */
242   public static final String REGIONSERVER_INFO_PORT =
243     "hbase.regionserver.info.port";
244 
245   /** A flag that enables automatic selection of regionserver info port */
246   public static final String REGIONSERVER_INFO_PORT_AUTO =
247       REGIONSERVER_INFO_PORT + ".auto";
248 
249   /** Parameter name for what region server implementation to use. */
250   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
251 
252   /** Parameter name for what master implementation to use. */
253   public static final String MASTER_IMPL= "hbase.master.impl";
254 
255   /** Parameter name for what hbase client implementation to use. */
256   public static final String HBASECLIENT_IMPL= "hbase.hbaseclient.impl";
257 
258   /** Parameter name for how often threads should wake up */
259   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
260 
261   /** Default value for thread wake frequency */
262   public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
263 
264   /** Parameter name for how often we should try to write a version file, before failing */
265   public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
266 
267   /** Parameter name for how often we should try to write a version file, before failing */
268   public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
269 
270   /** Parameter name for how often a region should should perform a major compaction */
271   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
272 
273   /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
274   public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
275   public static final int COMPACTION_KV_MAX_DEFAULT = 10;
276 
277   /** Parameter name for HBase instance root directory */
278   public static final String HBASE_DIR = "hbase.rootdir";
279 
280   /** Parameter name for HBase client IPC pool type */
281   public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
282 
283   /** Parameter name for HBase client IPC pool size */
284   public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
285 
286   /** Parameter name for HBase client operation timeout. */
287   public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
288 
289   /** Parameter name for HBase client operation timeout. */
290   public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
291     "hbase.client.meta.operation.timeout";
292 
293   /** Default HBase client operation timeout, which is tantamount to a blocking call */
294   public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
295 
296   /** Used to construct the name of the log directory for a region server */
297   public static final String HREGION_LOGDIR_NAME = "WALs";
298 
299   /** Used to construct the name of the splitlog directory for a region server */
300   public static final String SPLIT_LOGDIR_NAME = "splitWAL";
301 
302   /** Like the previous, but for old logs that are about to be deleted */
303   public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
304 
305   public static final String CORRUPT_DIR_NAME = "corrupt";
306 
307   /** Used by HBCK to sideline backup data */
308   public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
309 
310   /** Any artifacts left from migration can be moved here */
311   public static final String MIGRATION_NAME = ".migration";
312 
313   /**
314    * The directory from which co-processor/custom filter jars can be loaded
315    * dynamically by the region servers. This value can be overridden by the
316    * hbase.dynamic.jars.dir config.
317    */
318   public static final String LIB_DIR = "lib";
319 
320   /** Used to construct the name of the compaction directory during compaction */
321   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
322 
323   /** Conf key for the max file size after which we split the region */
324   public static final String HREGION_MAX_FILESIZE =
325       "hbase.hregion.max.filesize";
326 
327   /** Default maximum file size */
328   public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
329 
330   /**
331    * Max size of single row for Get's or Scan's without in-row scanning flag set.
332    */
333   public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
334 
335   /**
336    * Default max row size (1 Gb).
337    */
338   public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
339 
340   /**
341    * The max number of threads used for opening and closing stores or store
342    * files in parallel
343    */
344   public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
345     "hbase.hstore.open.and.close.threads.max";
346 
347   /**
348    * The default number for the max number of threads used for opening and
349    * closing stores or store files in parallel
350    */
351   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
352 
353   /**
354    * Block updates if memstore has hbase.hregion.memstore.block.multiplier
355    * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
356    * runaway memstore during spikes in update traffic.
357    */
358   public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
359           "hbase.hregion.memstore.block.multiplier";
360 
361   /**
362    * Default value for hbase.hregion.memstore.block.multiplier
363    */
364   public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
365 
366   /** Conf key for the memstore size at which we flush the memstore */
367   public static final String HREGION_MEMSTORE_FLUSH_SIZE =
368       "hbase.hregion.memstore.flush.size";
369 
370   public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
371       "hbase.hregion.edits.replay.skip.errors";
372 
373   public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
374       false;
375 
376   /** Maximum value length, enforced on KeyValue construction */
377   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
378 
379   /** name of the file for unique cluster ID */
380   public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
381 
382   /** Default value for cluster ID */
383   public static final String CLUSTER_ID_DEFAULT = "default-cluster";
384 
385   /** Parameter name for # days to keep MVCC values during a major compaction */
386   public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
387   /** At least to keep MVCC values in hfiles for 5 days */
388   public static final int MIN_KEEP_SEQID_PERIOD = 5;
389 
390   // Always store the location of the root table's HRegion.
391   // This HRegion is never split.
392 
393   // region name = table + startkey + regionid. This is the row key.
394   // each row in the root and meta tables describes exactly 1 region
395   // Do we ever need to know all the information that we are storing?
396 
397   // Note that the name of the root table starts with "-" and the name of the
398   // meta table starts with "." Why? it's a trick. It turns out that when we
399   // store region names in memory, we use a SortedMap. Since "-" sorts before
400   // "." (and since no other table name can start with either of these
401   // characters, the root region will always be the first entry in such a Map,
402   // followed by all the meta regions (which will be ordered by their starting
403   // row key as well), followed by all user tables. So when the Master is
404   // choosing regions to assign, it will always choose the root region first,
405   // followed by the meta regions, followed by user regions. Since the root
406   // and meta regions always need to be on-line, this ensures that they will
407   // be the first to be reassigned if the server(s) they are being served by
408   // should go down.
409 
410 
411   /**
412    * The hbase:meta table's name.
413    * @deprecated For upgrades of 0.94 to 0.96
414    */
415   @Deprecated  // for compat from 0.94 -> 0.96.
416   public static final byte[] META_TABLE_NAME = TableName.META_TABLE_NAME.getName();
417 
418   public static final String BASE_NAMESPACE_DIR = "data";
419 
420   /** delimiter used between portions of a region name */
421   public static final int META_ROW_DELIMITER = ',';
422 
423   /** The catalog family as a string*/
424   public static final String CATALOG_FAMILY_STR = "info";
425 
426   /** The catalog family */
427   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
428 
429   /** The RegionInfo qualifier as a string */
430   public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
431 
432   /** The regioninfo column qualifier */
433   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
434 
435   /** The server column qualifier */
436   public static final String SERVER_QUALIFIER_STR = "server";
437   /** The server column qualifier */
438   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
439 
440   /** The startcode column qualifier */
441   public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
442   /** The startcode column qualifier */
443   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
444 
445   /** The open seqnum column qualifier */
446   public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
447   /** The open seqnum column qualifier */
448   public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
449 
450   /** The state column qualifier */
451   public static final String STATE_QUALIFIER_STR = "state";
452 
453   public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
454 
455   /**
456    * The serverName column qualifier. Its the server where the region is
457    * transitioning on, while column server is the server where the region is
458    * opened on. They are the same when the region is in state OPEN.
459    */
460   public static final String SERVERNAME_QUALIFIER_STR = "sn";
461 
462   public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
463 
464   /** The lower-half split region column qualifier */
465   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
466 
467   /** The upper-half split region column qualifier */
468   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
469 
470   /** The lower-half merge region column qualifier */
471   public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes("mergeA");
472 
473   /** The upper-half merge region column qualifier */
474   public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes("mergeB");
475 
476   /**
477    * The meta table version column qualifier.
478    * We keep current version of the meta table in this column in <code>-ROOT-</code>
479    * table: i.e. in the 'info:v' column.
480    */
481   public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
482 
483   /**
484    * The current version of the meta table.
485    * - pre-hbase 0.92.  There is no META_VERSION column in the root table
486    * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
487    * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
488    * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
489    * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
490    * byte[] serialization from Writables to Protobuf.
491    * See HRegionInfo.VERSION
492    */
493   public static final short META_VERSION = 1;
494 
495   // Other constants
496 
497   /**
498    * An empty instance.
499    */
500   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
501 
502   /**
503    * Used by scanners, etc when they want to start at the beginning of a region
504    */
505   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
506 
507   /**
508    * Last row in a table.
509    */
510   public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
511 
512   /**
513     * Used by scanners and others when they're trying to detect the end of a
514     * table
515     */
516   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
517 
518   /**
519    * Max length a row can have because of the limitation in TFile.
520    */
521   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
522 
523   /**
524    * Timestamp to use when we want to refer to the latest cell.
525    * This is the timestamp sent by clients when no timestamp is specified on
526    * commit.
527    */
528   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
529 
530   /**
531    * Timestamp to use when we want to refer to the oldest cell.
532    * Special! Used in fake Cells only. Should never be the timestamp on an actual Cell returned to
533    * a client.
534    * @deprecated Should not be public since hbase-1.3.0. For internal use only. Move internal to
535    * Scanners flagged as special timestamp value never to be returned as timestamp on a Cell.
536    */
537   @Deprecated
538   public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
539 
540   /**
541    * LATEST_TIMESTAMP in bytes form
542    */
543   public static final byte [] LATEST_TIMESTAMP_BYTES = {
544     // big-endian
545     (byte) (LATEST_TIMESTAMP >>> 56),
546     (byte) (LATEST_TIMESTAMP >>> 48),
547     (byte) (LATEST_TIMESTAMP >>> 40),
548     (byte) (LATEST_TIMESTAMP >>> 32),
549     (byte) (LATEST_TIMESTAMP >>> 24),
550     (byte) (LATEST_TIMESTAMP >>> 16),
551     (byte) (LATEST_TIMESTAMP >>> 8),
552     (byte) LATEST_TIMESTAMP,
553   };
554 
555   /**
556    * Define for 'return-all-versions'.
557    */
558   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
559 
560   /**
561    * Unlimited time-to-live.
562    */
563 //  public static final int FOREVER = -1;
564   public static final int FOREVER = Integer.MAX_VALUE;
565 
566   /**
567    * Seconds in a week
568    */
569   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
570 
571   /**
572    * Seconds in a day, hour and minute
573    */
574   public static final int DAY_IN_SECONDS = 24 * 60 * 60;
575   public static final int HOUR_IN_SECONDS = 60 * 60;
576   public static final int MINUTE_IN_SECONDS = 60;
577 
578   //TODO: although the following are referenced widely to format strings for
579   //      the shell. They really aren't a part of the public API. It would be
580   //      nice if we could put them somewhere where they did not need to be
581   //      public. They could have package visibility
582   public static final String NAME = "NAME";
583   public static final String VERSIONS = "VERSIONS";
584   public static final String IN_MEMORY = "IN_MEMORY";
585   public static final String METADATA = "METADATA";
586   public static final String CONFIGURATION = "CONFIGURATION";
587 
588   /**
589    * Retrying we multiply hbase.client.pause setting by what we have in this array until we
590    * run out of array items.  Retries beyond this use the last number in the array.  So, for
591    * example, if hbase.client.pause is 1 second, and maximum retries count
592    * hbase.client.retries.number is 10, we will retry at the following intervals:
593    * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
594    * With 100ms, a back-off of 200 means 20s
595    */
596   public static final int [] RETRY_BACKOFF = {1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200};
597 
598   public static final String REGION_IMPL = "hbase.hregion.impl";
599 
600   /** modifyTable op for replacing the table descriptor */
601   @InterfaceAudience.Private
602   public static enum Modify {
603     CLOSE_REGION,
604     TABLE_COMPACT,
605     TABLE_FLUSH,
606     TABLE_MAJOR_COMPACT,
607     TABLE_SET_HTD,
608     TABLE_SPLIT
609   }
610 
611   /**
612    * Scope tag for locally scoped data.
613    * This data will not be replicated.
614    */
615   public static final int REPLICATION_SCOPE_LOCAL = 0;
616 
617   /**
618    * Scope tag for globally scoped data.
619    * This data will be replicated to all peers.
620    */
621   public static final int REPLICATION_SCOPE_GLOBAL = 1;
622 
623   /**
624    * Default cluster ID, cannot be used to identify a cluster so a key with
625    * this value means it wasn't meant for replication.
626    */
627   public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
628 
629   /**
630    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
631    * Controlled by the client.
632    */
633   public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
634       "hbase.client.scanner.max.result.size";
635 
636   /**
637    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
638    * Controlled by the server.
639    */
640   public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
641       "hbase.server.scanner.max.result.size";
642 
643   /**
644    * Maximum number of bytes returned when calling a scanner's next method.
645    * Note that when a single row is larger than this limit the row is still
646    * returned completely.
647    *
648    * The default value is 2MB.
649    */
650   public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
651 
652   /**
653    * Maximum number of bytes returned when calling a scanner's next method.
654    * Note that when a single row is larger than this limit the row is still
655    * returned completely.
656    * Safety setting to protect the region server.
657    *
658    * The default value is 100MB. (a client would rarely request larger chunks on purpose)
659    */
660   public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
661 
662   /**
663    * Parameter name for client pause value, used mostly as value to wait
664    * before running a retry of a failed get, region lookup, etc.
665    */
666   public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
667 
668   /**
669    * Default value of {@link #HBASE_CLIENT_PAUSE}.
670    */
671   public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
672 
673   /**
674    * The maximum number of concurrent connections the client will maintain.
675    */
676   public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
677 
678   /**
679    * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
680    */
681   public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
682 
683   /**
684    * The maximum number of concurrent connections the client will maintain to a single
685    * RegionServer.
686    */
687   public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
688 
689   /**
690    * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
691    */
692   public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
693 
694   /**
695    * The maximum number of concurrent connections the client will maintain to a single
696    * Region.
697    */
698   public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
699 
700   /**
701    * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
702    */
703   public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
704 
705   /**
706    * Parameter name for server pause value, used mostly as value to wait before
707    * running a retry of a failed operation.
708    */
709   public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
710 
711   /**
712    * Default value of {@link #HBASE_SERVER_PAUSE}.
713    */
714   public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
715 
716   /**
717    * Parameter name for maximum retries, used as maximum for all retryable
718    * operations such as fetching of the root region from root region server,
719    * getting a cell's value, starting a row update, etc.
720    */
721   public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
722 
723   /**
724    * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
725    */
726   public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 31;
727 
728   /**
729    * Parameter name to set the default scanner caching for all clients.
730    */
731   public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
732 
733   /**
734    * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
735    */
736   public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
737 
738   /**
739    * Parameter name for number of versions, kept by meta table.
740    */
741   public static String HBASE_META_VERSIONS = "hbase.meta.versions";
742 
743   /**
744    * Default value of {@link #HBASE_META_VERSIONS}.
745    */
746   public static int DEFAULT_HBASE_META_VERSIONS = 10;
747 
748   /**
749    * Parameter name for number of versions, kept by meta table.
750    */
751   public static String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
752 
753   /**
754    * Default value of {@link #HBASE_META_BLOCK_SIZE}.
755    */
756   public static int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
757 
758   /**
759    * Parameter name for number of rows that will be fetched when calling next on
760    * a scanner if it is not served from memory. Higher caching values will
761    * enable faster scanners but will eat up more memory and some calls of next
762    * may take longer and longer times when the cache is empty.
763    */
764   public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
765 
766   /**
767    * Default value of {@link #HBASE_META_SCANNER_CACHING}.
768    */
769   public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
770 
771   /**
772    * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
773    * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
774    * for all intents and purposes, are the same except for their instance ids, then they will not be
775    * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
776    * even if the instance ids are the same, it could result in non-shared
777    * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
778    * differ.
779    */
780   public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
781 
782   /**
783    * The client scanner timeout period in milliseconds.
784    */
785   public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = "hbase.client.scanner.timeout.period";
786 
787   /**
788    * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
789    * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
790    */
791   @Deprecated
792   public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
793       "hbase.regionserver.lease.period";
794 
795   /**
796    * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
797    */
798   public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
799 
800   /**
801    * timeout for each RPC
802    */
803   public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
804 
805   /**
806    * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
807    */
808   public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
809 
810   /**
811    * timeout for short operation RPC
812    */
813   public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
814       "hbase.rpc.shortoperation.timeout";
815 
816   /**
817    * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
818    */
819   public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
820 
821   /**
822    * Value indicating the server name was saved with no sequence number.
823    */
824   public static final long NO_SEQNUM = -1;
825 
826 
827   /*
828    * cluster replication constants.
829    */
830   public static final String
831       REPLICATION_ENABLE_KEY = "hbase.replication";
832   public static final boolean
833       REPLICATION_ENABLE_DEFAULT = true;
834   public static final String
835       REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
836   public static final String
837       REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
838   public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
839     "org.apache.hadoop.hbase.replication.regionserver.Replication";
840   public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
841   public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
842   /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
843   public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
844   /**
845    * Directory where the source cluster file system client configuration are placed which is used by
846    * sink cluster to copy HFiles from source cluster file system
847    */
848   public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
849 
850   /** Maximum time to retry for a failed bulk load request */
851   public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
852 
853   /** HBCK special code name used as server name when manipulating ZK nodes */
854   public static final String HBCK_CODE_NAME = "HBCKServerName";
855 
856   public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
857     "hbase.regionserver.hostname.seen.by.master";
858 
859   public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
860       "hbase.master.logcleaner.plugins";
861 
862   public static final String HBASE_REGION_SPLIT_POLICY_KEY =
863     "hbase.regionserver.region.split.policy";
864 
865   /** Whether nonces are enabled; default is true. */
866   public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
867 
868   /**
869    * Configuration key for the size of the block cache
870    */
871   public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
872     "hfile.block.cache.size";
873 
874   public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
875 
876   /*
877     * Minimum percentage of free heap necessary for a successful cluster startup.
878     */
879   public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
880 
881   public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
882       Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
883 
884   /**
885    * Pattern that matches a coprocessor specification. Form is:
886    * <code>
887    *&lt;coprocessor jar file location> '|' &lt<class name> ['|' &lt;priority> ['|' &lt;arguments>]]
888    * </code>
889    * ...where arguments are <code>&lt;KEY> '=' &lt;VALUE> [,...]</code>
890    * <p>For example: <code>hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2</code>
891    */
892   public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
893       Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
894 
895   public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
896   public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
897   public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
898       "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
899       CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
900 
901   /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
902   public static final int SOCKET_RETRY_WAIT_MS = 200;
903 
904   /** Host name of the local machine */
905   public static final String LOCALHOST = "localhost";
906 
907   /**
908    * If this parameter is set to true, then hbase will read
909    * data and then verify checksums. Checksum verification
910    * inside hdfs will be switched off.  However, if the hbase-checksum
911    * verification fails, then it will switch back to using
912    * hdfs checksums for verifiying data that is being read from storage.
913    *
914    * If this parameter is set to false, then hbase will not
915    * verify any checksums, instead it will depend on checksum verification
916    * being done in the hdfs client.
917    */
918   public static final String HBASE_CHECKSUM_VERIFICATION =
919       "hbase.regionserver.checksum.verify";
920 
921   public static final String LOCALHOST_IP = "127.0.0.1";
922 
923   /** Conf key that enables unflushed WAL edits directly being replayed to region servers
924    */
925   public static final String DISTRIBUTED_LOG_REPLAY_KEY = "hbase.master.distributed.log.replay";
926   public static final boolean DEFAULT_DISTRIBUTED_LOG_REPLAY_CONFIG = false;
927   public static final String DISALLOW_WRITES_IN_RECOVERING =
928       "hbase.regionserver.disallow.writes.when.recovering";
929   public static final boolean DEFAULT_DISALLOW_WRITES_IN_RECOVERING_CONFIG = false;
930 
931   public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
932   public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
933 
934   /*
935    * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT:
936    * -1  => Disable aborting
937    * 0   => Abort if even a single handler has died
938    * 0.x => Abort only when this percent of handlers have died
939    * 1   => Abort only all of the handers have died
940    */
941   public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
942       "hbase.regionserver.handler.abort.on.error.percent";
943   public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
944 
945   //High priority handlers to deal with admin requests and system table operation requests
946   public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
947       "hbase.regionserver.metahandler.count";
948   public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
949 
950   public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
951       "hbase.regionserver.replication.handler.count";
952   public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
953 
954   public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
955   public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
956 
957   /** Conf key that specifies timeout value to wait for a region ready */
958   public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
959       "hbase.master.log.replay.wait.region.timeout";
960 
961   /** Conf key for enabling meta replication */
962   public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
963   public static final boolean DEFAULT_USE_META_REPLICAS = false;
964   public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
965   public static final int DEFAULT_META_REPLICA_NUM = 1;
966 
967   /**
968    * The name of the configuration parameter that specifies
969    * the number of bytes in a newly created checksum chunk.
970    */
971   public static final String BYTES_PER_CHECKSUM =
972       "hbase.hstore.bytes.per.checksum";
973 
974   /**
975    * The name of the configuration parameter that specifies
976    * the name of an algorithm that is used to compute checksums
977    * for newly created blocks.
978    */
979   public static final String CHECKSUM_TYPE_NAME =
980       "hbase.hstore.checksum.algorithm";
981 
982   /** Enable file permission modification from standard hbase */
983   public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
984   /** File permission umask to use when creating hbase data files */
985   public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
986 
987   /** Configuration name of WAL Compression */
988   public static final String ENABLE_WAL_COMPRESSION =
989     "hbase.regionserver.wal.enablecompression";
990 
991   /** Configuration name of WAL storage policy
992    * Valid values are:
993    *  NONE: no preference in destination of block replicas
994    *  ONE_SSD: place only one block replica in SSD and the remaining in default storage
995    *  and ALL_SSD: place all block replicas on SSD
996    *
997    * See http://hadoop.apache.org/docs/r2.6.0/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html*/
998   public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
999   public static final String DEFAULT_WAL_STORAGE_POLICY = "NONE";
1000 
1001   /** Region in Transition metrics threshold time */
1002   public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1003       "hbase.metrics.rit.stuck.warning.threshold";
1004 
1005   public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1006 
1007   /** delimiter used between portions of a region name */
1008   public static final int DELIMITER = ',';
1009   public static final String HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
1010       "hbase.config.read.zookeeper.config";
1011   public static final boolean DEFAULT_HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
1012       false;
1013 
1014   /**
1015    * QOS attributes: these attributes are used to demarcate RPC call processing
1016    * by different set of handlers. For example, HIGH_QOS tagged methods are
1017    * handled by high priority handlers.
1018    */
1019   // normal_QOS < QOS_threshold < replication_QOS < replay_QOS < admin_QOS < high_QOS
1020   public static final int NORMAL_QOS = 0;
1021   public static final int QOS_THRESHOLD = 10;
1022   public static final int HIGH_QOS = 200;
1023   public static final int REPLICATION_QOS = 5;
1024   public static final int REPLAY_QOS = 6;
1025   public static final int ADMIN_QOS = 100;
1026   public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1027 
1028   /** Directory under /hbase where archived hfiles are stored */
1029   public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1030 
1031   /**
1032    * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
1033    * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
1034    * uni-directional.
1035    */
1036   public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1037 
1038   /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1039   public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1040 
1041   /** Temporary directory used for table creation and deletion */
1042   public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1043   /**
1044    * The period (in milliseconds) between computing region server point in time metrics
1045    */
1046   public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1047   public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1048   /** Directories that are not HBase table directories */
1049   public static final List<String> HBASE_NON_TABLE_DIRS =
1050     Collections.unmodifiableList(Arrays.asList(new String[] {
1051       HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
1052     }));
1053 
1054   /** Directories that are not HBase user table directories */
1055   public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1056     Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
1057       new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1058       HBASE_NON_TABLE_DIRS.toArray())));
1059 
1060   /** Health script related settings. */
1061   public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1062   public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1063   public static final String HEALTH_CHORE_WAKE_FREQ =
1064       "hbase.node.health.script.frequency";
1065   public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1066   /**
1067    * The maximum number of health check failures a server can encounter consecutively.
1068    */
1069   public static final String HEALTH_FAILURE_THRESHOLD =
1070       "hbase.node.health.failure.threshold";
1071   public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1072 
1073 
1074   /**
1075    * Setting to activate, or not, the publication of the status by the master. Default
1076    *  notification is by a multicast message.
1077    */
1078   public static final String STATUS_PUBLISHED = "hbase.status.published";
1079   public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1080 
1081   /**
1082    * IP to use for the multicast status messages between the master and the clients.
1083    * The default address is chosen as one among others within the ones suitable for multicast
1084    * messages.
1085    */
1086   public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1087   public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1088 
1089   /**
1090    * The address to use for binding the local socket for receiving multicast. Defaults to
1091    * 0.0.0.0.
1092    * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1093    */
1094   public static final String STATUS_MULTICAST_BIND_ADDRESS =
1095       "hbase.status.multicast.bind.address.ip";
1096   public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1097 
1098   /**
1099    * The port to use for the multicast messages.
1100    */
1101   public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1102   public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1103 
1104   public static final long NO_NONCE = 0;
1105 
1106   /** Default cipher for encryption */
1107   public static final String CIPHER_AES = "AES";
1108 
1109   /** Configuration key for the crypto algorithm provider, a class name */
1110   public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1111 
1112   /** Configuration key for the crypto key provider, a class name */
1113   public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1114 
1115   /** Configuration key for the crypto key provider parameters */
1116   public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1117       "hbase.crypto.keyprovider.parameters";
1118 
1119   /** Configuration key for the name of the master key for the cluster, a string */
1120   public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1121 
1122   /** Configuration key for the name of the alternate master key for the cluster, a string */
1123   public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1124     "hbase.crypto.master.alternate.key.name";
1125 
1126   /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1127   public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1128 
1129   /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1130   public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1131 
1132   /** Configuration key for the algorithm used for creating jks key, a string */
1133   public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1134 
1135   /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1136   public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1137       "hbase.crypto.alternate.key.algorithm";
1138 
1139   /** Configuration key for enabling WAL encryption, a boolean */
1140   public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1141 
1142   /** Configuration key for setting RPC codec class name */
1143   public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1144 
1145   /** Configuration key for setting replication codec class name */
1146   public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1147 
1148   /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1149   public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1150       "hbase.replication.source.maxthreads";
1151 
1152   public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1153 
1154   /** Config for pluggable consensus provider */
1155   public static final String HBASE_COORDINATED_STATE_MANAGER_CLASS =
1156     "hbase.coordinated.state.manager.class";
1157 
1158   /** Configuration key for SplitLog manager timeout */
1159   public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1160 
1161   /**
1162    * Configuration keys for Bucket cache
1163    */
1164   // TODO moving these bucket cache implementation specific configs to this level is violation of
1165   // encapsulation. But as these has to be referred from hbase-common and bucket cache
1166   // sits in hbase-server, there were no other go! Can we move the cache implementation to
1167   // hbase-common?
1168 
1169   /**
1170    * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1171    * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1172    * list of supported ioengine options.
1173    * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1174    */
1175   public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1176 
1177   /**
1178    * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1179    * memory size to give to the cache (if &lt; 1.0) OR, it is the capacity in
1180    * megabytes of the cache.
1181    */
1182   public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1183 
1184   /**
1185    * HConstants for fast fail on the client side follow
1186    */
1187   /**
1188    * Config for enabling/disabling the fast fail mode.
1189    */
1190   public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1191       "hbase.client.fast.fail.mode.enabled";
1192 
1193   public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT =
1194       false;
1195 
1196   public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1197       "hbase.client.fastfail.threshold";
1198 
1199   public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT =
1200       60000;
1201 
1202   public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1203       "hbase.client.fast.fail.cleanup.duration";
1204 
1205   public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT =
1206       600000;
1207 
1208   public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1209       "hbase.client.fast.fail.interceptor.impl";
1210 
1211   /** Config key for if the server should send backpressure and if the client should listen to
1212    * that backpressure from the server */
1213   public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1214   public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1215 
1216   public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1217       "hbase.heap.occupancy.low_water_mark";
1218   public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1219   public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1220       "hbase.heap.occupancy.high_water_mark";
1221   public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1222 
1223   /**
1224    * The max number of threads used for splitting storefiles in parallel during
1225    * the region split process.
1226    */
1227   public static final String REGION_SPLIT_THREADS_MAX =
1228     "hbase.regionserver.region.split.threads.max";
1229 
1230   /** Canary config keys */
1231   public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1232 
1233   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1234       "hbase.canary.write.perserver.regions.lowerLimit";
1235 
1236   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1237       "hbase.canary.write.perserver.regions.upperLimit";
1238 
1239   public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1240 
1241   public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1242       "hbase.canary.write.table.check.period";
1243   
1244   public static final String HBASE_CANARY_READ_RAW_SCAN_KEY = "hbase.canary.read.raw.enabled";
1245 
1246   /**
1247    * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1248    */
1249   public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1250   public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1251       "hbase.zookeeper.client.kerberos.principal";
1252   public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1253   public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1254       "hbase.zookeeper.server.kerberos.principal";
1255 
1256   /** Config key for hbase temporary directory in hdfs */
1257   public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1258   public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY = "/user/"
1259       + System.getProperty("user.name") + "/hbase-staging";
1260 
1261   private HConstants() {
1262     // Can't be instantiated with this ctor.
1263   }
1264 }