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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.ByteBuffer;
23  import java.nio.charset.Charset;
24  import java.util.Arrays;
25  import java.util.Collections;
26  import java.util.List;
27  import java.util.UUID;
28  import java.util.regex.Pattern;
29  
30  import org.apache.commons.lang.ArrayUtils;
31  import org.apache.hadoop.hbase.classification.InterfaceAudience;
32  import org.apache.hadoop.hbase.classification.InterfaceStability;
33  import org.apache.hadoop.hbase.util.Bytes;
34  
35  /**
36   * HConstants holds a bunch of HBase-related constants
37   */
38  @InterfaceAudience.Public
39  @InterfaceStability.Stable
40  public final class HConstants {
41    // NOTICE!!!! Please do not add a constants here, unless they are referenced by a lot of classes.
42  
43    //Bytes.UTF8_ENCODING should be updated if this changed
44    /** When we encode strings, we always specify UTF8 encoding */
45    public static final String UTF8_ENCODING = "UTF-8";
46  
47    //Bytes.UTF8_CHARSET should be updated if this changed
48    /** When we encode strings, we always specify UTF8 encoding */
49    public static final Charset UTF8_CHARSET = Charset.forName(UTF8_ENCODING);
50    /**
51     * Default block size for an HFile.
52     */
53    public final static int DEFAULT_BLOCKSIZE = 64 * 1024;
54  
55    /** Used as a magic return value while optimized index key feature enabled(HBASE-7845) */
56    public final static int INDEX_KEY_MAGIC = -2;
57    /*
58       * Name of directory that holds recovered edits written by the wal log
59       * splitting code, one per region
60       */
61    public static final String RECOVERED_EDITS_DIR = "recovered.edits";
62    /**
63     * The first four bytes of Hadoop RPC connections
64     */
65    public static final byte[] RPC_HEADER = new byte[] { 'H', 'B', 'a', 's' };
66    public static final byte RPC_CURRENT_VERSION = 0;
67  
68    // HFileBlock constants.
69  
70    /** The size data structures with minor version is 0 */
71    public static final int HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM = MAGIC_LENGTH + 2 * Bytes.SIZEOF_INT
72        + Bytes.SIZEOF_LONG;
73    /** The size of a version 2 HFile block header, minor version 1.
74     * There is a 1 byte checksum type, followed by a 4 byte bytesPerChecksum
75     * followed by another 4 byte value to store sizeofDataOnDisk.
76     */
77    public static final int HFILEBLOCK_HEADER_SIZE = HFILEBLOCK_HEADER_SIZE_NO_CHECKSUM +
78      Bytes.SIZEOF_BYTE + 2 * Bytes.SIZEOF_INT;
79    /** Just an array of bytes of the right size. */
80    public static final byte[] HFILEBLOCK_DUMMY_HEADER = new byte[HFILEBLOCK_HEADER_SIZE];
81  
82    //End HFileBlockConstants.
83  
84    /**
85     * Status codes used for return values of bulk operations.
86     */
87    @InterfaceAudience.Private
88    public enum OperationStatusCode {
89      NOT_RUN,
90      SUCCESS,
91      BAD_FAMILY,
92      SANITY_CHECK_FAILURE,
93      FAILURE;
94    }
95  
96    /** long constant for zero */
97    public static final Long ZERO_L = Long.valueOf(0L);
98    public static final String NINES = "99999999999999";
99    public static final String ZEROES = "00000000000000";
100 
101   // For migration
102 
103   /** name of version file */
104   public static final String VERSION_FILE_NAME = "hbase.version";
105 
106   /**
107    * Current version of file system.
108    * Version 4 supports only one kind of bloom filter.
109    * Version 5 changes versions in catalog table regions.
110    * Version 6 enables blockcaching on catalog tables.
111    * Version 7 introduces hfile -- hbase 0.19 to 0.20..
112    * Version 8 introduces namespace
113    */
114   // public static final String FILE_SYSTEM_VERSION = "6";
115   public static final String FILE_SYSTEM_VERSION = "8";
116 
117   // Configuration parameters
118 
119   //TODO: Is having HBase homed on port 60k OK?
120 
121   /** Cluster is in distributed mode or not */
122   public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
123 
124   /** Config for pluggable load balancers */
125   public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
126 
127   /** Config for balancing the cluster by table */
128   public static final String HBASE_MASTER_LOADBALANCE_BYTABLE = "hbase.master.loadbalance.bytable";
129 
130   /** The name of the ensemble table */
131   public static final String ENSEMBLE_TABLE_NAME = "hbase:ensemble";
132 
133   /** Config for pluggable region normalizer */
134   public static final String HBASE_MASTER_NORMALIZER_CLASS =
135     "hbase.master.normalizer.class";
136 
137   /** Cluster is standalone or pseudo-distributed */
138   public static final boolean CLUSTER_IS_LOCAL = false;
139 
140   /** Cluster is fully-distributed */
141   public static final boolean CLUSTER_IS_DISTRIBUTED = true;
142 
143   /** Default value for cluster distributed mode */
144   public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
145 
146   /** default host address */
147   public static final String DEFAULT_HOST = "0.0.0.0";
148 
149   /** Parameter name for port master listens on. */
150   public static final String MASTER_PORT = "hbase.master.port";
151 
152   /** default port that the master listens on */
153   public static final int DEFAULT_MASTER_PORT = 16000;
154 
155   /** default port for master web api */
156   public static final int DEFAULT_MASTER_INFOPORT = 16010;
157 
158   /** Configuration key for master web API port */
159   public static final String MASTER_INFO_PORT = "hbase.master.info.port";
160 
161   /** Parameter name for the master type being backup (waits for primary to go inactive). */
162   public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
163 
164   /**
165    * by default every master is a possible primary master unless the conf explicitly overrides it
166    */
167   public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
168 
169   /** Name of ZooKeeper quorum configuration parameter. */
170   public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
171 
172   /** Common prefix of ZooKeeper configuration properties */
173   public static final String ZK_CFG_PROPERTY_PREFIX =
174       "hbase.zookeeper.property.";
175 
176   public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
177       ZK_CFG_PROPERTY_PREFIX.length();
178 
179   /**
180    * The ZK client port key in the ZK properties map. The name reflects the
181    * fact that this is not an HBase configuration key.
182    */
183   public static final String CLIENT_PORT_STR = "clientPort";
184 
185   /** Parameter name for the client port that the zookeeper listens on */
186   public static final String ZOOKEEPER_CLIENT_PORT =
187       ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
188 
189   /** Default client port that the zookeeper listens on */
190   public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
191 
192   /**
193    * Parameter name for the wait time for the recoverable zookeeper
194    */
195   public static final String ZOOKEEPER_RECOVERABLE_WAITTIME =
196       "hbase.zookeeper.recoverable.waittime";
197 
198   /** Default wait time for the recoverable zookeeper */
199   public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
200 
201   /** Parameter name for the root dir in ZK for this cluster */
202   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
203 
204   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
205 
206   /**
207    * Parameter name for the limit on concurrent client-side zookeeper
208    * connections
209    */
210   public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
211       ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
212 
213   /** Parameter name for the ZK data directory */
214   public static final String ZOOKEEPER_DATA_DIR =
215       ZK_CFG_PROPERTY_PREFIX + "dataDir";
216 
217   /** Parameter name for the ZK tick time */
218   public static final String ZOOKEEPER_TICK_TIME =
219       ZK_CFG_PROPERTY_PREFIX + "tickTime";
220 
221   /** Default limit on concurrent client-side zookeeper connections */
222   public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
223 
224   /** Configuration key for ZooKeeper session timeout */
225   public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
226 
227   /** Default value for ZooKeeper session timeout */
228   public static final int DEFAULT_ZK_SESSION_TIMEOUT = 180 * 1000;
229 
230   /** Configuration key for whether to use ZK.multi */
231   public static final String ZOOKEEPER_USEMULTI = "hbase.zookeeper.useMulti";
232 
233   /** Parameter name for port region server listens on. */
234   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
235 
236   /** Default port region server listens on. */
237   public static final int DEFAULT_REGIONSERVER_PORT = 16020;
238 
239   /** default port for region server web api */
240   public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
241 
242   /** A configuration key for regionserver info port */
243   public static final String REGIONSERVER_INFO_PORT =
244     "hbase.regionserver.info.port";
245 
246   /** A flag that enables automatic selection of regionserver info port */
247   public static final String REGIONSERVER_INFO_PORT_AUTO =
248       REGIONSERVER_INFO_PORT + ".auto";
249 
250   /** Parameter name for what region server implementation to use. */
251   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
252 
253   /** Parameter name for what master implementation to use. */
254   public static final String MASTER_IMPL= "hbase.master.impl";
255 
256   /** Parameter name for what hbase client implementation to use. */
257   public static final String HBASECLIENT_IMPL= "hbase.hbaseclient.impl";
258 
259   /** Parameter name for how often threads should wake up */
260   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
261 
262   /** Default value for thread wake frequency */
263   public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
264 
265   /** Parameter name for how often we should try to write a version file, before failing */
266   public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
267 
268   /** Parameter name for how often we should try to write a version file, before failing */
269   public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
270 
271   /** Parameter name for how often a region should should perform a major compaction */
272   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
273 
274   /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
275   public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
276   public static final int COMPACTION_KV_MAX_DEFAULT = 10;
277 
278   /** Parameter name for HBase instance root directory */
279   public static final String HBASE_DIR = "hbase.rootdir";
280 
281   /** Parameter name for HBase client IPC pool type */
282   public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
283 
284   /** Parameter name for HBase client IPC pool size */
285   public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
286 
287   /** Parameter name for HBase client operation timeout, which overrides RPC timeout */
288   public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
289 
290   /** Parameter name for HBase client operation timeout, which overrides RPC timeout */
291   public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
292     "hbase.client.meta.operation.timeout";
293 
294   /** Default HBase client operation timeout, which is tantamount to a blocking call */
295   public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = 1200000;
296 
297   /** Used to construct the name of the log directory for a region server */
298   public static final String HREGION_LOGDIR_NAME = "WALs";
299 
300   /** Used to construct the name of the splitlog directory for a region server */
301   public static final String SPLIT_LOGDIR_NAME = "splitWAL";
302 
303   /** Like the previous, but for old logs that are about to be deleted */
304   public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
305 
306   public static final String CORRUPT_DIR_NAME = "corrupt";
307 
308   /** Used by HBCK to sideline backup data */
309   public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
310 
311   /** Any artifacts left from migration can be moved here */
312   public static final String MIGRATION_NAME = ".migration";
313 
314   /**
315    * The directory from which co-processor/custom filter jars can be loaded
316    * dynamically by the region servers. This value can be overridden by the
317    * hbase.dynamic.jars.dir config.
318    */
319   public static final String LIB_DIR = "lib";
320 
321   /** Used to construct the name of the compaction directory during compaction */
322   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
323 
324   /** Conf key for the max file size after which we split the region */
325   public static final String HREGION_MAX_FILESIZE =
326       "hbase.hregion.max.filesize";
327 
328   /** Default maximum file size */
329   public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
330 
331   /**
332    * Max size of single row for Get's or Scan's without in-row scanning flag set.
333    */
334   public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
335 
336   /**
337    * Default max row size (1 Gb).
338    */
339   public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
340 
341   /**
342    * The max number of threads used for opening and closing stores or store
343    * files in parallel
344    */
345   public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
346     "hbase.hstore.open.and.close.threads.max";
347 
348   /**
349    * The default number for the max number of threads used for opening and
350    * closing stores or store files in parallel
351    */
352   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
353 
354   /**
355    * Block updates if memstore has hbase.hregion.memstore.block.multiplier
356    * times hbase.hregion.memstore.flush.size bytes.  Useful preventing
357    * runaway memstore during spikes in update traffic.
358    */
359   public static final String HREGION_MEMSTORE_BLOCK_MULTIPLIER =
360           "hbase.hregion.memstore.block.multiplier";
361 
362   /**
363    * Default value for hbase.hregion.memstore.block.multiplier
364    */
365   public static final int DEFAULT_HREGION_MEMSTORE_BLOCK_MULTIPLIER = 4;
366 
367   /** Conf key for the memstore size at which we flush the memstore */
368   public static final String HREGION_MEMSTORE_FLUSH_SIZE =
369       "hbase.hregion.memstore.flush.size";
370 
371   public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
372       "hbase.hregion.edits.replay.skip.errors";
373 
374   public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
375       false;
376 
377   /** Maximum value length, enforced on KeyValue construction */
378   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
379 
380   /** name of the file for unique cluster ID */
381   public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
382 
383   /** Default value for cluster ID */
384   public static final String CLUSTER_ID_DEFAULT = "default-cluster";
385 
386   /** Parameter name for # days to keep MVCC values during a major compaction */
387   public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
388   /** At least to keep MVCC values in hfiles for 5 days */
389   public static final int MIN_KEEP_SEQID_PERIOD = 5;
390 
391   // Always store the location of the root table's HRegion.
392   // This HRegion is never split.
393 
394   // region name = table + startkey + regionid. This is the row key.
395   // each row in the root and meta tables describes exactly 1 region
396   // Do we ever need to know all the information that we are storing?
397 
398   // Note that the name of the root table starts with "-" and the name of the
399   // meta table starts with "." Why? it's a trick. It turns out that when we
400   // store region names in memory, we use a SortedMap. Since "-" sorts before
401   // "." (and since no other table name can start with either of these
402   // characters, the root region will always be the first entry in such a Map,
403   // followed by all the meta regions (which will be ordered by their starting
404   // row key as well), followed by all user tables. So when the Master is
405   // choosing regions to assign, it will always choose the root region first,
406   // followed by the meta regions, followed by user regions. Since the root
407   // and meta regions always need to be on-line, this ensures that they will
408   // be the first to be reassigned if the server(s) they are being served by
409   // should go down.
410 
411 
412   /**
413    * The hbase:meta table's name.
414    * @deprecated For upgrades of 0.94 to 0.96
415    */
416   @Deprecated  // for compat from 0.94 -> 0.96.
417   public static final byte[] META_TABLE_NAME = TableName.META_TABLE_NAME.getName();
418 
419   public static final String BASE_NAMESPACE_DIR = "data";
420 
421   /** delimiter used between portions of a region name */
422   public static final int META_ROW_DELIMITER = ',';
423 
424   /** The catalog family as a string*/
425   public static final String CATALOG_FAMILY_STR = "info";
426 
427   /** The catalog family */
428   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
429 
430   /** The RegionInfo qualifier as a string */
431   public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
432 
433   /** The regioninfo column qualifier */
434   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
435 
436   /** The server column qualifier */
437   public static final String SERVER_QUALIFIER_STR = "server";
438   /** The server column qualifier */
439   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
440 
441   /** The startcode column qualifier */
442   public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
443   /** The startcode column qualifier */
444   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
445 
446   /** The open seqnum column qualifier */
447   public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
448   /** The open seqnum column qualifier */
449   public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
450 
451   /** The state column qualifier */
452   public static final String STATE_QUALIFIER_STR = "state";
453 
454   public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
455 
456   /**
457    * The serverName column qualifier. Its the server where the region is
458    * transitioning on, while column server is the server where the region is
459    * opened on. They are the same when the region is in state OPEN.
460    */
461   public static final String SERVERNAME_QUALIFIER_STR = "sn";
462 
463   public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
464 
465   /** The lower-half split region column qualifier */
466   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
467 
468   /** The upper-half split region column qualifier */
469   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
470 
471   /** The lower-half merge region column qualifier */
472   public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes("mergeA");
473 
474   /** The upper-half merge region column qualifier */
475   public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes("mergeB");
476 
477   /** The catalog family as a string*/
478   public static final String TABLE_FAMILY_STR = "table";
479 
480   /** The catalog family */
481   public static final byte [] TABLE_FAMILY = Bytes.toBytes(TABLE_FAMILY_STR);
482 
483   /** The serialized table state qualifier */
484   public static final byte[] TABLE_STATE_QUALIFIER = Bytes.toBytes("state");
485 
486 
487   /**
488    * The meta table version column qualifier.
489    * We keep current version of the meta table in this column in <code>-ROOT-</code>
490    * table: i.e. in the 'info:v' column.
491    */
492   public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
493 
494   /**
495    * The current version of the meta table.
496    * - pre-hbase 0.92.  There is no META_VERSION column in the root table
497    * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
498    * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
499    * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
500    * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
501    * byte[] serialization from Writables to Protobuf.
502    * See HRegionInfo.VERSION
503    */
504   public static final short META_VERSION = 1;
505 
506   // Other constants
507 
508   /**
509    * An empty instance.
510    */
511   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
512 
513   public static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.wrap(EMPTY_BYTE_ARRAY);
514 
515   /**
516    * Used by scanners, etc when they want to start at the beginning of a region
517    */
518   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
519 
520   /**
521    * Last row in a table.
522    */
523   public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
524 
525   /**
526     * Used by scanners and others when they're trying to detect the end of a
527     * table
528     */
529   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
530 
531   /**
532    * Max length a row can have because of the limitation in TFile.
533    */
534   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
535 
536   /**
537    * Timestamp to use when we want to refer to the latest cell.
538    * This is the timestamp sent by clients when no timestamp is specified on
539    * commit.
540    */
541   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
542 
543   /**
544    * Timestamp to use when we want to refer to the oldest cell.
545    */
546   public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
547 
548   /**
549    * LATEST_TIMESTAMP in bytes form
550    */
551   public static final byte [] LATEST_TIMESTAMP_BYTES = {
552     // big-endian
553     (byte) (LATEST_TIMESTAMP >>> 56),
554     (byte) (LATEST_TIMESTAMP >>> 48),
555     (byte) (LATEST_TIMESTAMP >>> 40),
556     (byte) (LATEST_TIMESTAMP >>> 32),
557     (byte) (LATEST_TIMESTAMP >>> 24),
558     (byte) (LATEST_TIMESTAMP >>> 16),
559     (byte) (LATEST_TIMESTAMP >>> 8),
560     (byte) LATEST_TIMESTAMP,
561   };
562 
563   /**
564    * Define for 'return-all-versions'.
565    */
566   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
567 
568   /**
569    * Unlimited time-to-live.
570    */
571 //  public static final int FOREVER = -1;
572   public static final int FOREVER = Integer.MAX_VALUE;
573 
574   /**
575    * Seconds in a week
576    */
577   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
578 
579   /**
580    * Seconds in a day, hour and minute
581    */
582   public static final int DAY_IN_SECONDS = 24 * 60 * 60;
583   public static final int HOUR_IN_SECONDS = 60 * 60;
584   public static final int MINUTE_IN_SECONDS = 60;
585 
586   //TODO: although the following are referenced widely to format strings for
587   //      the shell. They really aren't a part of the public API. It would be
588   //      nice if we could put them somewhere where they did not need to be
589   //      public. They could have package visibility
590   public static final String NAME = "NAME";
591   public static final String VERSIONS = "VERSIONS";
592   public static final String IN_MEMORY = "IN_MEMORY";
593   public static final String METADATA = "METADATA";
594   public static final String CONFIGURATION = "CONFIGURATION";
595 
596   /**
597    * Retrying we multiply hbase.client.pause setting by what we have in this array until we
598    * run out of array items.  Retries beyond this use the last number in the array.  So, for
599    * example, if hbase.client.pause is 1 second, and maximum retries count
600    * hbase.client.retries.number is 10, we will retry at the following intervals:
601    * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
602    * With 100ms, a back-off of 200 means 20s
603    */
604   public static final int [] RETRY_BACKOFF = {1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200};
605 
606   public static final String REGION_IMPL = "hbase.hregion.impl";
607 
608   /** modifyTable op for replacing the table descriptor */
609   @InterfaceAudience.Private
610   public static enum Modify {
611     CLOSE_REGION,
612     TABLE_COMPACT,
613     TABLE_FLUSH,
614     TABLE_MAJOR_COMPACT,
615     TABLE_SET_HTD,
616     TABLE_SPLIT
617   }
618 
619   /**
620    * Scope tag for locally scoped data.
621    * This data will not be replicated.
622    */
623   public static final int REPLICATION_SCOPE_LOCAL = 0;
624 
625   /**
626    * Scope tag for globally scoped data.
627    * This data will be replicated to all peers.
628    */
629   public static final int REPLICATION_SCOPE_GLOBAL = 1;
630 
631   /**
632    * Default cluster ID, cannot be used to identify a cluster so a key with
633    * this value means it wasn't meant for replication.
634    */
635   public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
636 
637   /**
638    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
639    * Controlled by the client.
640    */
641   public static final String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY =
642       "hbase.client.scanner.max.result.size";
643 
644   /**
645    * Parameter name for maximum number of bytes returned when calling a scanner's next method.
646    * Controlled by the server.
647    */
648   public static final String HBASE_SERVER_SCANNER_MAX_RESULT_SIZE_KEY =
649       "hbase.server.scanner.max.result.size";
650 
651   /**
652    * Maximum number of bytes returned when calling a scanner's next method.
653    * Note that when a single row is larger than this limit the row is still
654    * returned completely.
655    *
656    * The default value is 2MB.
657    */
658   public static final long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = 2 * 1024 * 1024;
659 
660   /**
661    * Maximum number of bytes returned when calling a scanner's next method.
662    * Note that when a single row is larger than this limit the row is still
663    * returned completely.
664    * Safety setting to protect the region server.
665    *
666    * The default value is 100MB. (a client would rarely request larger chunks on purpose)
667    */
668   public static final long DEFAULT_HBASE_SERVER_SCANNER_MAX_RESULT_SIZE = 100 * 1024 * 1024;
669 
670   /**
671    * Parameter name for client pause value, used mostly as value to wait
672    * before running a retry of a failed get, region lookup, etc.
673    */
674   public static final String HBASE_CLIENT_PAUSE = "hbase.client.pause";
675 
676   /**
677    * Default value of {@link #HBASE_CLIENT_PAUSE}.
678    */
679   public static final long DEFAULT_HBASE_CLIENT_PAUSE = 100;
680 
681   /**
682    * The maximum number of concurrent connections the client will maintain.
683    */
684   public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
685 
686   /**
687    * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
688    */
689   public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
690 
691   /**
692    * The maximum number of concurrent connections the client will maintain to a single
693    * RegionServer.
694    */
695   public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
696 
697   /**
698    * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
699    */
700   public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
701 
702   /**
703    * The maximum number of concurrent connections the client will maintain to a single
704    * Region.
705    */
706   public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
707 
708   /**
709    * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
710    */
711   public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
712 
713   /**
714    * Parameter name for server pause value, used mostly as value to wait before
715    * running a retry of a failed operation.
716    */
717   public static final String HBASE_SERVER_PAUSE = "hbase.server.pause";
718 
719   /**
720    * Default value of {@link #HBASE_SERVER_PAUSE}.
721    */
722   public static final int DEFAULT_HBASE_SERVER_PAUSE = 1000;
723 
724   /**
725    * Parameter name for maximum retries, used as maximum for all retryable
726    * operations such as fetching of the root region from root region server,
727    * getting a cell's value, starting a row update, etc.
728    */
729   public static final String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
730 
731   /**
732    * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
733    */
734   public static final int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 31;
735 
736   /**
737    * Parameter name to set the default scanner caching for all clients.
738    */
739   public static final String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
740 
741   /**
742    * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
743    */
744   public static final int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = Integer.MAX_VALUE;
745 
746   /**
747    * Parameter name for number of rows that will be fetched when calling next on
748    * a scanner if it is not served from memory. Higher caching values will
749    * enable faster scanners but will eat up more memory and some calls of next
750    * may take longer and longer times when the cache is empty.
751    */
752   public static final String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
753 
754   /**
755    * Default value of {@link #HBASE_META_SCANNER_CACHING}.
756    */
757   public static final int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
758 
759   /**
760    * Parameter name for number of versions, kept by meta table.
761    */
762   public static final String HBASE_META_VERSIONS = "hbase.meta.versions";
763 
764   /**
765    * Default value of {@link #HBASE_META_VERSIONS}.
766    */
767   public static final int DEFAULT_HBASE_META_VERSIONS = 3;
768 
769   /**
770    * Parameter name for number of versions, kept by meta table.
771    */
772   public static final String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
773 
774   /**
775    * Default value of {@link #HBASE_META_BLOCK_SIZE}.
776    */
777   public static final int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
778 
779   /**
780    * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
781    * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
782    * for all intents and purposes, are the same except for their instance ids, then they will not be
783    * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
784    * even if the instance ids are the same, it could result in non-shared
785    * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
786    * differ.
787    */
788   public static final String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
789 
790   /**
791    * The client scanner timeout period in milliseconds.
792    */
793   public static final String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD =
794       "hbase.client.scanner.timeout.period";
795 
796   /**
797    * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
798    * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
799    */
800   @Deprecated
801   public static final String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
802       "hbase.regionserver.lease.period";
803 
804   /**
805    * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
806    */
807   public static final int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
808 
809   /**
810    * timeout for each RPC
811    */
812   public static final String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
813 
814   /**
815    * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
816    */
817   public static final int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
818 
819   /**
820    * timeout for short operation RPC
821    */
822   public static final String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY =
823       "hbase.rpc.shortoperation.timeout";
824 
825   /**
826    * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
827    */
828   public static final int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
829 
830   /**
831    * Value indicating the server name was saved with no sequence number.
832    */
833   public static final long NO_SEQNUM = -1;
834 
835 
836   /*
837    * cluster replication constants.
838    */
839   public static final String
840       REPLICATION_ENABLE_KEY = "hbase.replication";
841   public static final boolean
842       REPLICATION_ENABLE_DEFAULT = true;
843   public static final String
844       REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
845   public static final String
846       REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
847   public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
848     "org.apache.hadoop.hbase.replication.regionserver.Replication";
849   public static final String REPLICATION_BULKLOAD_ENABLE_KEY = "hbase.replication.bulkload.enabled";
850   public static final boolean REPLICATION_BULKLOAD_ENABLE_DEFAULT = false;
851   /** Replication cluster id of source cluster which uniquely identifies itself with peer cluster */
852   public static final String REPLICATION_CLUSTER_ID = "hbase.replication.cluster.id";
853   /**
854    * Directory where the source cluster file system client configuration are placed which is used by
855    * sink cluster to copy HFiles from source cluster file system
856    */
857   public static final String REPLICATION_CONF_DIR = "hbase.replication.conf.dir";
858 
859   /** Maximum time to retry for a failed bulk load request */
860   public static final String BULKLOAD_MAX_RETRIES_NUMBER = "hbase.bulkload.retries.number";
861 
862   /** HBCK special code name used as server name when manipulating ZK nodes */
863   public static final String HBCK_CODE_NAME = "HBCKServerName";
864 
865   public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
866     "hbase.regionserver.hostname.seen.by.master";
867 
868   public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
869       "hbase.master.logcleaner.plugins";
870 
871   public static final String HBASE_REGION_SPLIT_POLICY_KEY =
872     "hbase.regionserver.region.split.policy";
873 
874   /** Whether nonces are enabled; default is true. */
875   public static final String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
876 
877   /**
878    * Configuration key for the size of the block cache
879    */
880   public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
881     "hfile.block.cache.size";
882 
883   public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
884 
885   /*
886     * Minimum percentage of free heap necessary for a successful cluster startup.
887     */
888   public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
889 
890   public static final Pattern CP_HTD_ATTR_KEY_PATTERN =
891       Pattern.compile("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
892 
893   /**
894    * <pre>
895    * Pattern that matches a coprocessor specification. Form is:
896    * {@code <coprocessor jar file location> '|' <class name> ['|' <priority> ['|' <arguments>]]}
897    * where arguments are {@code <KEY> '=' <VALUE> [,...]}
898    * For example: {@code hdfs:///foo.jar|com.foo.FooRegionObserver|1001|arg1=1,arg2=2}
899    * </pre>
900    */
901   public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
902       Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
903 
904   public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
905   public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
906   public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
907       "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
908       CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
909 
910   /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
911   public static final int SOCKET_RETRY_WAIT_MS = 200;
912 
913   /** Host name of the local machine */
914   public static final String LOCALHOST = "localhost";
915 
916   /**
917    * If this parameter is set to true, then hbase will read
918    * data and then verify checksums. Checksum verification
919    * inside hdfs will be switched off.  However, if the hbase-checksum
920    * verification fails, then it will switch back to using
921    * hdfs checksums for verifiying data that is being read from storage.
922    *
923    * If this parameter is set to false, then hbase will not
924    * verify any checksums, instead it will depend on checksum verification
925    * being done in the hdfs client.
926    */
927   public static final String HBASE_CHECKSUM_VERIFICATION =
928       "hbase.regionserver.checksum.verify";
929 
930   public static final String LOCALHOST_IP = "127.0.0.1";
931 
932   /** Conf key that enables unflushed WAL edits directly being replayed to region servers */
933   public static final String DISTRIBUTED_LOG_REPLAY_KEY = "hbase.master.distributed.log.replay";
934   public static final boolean DEFAULT_DISTRIBUTED_LOG_REPLAY_CONFIG = false;
935   public static final String DISALLOW_WRITES_IN_RECOVERING =
936       "hbase.regionserver.disallow.writes.when.recovering";
937   public static final boolean DEFAULT_DISALLOW_WRITES_IN_RECOVERING_CONFIG = false;
938 
939   public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
940   public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
941 
942   /*
943    * REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT:
944    * -1  => Disable aborting
945    * 0   => Abort if even a single handler has died
946    * 0.x => Abort only when this percent of handlers have died
947    * 1   => Abort only all of the handers have died
948    */
949   public static final String REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT =
950       "hbase.regionserver.handler.abort.on.error.percent";
951   public static final double DEFAULT_REGION_SERVER_HANDLER_ABORT_ON_ERROR_PERCENT = 0.5;
952 
953   //High priority handlers to deal with admin requests and system table operation requests
954   public static final String REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT =
955       "hbase.regionserver.metahandler.count";
956   public static final int DEFAULT_REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT = 20;
957 
958   public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
959       "hbase.regionserver.replication.handler.count";
960   public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
961 
962   public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
963   public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
964 
965   /** Conf key that specifies timeout value to wait for a region ready */
966   public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
967       "hbase.master.log.replay.wait.region.timeout";
968 
969   /** Conf key for enabling meta replication */
970   public static final String USE_META_REPLICAS = "hbase.meta.replicas.use";
971   public static final boolean DEFAULT_USE_META_REPLICAS = false;
972   public static final String META_REPLICAS_NUM = "hbase.meta.replica.count";
973   public static final int DEFAULT_META_REPLICA_NUM = 1;
974 
975   /**
976    * The name of the configuration parameter that specifies
977    * the number of bytes in a newly created checksum chunk.
978    */
979   public static final String BYTES_PER_CHECKSUM =
980       "hbase.hstore.bytes.per.checksum";
981 
982   /**
983    * The name of the configuration parameter that specifies
984    * the name of an algorithm that is used to compute checksums
985    * for newly created blocks.
986    */
987   public static final String CHECKSUM_TYPE_NAME =
988       "hbase.hstore.checksum.algorithm";
989 
990   /** Enable file permission modification from standard hbase */
991   public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
992   /** File permission umask to use when creating hbase data files */
993   public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
994 
995   /** Configuration name of WAL Compression */
996   public static final String ENABLE_WAL_COMPRESSION =
997     "hbase.regionserver.wal.enablecompression";
998 
999   /** Configuration name of WAL storage policy
1000    * Valid values are:
1001    *  NONE: no preference in destination of block replicas
1002    *  ONE_SSD: place only one block replica in SSD and the remaining in default storage
1003    *  and ALL_SSD: place all block replicas on SSD
1004    *
1005    * See http://hadoop.apache.org/docs/r2.6.0/hadoop-project-dist/hadoop-hdfs/ArchivalStorage.html*/
1006   public static final String WAL_STORAGE_POLICY = "hbase.wal.storage.policy";
1007   public static final String DEFAULT_WAL_STORAGE_POLICY = "NONE";
1008 
1009   /** Region in Transition metrics threshold time */
1010   public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
1011       "hbase.metrics.rit.stuck.warning.threshold";
1012 
1013   public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
1014 
1015   /** delimiter used between portions of a region name */
1016   public static final int DELIMITER = ',';
1017 
1018   /**
1019    * QOS attributes: these attributes are used to demarcate RPC call processing
1020    * by different set of handlers. For example, HIGH_QOS tagged methods are
1021    * handled by high priority handlers.
1022    */
1023   // normal_QOS < QOS_threshold < replication_QOS < replay_QOS < admin_QOS < high_QOS
1024   public static final int NORMAL_QOS = 0;
1025   public static final int QOS_THRESHOLD = 10;
1026   public static final int HIGH_QOS = 200;
1027   public static final int REPLICATION_QOS = 5;
1028   public static final int REPLAY_QOS = 6;
1029   public static final int ADMIN_QOS = 100;
1030   public static final int SYSTEMTABLE_QOS = HIGH_QOS;
1031 
1032   /** Directory under /hbase where archived hfiles are stored */
1033   public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
1034 
1035   /**
1036    * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
1037    * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
1038    * uni-directional.
1039    */
1040   public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
1041 
1042   /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
1043   public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
1044 
1045   /** Temporary directory used for table creation and deletion */
1046   public static final String HBASE_TEMP_DIRECTORY = ".tmp";
1047   /**
1048    * The period (in milliseconds) between computing region server point in time metrics
1049    */
1050   public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
1051   public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
1052   /** Directories that are not HBase table directories */
1053   public static final List<String> HBASE_NON_TABLE_DIRS =
1054     Collections.unmodifiableList(Arrays.asList(new String[] {
1055       HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
1056     }));
1057 
1058   /** Directories that are not HBase user table directories */
1059   public static final List<String> HBASE_NON_USER_TABLE_DIRS =
1060     Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
1061       new String[] { TableName.META_TABLE_NAME.getNameAsString() },
1062       HBASE_NON_TABLE_DIRS.toArray())));
1063 
1064   /** Health script related settings. */
1065   public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
1066   public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
1067   public static final String HEALTH_CHORE_WAKE_FREQ =
1068       "hbase.node.health.script.frequency";
1069   public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
1070   /**
1071    * The maximum number of health check failures a server can encounter consecutively.
1072    */
1073   public static final String HEALTH_FAILURE_THRESHOLD =
1074       "hbase.node.health.failure.threshold";
1075   public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
1076 
1077 
1078   /**
1079    * Setting to activate, or not, the publication of the status by the master. Default
1080    *  notification is by a multicast message.
1081    */
1082   public static final String STATUS_PUBLISHED = "hbase.status.published";
1083   public static final boolean STATUS_PUBLISHED_DEFAULT = false;
1084 
1085   /**
1086    * IP to use for the multicast status messages between the master and the clients.
1087    * The default address is chosen as one among others within the ones suitable for multicast
1088    * messages.
1089    */
1090   public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
1091   public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
1092 
1093   /**
1094    * The address to use for binding the local socket for receiving multicast. Defaults to
1095    * 0.0.0.0.
1096    * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
1097    */
1098   public static final String STATUS_MULTICAST_BIND_ADDRESS =
1099       "hbase.status.multicast.bind.address.ip";
1100   public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1101 
1102   /**
1103    * The port to use for the multicast messages.
1104    */
1105   public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1106   public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1107 
1108   public static final long NO_NONCE = 0;
1109 
1110   /** Default cipher for encryption */
1111   public static final String CIPHER_AES = "AES";
1112 
1113   /** Configuration key for the crypto algorithm provider, a class name */
1114   public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1115 
1116   /** Configuration key for the crypto key provider, a class name */
1117   public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1118 
1119   /** Configuration key for the crypto key provider parameters */
1120   public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1121       "hbase.crypto.keyprovider.parameters";
1122 
1123   /** Configuration key for the name of the master key for the cluster, a string */
1124   public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1125 
1126   /** Configuration key for the name of the alternate master key for the cluster, a string */
1127   public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1128     "hbase.crypto.master.alternate.key.name";
1129 
1130   /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1131   public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1132 
1133   /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1134   public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1135 
1136   /** Configuration key for the algorithm used for creating jks key, a string */
1137   public static final String CRYPTO_KEY_ALGORITHM_CONF_KEY = "hbase.crypto.key.algorithm";
1138 
1139   /** Configuration key for the name of the alternate cipher algorithm for the cluster, a string */
1140   public static final String CRYPTO_ALTERNATE_KEY_ALGORITHM_CONF_KEY =
1141       "hbase.crypto.alternate.key.algorithm";
1142 
1143   /** Configuration key for enabling WAL encryption, a boolean */
1144   public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1145 
1146   /** Configuration key for setting RPC codec class name */
1147   public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1148 
1149   /** Configuration key for setting replication codec class name */
1150   public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1151 
1152   /** Maximum number of threads used by the replication source for shipping edits to the sinks */
1153   public static final String REPLICATION_SOURCE_MAXTHREADS_KEY =
1154       "hbase.replication.source.maxthreads";
1155 
1156   public static final int REPLICATION_SOURCE_MAXTHREADS_DEFAULT = 10;
1157 
1158   /** Config for pluggable consensus provider */
1159   public static final String HBASE_COORDINATED_STATE_MANAGER_CLASS =
1160     "hbase.coordinated.state.manager.class";
1161 
1162   /** Configuration key for SplitLog manager timeout */
1163   public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1164 
1165   /**
1166    * Configuration keys for Bucket cache
1167    */
1168   // TODO moving these bucket cache implementation specific configs to this level is violation of
1169   // encapsulation. But as these has to be referred from hbase-common and bucket cache
1170   // sits in hbase-server, there were no other go! Can we move the cache implementation to
1171   // hbase-common?
1172 
1173   /**
1174    * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1175    * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1176    * list of supported ioengine options.
1177    * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1178    */
1179   public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1180 
1181   /**
1182    * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1183    * memory size to give to the cache (if &lt; 1.0) OR, it is the capacity in
1184    * megabytes of the cache.
1185    */
1186   public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1187 
1188   /**
1189    * HConstants for fast fail on the client side follow
1190    */
1191   /**
1192    * Config for enabling/disabling the fast fail mode.
1193    */
1194   public static final String HBASE_CLIENT_FAST_FAIL_MODE_ENABLED =
1195       "hbase.client.fast.fail.mode.enabled";
1196 
1197   public static final boolean HBASE_CLIENT_ENABLE_FAST_FAIL_MODE_DEFAULT =
1198       false;
1199 
1200   public static final String HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS =
1201       "hbase.client.fastfail.threshold";
1202 
1203   public static final long HBASE_CLIENT_FAST_FAIL_THREASHOLD_MS_DEFAULT =
1204       60000;
1205 
1206   public static final String HBASE_CLIENT_FAST_FAIL_CLEANUP_MS_DURATION_MS =
1207       "hbase.client.fast.fail.cleanup.duration";
1208 
1209   public static final long HBASE_CLIENT_FAST_FAIL_CLEANUP_DURATION_MS_DEFAULT =
1210       600000;
1211 
1212   public static final String HBASE_CLIENT_FAST_FAIL_INTERCEPTOR_IMPL =
1213       "hbase.client.fast.fail.interceptor.impl";
1214 
1215   /** Config key for if the server should send backpressure and if the client should listen to
1216    * that backpressure from the server */
1217   public static final String ENABLE_CLIENT_BACKPRESSURE = "hbase.client.backpressure.enabled";
1218   public static final boolean DEFAULT_ENABLE_CLIENT_BACKPRESSURE = false;
1219 
1220   public static final String HEAP_OCCUPANCY_LOW_WATERMARK_KEY =
1221       "hbase.heap.occupancy.low_water_mark";
1222   public static final float DEFAULT_HEAP_OCCUPANCY_LOW_WATERMARK = 0.95f;
1223   public static final String HEAP_OCCUPANCY_HIGH_WATERMARK_KEY =
1224       "hbase.heap.occupancy.high_water_mark";
1225   public static final float DEFAULT_HEAP_OCCUPANCY_HIGH_WATERMARK = 0.98f;
1226 
1227   /**
1228    * The max number of threads used for splitting storefiles in parallel during
1229    * the region split process.
1230    */
1231   public static final String REGION_SPLIT_THREADS_MAX =
1232     "hbase.regionserver.region.split.threads.max";
1233 
1234   /** Canary config keys */
1235   public static final String HBASE_CANARY_WRITE_DATA_TTL_KEY = "hbase.canary.write.data.ttl";
1236 
1237   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_LOWERLIMIT_KEY =
1238       "hbase.canary.write.perserver.regions.lowerLimit";
1239 
1240   public static final String HBASE_CANARY_WRITE_PERSERVER_REGIONS_UPPERLIMIT_KEY =
1241       "hbase.canary.write.perserver.regions.upperLimit";
1242 
1243   public static final String HBASE_CANARY_WRITE_VALUE_SIZE_KEY = "hbase.canary.write.value.size";
1244 
1245   public static final String HBASE_CANARY_WRITE_TABLE_CHECK_PERIOD_KEY =
1246       "hbase.canary.write.table.check.period";
1247 
1248   /**
1249    * Configuration keys for programmatic JAAS configuration for secured ZK interaction
1250    */
1251   public static final String ZK_CLIENT_KEYTAB_FILE = "hbase.zookeeper.client.keytab.file";
1252   public static final String ZK_CLIENT_KERBEROS_PRINCIPAL =
1253       "hbase.zookeeper.client.kerberos.principal";
1254   public static final String ZK_SERVER_KEYTAB_FILE = "hbase.zookeeper.server.keytab.file";
1255   public static final String ZK_SERVER_KERBEROS_PRINCIPAL =
1256       "hbase.zookeeper.server.kerberos.principal";
1257 
1258   /** Config key for hbase temporary directory in hdfs */
1259   public static final String TEMPORARY_FS_DIRECTORY_KEY = "hbase.fs.tmp.dir";
1260   public static final String DEFAULT_TEMPORARY_HDFS_DIRECTORY = "/user/"
1261       + System.getProperty("user.name") + "/hbase-staging";
1262 
1263   private HConstants() {
1264     // Can't be instantiated with this ctor.
1265   }
1266 }