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