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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 ByteBuffer RPC_HEADER = ByteBuffer.wrap("HBas".getBytes());
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    public enum OperationStatusCode {
88      NOT_RUN,
89      SUCCESS,
90      BAD_FAMILY,
91      SANITY_CHECK_FAILURE,
92      FAILURE;
93    }
94  
95    /** long constant for zero */
96    public static final Long ZERO_L = Long.valueOf(0L);
97    public static final String NINES = "99999999999999";
98    public static final String ZEROES = "00000000000000";
99  
100   // For migration
101 
102   /** name of version file */
103   public static final String VERSION_FILE_NAME = "hbase.version";
104 
105   /**
106    * Current version of file system.
107    * Version 4 supports only one kind of bloom filter.
108    * Version 5 changes versions in catalog table regions.
109    * Version 6 enables blockcaching on catalog tables.
110    * Version 7 introduces hfile -- hbase 0.19 to 0.20..
111    * Version 8 introduces namespace
112    */
113   // public static final String FILE_SYSTEM_VERSION = "6";
114   public static final String FILE_SYSTEM_VERSION = "8";
115 
116   // Configuration parameters
117 
118   //TODO: Is having HBase homed on port 60k OK?
119 
120   /** Cluster is in distributed mode or not */
121   public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
122 
123   /** Config for pluggable load balancers */
124   public static final String HBASE_MASTER_LOADBALANCER_CLASS = "hbase.master.loadbalancer.class";
125 
126   /** Cluster is standalone or pseudo-distributed */
127   public static final boolean CLUSTER_IS_LOCAL = false;
128 
129   /** Cluster is fully-distributed */
130   public static final boolean CLUSTER_IS_DISTRIBUTED = true;
131 
132   /** Default value for cluster distributed mode */
133   public static final boolean DEFAULT_CLUSTER_DISTRIBUTED = CLUSTER_IS_LOCAL;
134 
135   /** default host address */
136   public static final String DEFAULT_HOST = "0.0.0.0";
137 
138   /** Parameter name for port master listens on. */
139   public static final String MASTER_PORT = "hbase.master.port";
140 
141   /** default port that the master listens on */
142   public static final int DEFAULT_MASTER_PORT = 16000;
143 
144   /** default port for master web api */
145   public static final int DEFAULT_MASTER_INFOPORT = 16010;
146 
147   /** Configuration key for master web API port */
148   public static final String MASTER_INFO_PORT = "hbase.master.info.port";
149 
150   /** Parameter name for the master type being backup (waits for primary to go inactive). */
151   public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
152 
153   /**
154    * by default every master is a possible primary master unless the conf explicitly overrides it
155    */
156   public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
157 
158   /** Name of ZooKeeper quorum configuration parameter. */
159   public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
160 
161   /** Name of ZooKeeper config file in conf/ directory. */
162   public static final String ZOOKEEPER_CONFIG_NAME = "zoo.cfg";
163 
164   /** Common prefix of ZooKeeper configuration properties */
165   public static final String ZK_CFG_PROPERTY_PREFIX =
166       "hbase.zookeeper.property.";
167 
168   public static final int ZK_CFG_PROPERTY_PREFIX_LEN =
169       ZK_CFG_PROPERTY_PREFIX.length();
170 
171   /**
172    * The ZK client port key in the ZK properties map. The name reflects the
173    * fact that this is not an HBase configuration key.
174    */
175   public static final String CLIENT_PORT_STR = "clientPort";
176 
177   /** Parameter name for the client port that the zookeeper listens on */
178   public static final String ZOOKEEPER_CLIENT_PORT =
179       ZK_CFG_PROPERTY_PREFIX + CLIENT_PORT_STR;
180 
181   /** Default client port that the zookeeper listens on */
182   public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
183 
184   /**
185    * Parameter name for the wait time for the recoverable zookeeper
186    */
187   public static final String ZOOKEEPER_RECOVERABLE_WAITTIME =
188       "hbase.zookeeper.recoverable.waittime";
189 
190   /** Default wait time for the recoverable zookeeper */
191   public static final long DEFAULT_ZOOKEPER_RECOVERABLE_WAITIME = 10000;
192 
193   /** Parameter name for the root dir in ZK for this cluster */
194   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
195 
196   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
197 
198   /**
199    * Parameter name for the limit on concurrent client-side zookeeper
200    * connections
201    */
202   public static final String ZOOKEEPER_MAX_CLIENT_CNXNS =
203       ZK_CFG_PROPERTY_PREFIX + "maxClientCnxns";
204 
205   /** Parameter name for the ZK data directory */
206   public static final String ZOOKEEPER_DATA_DIR =
207       ZK_CFG_PROPERTY_PREFIX + "dataDir";
208 
209   /** Default limit on concurrent client-side zookeeper connections */
210   public static final int DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS = 300;
211 
212   /** Configuration key for ZooKeeper session timeout */
213   public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
214 
215   /** Default value for ZooKeeper session timeout */
216   public static final int DEFAULT_ZK_SESSION_TIMEOUT = 180 * 1000;
217 
218   /** Configuration key for whether to use ZK.multi */
219   public static final String ZOOKEEPER_USEMULTI = "hbase.zookeeper.useMulti";
220 
221   /** Parameter name for port region server listens on. */
222   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
223 
224   /** Default port region server listens on. */
225   public static final int DEFAULT_REGIONSERVER_PORT = 16020;
226 
227   /** default port for region server web api */
228   public static final int DEFAULT_REGIONSERVER_INFOPORT = 16030;
229 
230   /** A configuration key for regionserver info port */
231   public static final String REGIONSERVER_INFO_PORT =
232     "hbase.regionserver.info.port";
233 
234   /** A flag that enables automatic selection of regionserver info port */
235   public static final String REGIONSERVER_INFO_PORT_AUTO =
236       REGIONSERVER_INFO_PORT + ".auto";
237 
238   /** Parameter name for what region server implementation to use. */
239   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
240 
241   /** Parameter name for what master implementation to use. */
242   public static final String MASTER_IMPL= "hbase.master.impl";
243 
244   /** Parameter name for what hbase client implementation to use. */
245   public static final String HBASECLIENT_IMPL= "hbase.hbaseclient.impl";
246 
247   /** Parameter name for how often threads should wake up */
248   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
249 
250   /** Default value for thread wake frequency */
251   public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
252 
253   /** Parameter name for how often we should try to write a version file, before failing */
254   public static final String VERSION_FILE_WRITE_ATTEMPTS = "hbase.server.versionfile.writeattempts";
255 
256   /** Parameter name for how often we should try to write a version file, before failing */
257   public static final int DEFAULT_VERSION_FILE_WRITE_ATTEMPTS = 3;
258 
259   /** Parameter name for how often a region should should perform a major compaction */
260   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
261 
262   /** Parameter name for the maximum batch of KVs to be used in flushes and compactions */
263   public static final String COMPACTION_KV_MAX = "hbase.hstore.compaction.kv.max";
264   public static final int COMPACTION_KV_MAX_DEFAULT = 10;
265 
266   /** Parameter name for HBase instance root directory */
267   public static final String HBASE_DIR = "hbase.rootdir";
268 
269   /** Parameter name for HBase client IPC pool type */
270   public static final String HBASE_CLIENT_IPC_POOL_TYPE = "hbase.client.ipc.pool.type";
271 
272   /** Parameter name for HBase client IPC pool size */
273   public static final String HBASE_CLIENT_IPC_POOL_SIZE = "hbase.client.ipc.pool.size";
274 
275   /** Parameter name for HBase client operation timeout, which overrides RPC timeout */
276   public static final String HBASE_CLIENT_OPERATION_TIMEOUT = "hbase.client.operation.timeout";
277 
278   /** Parameter name for HBase client operation timeout, which overrides RPC timeout */
279   public static final String HBASE_CLIENT_META_OPERATION_TIMEOUT =
280     "hbase.client.meta.operation.timeout";
281 
282   /** Default HBase client operation timeout, which is tantamount to a blocking call */
283   public static final int DEFAULT_HBASE_CLIENT_OPERATION_TIMEOUT = Integer.MAX_VALUE;
284 
285   /** Used to construct the name of the log directory for a region server */
286   public static final String HREGION_LOGDIR_NAME = "WALs";
287 
288   /** Used to construct the name of the splitlog directory for a region server */
289   public static final String SPLIT_LOGDIR_NAME = "splitWAL";
290 
291   /** Like the previous, but for old logs that are about to be deleted */
292   public static final String HREGION_OLDLOGDIR_NAME = "oldWALs";
293 
294   public static final String CORRUPT_DIR_NAME = "corrupt";
295 
296   /** Used by HBCK to sideline backup data */
297   public static final String HBCK_SIDELINEDIR_NAME = ".hbck";
298 
299   /** Any artifacts left from migration can be moved here */
300   public static final String MIGRATION_NAME = ".migration";
301 
302   /**
303    * The directory from which co-processor/custom filter jars can be loaded
304    * dynamically by the region servers. This value can be overridden by the
305    * hbase.dynamic.jars.dir config.
306    */
307   public static final String LIB_DIR = "lib";
308 
309   /** Used to construct the name of the compaction directory during compaction */
310   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
311 
312   /** Conf key for the max file size after which we split the region */
313   public static final String HREGION_MAX_FILESIZE =
314       "hbase.hregion.max.filesize";
315 
316   /** Default maximum file size */
317   public static final long DEFAULT_MAX_FILE_SIZE = 10 * 1024 * 1024 * 1024L;
318 
319   /**
320    * Max size of single row for Get's or Scan's without in-row scanning flag set.
321    */
322   public static final String TABLE_MAX_ROWSIZE_KEY = "hbase.table.max.rowsize";
323 
324   /**
325    * Default max row size (1 Gb).
326    */
327   public static final long TABLE_MAX_ROWSIZE_DEFAULT = 1024 * 1024 * 1024L;
328 
329   /**
330    * The max number of threads used for opening and closing stores or store
331    * files in parallel
332    */
333   public static final String HSTORE_OPEN_AND_CLOSE_THREADS_MAX =
334     "hbase.hstore.open.and.close.threads.max";
335 
336   /**
337    * The default number for the max number of threads used for opening and
338    * closing stores or store files in parallel
339    */
340   public static final int DEFAULT_HSTORE_OPEN_AND_CLOSE_THREADS_MAX = 1;
341 
342 
343   /** Conf key for the memstore size at which we flush the memstore */
344   public static final String HREGION_MEMSTORE_FLUSH_SIZE =
345       "hbase.hregion.memstore.flush.size";
346 
347   public static final String HREGION_EDITS_REPLAY_SKIP_ERRORS =
348       "hbase.hregion.edits.replay.skip.errors";
349 
350   public static final boolean DEFAULT_HREGION_EDITS_REPLAY_SKIP_ERRORS =
351       false;
352 
353   /** Maximum value length, enforced on KeyValue construction */
354   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE - 1;
355 
356   /** name of the file for unique cluster ID */
357   public static final String CLUSTER_ID_FILE_NAME = "hbase.id";
358 
359   /** Default value for cluster ID */
360   public static final String CLUSTER_ID_DEFAULT = "default-cluster";
361 
362   /** Parameter name for # days to keep MVCC values during a major compaction */
363   public static final String KEEP_SEQID_PERIOD = "hbase.hstore.compaction.keep.seqId.period";
364   /** At least to keep MVCC values in hfiles for 5 days */
365   public static final int MIN_KEEP_SEQID_PERIOD = 5;
366 
367   // Always store the location of the root table's HRegion.
368   // This HRegion is never split.
369 
370   // region name = table + startkey + regionid. This is the row key.
371   // each row in the root and meta tables describes exactly 1 region
372   // Do we ever need to know all the information that we are storing?
373 
374   // Note that the name of the root table starts with "-" and the name of the
375   // meta table starts with "." Why? it's a trick. It turns out that when we
376   // store region names in memory, we use a SortedMap. Since "-" sorts before
377   // "." (and since no other table name can start with either of these
378   // characters, the root region will always be the first entry in such a Map,
379   // followed by all the meta regions (which will be ordered by their starting
380   // row key as well), followed by all user tables. So when the Master is
381   // choosing regions to assign, it will always choose the root region first,
382   // followed by the meta regions, followed by user regions. Since the root
383   // and meta regions always need to be on-line, this ensures that they will
384   // be the first to be reassigned if the server(s) they are being served by
385   // should go down.
386 
387 
388   /**
389    * The hbase:meta table's name.
390    * 
391    */
392   @Deprecated  // for compat from 0.94 -> 0.96.
393   public static final byte[] META_TABLE_NAME = TableName.META_TABLE_NAME.getName();
394 
395   public static final String BASE_NAMESPACE_DIR = "data";
396 
397   /** delimiter used between portions of a region name */
398   public static final int META_ROW_DELIMITER = ',';
399 
400   /** The catalog family as a string*/
401   public static final String CATALOG_FAMILY_STR = "info";
402 
403   /** The catalog family */
404   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
405 
406   /** The RegionInfo qualifier as a string */
407   public static final String REGIONINFO_QUALIFIER_STR = "regioninfo";
408 
409   /** The regioninfo column qualifier */
410   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes(REGIONINFO_QUALIFIER_STR);
411 
412   /** The server column qualifier */
413   public static final String SERVER_QUALIFIER_STR = "server";
414   /** The server column qualifier */
415   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes(SERVER_QUALIFIER_STR);
416 
417   /** The startcode column qualifier */
418   public static final String STARTCODE_QUALIFIER_STR = "serverstartcode";
419   /** The startcode column qualifier */
420   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes(STARTCODE_QUALIFIER_STR);
421 
422   /** The open seqnum column qualifier */
423   public static final String SEQNUM_QUALIFIER_STR = "seqnumDuringOpen";
424   /** The open seqnum column qualifier */
425   public static final byte [] SEQNUM_QUALIFIER = Bytes.toBytes(SEQNUM_QUALIFIER_STR);
426 
427   /** The state column qualifier */
428   public static final String STATE_QUALIFIER_STR = "state";
429 
430   public static final byte [] STATE_QUALIFIER = Bytes.toBytes(STATE_QUALIFIER_STR);
431 
432   /**
433    * The serverName column qualifier. Its the server where the region is
434    * transitioning on, while column server is the server where the region is
435    * opened on. They are the same when the region is in state OPEN.
436    */
437   public static final String SERVERNAME_QUALIFIER_STR = "sn";
438 
439   public static final byte [] SERVERNAME_QUALIFIER = Bytes.toBytes(SERVERNAME_QUALIFIER_STR);
440 
441   /** The lower-half split region column qualifier */
442   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
443 
444   /** The upper-half split region column qualifier */
445   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
446 
447   /** The lower-half merge region column qualifier */
448   public static final byte[] MERGEA_QUALIFIER = Bytes.toBytes("mergeA");
449 
450   /** The upper-half merge region column qualifier */
451   public static final byte[] MERGEB_QUALIFIER = Bytes.toBytes("mergeB");
452 
453   /**
454    * The meta table version column qualifier.
455    * We keep current version of the meta table in this column in <code>-ROOT-</code>
456    * table: i.e. in the 'info:v' column.
457    */
458   public static final byte [] META_VERSION_QUALIFIER = Bytes.toBytes("v");
459 
460   /**
461    * The current version of the meta table.
462    * - pre-hbase 0.92.  There is no META_VERSION column in the root table
463    * in this case. The meta has HTableDescriptor serialized into the HRegionInfo;
464    * - version 0 is 0.92 and 0.94. Meta data has serialized HRegionInfo's using
465    * Writable serialization, and HRegionInfo's does not contain HTableDescriptors.
466    * - version 1 for 0.96+ keeps HRegionInfo data structures, but changes the
467    * byte[] serialization from Writables to Protobuf.
468    * See HRegionInfo.VERSION
469    */
470   public static final short META_VERSION = 1;
471 
472   // Other constants
473 
474   /**
475    * An empty instance.
476    */
477   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
478 
479   /**
480    * Used by scanners, etc when they want to start at the beginning of a region
481    */
482   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
483 
484   /**
485    * Last row in a table.
486    */
487   public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
488 
489   /**
490     * Used by scanners and others when they're trying to detect the end of a
491     * table
492     */
493   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
494 
495   /**
496    * Max length a row can have because of the limitation in TFile.
497    */
498   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
499 
500   /**
501    * Timestamp to use when we want to refer to the latest cell.
502    * This is the timestamp sent by clients when no timestamp is specified on
503    * commit.
504    */
505   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
506 
507   /**
508    * Timestamp to use when we want to refer to the oldest cell.
509    */
510   public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
511 
512   /**
513    * LATEST_TIMESTAMP in bytes form
514    */
515   public static final byte [] LATEST_TIMESTAMP_BYTES = {
516     // big-endian
517     (byte) (LATEST_TIMESTAMP >>> 56),
518     (byte) (LATEST_TIMESTAMP >>> 48),
519     (byte) (LATEST_TIMESTAMP >>> 40),
520     (byte) (LATEST_TIMESTAMP >>> 32),
521     (byte) (LATEST_TIMESTAMP >>> 24),
522     (byte) (LATEST_TIMESTAMP >>> 16),
523     (byte) (LATEST_TIMESTAMP >>> 8),
524     (byte) LATEST_TIMESTAMP,
525   };
526 
527   /**
528    * Define for 'return-all-versions'.
529    */
530   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
531 
532   /**
533    * Unlimited time-to-live.
534    */
535 //  public static final int FOREVER = -1;
536   public static final int FOREVER = Integer.MAX_VALUE;
537 
538   /**
539    * Seconds in a week
540    */
541   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
542 
543   /**
544    * Seconds in a day, hour and minute
545    */
546   public static final int DAY_IN_SECONDS = 24 * 60 * 60;
547   public static final int HOUR_IN_SECONDS = 60 * 60;
548   public static final int MINUTE_IN_SECONDS = 60;
549 
550   //TODO: although the following are referenced widely to format strings for
551   //      the shell. They really aren't a part of the public API. It would be
552   //      nice if we could put them somewhere where they did not need to be
553   //      public. They could have package visibility
554   public static final String NAME = "NAME";
555   public static final String VERSIONS = "VERSIONS";
556   public static final String IN_MEMORY = "IN_MEMORY";
557   public static final String METADATA = "METADATA";
558   public static final String CONFIGURATION = "CONFIGURATION";
559 
560   /**
561    * Retrying we multiply hbase.client.pause setting by what we have in this array until we
562    * run out of array items.  Retries beyond this use the last number in the array.  So, for
563    * example, if hbase.client.pause is 1 second, and maximum retries count
564    * hbase.client.retries.number is 10, we will retry at the following intervals:
565    * 1, 2, 3, 5, 10, 20, 40, 100, 100, 100.
566    * With 100ms, a back-off of 200 means 20s
567    */
568   public static int RETRY_BACKOFF[] = { 1, 2, 3, 5, 10, 20, 40, 100, 100, 100, 100, 200, 200 };
569 
570   public static final String REGION_IMPL = "hbase.hregion.impl";
571 
572   /** modifyTable op for replacing the table descriptor */
573   public static enum Modify {
574     CLOSE_REGION,
575     TABLE_COMPACT,
576     TABLE_FLUSH,
577     TABLE_MAJOR_COMPACT,
578     TABLE_SET_HTD,
579     TABLE_SPLIT
580   }
581 
582   /**
583    * Scope tag for locally scoped data.
584    * This data will not be replicated.
585    */
586   public static final int REPLICATION_SCOPE_LOCAL = 0;
587 
588   /**
589    * Scope tag for globally scoped data.
590    * This data will be replicated to all peers.
591    */
592   public static final int REPLICATION_SCOPE_GLOBAL = 1;
593 
594   /**
595    * Default cluster ID, cannot be used to identify a cluster so a key with
596    * this value means it wasn't meant for replication.
597    */
598   public static final UUID DEFAULT_CLUSTER_ID = new UUID(0L,0L);
599 
600     /**
601      * Parameter name for maximum number of bytes returned when calling a
602      * scanner's next method.
603      */
604   public static String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY = "hbase.client.scanner.max.result.size";
605 
606   /**
607    * Maximum number of bytes returned when calling a scanner's next method.
608    * Note that when a single row is larger than this limit the row is still
609    * returned completely.
610    *
611    * The default value is unlimited.
612    */
613   public static long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = Long.MAX_VALUE;
614 
615   /**
616    * Parameter name for client pause value, used mostly as value to wait
617    * before running a retry of a failed get, region lookup, etc.
618    */
619   public static String HBASE_CLIENT_PAUSE = "hbase.client.pause";
620 
621   /**
622    * Default value of {@link #HBASE_CLIENT_PAUSE}.
623    */
624   public static long DEFAULT_HBASE_CLIENT_PAUSE = 100;
625 
626   /**
627    * The maximum number of concurrent connections the client will maintain.
628    */
629   public static final String HBASE_CLIENT_MAX_TOTAL_TASKS = "hbase.client.max.total.tasks";
630 
631   /**
632    * Default value of {@link #HBASE_CLIENT_MAX_TOTAL_TASKS}.
633    */
634   public static final int DEFAULT_HBASE_CLIENT_MAX_TOTAL_TASKS = 100;
635 
636   /**
637    * The maximum number of concurrent connections the client will maintain to a single
638    * RegionServer.
639    */
640   public static final String HBASE_CLIENT_MAX_PERSERVER_TASKS = "hbase.client.max.perserver.tasks";
641 
642   /**
643    * Default value of {@link #HBASE_CLIENT_MAX_PERSERVER_TASKS}.
644    */
645   public static final int DEFAULT_HBASE_CLIENT_MAX_PERSERVER_TASKS = 2;
646 
647   /**
648    * The maximum number of concurrent connections the client will maintain to a single
649    * Region.
650    */
651   public static final String HBASE_CLIENT_MAX_PERREGION_TASKS = "hbase.client.max.perregion.tasks";
652 
653   /**
654    * Default value of {@link #HBASE_CLIENT_MAX_PERREGION_TASKS}.
655    */
656   public static final int DEFAULT_HBASE_CLIENT_MAX_PERREGION_TASKS = 1;
657 
658   /**
659    * Parameter name for server pause value, used mostly as value to wait before
660    * running a retry of a failed operation.
661    */
662   public static String HBASE_SERVER_PAUSE = "hbase.server.pause";
663 
664   /**
665    * Default value of {@link #HBASE_SERVER_PAUSE}.
666    */
667   public static int DEFAULT_HBASE_SERVER_PAUSE = 1000;
668 
669   /**
670    * Parameter name for maximum retries, used as maximum for all retryable
671    * operations such as fetching of the root region from root region server,
672    * getting a cell's value, starting a row update, etc.
673    */
674   public static String HBASE_CLIENT_RETRIES_NUMBER = "hbase.client.retries.number";
675 
676   /**
677    * Default value of {@link #HBASE_CLIENT_RETRIES_NUMBER}.
678    */
679   public static int DEFAULT_HBASE_CLIENT_RETRIES_NUMBER = 31;
680 
681   /**
682    * Parameter name to set the default scanner caching for all clients.
683    */
684   public static String HBASE_CLIENT_SCANNER_CACHING = "hbase.client.scanner.caching";
685 
686   /**
687    * Default value for {@link #HBASE_CLIENT_SCANNER_CACHING}
688    */
689   public static int DEFAULT_HBASE_CLIENT_SCANNER_CACHING = 100;
690 
691   /**
692    * Parameter name for number of rows that will be fetched when calling next on
693    * a scanner if it is not served from memory. Higher caching values will
694    * enable faster scanners but will eat up more memory and some calls of next
695    * may take longer and longer times when the cache is empty.
696    */
697   public static String HBASE_META_SCANNER_CACHING = "hbase.meta.scanner.caching";
698 
699   /**
700    * Default value of {@link #HBASE_META_SCANNER_CACHING}.
701    */
702   public static int DEFAULT_HBASE_META_SCANNER_CACHING = 100;
703 
704   /**
705    * Parameter name for number of versions, kept by meta table.
706    */
707   public static String HBASE_META_VERSIONS = "hbase.meta.versions";
708 
709   /**
710    * Default value of {@link #HBASE_META_VERSIONS}.
711    */
712   public static int DEFAULT_HBASE_META_VERSIONS = 3;
713 
714   /**
715    * Parameter name for number of versions, kept by meta table.
716    */
717   public static String HBASE_META_BLOCK_SIZE = "hbase.meta.blocksize";
718 
719   /**
720    * Default value of {@link #HBASE_META_BLOCK_SIZE}.
721    */
722   public static int DEFAULT_HBASE_META_BLOCK_SIZE = 8 * 1024;
723 
724   /**
725    * Parameter name for unique identifier for this {@link org.apache.hadoop.conf.Configuration}
726    * instance. If there are two or more {@link org.apache.hadoop.conf.Configuration} instances that,
727    * for all intents and purposes, are the same except for their instance ids, then they will not be
728    * able to share the same org.apache.hadoop.hbase.client.HConnection instance. On the other hand,
729    * even if the instance ids are the same, it could result in non-shared
730    * org.apache.hadoop.hbase.client.HConnection instances if some of the other connection parameters
731    * differ.
732    */
733   public static String HBASE_CLIENT_INSTANCE_ID = "hbase.client.instance.id";
734 
735   /**
736    * The client scanner timeout period in milliseconds.
737    */
738   public static String HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = "hbase.client.scanner.timeout.period";
739 
740   /**
741    * Use {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD} instead.
742    * @deprecated This config option is deprecated. Will be removed at later releases after 0.96.
743    */
744   @Deprecated
745   public static String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
746       "hbase.regionserver.lease.period";
747 
748   /**
749    * Default value of {@link #HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD}.
750    */
751   public static int DEFAULT_HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD = 60000;
752 
753   /**
754    * timeout for each RPC
755    */
756   public static String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
757 
758   /**
759    * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
760    */
761   public static int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
762 
763   /**
764    * timeout for short operation RPC
765    */
766   public static String HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY = "hbase.rpc.shortoperation.timeout";
767 
768   /**
769    * Default value of {@link #HBASE_RPC_SHORTOPERATION_TIMEOUT_KEY}
770    */
771   public static int DEFAULT_HBASE_RPC_SHORTOPERATION_TIMEOUT = 10000;
772 
773   /**
774    * Value indicating the server name was saved with no sequence number.
775    */
776   public static final long NO_SEQNUM = -1;
777 
778 
779   /*
780    * cluster replication constants.
781    */
782   public static final String
783       REPLICATION_ENABLE_KEY = "hbase.replication";
784   public static final boolean
785       REPLICATION_ENABLE_DEFAULT = true;
786   public static final String
787       REPLICATION_SOURCE_SERVICE_CLASSNAME = "hbase.replication.source.service";
788   public static final String
789       REPLICATION_SINK_SERVICE_CLASSNAME = "hbase.replication.sink.service";
790   public static final String REPLICATION_SERVICE_CLASSNAME_DEFAULT =
791     "org.apache.hadoop.hbase.replication.regionserver.Replication";
792 
793   /** HBCK special code name used as server name when manipulating ZK nodes */
794   public static final String HBCK_CODE_NAME = "HBCKServerName";
795 
796   public static final String KEY_FOR_HOSTNAME_SEEN_BY_MASTER =
797     "hbase.regionserver.hostname.seen.by.master";
798 
799   public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
800       "hbase.master.logcleaner.plugins";
801 
802   public static final String HBASE_REGION_SPLIT_POLICY_KEY =
803     "hbase.regionserver.region.split.policy";
804 
805   /** Whether nonces are enabled; default is true. */
806   public static String HBASE_RS_NONCES_ENABLED = "hbase.regionserver.nonces.enabled";
807 
808   /**
809    * Configuration key for the size of the block cache
810    */
811   public static final String HFILE_BLOCK_CACHE_SIZE_KEY =
812     "hfile.block.cache.size";
813 
814   public static final float HFILE_BLOCK_CACHE_SIZE_DEFAULT = 0.4f;
815 
816   /*
817     * Minimum percentage of free heap necessary for a successful cluster startup.
818     */
819   public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
820 
821   public static final Pattern CP_HTD_ATTR_KEY_PATTERN = Pattern.compile
822       ("^coprocessor\\$([0-9]+)$", Pattern.CASE_INSENSITIVE);
823   public static final Pattern CP_HTD_ATTR_VALUE_PATTERN =
824       Pattern.compile("(^[^\\|]*)\\|([^\\|]+)\\|[\\s]*([\\d]*)[\\s]*(\\|.*)?$");
825 
826   public static final String CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN = "[^=,]+";
827   public static final String CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN = "[^,]+";
828   public static final Pattern CP_HTD_ATTR_VALUE_PARAM_PATTERN = Pattern.compile(
829       "(" + CP_HTD_ATTR_VALUE_PARAM_KEY_PATTERN + ")=(" +
830       CP_HTD_ATTR_VALUE_PARAM_VALUE_PATTERN + "),?");
831 
832   /** The delay when re-trying a socket operation in a loop (HBASE-4712) */
833   public static final int SOCKET_RETRY_WAIT_MS = 200;
834 
835   /** Host name of the local machine */
836   public static final String LOCALHOST = "localhost";
837 
838   /**
839    * If this parameter is set to true, then hbase will read
840    * data and then verify checksums. Checksum verification
841    * inside hdfs will be switched off.  However, if the hbase-checksum
842    * verification fails, then it will switch back to using
843    * hdfs checksums for verifiying data that is being read from storage.
844    *
845    * If this parameter is set to false, then hbase will not
846    * verify any checksums, instead it will depend on checksum verification
847    * being done in the hdfs client.
848    */
849   public static final String HBASE_CHECKSUM_VERIFICATION =
850       "hbase.regionserver.checksum.verify";
851 
852   public static final String LOCALHOST_IP = "127.0.0.1";
853 
854   /** Conf key that enables unflushed WAL edits directly being replayed to region servers */
855   public static final String DISTRIBUTED_LOG_REPLAY_KEY = "hbase.master.distributed.log.replay";
856   /**
857    * Default 'distributed log replay' as true since hbase 0.99.0
858    */
859   public static final boolean DEFAULT_DISTRIBUTED_LOG_REPLAY_CONFIG = true;
860   public static final String DISALLOW_WRITES_IN_RECOVERING =
861       "hbase.regionserver.disallow.writes.when.recovering";
862   public static final boolean DEFAULT_DISALLOW_WRITES_IN_RECOVERING_CONFIG = false;
863 
864   public static final String REGION_SERVER_HANDLER_COUNT = "hbase.regionserver.handler.count";
865   public static final int DEFAULT_REGION_SERVER_HANDLER_COUNT = 30;
866 
867   public static final String REGION_SERVER_META_HANDLER_COUNT =
868       "hbase.regionserver.metahandler.count";
869   public static final int DEFAULT_REGION_SERVER_META_HANDLER_COUNT = 10;
870 
871   public static final String REGION_SERVER_REPLICATION_HANDLER_COUNT =
872       "hbase.regionserver.replication.handler.count";
873   public static final int DEFAULT_REGION_SERVER_REPLICATION_HANDLER_COUNT = 3;
874 
875   public static final String MASTER_HANDLER_COUNT = "hbase.master.handler.count";
876   public static final int DEFAULT_MASTER_HANLDER_COUNT = 25;
877 
878   /** Conf key that specifies timeout value to wait for a region ready */
879   public static final String LOG_REPLAY_WAIT_REGION_TIMEOUT =
880       "hbase.master.log.replay.wait.region.timeout";
881 
882   /**
883    * The name of the configuration parameter that specifies
884    * the number of bytes in a newly created checksum chunk.
885    */
886   public static final String BYTES_PER_CHECKSUM =
887       "hbase.hstore.bytes.per.checksum";
888 
889   /**
890    * The name of the configuration parameter that specifies
891    * the name of an algorithm that is used to compute checksums
892    * for newly created blocks.
893    */
894   public static final String CHECKSUM_TYPE_NAME =
895       "hbase.hstore.checksum.algorithm";
896 
897   /** Enable file permission modification from standard hbase */
898   public static final String ENABLE_DATA_FILE_UMASK = "hbase.data.umask.enable";
899   /** File permission umask to use when creating hbase data files */
900   public static final String DATA_FILE_UMASK_KEY = "hbase.data.umask";
901 
902   /** Configuration name of HLog Compression */
903   public static final String ENABLE_WAL_COMPRESSION =
904     "hbase.regionserver.wal.enablecompression";
905 
906   /** Region in Transition metrics threshold time */
907   public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD="hbase.metrics.rit.stuck.warning.threshold";
908 
909   public static final String LOAD_BALANCER_SLOP_KEY = "hbase.regions.slop";
910 
911   /**
912    * The byte array represents for NO_NEXT_INDEXED_KEY;
913    * The actual value is irrelevant because this is always compared by reference.
914    */
915   public static final byte [] NO_NEXT_INDEXED_KEY = Bytes.toBytes("NO_NEXT_INDEXED_KEY");
916   /** delimiter used between portions of a region name */
917   public static final int DELIMITER = ',';
918   public static final String HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
919       "hbase.config.read.zookeeper.config";
920   public static final boolean DEFAULT_HBASE_CONFIG_READ_ZOOKEEPER_CONFIG =
921       false;
922 
923   /**
924    * QOS attributes: these attributes are used to demarcate RPC call processing
925    * by different set of handlers. For example, HIGH_QOS tagged methods are
926    * handled by high priority handlers.
927    */
928   public static final int NORMAL_QOS = 0;
929   public static final int QOS_THRESHOLD = 10;
930   public static final int HIGH_QOS = 100;
931   public static final int REPLICATION_QOS = 5; // normal_QOS < replication_QOS < high_QOS
932   public static final int REPLAY_QOS = 6; // REPLICATION_QOS < REPLAY_QOS < high_QOS
933 
934   /** Directory under /hbase where archived hfiles are stored */
935   public static final String HFILE_ARCHIVE_DIRECTORY = "archive";
936 
937   /**
938    * Name of the directory to store all snapshots. See SnapshotDescriptionUtils for
939    * remaining snapshot constants; this is here to keep HConstants dependencies at a minimum and
940    * uni-directional.
941    */
942   public static final String SNAPSHOT_DIR_NAME = ".hbase-snapshot";
943 
944   /* Name of old snapshot directory. See HBASE-8352 for details on why it needs to be renamed */
945   public static final String OLD_SNAPSHOT_DIR_NAME = ".snapshot";
946 
947   /** Temporary directory used for table creation and deletion */
948   public static final String HBASE_TEMP_DIRECTORY = ".tmp";
949   /**
950    * The period (in milliseconds) between computing region server point in time metrics
951    */
952   public static final String REGIONSERVER_METRICS_PERIOD = "hbase.regionserver.metrics.period";
953   public static final long DEFAULT_REGIONSERVER_METRICS_PERIOD = 5000;
954   /** Directories that are not HBase table directories */
955   public static final List<String> HBASE_NON_TABLE_DIRS =
956     Collections.unmodifiableList(Arrays.asList(new String[] {
957       HBCK_SIDELINEDIR_NAME, HBASE_TEMP_DIRECTORY, MIGRATION_NAME
958     }));
959 
960   /** Directories that are not HBase user table directories */
961   public static final List<String> HBASE_NON_USER_TABLE_DIRS =
962     Collections.unmodifiableList(Arrays.asList((String[])ArrayUtils.addAll(
963       new String[] { TableName.META_TABLE_NAME.getNameAsString() },
964       HBASE_NON_TABLE_DIRS.toArray())));
965 
966   /** Health script related settings. */
967   public static final String HEALTH_SCRIPT_LOC = "hbase.node.health.script.location";
968   public static final String HEALTH_SCRIPT_TIMEOUT = "hbase.node.health.script.timeout";
969   public static final String HEALTH_CHORE_WAKE_FREQ =
970       "hbase.node.health.script.frequency";
971   public static final long DEFAULT_HEALTH_SCRIPT_TIMEOUT = 60000;
972   /**
973    * The maximum number of health check failures a server can encounter consecutively.
974    */
975   public static final String HEALTH_FAILURE_THRESHOLD =
976       "hbase.node.health.failure.threshold";
977   public static final int DEFAULT_HEALTH_FAILURE_THRESHOLD = 3;
978 
979 
980   /**
981    * Setting to activate, or not, the publication of the status by the master. Default
982    *  notification is by a multicast message.
983    */
984   public static final String STATUS_PUBLISHED = "hbase.status.published";
985   public static final boolean STATUS_PUBLISHED_DEFAULT = false;
986 
987   /**
988    * IP to use for the multicast status messages between the master and the clients.
989    * The default address is chosen as one among others within the ones suitable for multicast
990    * messages.
991    */
992   public static final String STATUS_MULTICAST_ADDRESS = "hbase.status.multicast.address.ip";
993   public static final String DEFAULT_STATUS_MULTICAST_ADDRESS = "226.1.1.3";
994 
995   /**
996    * The address to use for binding the local socket for receiving multicast. Defaults to
997    * 0.0.0.0.
998    * @see <a href="https://issues.apache.org/jira/browse/HBASE-9961">HBASE-9961</a>
999    */
1000   public static final String STATUS_MULTICAST_BIND_ADDRESS = "hbase.status.multicast.bind.address.ip";
1001   public static final String DEFAULT_STATUS_MULTICAST_BIND_ADDRESS = "0.0.0.0";
1002 
1003   /**
1004    * The port to use for the multicast messages.
1005    */
1006   public static final String STATUS_MULTICAST_PORT = "hbase.status.multicast.address.port";
1007   public static final int DEFAULT_STATUS_MULTICAST_PORT = 16100;
1008 
1009   public static final long NO_NONCE = 0;
1010 
1011   /** Configuration key for the crypto algorithm provider, a class name */
1012   public static final String CRYPTO_CIPHERPROVIDER_CONF_KEY = "hbase.crypto.cipherprovider";
1013 
1014   /** Configuration key for the crypto key provider, a class name */
1015   public static final String CRYPTO_KEYPROVIDER_CONF_KEY = "hbase.crypto.keyprovider";
1016 
1017   /** Configuration key for the crypto key provider parameters */
1018   public static final String CRYPTO_KEYPROVIDER_PARAMETERS_KEY =
1019       "hbase.crypto.keyprovider.parameters";
1020 
1021   /** Configuration key for the name of the master key for the cluster, a string */
1022   public static final String CRYPTO_MASTERKEY_NAME_CONF_KEY = "hbase.crypto.master.key.name";
1023 
1024   /** Configuration key for the name of the alternate master key for the cluster, a string */
1025   public static final String CRYPTO_MASTERKEY_ALTERNATE_NAME_CONF_KEY =
1026     "hbase.crypto.master.alternate.key.name";
1027 
1028   /** Configuration key for the algorithm to use when encrypting the WAL, a string */
1029   public static final String CRYPTO_WAL_ALGORITHM_CONF_KEY = "hbase.crypto.wal.algorithm";
1030 
1031   /** Configuration key for the name of the master WAL encryption key for the cluster, a string */
1032   public static final String CRYPTO_WAL_KEY_NAME_CONF_KEY = "hbase.crypto.wal.key.name";
1033 
1034   /** Configuration key for enabling HLog encryption, a boolean */
1035   public static final String ENABLE_WAL_ENCRYPTION = "hbase.regionserver.wal.encryption";
1036 
1037   /** Configuration key for setting RPC codec class name */
1038   public static final String RPC_CODEC_CONF_KEY = "hbase.client.rpc.codec";
1039 
1040   /** Configuration key for setting replication codec class name */
1041   public static final String REPLICATION_CODEC_CONF_KEY = "hbase.replication.rpc.codec";
1042 
1043   /** Config for pluggable consensus provider */
1044   public static final String HBASE_COORDINATED_STATE_MANAGER_CLASS =
1045     "hbase.coordinated.state.manager.class";
1046 
1047   /** Configuration key for SplitLog manager timeout */
1048   public static final String HBASE_SPLITLOG_MANAGER_TIMEOUT = "hbase.splitlog.manager.timeout";
1049 
1050   /**
1051    * Configuration keys for Bucket cache
1052    */
1053   // TODO moving these bucket cache implementation specific configs to this level is violation of
1054   // encapsulation. But as these has to be referred from hbase-common and bucket cache
1055   // sits in hbase-server, there were no other go! Can we move the cache implementation to
1056   // hbase-common?
1057 
1058   /**
1059    * Current ioengine options in include: heap, offheap and file:PATH (where PATH is the path
1060    * to the file that will host the file-based cache.  See BucketCache#getIOEngineFromName() for
1061    * list of supported ioengine options.
1062    * <p>Set this option and a non-zero {@link #BUCKET_CACHE_SIZE_KEY} to enable bucket cache.
1063    */
1064   public static final String BUCKET_CACHE_IOENGINE_KEY = "hbase.bucketcache.ioengine";
1065 
1066   /**
1067    * When using bucket cache, this is a float that EITHER represents a percentage of total heap
1068    * memory size to give to the cache (if < 1.0) OR, it is the capacity in megabytes of the cache.
1069    */
1070   public static final String BUCKET_CACHE_SIZE_KEY = "hbase.bucketcache.size";
1071 
1072   private HConstants() {
1073     // Can't be instantiated with this ctor.
1074   }
1075 }