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1   /**
2    * Copyright 2010 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase;
21  
22  import org.apache.hadoop.hbase.ipc.HRegionInterface;
23  import org.apache.hadoop.hbase.util.Bytes;
24  
25  /**
26   * HConstants holds a bunch of HBase-related constants
27   */
28  public final class HConstants {
29    /**
30     * Status codes used for return values of bulk operations.
31     */
32    public enum OperationStatusCode {
33      NOT_RUN,
34      SUCCESS,
35      BAD_FAMILY,
36      FAILURE;
37    }
38  
39    /** long constant for zero */
40    public static final Long ZERO_L = Long.valueOf(0L);
41    public static final String NINES = "99999999999999";
42    public static final String ZEROES = "00000000000000";
43  
44    // For migration
45  
46    /** name of version file */
47    public static final String VERSION_FILE_NAME = "hbase.version";
48  
49    /**
50     * Current version of file system.
51     * Version 4 supports only one kind of bloom filter.
52     * Version 5 changes versions in catalog table regions.
53     * Version 6 enables blockcaching on catalog tables.
54     * Version 7 introduces hfile -- hbase 0.19 to 0.20..
55     */
56    // public static final String FILE_SYSTEM_VERSION = "6";
57    public static final String FILE_SYSTEM_VERSION = "7";
58  
59    // Configuration parameters
60  
61    //TODO: Is having HBase homed on port 60k OK?
62  
63    /** Cluster is in distributed mode or not */
64    public static final String CLUSTER_DISTRIBUTED = "hbase.cluster.distributed";
65  
66    /** Cluster is standalone or pseudo-distributed */
67    public static final String CLUSTER_IS_LOCAL = "false";
68  
69    /** Cluster is fully-distributed */
70    public static final String CLUSTER_IS_DISTRIBUTED = "true";
71  
72    /** default host address */
73    public static final String DEFAULT_HOST = "0.0.0.0";
74  
75    /** Parameter name for port master listens on. */
76    public static final String MASTER_PORT = "hbase.master.port";
77  
78    /** default port that the master listens on */
79    public static final int DEFAULT_MASTER_PORT = 60000;
80  
81    /** default port for master web api */
82    public static final int DEFAULT_MASTER_INFOPORT = 60010;
83  
84    /** Parameter name for the master type being backup (waits for primary to go inactive). */
85    public static final String MASTER_TYPE_BACKUP = "hbase.master.backup";
86  
87    /** by default every master is a possible primary master unless the conf explicitly overrides it */
88    public static final boolean DEFAULT_MASTER_TYPE_BACKUP = false;
89  
90    /** Name of ZooKeeper quorum configuration parameter. */
91    public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
92  
93    /** Name of ZooKeeper config file in conf/ directory. */
94    public static final String ZOOKEEPER_CONFIG_NAME = "zoo.cfg";
95  
96    /** Parameter name for number of times to retry writes to ZooKeeper. */
97    public static final String ZOOKEEPER_RETRIES = "zookeeper.retries";
98    /** Default number of times to retry writes to ZooKeeper. */
99    public static final int DEFAULT_ZOOKEEPER_RETRIES = 5;
100 
101   /** Parameter name for ZooKeeper pause between retries. In milliseconds. */
102   public static final String ZOOKEEPER_PAUSE = "zookeeper.pause";
103   /** Default ZooKeeper pause value. In milliseconds. */
104   public static final int DEFAULT_ZOOKEEPER_PAUSE = 2 * 1000;
105 
106   /** default client port that the zookeeper listens on */
107   public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
108 
109   /** Parameter name for the root dir in ZK for this cluster */
110   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
111 
112   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
113 
114   /** Parameter name for port region server listens on. */
115   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
116 
117   /** Default port region server listens on. */
118   public static final int DEFAULT_REGIONSERVER_PORT = 60020;
119 
120   /** default port for region server web api */
121   public static final int DEFAULT_REGIONSERVER_INFOPORT = 60030;
122 
123   /** Parameter name for what region server interface to use. */
124   public static final String REGION_SERVER_CLASS = "hbase.regionserver.class";
125 
126   /** Parameter name for what region server implementation to use. */
127   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
128 
129   /** Default region server interface class name. */
130   public static final String DEFAULT_REGION_SERVER_CLASS = HRegionInterface.class.getName();
131 
132   /** Parameter name for how often threads should wake up */
133   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
134 
135   /** Parameter name for how often a region should should perform a major compaction */
136   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
137 
138   /** Parameter name for HBase instance root directory */
139   public static final String HBASE_DIR = "hbase.rootdir";
140 
141   /** Used to construct the name of the log directory for a region server
142    * Use '.' as a special character to seperate the log files from table data */
143   public static final String HREGION_LOGDIR_NAME = ".logs";
144 
145   /** Like the previous, but for old logs that are about to be deleted */
146   public static final String HREGION_OLDLOGDIR_NAME = ".oldlogs";
147 
148   /** Used to construct the name of the compaction directory during compaction */
149   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
150 
151   /** Default maximum file size */
152   public static final long DEFAULT_MAX_FILE_SIZE = 256 * 1024 * 1024;
153 
154   /** Default size of a reservation block   */
155   public static final int DEFAULT_SIZE_RESERVATION_BLOCK = 1024 * 1024 * 5;
156 
157   /** Maximum value length, enforced on KeyValue construction */
158   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE;
159 
160   // Always store the location of the root table's HRegion.
161   // This HRegion is never split.
162 
163   // region name = table + startkey + regionid. This is the row key.
164   // each row in the root and meta tables describes exactly 1 region
165   // Do we ever need to know all the information that we are storing?
166 
167   // Note that the name of the root table starts with "-" and the name of the
168   // meta table starts with "." Why? it's a trick. It turns out that when we
169   // store region names in memory, we use a SortedMap. Since "-" sorts before
170   // "." (and since no other table name can start with either of these
171   // characters, the root region will always be the first entry in such a Map,
172   // followed by all the meta regions (which will be ordered by their starting
173   // row key as well), followed by all user tables. So when the Master is
174   // choosing regions to assign, it will always choose the root region first,
175   // followed by the meta regions, followed by user regions. Since the root
176   // and meta regions always need to be on-line, this ensures that they will
177   // be the first to be reassigned if the server(s) they are being served by
178   // should go down.
179 
180 
181   //
182   // New stuff.  Making a slow transition.
183   //
184 
185   /** The root table's name.*/
186   public static final byte [] ROOT_TABLE_NAME = Bytes.toBytes("-ROOT-");
187 
188   /** The META table's name. */
189   public static final byte [] META_TABLE_NAME = Bytes.toBytes(".META.");
190 
191   /** delimiter used between portions of a region name */
192   public static final int META_ROW_DELIMITER = ',';
193 
194   /** The catalog family as a string*/
195   public static final String CATALOG_FAMILY_STR = "info";
196 
197   /** The catalog family */
198   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
199 
200   /** The catalog historian family */
201   public static final byte [] CATALOG_HISTORIAN_FAMILY = Bytes.toBytes("historian");
202 
203   /** The regioninfo column qualifier */
204   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes("regioninfo");
205 
206   /** The server column qualifier */
207   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes("server");
208 
209   /** The startcode column qualifier */
210   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes("serverstartcode");
211 
212   /** The lower-half split region column qualifier */
213   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
214 
215   /** The upper-half split region column qualifier */
216   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
217 
218   // Other constants
219 
220   /**
221    * An empty instance.
222    */
223   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
224 
225   /**
226    * Used by scanners, etc when they want to start at the beginning of a region
227    */
228   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
229 
230   /**
231    * Last row in a table.
232    */
233   public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
234 
235   /**
236     * Used by scanners and others when they're trying to detect the end of a
237     * table
238     */
239   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
240 
241   /**
242    * Max length a row can have because of the limitation in TFile.
243    */
244   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
245 
246   /** When we encode strings, we always specify UTF8 encoding */
247   public static final String UTF8_ENCODING = "UTF-8";
248 
249   /**
250    * Timestamp to use when we want to refer to the latest cell.
251    * This is the timestamp sent by clients when no timestamp is specified on
252    * commit.
253    */
254   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
255 
256   /**
257    * LATEST_TIMESTAMP in bytes form
258    */
259   public static final byte [] LATEST_TIMESTAMP_BYTES = Bytes.toBytes(LATEST_TIMESTAMP);
260 
261   /**
262    * Define for 'return-all-versions'.
263    */
264   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
265 
266   /**
267    * Unlimited time-to-live.
268    */
269 //  public static final int FOREVER = -1;
270   public static final int FOREVER = Integer.MAX_VALUE;
271 
272   /**
273    * Seconds in a week
274    */
275   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
276 
277   //TODO: HBASE_CLIENT_RETRIES_NUMBER_KEY is only used by TestMigrate. Move it
278   //      there.
279   public static final String HBASE_CLIENT_RETRIES_NUMBER_KEY =
280     "hbase.client.retries.number";
281 
282   //TODO: although the following are referenced widely to format strings for
283   //      the shell. They really aren't a part of the public API. It would be
284   //      nice if we could put them somewhere where they did not need to be
285   //      public. They could have package visibility
286   public static final String NAME = "NAME";
287   public static final String VERSIONS = "VERSIONS";
288   public static final String IN_MEMORY = "IN_MEMORY";
289 
290   /**
291    * This is a retry backoff multiplier table similar to the BSD TCP syn
292    * backoff table, a bit more aggressive than simple exponential backoff.
293    */
294   public static int RETRY_BACKOFF[] = { 1, 1, 1, 2, 2, 4, 4, 8, 16, 32 };
295 
296   public static final String REGION_IMPL = "hbase.hregion.impl";
297 
298   /** modifyTable op for replacing the table descriptor */
299   public static enum Modify {
300     CLOSE_REGION,
301     TABLE_COMPACT,
302     TABLE_FLUSH,
303     TABLE_MAJOR_COMPACT,
304     TABLE_SET_HTD,
305     TABLE_SPLIT
306   }
307 
308   /**
309    * Scope tag for locally scoped data.
310    * This data will not be replicated.
311    */
312   public static final int REPLICATION_SCOPE_LOCAL = 0;
313 
314   /**
315    * Scope tag for globally scoped data.
316    * This data will be replicated to all peers.
317    */
318   public static final int REPLICATION_SCOPE_GLOBAL = 1;
319 
320   /**
321    * Default cluster ID, cannot be used to identify a cluster so a key with
322    * this value means it wasn't meant for replication.
323    */
324   public static final byte DEFAULT_CLUSTER_ID = 0;
325 
326     /**
327      * Parameter name for maximum number of bytes returned when calling a
328      * scanner's next method.
329      */
330   public static String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY = "hbase.client.scanner.max.result.size";
331 
332   /**
333    * Maximum number of bytes returned when calling a scanner's next method.
334    * Note that when a single row is larger than this limit the row is still
335    * returned completely.
336    *
337    * The default value is unlimited.
338    */
339   public static long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = Long.MAX_VALUE;
340 
341 
342   /**
343    * HRegion server lease period in milliseconds. Clients must report in within this period
344    * else they are considered dead. Unit measured in ms (milliseconds).
345    */
346   public static String HBASE_REGIONSERVER_LEASE_PERIOD_KEY   = "hbase.regionserver.lease.period";
347 
348 
349   /**
350    * Default value of {@link #HBASE_REGIONSERVER_LEASE_PERIOD_KEY}.
351    */
352   public static long DEFAULT_HBASE_REGIONSERVER_LEASE_PERIOD = 60000;
353 
354   public static final String
355       REPLICATION_ENABLE_KEY = "hbase.replication";
356 
357   private HConstants() {
358     // Can't be instantiated with this ctor.
359   }
360 }