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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    /** default client port that the zookeeper listens on */
97    public static final int DEFAULT_ZOOKEPER_CLIENT_PORT = 2181;
98  
99    /** Parameter name for the root dir in ZK for this cluster */
100   public static final String ZOOKEEPER_ZNODE_PARENT = "zookeeper.znode.parent";
101 
102   public static final String DEFAULT_ZOOKEEPER_ZNODE_PARENT = "/hbase";
103 
104   /** Parameter name for port region server listens on. */
105   public static final String REGIONSERVER_PORT = "hbase.regionserver.port";
106 
107   /** Default port region server listens on. */
108   public static final int DEFAULT_REGIONSERVER_PORT = 60020;
109 
110   /** default port for region server web api */
111   public static final int DEFAULT_REGIONSERVER_INFOPORT = 60030;
112 
113   /** Parameter name for what region server interface to use. */
114   public static final String REGION_SERVER_CLASS = "hbase.regionserver.class";
115 
116   /** Parameter name for what region server implementation to use. */
117   public static final String REGION_SERVER_IMPL= "hbase.regionserver.impl";
118 
119   /** Default region server interface class name. */
120   public static final String DEFAULT_REGION_SERVER_CLASS = HRegionInterface.class.getName();
121 
122   /** Parameter name for what master implementation to use. */
123   public static final String MASTER_IMPL= "hbase.master.impl";
124 
125   /** Parameter name for how often threads should wake up */
126   public static final String THREAD_WAKE_FREQUENCY = "hbase.server.thread.wakefrequency";
127 
128   /** Default value for thread wake frequency */
129   public static final int DEFAULT_THREAD_WAKE_FREQUENCY = 10 * 1000;
130   
131   /** Parameter name for how often a region should should perform a major compaction */
132   public static final String MAJOR_COMPACTION_PERIOD = "hbase.hregion.majorcompaction";
133 
134   /** Parameter name for HBase instance root directory */
135   public static final String HBASE_DIR = "hbase.rootdir";
136 
137   /** Used to construct the name of the log directory for a region server
138    * Use '.' as a special character to seperate the log files from table data */
139   public static final String HREGION_LOGDIR_NAME = ".logs";
140 
141   /** Like the previous, but for old logs that are about to be deleted */
142   public static final String HREGION_OLDLOGDIR_NAME = ".oldlogs";
143 
144   /** Used to construct the name of the compaction directory during compaction */
145   public static final String HREGION_COMPACTIONDIR_NAME = "compaction.dir";
146 
147   /** Default maximum file size */
148   public static final long DEFAULT_MAX_FILE_SIZE = 256 * 1024 * 1024;
149 
150   /** Default size of a reservation block   */
151   public static final int DEFAULT_SIZE_RESERVATION_BLOCK = 1024 * 1024 * 5;
152 
153   /** Maximum value length, enforced on KeyValue construction */
154   public static final int MAXIMUM_VALUE_LENGTH = Integer.MAX_VALUE;
155 
156   // Always store the location of the root table's HRegion.
157   // This HRegion is never split.
158 
159   // region name = table + startkey + regionid. This is the row key.
160   // each row in the root and meta tables describes exactly 1 region
161   // Do we ever need to know all the information that we are storing?
162 
163   // Note that the name of the root table starts with "-" and the name of the
164   // meta table starts with "." Why? it's a trick. It turns out that when we
165   // store region names in memory, we use a SortedMap. Since "-" sorts before
166   // "." (and since no other table name can start with either of these
167   // characters, the root region will always be the first entry in such a Map,
168   // followed by all the meta regions (which will be ordered by their starting
169   // row key as well), followed by all user tables. So when the Master is
170   // choosing regions to assign, it will always choose the root region first,
171   // followed by the meta regions, followed by user regions. Since the root
172   // and meta regions always need to be on-line, this ensures that they will
173   // be the first to be reassigned if the server(s) they are being served by
174   // should go down.
175 
176 
177   //
178   // New stuff.  Making a slow transition.
179   //
180 
181   /** The root table's name.*/
182   public static final byte [] ROOT_TABLE_NAME = Bytes.toBytes("-ROOT-");
183 
184   /** The META table's name. */
185   public static final byte [] META_TABLE_NAME = Bytes.toBytes(".META.");
186 
187   /** delimiter used between portions of a region name */
188   public static final int META_ROW_DELIMITER = ',';
189 
190   /** The catalog family as a string*/
191   public static final String CATALOG_FAMILY_STR = "info";
192 
193   /** The catalog family */
194   public static final byte [] CATALOG_FAMILY = Bytes.toBytes(CATALOG_FAMILY_STR);
195 
196   /** The regioninfo column qualifier */
197   public static final byte [] REGIONINFO_QUALIFIER = Bytes.toBytes("regioninfo");
198 
199   /** The server column qualifier */
200   public static final byte [] SERVER_QUALIFIER = Bytes.toBytes("server");
201 
202   /** The startcode column qualifier */
203   public static final byte [] STARTCODE_QUALIFIER = Bytes.toBytes("serverstartcode");
204 
205   /** The lower-half split region column qualifier */
206   public static final byte [] SPLITA_QUALIFIER = Bytes.toBytes("splitA");
207 
208   /** The upper-half split region column qualifier */
209   public static final byte [] SPLITB_QUALIFIER = Bytes.toBytes("splitB");
210 
211   // Other constants
212 
213   /**
214    * An empty instance.
215    */
216   public static final byte [] EMPTY_BYTE_ARRAY = new byte [0];
217 
218   /**
219    * Used by scanners, etc when they want to start at the beginning of a region
220    */
221   public static final byte [] EMPTY_START_ROW = EMPTY_BYTE_ARRAY;
222 
223   /**
224    * Last row in a table.
225    */
226   public static final byte [] EMPTY_END_ROW = EMPTY_START_ROW;
227 
228   /**
229     * Used by scanners and others when they're trying to detect the end of a
230     * table
231     */
232   public static final byte [] LAST_ROW = EMPTY_BYTE_ARRAY;
233 
234   /**
235    * Max length a row can have because of the limitation in TFile.
236    */
237   public static final int MAX_ROW_LENGTH = Short.MAX_VALUE;
238 
239   /** When we encode strings, we always specify UTF8 encoding */
240   public static final String UTF8_ENCODING = "UTF-8";
241 
242   /**
243    * Timestamp to use when we want to refer to the latest cell.
244    * This is the timestamp sent by clients when no timestamp is specified on
245    * commit.
246    */
247   public static final long LATEST_TIMESTAMP = Long.MAX_VALUE;
248 
249   /**
250    * Timestamp to use when we want to refer to the oldest cell.
251    */
252   public static final long OLDEST_TIMESTAMP = Long.MIN_VALUE;
253 
254   /**
255    * LATEST_TIMESTAMP in bytes form
256    */
257   public static final byte [] LATEST_TIMESTAMP_BYTES = Bytes.toBytes(LATEST_TIMESTAMP);
258 
259   /**
260    * Define for 'return-all-versions'.
261    */
262   public static final int ALL_VERSIONS = Integer.MAX_VALUE;
263 
264   /**
265    * Unlimited time-to-live.
266    */
267 //  public static final int FOREVER = -1;
268   public static final int FOREVER = Integer.MAX_VALUE;
269 
270   /**
271    * Seconds in a week
272    */
273   public static final int WEEK_IN_SECONDS = 7 * 24 * 3600;
274 
275   //TODO: although the following are referenced widely to format strings for
276   //      the shell. They really aren't a part of the public API. It would be
277   //      nice if we could put them somewhere where they did not need to be
278   //      public. They could have package visibility
279   public static final String NAME = "NAME";
280   public static final String VERSIONS = "VERSIONS";
281   public static final String IN_MEMORY = "IN_MEMORY";
282 
283   /**
284    * This is a retry backoff multiplier table similar to the BSD TCP syn
285    * backoff table, a bit more aggressive than simple exponential backoff.
286    */
287   public static int RETRY_BACKOFF[] = { 1, 1, 1, 2, 2, 4, 4, 8, 16, 32 };
288 
289   public static final String REGION_IMPL = "hbase.hregion.impl";
290 
291   /** modifyTable op for replacing the table descriptor */
292   public static enum Modify {
293     CLOSE_REGION,
294     TABLE_COMPACT,
295     TABLE_FLUSH,
296     TABLE_MAJOR_COMPACT,
297     TABLE_SET_HTD,
298     TABLE_SPLIT
299   }
300 
301   /**
302    * Scope tag for locally scoped data.
303    * This data will not be replicated.
304    */
305   public static final int REPLICATION_SCOPE_LOCAL = 0;
306 
307   /**
308    * Scope tag for globally scoped data.
309    * This data will be replicated to all peers.
310    */
311   public static final int REPLICATION_SCOPE_GLOBAL = 1;
312 
313   /**
314    * Default cluster ID, cannot be used to identify a cluster so a key with
315    * this value means it wasn't meant for replication.
316    */
317   public static final byte DEFAULT_CLUSTER_ID = 0;
318 
319     /**
320      * Parameter name for maximum number of bytes returned when calling a
321      * scanner's next method.
322      */
323   public static String HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY = "hbase.client.scanner.max.result.size";
324 
325   /**
326    * Maximum number of bytes returned when calling a scanner's next method.
327    * Note that when a single row is larger than this limit the row is still
328    * returned completely.
329    *
330    * The default value is unlimited.
331    */
332   public static long DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE = Long.MAX_VALUE;
333 
334 
335   /**
336    * HRegion server lease period in milliseconds. Clients must report in within this period
337    * else they are considered dead. Unit measured in ms (milliseconds).
338    */
339   public static String HBASE_REGIONSERVER_LEASE_PERIOD_KEY =
340     "hbase.regionserver.lease.period";
341 
342 
343   /**
344    * Default value of {@link #HBASE_REGIONSERVER_LEASE_PERIOD_KEY}.
345    */
346   public static long DEFAULT_HBASE_REGIONSERVER_LEASE_PERIOD = 60000;
347   
348   /**
349    * timeout for each RPC
350    */
351   public static String HBASE_RPC_TIMEOUT_KEY = "hbase.rpc.timeout";
352   
353   /**
354    * Default value of {@link #HBASE_RPC_TIMEOUT_KEY}
355    */
356   public static int DEFAULT_HBASE_RPC_TIMEOUT = 60000;
357 
358   public static final String
359       REPLICATION_ENABLE_KEY = "hbase.replication";
360 
361   /** HBCK special code name used as server name when manipulating ZK nodes */
362   public static final String HBCK_CODE_NAME = "HBCKServerName";
363 
364   public static final String HBASE_MASTER_LOGCLEANER_PLUGINS =
365       "hbase.master.logcleaner.plugins";
366 
367    /*
368     * Minimum percentage of free heap necessary for a successful cluster startup.
369     */
370   public static final float HBASE_CLUSTER_MINIMUM_MEMORY_THRESHOLD = 0.2f;
371 
372   private HConstants() {
373     // Can't be instantiated with this ctor.
374   }
375 }