1 /**
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19 package org.apache.hadoop.hbase.wal;
20
21 import org.apache.hadoop.conf.Configuration;
22 import org.apache.hadoop.hbase.NamespaceDescriptor;
23 import org.apache.hadoop.hbase.classification.InterfaceAudience;
24 import org.apache.hadoop.hbase.util.Bytes;
25 import org.apache.hadoop.hbase.wal.RegionGroupingProvider.RegionGroupingStrategy;
26
27 /**
28 * A WAL grouping strategy based on namespace.
29 * Notice: the wal-group mapping might change if we support dynamic namespace updating later,
30 * and special attention needed if we support feature like group-based replication.
31 */
32 @InterfaceAudience.Private
33 public class NamespaceGroupingStrategy implements RegionGroupingStrategy {
34 private String providerId;
35
36 @Override
37 public String group(byte[] identifier, byte[] namespace) {
38 String namespaceString;
39 if (namespace == null || namespace.length == 0) {
40 namespaceString = NamespaceDescriptor.DEFAULT_NAMESPACE_NAME_STR;
41 } else {
42 namespaceString = Bytes.toString(namespace);
43 }
44 return providerId + GROUP_NAME_DELIMITER + namespaceString;
45 }
46
47 @Override
48 public void init(Configuration config, String providerId) {
49 this.providerId = providerId;
50 }
51
52 }