1 /*
2 * Copyright 2021 TiKV Project Authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 */
17
18 package org.tikv.common.replica;
19
20 import java.util.ArrayList;
21 import java.util.Collections;
22 import java.util.List;
23
24 public class LeaderFollowerReplicaSelector implements ReplicaSelector {
25 @Override
26 public List<Store> select(Region region) {
27 Store[] stores = region.getStores();
28 Store leader = region.getLeader();
29 List<Store> list = new ArrayList<>(stores.length);
30 for (Store store : stores) {
31 if (!store.isLearner() && !leader.equals(store)) {
32 list.add(store);
33 }
34 }
35 Collections.shuffle(list);
36 list.add(leader);
37 return list;
38 }
39 }