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
19 package org.apache.hadoop.hbase.quotas;
20
21 import java.util.List;
22
23 import org.apache.hadoop.hbase.classification.InterfaceAudience;
24 import org.apache.hadoop.hbase.classification.InterfaceStability;
25 import org.apache.hadoop.hbase.client.Mutation;
26 import org.apache.hadoop.hbase.client.Result;
27
28 /**
29 * Interface that allows to check the quota available for an operation.
30 */
31 @InterfaceAudience.Private
32 @InterfaceStability.Evolving
33 public interface OperationQuota {
34 public enum OperationType { MUTATE, GET, SCAN }
35
36 /**
37 * Keeps track of the average data size of operations like get, scan, mutate
38 */
39 public class AvgOperationSize {
40 private final long[] sizeSum;
41 private final long[] count;
42
43 public AvgOperationSize() {
44 int size = OperationType.values().length;
45 sizeSum = new long[size];
46 count = new long[size];
47 for (int i = 0; i < size; ++i) {
48 sizeSum[i] = 0;
49 count[i] = 0;
50 }
51 }
52
53 public void addOperationSize(OperationType type, long size) {
54 if (size > 0) {
55 int index = type.ordinal();
56 sizeSum[index] += size;
57 count[index]++;
58 }
59 }
60
61 public long getAvgOperationSize(OperationType type) {
62 int index = type.ordinal();
63 return count[index] > 0 ? sizeSum[index] / count[index] : 0;
64 }
65
66 public long getOperationSize(OperationType type) {
67 return sizeSum[type.ordinal()];
68 }
69
70 public void addGetResult(final Result result) {
71 long size = QuotaUtil.calculateResultSize(result);
72 addOperationSize(OperationType.GET, size);
73 }
74
75 public void addScanResult(final List<Result> results) {
76 long size = QuotaUtil.calculateResultSize(results);
77 addOperationSize(OperationType.SCAN, size);
78 }
79
80 public void addMutation(final Mutation mutation) {
81 long size = QuotaUtil.calculateMutationSize(mutation);
82 addOperationSize(OperationType.MUTATE, size);
83 }
84 }
85
86 /**
87 * Checks if it is possible to execute the specified operation.
88 * The quota will be estimated based on the number of operations to perform
89 * and the average size accumulated during time.
90 *
91 * @param numWrites number of write operation that will be performed
92 * @param numReads number of small-read operation that will be performed
93 * @param numScans number of long-read operation that will be performed
94 * @throws ThrottlingException if the operation cannot be performed
95 */
96 void checkQuota(int numWrites, int numReads, int numScans)
97 throws ThrottlingException;
98
99 /** Cleanup method on operation completion */
100 void close();
101
102 /**
103 * Add a get result. This will be used to calculate the exact quota and
104 * have a better short-read average size for the next time.
105 */
106 void addGetResult(Result result);
107
108 /**
109 * Add a scan result. This will be used to calculate the exact quota and
110 * have a better long-read average size for the next time.
111 */
112 void addScanResult(List<Result> results);
113
114 /**
115 * Add a mutation result. This will be used to calculate the exact quota and
116 * have a better mutation average size for the next time.
117 */
118 void addMutation(Mutation mutation);
119
120 /** @return the number of bytes available to read to avoid exceeding the quota */
121 long getReadAvailable();
122
123 /** @return the number of bytes available to write to avoid exceeding the quota */
124 long getWriteAvailable();
125
126 /** @return the average data size of the specified operation */
127 long getAvgOperationSize(OperationType type);
128 }