2 * ============LICENSE_START=======================================================
4 * ================================================================================
5 * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
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7 * Licensed under the Apache License, Version 2.0 (the "License");
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16 * See the License for the specific language governing permissions and
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20 * ECOMP is a trademark and service mark of AT&T Intellectual Property.
22 package org.onap.aai.util;
25 * logging to hbase encountered hotspotting issues, so per
26 * http://archive.cloudera.com/cdh5/cdh/5/hbase-0.98.6-cdh5.3.8/book/rowkey.design.html
27 * we decided to salt the rowkeys
28 * as these keys are generated in a couple places, I made a class to contain that logic
30 public class HbaseSaltPrefixer {
31 private int NUM_REGION_BUCKETS = 3; //the number of hbase region servers per cluster
33 private static class SingletonHolder{
34 private static final HbaseSaltPrefixer INSTANCE = new HbaseSaltPrefixer();
38 * Instantiates a new hbase salt prefixer.
40 private HbaseSaltPrefixer(){}
43 * Gets the single instance of HbaseSaltPrefixer.
45 * @return single instance of HbaseSaltPrefixer
47 public static HbaseSaltPrefixer getInstance() {
48 return SingletonHolder.INSTANCE;
57 public String prependSalt(String key) {
58 int salt = Math.abs(key.hashCode()) % NUM_REGION_BUCKETS;
59 return salt + "-" + key;