virajjasani commented on a change in pull request #978: HBASE-22285 A normalizer which merges small size regions with adjacen… URL: https://github.com/apache/hbase/pull/978#discussion_r362306472
########## File path: hbase-server/src/main/java/org/apache/hadoop/hbase/master/normalizer/MergeNormalizer.java ########## @@ -0,0 +1,131 @@ +/** + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.hadoop.hbase.master.normalizer; + +import java.sql.Timestamp; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; +import org.apache.hadoop.hbase.HBaseConfiguration; +import org.apache.hadoop.hbase.HBaseIOException; +import org.apache.hadoop.hbase.HConstants; +import org.apache.hadoop.hbase.TableName; +import org.apache.hadoop.hbase.client.RegionInfo; +import org.apache.yetus.audience.InterfaceAudience; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Implementation of MergeNormalizer Logic in use: + * <ol> + * <li>get all regions of a given table + * <li>get avg size S of each region (by total size of store files reported in RegionLoad) + * <li>two regions R1 and its neighbour R2 are merged, if R1 + R2 < S, and all such regions are + * returned to be merged + * <li>Otherwise, no action is performed + * </ol> + * <p> + * Region sizes are coarse and approximate on the order of megabytes. Also, empty regions (less than + * 1MB) are also merged if the age of region is > MIN_DURATION_FOR_MERGE (default 2) + * </p> + */ + +@InterfaceAudience.Private +public class MergeNormalizer extends BaseNormalizer { + private static final Logger LOG = LoggerFactory.getLogger(MergeNormalizer.class); + private static final int MIN_REGION_COUNT = 3; + + private int minRegionCount; + private static long[] skippedCount = new long[NormalizationPlan.PlanType.values().length]; + + public MergeNormalizer() { + minRegionCount = HBaseConfiguration.create().getInt("hbase.normalizer.min.region.count", 3); Review comment: Also, value `3` here can be replaced with `MIN_REGION_COUNT` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
